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Production of crystallized pear (var. D´anju) using osmotic dehydration Manivel, R. A; Yahuaca, J. B.
Laboratorio de Análisis de Alimentos, Laboratorio de Biotecnología
Facultad de Quimicofarmacobiología, Universidad Michoacana de San Nicolás de Hidalgo Calle Tzintzuntzan #173 Col. Matamoros, Morelia Mich. México
E-mail: ramch03hotmail.com
Osmotic dehydration represents a technological alternative to reduce post-harvest losses of fruits. The objective of this work was to study the influence of the concentration of the osmotic agent (sucrose) and the temperature on the osmotic dehydration of pear fruits. For the study pears var. "D´anju" were obtained from the local market, selected, peeled, sliced quarters and immersed in osmotic solution (sucrose syrup of 50° and 60° Brix) at 70°, 80°and 90°C. The pieces were removed after 30, 60, 120, 180, 240, 300, 360, 420 y 480 min. The variables studied were solute gain (GS), water loss (PA) in fruits and °Brix reduction in the syrup. For all treatments, water loss and solids gain increased at significant level in the high concentration solution (60°Brix) and high temperature (90° C). The highest PA, and GS were obtained in shorter time when the pear immersed was at 60°Brix at 80° and 90°C than with 50°Brix at all temperatures. The observations of the present work about GS and PA allow concluding that the concentration of the syrup and the temperature influences the process of osmotic dehydration of pear. In all cases the water loss was more important than the solids gain.
FP-02 Effect of Osmotic Dehydration on the Quality of a Banana Snack Product
Tapia-Molina, A. R., Calderón-Santoyo, M. Luna-Solano, G. and Ragazzo-Sánchez, J. A. 1Instituto Tecnológico de Tepic. Laboratorio Integral de Investigación en Alimentos. Av. Tecnológico
No. 2595 C.P. 63175. Tepic, Nayarit, MÉXICO, Tel. (311) 213 15 43.
2Instituto Tecnologico de Orizaba, Division de Estudios de Posgrado e Investigacion, Av. Oriente 9 no. 852, Orizaba, Veracruz, 94320 [email protected]
Osmotic dehydration was examined as a pretreatment before frying in order to produce a fried banana snack with a low fat content. A relationship between dehydration kinetics as well as frying kinetics and the type of solution used for osmotic dehydration before frying of banana snacks has been developed to demonstrate that oil uptake during frying is a direct function of water content. The effect of osmotic dehydration on sensory properties (flavor and texture) and microbiological quality (aerobic bacterial, fungal, and yeast counts) of the banana snack was also investigated. Sugar solutions at two concentrations (40° and 60 °Bx) and 3 soaking times (2, 4, and 6 h) were used. Results showed that osmotic drying pretreatment significantly reduced oil uptake in banana snacks during frying and sensory properties were improved. The osmotic treatment also maintained the good microbiological status of the product.
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Evaluation of Ohmic Heating Processing Parameters on Nixtamalized Corn Flour Quality
Gaytán-Martínez, M., Figueroa-Cárdenas, JD., Vázquez-Landaverde, P., Morales-Sánchez, E. Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Libramiento
Norponiente No. 2000. Real de Juriquilla. C.P. 76230. Querétaro, Qro. México.
Nixtamalization (alkaline cooking) is the primary step in the production of products such as corn chips, corn tortillas and tortilla chips. The process involves cooking and steeping of corn in excess water with lime added to produce nixtamal. Commercial nixtamalization results in 5–14% corn solids loss in the liquid effluent generated during cooking-steeping and washing. Loss of corn solids not only causes economic loss to corn processors but also creates costly waste and wastewater disposal problems. Ohmic heating works by passing an electric current through the food causing internal heat generation. The objective of this work was to assess which ohmic heating process parameters had a greater impact on the quality of nixtamalized corn products. The independent variables analyzed were particle size (0.5 and 0.8 mm), moisture content (50 - 70%), lime concentration (0-0.4%), voltage (80 - 110 V) and the final cooking temperature (90 – 110 °C). Three main products were obtained: flour, dough and tortillas. For flour and dough, water-absorption capacity and viscosity were measured; while yield, texture and moisture content were measured for tortillas. Results showed that moisture, final cooking temperature and voltage were the most significant factors ( =0.05) influencing product quality. The response variables more affected by the process were viscosity, moisture and yield. It was concluded that ohmic heating is able to produce nixtamalized corn products with good quality, having great potential to be used in the corn processing industry.
FP-04 Determination of Reducing Sugars in Selected Variants of Agave mezcalero (Agave
duranguensis) from the Southeast of Durango Cifuentes, D. L. A.; Gómez, O. S; Hernández, V. V.
Biotecnología y alimentos, CIIDIR-IPN, Unidad Dgo. Sigma s/n Fracc. 20 de Noviembre II C. P. 34220 Durango, Dgo. México. e-mail: [email protected].
The production of mezcal is made from Agave at southeast of Durango. Frequently, Agave has strong variation in total reducing sugars, weight of head and time of maturation, these differences make to vary the volume and quality of mezcal from lot to lot. To determine the variation of weight of heads and their total of reducing sugars, three localities were selected: Ejidos El Caliche, Los Olagues y Los Ojitos from Nombre de Dios, Durango. The sample was obtained from 513 agaves (heads) from Ejido El Caliche, to determine the variation of weight (kg) of agaves used to produce mezcal. The determination of total reducing sugars was conducted on samples from 17 selected agaves in Ejidos El Caliche, Los Olagues y Los Ojitos. It was found that 66.1% of the agaves used to produce mezcal, oscillate between 6.9 and 18.8 kg, whereas agaves with weights of 30.7 to 54.6 kg only constitutes 28% and finally, agaves of 66.4 to 233 kg only represent the 5.9%. Statistical differences were found related to reducing sugars, in the heads sampled from different selected sites. The total reducing sugars concentration presented a variation 8 to 26%. The greatest reducing sugars concentration for the head harvested was in Ejido Los Olagues with 22.5% and Ejido Ojitos de Moreno with 22.3%. The average of total reducing sugars from three ejidos was 17.6%. In conclusion, the relation found between weight and total reducing sugars was, agaves with weight of 70 to 233 kg, had total reducing sugars from 13 to 16%, whereas agaves of 25 to 60 kg had a concentration from 8 to 26%.
(keywords: cenizo, mezcal, Agave duranguensis)
40
Evaluation of stability and production of carbon dioxide in mother doughs and direct doughs from strong flours
Gómez, O. S.; Orea, L. G.; Hernández, V. V.
aBiotecnología y alimentos, CIIDIR-IPN, Unidad Dgo. Sigma s/n Fracc. 20 de Noviembre II C. P. 34220 Durango, Dgo. México.Correo-e: [email protected].
The study of rheology of baking doughs is important for wheat trading, flour quality and its transformation into bread. Bakers can standardize the phases of baking process, but it is necessary to have the knowledge about stability of doughs, CO2 retention capacity and volume that doughs can develop, because these properties are directly related to the quality of bread. In this work the stability and production of CO2 from baking doughs were evaluated using different percentages of mother dough and direct dough. The flour used in this work was Turbo remix 40 of good baking quality. The fermentation time of mother dough was 3 h, 6 h and 9 h. The mother dough percentages used were 100, 75, 50, 25 and zero, the complement was direct dough; the developing dough and its CO2 production were evaluated to each sample. The rheofermentograms were obtained in the Rheofermentometer F2 showed important parameters such as maximum height (Hm), height of second fermentation (h), time, maximum volume, height of bread (T1), time to end of the test (T2), maximum height of gaseous detachment (H‟m), maximum time of gaseous detachment (T‟1), time where the curves are separeted ((Tx), total volume of CO2 (Vt), lost volume (Vp), retained volume (Vr), and retention coefficient (Cr). A completely randomized design with a factorial arrangement was used. The data obtained were analyzed by means of analysis of variance, with p≤0.05 and comparison of means by the Tukey test. The best rheological treatment of dough was obtained when 25% of mother dough, fermented during 6 h, at 25°C, 70% relative humidity and 75% direct dough were utilized. With a CO2 retention coefficient of 96.8%, volume of dough was considered as very good, showing good stability.
FP-06 Effect of Hot Air Drying on Quality Parameters of Pulp of Lychee (Litchi chinensis
Sonn) Fruit
Castro-Ahumada, J. O., Carrillo-López, A., Caro-Corrales, J. J., and Zazueta-Morales, J. J. Maestría en Ciencia y Tecnología de Alimentos, Universidad Autónoma de Sinaloa, Apdo. Postal 1354,
CP 80000, Culiacán, Sinaloa, México. Corresponding: [email protected].
Ninety eight percent of Mexican Lychee (Litchi chinensis Sonn.) fruit is commercialized as fresh fruit, but the highly perishable nature of the fruit produces very high postharvest losses (about 50%). It is very important to study new alternatives to process this fruit. The objective of this work was to study the effect of drying temperature (60, 70, and 80°C) on the dried pulp quality (bulk density (BD), shrinkage, water adsorption (WA), water activity (aw), and total color difference (E)) and engineering parameters (mass transfer coefficient (kY) and effective diffusivity (Deff)). The whole fruit was blanched, peeled, cutted and dried, the experiment was carried out at a constant air velocity (1.45 m/s) using a laboratory convective tray drier, the air was heated using liquified petroleum gas (LPG). Effective moisture diffusivity was estimated using the finite element method (FEM) because the shape of the fruit was irregular, and the results were analyzed as mean values with standard deviations. Differences between mean values were established using Fisher‟s test Values were considered at 95% level of significance (p<0.05). Most of analyzed responses were significantly (p<0.05) affected by temperature. BD and shrinkage increased as temperature was higher, and as temperature increased WA and aw decreased. The E of lychee was significantly affected by temperature and the fruit dried with the lowest temperature showed the lowest E value. The moisture flux increased as temperature increased, but the kY did not significantly change. Deff increased as drying advanced. Good agreement was observed between unaccomplished moisture fraction estimated using FEM and those obtained from experiments for different drying air temperatures. The results suggested that the best temperature to dry lychee is 70ºC because of the good results found in every analyzed responses and the short required time to be processed.
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Functionality and Stability of Polyphenols of Oat-Soy Cookies Heras-Ramírez, M.E., Vidal-Quintanar, R.L.
Departamento de Investigación y Posgrado en Alimentos. Universidad de Sonora P.O. Box 1658, Colonia Centro. Hermosillo Sonora Mex. Phone and fax + (662) 259-22-07 al 09 [email protected]
Cookies were formulated with three levels of soybean, oats and fat sources (33) to evaluate the stability and functionality of the polyphenols during high temperature storage, 45-75°C, and 55% humidity. In a previous study, the oats-soybean cookies had 95% acceptances (p<0.5) with four points or higher value (0-5 scale). The main objective was to measure the rate of lipid oxidation and the presence of polyphenols as an antioxidant in the cookies during the storage time. Lipid oxidation was evaluated by conjugated dienes acids, peroxide value and p-anasidine index. The amount of polyphenols compound present in each cookie formula was evaluated by the Folin-Ciocalteu method and the antioxidant activity by the TAS total antioxidants method of Randox Laboratory. Each type and concentration of fat was observed to have a different effect (p<0.05) in lipid oxidation rate, antioxidant remaining and quality of cookies. The amount and antioxidant activity were lost at higher rate for the fish oil formulas than for shortening. The activity of the polyphenols antioxidants had a first order rate reaction type. The fish oil cookies had lost 90% (p<0.05) of its shelf life in the first week compared with 3-4week of the others cookies formulas. Oats-soybean cookies with olive oil contained lower saturated fat, enticing sensory characteristics, and had longer shelf life than salmon oil.
FP-09 Response Surface Methodology applied to obtain precooked dehydrated slices of
Winter Squash (Cucurbita moschata D.) cv. Cehualca
Aguilar-Gutiérrez, F., Zazueta-Morales, J.J., Caro-Corrales, J.J., Camacho-Hernández, I.L., Jacobo-Valenzuela, N., and Aguilar-Palazuelos, E.
Maestría en Ciencia y Tecnología de Alimentos, Universidad Autónoma de Sinaloa, Apdo. Postal 1354, CP 80000, Culiacán, Sin., México. Correspondence (e-mail: [email protected]).
Winter squash (Cucurbita moschata Duchense) is a vegetable produced and consumed in Mexico as a decorative for typical regional candies but it is used mainly as an animal feed. Its high carotene and dietary fiber, makes necessary the study for new technological alternatives for a better improvement in human feed. The objective of this project was to study the effect of the thickness (Th: 4, 6 and 8 mm) and drying temperature (DT: 60, 72 and 84 °C) on physicochemical characteristics (Water adsorption index, WAI; swelling index, SI; shrinkage, S and color: L*, a*, b*, C and °Hue) of precooked dehydrated slices of winter squash cv. Cehualca. A 3x3 factorial experimental design and response surface methodology were used for data analysis and optimization of the process. Values of R2adj for WAI, SI, and S were 0.63, whereas for L*, b* and C they were 0.47. Values of p of Fmodel0.001 and variability coefficients
17% were obtained (but for SI and a*). Most of the evaluated responses showed lack of fit (p0.05). As Th of slices decreased and DT increased, WAI and S increased; while as Th and DT decreased, SI increased. On the other hand, Th showed a higher effect on color parameters than DT. In general, the highest values of the L*, b* and C parameters were achieved at low thickness of the slices (4 mm). The obtained data suggest it is possible to manufacture precooked dehydrated slices from winter squash cv. Cehualca which could be used as snack foods, with the eventual benefit of its high carotene and dietary fiber. Nevertheless, more studies to optimize the process and to estimate the loss of nutriments as on sensorial acceptance are recommended.
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Growth Evaluation of Nile Tilapia Oreochromis niloticus Fed Using a Non Conventional Protein Food Formulation
Mendiola-Campuzano J.V.H., Duran-Mendoza, T., Hernández-Vélez, R.M., Angulo-Guerrero, O., Urrieta Saltijeral, J.M.
Departamento de Ingeniería Química, Bioquímica y ambiental. Instituto Tecnológico de Villahermosa. Carretera Vhsa-Frontera Km 3.5 Ciudad Industrial Villahermosa, 86010 Tabasco, México. Unidad de
Investigación en alimentos (UNIDA). Instituto Tecnológico de Veracruz. Miguel Angel de Quevedo 2779. Col. Formando Hogar. Veracruz, Ver. División Académica multidisciplinaria de los Ríos de la
Universidad Juárez Autónoma de Tabasco. Tenosique, Tabasco. [email protected] ; [email protected]
In recent years animal feed industry for aquaculture has registered an increase in production worldwide. The quality of balanced food is highly dependent on appropriate good quality raw materials. In the present work an experimental food with animal and vegetable protein sources (33 % by weight), in substitution of fishmeal was formulated in order to evaluate nutrimental and microbiological quality, as well as its in vitro digestibility, and the effect in the growth of young Oreochromis niloticus. Treatments were compared with a commercial food Nutripec. In both foods nutrimental quality (protein, crude fiber, fat, free nitrogen extract, ashes and humidity), microbiological analyses (coliforms, mesophiles, fungi and yeast), digestibility in vitro (enzymatic method) and the effect on growth (by means biometry‟s) of 180 organisms were evaluated. A Pearson‟s square design was applied to determine the composition of supplementing nutrients. The results for the experimental food showed an acceptable nutrimental and microbiological quality, a high digestibility but its effect on growth was smaller in comparison with organisms fed with a commercial food for young tilapia (Nutripec®), the average weight gain was greater for commercial food (8,646±4,943 g) compared to experimental food (5,555±2,329 g). However, a homogenous population growth was obtained with the experimental food. This represents an advantage during tilapia culture since we avoided competition by food and space, because the fish have similar length and weight. The physicochemical parameters evaluated in a pilot unit of aquaculture (temperature, pH, dissolved oxygen, total ammonium), stayed in optimal ranks for tilapia culture. It is concluded that the experimental food can be a good alternative in the feeding of young tilapia to obtain a homogeneous population of a productive system.
FP-12 Clean Production of Smoked Trout (Oncorhynchus mykiss) Processing. A
Preliminary Study
Medina, H. E., Burciaga, S. M. E., Pérez, L. M. E., Delgado, E. CIIDIR-IPN, Unidad Dgo., Becarias COFAA; Instituto Tecnológico de Dgo. Sigma S/N Fracc. 20 de Noviembre II, Durango, Dgo. [email protected]
A clean production is defined as processing or manufacturing system, in which waste minimization and prevention practices are continuously applied. These practices include preservation of raw materials and energy, disposal of toxic inputs, and reduction in toxic outputs. The aim of this investigation was to standardize the process for smoked trout. The results will be applied to establish a clean production of trout processing. Rainbow trout (Oncorhynchus mykiss) were eviscerated and their fillets immersed in a brine with 5% NaCl for three different periods (15, 20 or 30 min). The amounts of solid and liquid residues obtained during processing were determined. Data were analyzed by ANOVA at a significance of α = 0.05. The results show that after 30 min. in the salt solution, samples reached the required salt concentration (1.13%). The time that the fillet remained immersed in the brine had a significant effect (p = 0.004) on salt concentration of the fillet. Only 55.5% of the trout could be used as fillet, while the rest may be considered as an industrial residue. A total of 2 L/kg trout of residual wastewater was produced. These residues contain elevated concentration of organic matter, which makes them highly polluting. Industrial residues as the ones generated from this work may be used as raw materials in other processes, such as fishmeal, fish oil and biodiesel production. Further investigations will include a water processing system to treat residual water from the process.
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Rye and whole wheat sourdough bread enriched with fermented chick pea Aguilera-Reyes LV, Reyes-Vega ML, De la Garza-Toledo H
Universidad Autónoma de Coahuila, Departamento de Investigación en Alimentos
Blvd. V Carranza s/n, 25280 Saltillo, Coahuila, México Corresponding author: [email protected]
Bread production is based in an ancient Egyptian technology that evolved upon the time; however, the actual technology, faster than the ancient, is responsible of the new flavor of bread, which has lost some desirable sensory characteristics. The objective of this work is the development of sourdough bread enriched with a fermented paste of chick pea to improve nutritional value of bread. Chick pea was fermented with
Lactobacillus casei and incorporated into wheat flour, water and sugar to obtain a
sourdough. This was used to prepare rye and whole wheat dough, which were baked to obtain the corresponding sourdough bread. Rye and whole wheat breads were also prepared without sourdough. The following characteristics were determined: pH, bacteria and yeast count of fermented chick pea paste and sourdough, bread weight, height, thickness, and length, texture profile analysis (TPA, Instron) and sensory analysis, as well as crust thickness. In addition, the bread cells were observed by means of a scanning electron microscope. Sourdough breads were more porous than traditional bread, their crust was thicker and sensory analysis showed that their flavor and texture were improved. TPA confirmed the last characteristics. Sourdough bread cells were approximately of the same size with well structured walls. Sourdough bread obtained by this method, especially rye sourdough bread was very well accepted by consumers.
FP-14 Manufacture of Asadero Cheese with a vegetable rennet from Solanum
elaeagnifolium
Aquino-Favela, A., López-Díaz, J.A., Vargas-Requena, C.L. y Martínez-Ruiz, N.R. Laboratorio de Ciencias de los Alimentos; Laboratorio de Biotecnología, Departamento de Ciencias Básicas, Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente
del Pronaf y Estocolmo s/n, Cd. Juárez, Chihuahua, México. C.P. 32300. email: [email protected]
The growing production of cheese in the world has led to a shortage in animal rennet. Chymosin is the responsible enzyme of milk coagulation, acting by a specific proteolysis on the casein of milk. Due to rennet shortage, the cheese industry has to look for new alternatives such as microbial rennet from Mucor pusillus, Endothia parasitica and Mucor miehei and the vegetal rennets from Cynaras, Gallium, Pinguicula, Whitania and Ficus. In the north of Mexico and south of the United States, there is a plant known as “Trompillo” (Solanum elaeagnifolium) and people from the State of Chihuahua use its fruit in the production of artisan cheese. The information about this plant and its fruit is very scarce and its use in the cheese manufacture is still empiric; these reasons motivated this investigation. In this work it was established the coagulant capacity of Trompillo extract on the casein‟s milk and finally this extract was applied in the manufacture of Asadero cheese. The Trompillo‟s fruit composition was analyzed in different maturations levels using the AOAC methods. Next, enzyme extraction was carried out by precipitation with ammonium sulfate and coagulant activity (rennet strength) was determined. Finally, the extract obtained was used in the Asadero cheese manufacture. The cheese was compared with an Asadero cheese elaborated with commercial rennet, by means of sensory test. The results showed that the mature fruit had a higher protein concentration and resulted in a better coagulation. Regarding the coagulant activity, the extract obtained from this fruit had lower rennet strength than commercial rennet. However, in the sensory test the Asadero cheese made with vegetal rennet was preferred over the Asadero cheese made with commercial rennet. From those results, it is possible to establish that Trompillo‟s (Solanum elaeagnifolium) fruit can be used for as a source of vegetal rennet, and can be used by the Cheese Industry as an animal rennet substitute.
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FP-15 Effect of the Process Conditions on Humidity and Solubility of Spray Dried Sabila
Gel (Aloe vera)
Pool-Gómez, J.E.M. Solís, S., Tamayo, J., Escamilla-Sánchez, J.B. and Rivera–Muñoz G. 1Universidad Autónoma de Campeche. Facultad de Ciencias Químico Biológicas 2
Instituto Tecnológico de Mérida. Departamento de Ingeniería Química y Bioquímica Km. 5 Carretera Mérida-Progreso S/N, Mérida, Yucatán, México C.P. 97118
Mérida, Yucatán. [email protected]
In Yucatan, sabila (Aloe vera) represents a good alternative for increasing income of the farmers by means of its cultivation and industrialization. Hence, this activity is a very important option for the regions of the state where the henequen was cultivated before. The sabila is considered an exotic plant, whose leaves are constituted of an epidermis, vascular faces and a crystalline colorless mucilaginous cellular tissue known as gel. This gel is demanded in the international market in concentrated form of 1:20, 1:40 and freeze dried gel powders with a concentration of 1:200. An alternative for this process is the spray drying. For this reason, the objective of this work was to evaluate the effect of spray drying temperature, (140 and 160°C); air flow, (21 and 28 m3h-1); spray drying pressure, (0.6 and 1.2 bar) and dilution of the gel in water, (1:1 and 1:0,5). This evaluation was carried out using a factorial design 24. The best sabila powder was achieved using a drying temperature of 160 °C, an air flow of 28 m3h-1, a feeding flow of 350 mLh-1, a spray pressure of 1.2 bar and a sabila gel dilution of 1:1. With this condition, the spray dried gel powders produced had a moisture content of 5.17±1.21% and a solubility of 20.58±0.96 %.
FP-16 Tangential Filtration of Macro and Micromolecules
Orozco-Alvarez, C., García-Salas, S., Ríos-Domínguez, I.
Bioengineering Department. Inter-Professional Unit of Biotechnology. IPN. Av. Acueducto S/N. Col. Barrio La laguna Ticomán. G. A. Madero. México, D.F.
Fax: 57 29 60 00 ext. 56305. e-mail: [email protected].
We worked the ultrafiltration and reverse osmosis in a spiral pilot equipment with a filtration area of 6.5 m2 and a membrane step of 0.8 x10-3 m. Working conditions were at 25 ºC, pressures from 0 to 2000 kPa and pHs was about 6 and 7. We also applied a polarizing gel model to determine k and Cg constants. In the ultrafiltration equipment the results were as follows: When working with suspension yeast at 30 g/L and at the maximum pressure we obtained a 5 x10-6 m/s flux, while at 250 g/L, filtration flux is reduced to 60%. In applying the polarizing gel model we obtained a k value of 4.5 x10-6 m/s and a Cg of 323 g/L. When working with whey at 30 g/L and at the maximum pressure we obtained a 2.8 x10-6 m/s flux. At 200 g/L, filtration flux is reduced to 50%. Constants values in the polarizing gel model were: a k of 1 x10-6 m/s and a Cg of 570 g/L. The results in the reverse osmosis equipment were as follows: When working with NaCl solution at 1 g/L and at the maximum pressure we obtained a 15 x10-6 m/s, and this is reduced up to seven times when the concentration of salts rose up to 150 times. In applying the polarizing gel model we obtained a k value of 2 x10-6 m/s and a Cg of 535 g/L. When working with sucrose solutions at 150 g/L and at the maximum pressure we obtained a 12 x10-6 m/s flux, and this is reduced up to six times when the concentration of sucrose is raised four times. Constants values in the polarizing gel model for k y Cg were 6.4 x10-6 m/s and 850 g/L, respectively.
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FP-17 Calculation Methodology to Predict Drying Time in a Solar Dryer
Orozco-Alvarez, C., Angeles-Martinez, D., Garcia-Salas, S. Bioengineering Department. Inter-Professional Unit of Biotechnology. IPN. Av. Acueducto S / N. Col. Barrio La Laguna Ticomán. G. A. Madero. Mexico City
Fax: 57 29 60 00 ext. 56305. e-mail: [email protected]
The current project developed a sequence of calculations to estimate the drying time of a specific material using a solar dryer of integral type that works with natural air convection and is heated inside the dryer by solar radiation. Calculation bases are presented below. Material to dry: carrot slices of 5 mm thick; initial and final moisture, 91 % and 15 % respectively; air temperature inside the drier: 50 to 65 °C; speed of air entering the drier: 0.1 to 0.5 m / s, with an absolute humidity of 0.01, and leaving the dryer a temperature of 5 to 10 °C lower than the temperature of entry. In the calculation sequence, different temperatures and drying air flows are tested up to get the drying of the material, accomplishing with the following conditions: air relative humidity at the exit of the dryer should be lower than balance humidity, and in the final calculation we must verify that air velocity is equal to the proposed value at the beginning of the sequence.
With the above conditions already met, sequence calculation gives the following results. At a temperature of 65 ºC drying time is of 11 hours of sunlight; while at 50 °C time is increased up to 33 hours, these drying times are similar to those reported in experimental works. Knowing that it can be obtained a solar radiation of 400 W/m2 a day, we can go through the sequence of calculation to estimate the size of a solar type-tent dryer to perform the drying of a determined fruit or vegetable quantity.
(keywords: drying, solar radiation, fruits, vegetables)
FP-18 Analysis of Quality Protein Changes in Nixtamalized QPM Flours as a Function of
the Steeping Time
Rojas-Molina, E. Gutiérrez, M.E. Cortés-Acevedo, A. Falcón, R. Bressani, A. Rojas,C. Ibarra, J.L. Pons-Hernández, S.H. Guzmán-Maldonado, A. Cornejo-Villegas, and M.E. Rodríguez.
Facultad de Ciencias Naturales, Licenciatura en Nutrición, Universidad Autónoma de Querétaro, Querétaro, México.Departamento de Posgrado e Investigación. Facultad de Ingeniería, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, Querétaro, México.Facultad de Estudios Superiores
Cuautitlán, Universidad Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán, México.Laboratorio de Neurofarmacología Marina, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla.Centro de Ciencia y Tecnología de Alimentos,Universidad del
Valle de Guatemala.
Facultad de Química, Departamento de Investigación en Productos Naturales, Universidad Autónoma de Querétaro. Cerro de las Campanas S/N, Querétaro, México.7Unidad de Biotecnología. Campo Experimental Bajío, INIFAP. Celaya Guanajuato, México.8Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, C.P. 76230, A.P.
1-1010, Mé[email protected], [email protected]
This work shows the protein changes in Quality Protein Maize (QPM H-368C) during the traditional nixtamalization process as a function of the steeping time from 0 to 15 h. Protein content (N x 6.25), pH, protein fractionation, reactive lysine, essential amino acids and protein digestibility were analyzed to explain the protein quality modifications in nixtamalized corn flours (NQF). The thermo-alkaline process increased significantly (P ≤ 0.05) the protein content (5.57 ± 0.86%) in NQF obtained at 3, 5, 7, 9, 11, 13 and 15 h of steeping time compared with native corn or corn without treatment (NC). The pH of NQF were not proportional to the steeping time and significantly different (P ≤ 0.05) between them. At 5 h critical steeping time the total lysine and reactive lysine content decreased severely (36 and 32% respectively) with statistical differences (P ≤ 0.05) compared to NC. On the other hand, the tryptophan content decreased significantly (P ≤ 0.05) at steeping times from 5 to 15 h (38.70 ± 6.7%) compared to NC. The changes in the lysine and tryptophan content were not proportional to the steeping time. The protein recovery in the albumins and globulins fraction diminished (P ≤ 0.05) with respect to raw corn. The protein recovery for γ-zeins, glutelin-like, glutelins and residue increased. A significant (P ≤ 0.05) decrease in the essential amino acids in NQF obtained from 3 to 7 h of steeping time compared with NC was found. Equally important was the reduction in protein digestibility observed in NQF steeped at long steeping times (from 11 to 15 h) with significant (P ≤ 0.05) differences compared with NC. The protein solubility distribution along the steeping step and the essential amino acids location, specifically lysine in corn kernel could explain partially the protein quality changes observed in this research. Finally, these results contribute to conciliate the discrepancies associated with the protein quality modifications in nixtamalized corn reported previously in literature.
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FP-19 Effect of Temperature and Steeping Time on Calcium and Phosphorus Content in
Nixtamalized Corn Flours Obtained by the Traditional Nixtamalization Process I. Rojas-Molina, E. Gutiérrez, J.L. Arjona-Román, L. Baños, M. Cortés-Álvarez, L. Campos-Solís, M.
Hernández, A. Cornejo and M.E. Rodríguez.
Facultad de Ciencias Naturales, Licenciatura en Nutrición, Universidad Autónoma de Querétaro, Querétaro, México.Departamento de Posgrado e Investigación. Facultad de Ingeniería, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, Querétaro, México.Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán, México.Instituto de Materiales, Universidad Nacional Autónoma de México, México.Posgrado en Ciencias Biomédicas,
Universidad Nacional Autónoma de México, México.Universidad del Valle de México, Campus Querétaro, México.
Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, C.P. 76230, A.P. 1-1010, Mé[email protected] ó
This research shows the effect of temperature (72, 82 and 92°C) and steeping time (0, 1, 3, 5, 7, 9, 11, 13 and 15 h) on calcium and phosphorus content in nixtamalized corn flours (NCF) obtained by the traditional nixtamalization process. Atomic absorption spectroscopy and UV-vis spectroscopy methods were used to study the calcium and phosphorus content, as well as, the Ca/P ratio in NCF. Additionally, the deposition and identification of calcium compounds in nixtamalized corn pericarp were analyzed by low vacuum scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction techniques. Furthermore, dry matter loss in NCF is reported. It was found that as the temperature increases the Ca enhances and the phosphorus content decreases with statistical differences (P ≤ 0.05) between thermal treatments. Calcium compounds were found in pericarp samples, which were identified as calcite. The thermo-alkaline process increased significantly (P ≤ 0.05) the carbonate calcium content (8.98% ± 0.14, 9.28% ± 0.24 and 9.89% ± 0.24) in NCF obtained at 72, 82 and 92°C, respectively. It was found statistical differences (P ≤ 0.05) in phosphorous content in NCF obtained at different cooking temperatures. In addition, there was a significant correlation between phosphorus levels and steeping time at 92°C (r = -0.91). The calcium/phosphorous ratio in NCF obtained at 72, 82 and 92°C was in average 0.45 ± 0.03, 0.61 ± 0.05 and 0.82 ± 0.05, respectively. In consequence, the Ca/P ratio increased when cooking temperature enhanced, nevertheless, there was no a correlation between Ca/P ratio and steeping time. There was a high correlation (P≤ 0.01) between dry matter loss and steeping time (r = 0.99) in NCF, this fact influenced the Ca/P ratio due to calcium attached to pericarp. Maximum values in Ca/P ratio were detected at 7 h of steeping time in NCF obtained at 82 and 92°C and at 9 h in NCF cooked at 72°C. These results can be used with industrial purposes, in order to assess a maximum calcium/phosphorus ratio, and at the same time, to avoid the loss of pericarp for increasing the functional properties of NCF.
FP-20 Study of calcium Ion Diffusion in Nixtamalized Quality Protein Maize as a
Function of the Cooking Temperature
E. Gutierrez, Isela Rojas-Molina, J. L. Pons-Hernandez, H. Guzman, B. Aguas-Angel, J. Arenas, Pilar Fernandez, G. Herrera, M.E. Rodríguez.
Departamento de Posgrado e Investigación. Facultad de Ingeniería, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, Querétaro, México.Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán, México. E-mail:Facultad de Ciencias Naturales, Licenciatura en Nutrición, Universidad Autónoma de Querétaro, Querétaro, México.Instituto
Nacional de Investigaciones Forestales Agrícolas y Pecuarias, Campus Celaya, Celaya, Guanajuato, México.
Instituto de Física, Universidad Nacional Autónoma de México, México, D. F. Instituto de Geografía, Universidad Nacional Autónoma de México, México, D.F.Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, C.P. 76230, A.P.
1-1010, C.P. 76000, México. [email protected], [email protected]
In this report, the effect of temperature on the calcium content of Quality Protein Maize (QPM H-368C) during the nixtamalization process as a function of the steeping time for three cooking temperatures (72, 82 and 92°C) is presented. Also, for the first time, we report in physicochemical terms the end of the cooking stage during the nixtamalization process that was established when the moisture content in corn kernels reached a value of 36% (w/w) with a lime concentration of 1% (w/v) independent of the cooking temperature. Atomic absorption spectroscopy was used to determine the calcium concentration in the whole kernel and in its different anatomical components, pericarp, endosperm, and germ, as well as in 10% of the outermost layers, the next 10%, and the remaining 80% of the endosperm as a function of the steeping time. It was found that if the cooking temperature increases, the calcium content increases also. For steeping times in the range of 5–7 hr, a relative maximum was found in the calcium contents of 0.24, 0.21, and 0.18%, w/w, in QPM H-368 flours at 92, 82, and 72°C, respectively. Calcium was found in the most external layers in the endosperm and minimum diffusion occurs in the internal 80%. Phosphorous was measured by using UV spectroscopy and the results showed that it remains constant at 0.24% throughout the process. Scanning electron microscopy analysis was used to explain the calcium ion diffusion in the kernel. The physical changes in the pericarp govern the calcium diffusion process.
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FP-21 Physicochemical Characterization of Nopal Pads (Opuntia ficus indica) and Dry
Vacuum Nopal Powders as a Function of the Maturation
I. Rojas-Molina, M. E. Rodríguez-Garcia, C. de Lira, E. Hernández-Becerra, M. A. Cornejo-Villegas, E. Gutiérrez, R. Reynoso, L. C. Quintero, A. Del-Real, T. A. Zepeda, C. Muñoz-Torres and M. A. Aguilera.
Facultad de Ciencias Naturales, Licenciatura en Nutrición, Universidad Autónoma de Querétaro, Querétaro, México. E-mail: [email protected] ó [email protected]. Departamento de Posgrado e Investigación. Facultad de Ingeniería, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, Querétaro, México.Centro de Física Aplicada y Tecnología Avanzada, Universidad
Nacional Autónoma de México, Campus Juriquilla, Querétaro, C.P. 76230, A.P. 1-1010, México.Programa de Posgrado en Alimentos del Centro de la República (PROPAC). Facultad de Química. Universidad Autónoma de Querétaro.Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán, México. Laboratorio de Espectroscopia de Absorción Atómica. Centro de Geociencias, Universidad Nacional Autónoma de México, México.
This paper presents the physicochemical and nutrimental characterization of fresh nopal
(Opuntia ficus indica, Redonda variety) and nopal powder produced at different stages
of development. Nopal powder was obtained by dry vacuum technique using 102 mm Hg and low temperature (40°C). The results showed that the nutrimental and mineral composition of nopal changes as a function of the maturation as follow: The ash content increases from 18.41 for nopalitos (60 g of weight) to 23.24% (nopal pads 200 g); calcium content increases from 1.52 to 3.72%, while phosphorous exhibits an opposite trend: 0.43 to 0.27%, respectively. Calcium oxalate was determined by X-ray diffraction, scanning electron microscopy (SEM) and quantified by using atomic absorption spectroscopy. Calcium oxalate decreases from 7.95 to 3.47 mg/g and the Ca/P ratio varies from 3.6 to 11. The soluble fiber decreases from 25.22 to 14.91%, while insoluble fiber increases from 29.87 to 41.65%. These results suggest that nopal could be an important source of minerals within the diets of people in Mexico and the rest of Latin America.
FP-22 Modelling the Kinetics of Fluidized Bed Drying of Peas Using Peleg‟s Approach
Juan Mercado Flores, Melva López Orozco, Gerardo Martínez Soto, Jazmín Camarena Martínez. Instituto de Ciencias Agrícolas de la Universidad de Guanajuato.
In this research work, it is presented the application of a mathematical method based on the Peleg equation for the kinetics of food drying. It took 16 experiments in which a certain amount of peas (Pisum sativum) were dehydrated in a fluidized bed dryer. A Greek-Latin square experimental design with 4 variables was used: Heat temperature, radius of the particle, air´s velocity and bed height, in 4 levels each one. Sample mass was determined at regular time intervals of 10 min until the equilibrium moisture was reached. The Peleg´s Method was used on these data and were obtained two important dry parameters by linear regression, “a”, mass fraction lose of water; and, 1/b, the time when “a” is diminished by a half and it was obtained an average determination coefficient of R2 = 0.9967. Once these parameter were obtained, it was analyzed their dependence of the 4 variables by a variance method using the statistical program Statgraphics Plus 5.1. With this model, it was achieved the simplification of the study of process of dry by flowed bed in peas. Furthermore, an equation was determined to ease the collecting data for a dry process simulator under condition close to the studied ones.
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FP-23 Textural and Sensory Evaluation of Cookies Prepared with Chickpea (Cicer
arietinum) and Wheat (Triticum spp.) Flour Mixtures Sánchez Cruz, V.; Chaires-Martínez, L. and Jiménez-Avalos, H.A.
Food Research Center. Instituto Tecnológico Superior de Alamo Temapache (CIA-ITSAT). Potrero del Llano-Tuxpan, Km 6.5. Xoyotitla, Alamo Temapache. Veracruz, México. Tel. 0176584-40038 and 39.
email. [email protected]
Chickpea is one of the most important leguminous produced in Mexico, its annual production occupies the third place; however, it does not present a high consumption
per capita due to diverse factors although it has a great nutritional value. Thus, the aim
of this work was to elaborate cookies with mixtures of chickpea and wheat flour at several proportions and to evaluate its textural and sensorial properties. Chickpea flour was produced in the lab whereas wheat flour was of commercial brand. Cookies were prepared and the texture of the dough and of the finished product was evaluated using a CNS Farnell Brokfield (QTS-25) texture analyzer. Dough was placed in 50 ml vessels and uniaxially compressed into 15 mm in a double cycle at a constant rate of 30 mm/min and a 5 s waiting period, with a 2.5 cm in diameter cylindrical acrylic probe attached to the same texture analyzer. For the cookies, a compression proof was carried out using uniaxially deforming samples of 7 mm at a constant speed of 30 mm/min using the three point bend probe. Statistical analysis was carried out with a TexturePro v2.0 and SPSS v11.0 software. Results shown that hardness in chickpea flour samples was significantly higher (P<0.05) than that of 100% wheat flour (up to 200 %); whereas the cohesiveness, springiness and adhesiveness parameters were significantly low (up to 70, 30 and 75 % respectively); gumminess did not present significant differences attributed to the increasing concentration of chickpea flour. In sensorial analyses, the acceptance proof carried out with the cookies showed that it was not notorious the presence of chickpea flour in the samples since significant difference was not observed in the values granted by the not trained judges; besides they accepted well the product. With the previous thing, we conclude that chickpea flour is a good alternative to strengthening the bakery products without affecting to great extent textural and sensorial characteristics.
FP-24 Thixotropy and Flow Behavior of Ternary Dispersions of Biopolymers
Arámbula-Peña, A. L., Ramos-Ramírez, E. G., Salazar-Montoya, J. A. Department of Biotechnology and Bioengineering, CINVESTAV-IPN. Av. IPN 2508, P. O. Box 14-740, C. P. 07360 México 14, D. F. México.
Email: [email protected]
Some biopolymers have gelatinization, emulsification and thickening properties, reason why food industries uses them like additives. The propylenglycol alginate (PGA) is used like foam stabilizer. The gum arabic (GA) is very soluble in water and it has many applications in the industry like foam stabilizer, flavor fixer, emulsifying of drinks, dehydrated soaps and sauces. The tragacanth gum (TG) is resisted to acid way; the industry uses it to stabilize soaps, ice cream, dairy and confectionary products. The main objective of this research was the determination of the thixotropy and flow behavior of ternary dispersions at different concentrations. Design of random blocks was used for research of mixtures behavior at different concentrations of three biopolymers (PGA, GA, TG). The rheological parameters were obtained by a low stress rheometer LS 100 (Paar Physica, Germany). The mixture containing the biggest quantity of PGA had the highest viscosity (112.9 mPa s). Whereas the mixture containing the biggest quantity of GA had the highest thixotropy (1214.95 Pa/s), at the same time it had the lowest viscosity (35.2 mPas). On the other hand, the mixture containing the biggest quantity of TG had the lowest thixotropy (80.85 Pa/s). The rheological model used to describe the mixture parameters was Ostwald-de-Waele. The mixture containing the biggest quantity of GA presents a diminution of 63.35% in consistency coefficient with respect to the mixture containing the biggest quantity of TG. All mixtures presented a flow behavior index below to 1, in an interval of 0.529 to 0.667. The mixtures presented a non-Newtonian behavior of shear thinning flow; in which when the shear rate increasing, the viscosity decreases.
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FP-25 Creep Rheological Behavior of Dispersions Containing Gum Arabic
and Soy Protein Mixtures
Jiménez-Avalos,H. A., Ramos-Ramírez, E. G., Salazar-Montoya, J. A. Department of Biotechnology and Bioengineering. CINVESTAV-IPN. Av. IPN 2508, P. O. Box 14-740, C. P. 07360 México 14, D. F. México.
E-mail: [email protected] Current Address: Food Research Center. Instituto Tecnológico Superior del Alamo Temapache, Km 6.5 Carretera Potrero del Llano-Tuxpan.
Xoyotitla, Alamo Temapache, Veracruz.
Gum arabic is used in diverse foods by its properties like thickening agent, which have been mixed with other biopolymers as soy proteins, they give textures to the food to be more accepted by the consumers. The aim of this study was to determinate the creep rheological behavior of dispersions containing gum arabic (GA), soy proteins (SP) and its mixtures (GA/SP). GA dispersions (10 and 15%, w/v), SP dispersions (1 to 8%, w/v) and mixtures GA/SP (values of conc?) were prepared. Rheological creep test were performed in a low stress rheometer LS 100 (Paar Physica, Germany). In creep curves for GA dispersions, no recovery was observed when the applied stress was suspended, since the dispersions behaved as viscoelastic liquids; while in the SP dispersions at 8%, it was observed a recovery of 96%, behaved as viscoelastic solids. In the mixtures GA/SP no recovery was observed when the applied stress was suspended, which indicates that when mixing GA and SP, the typical behavior of viscoelastic liquid predominates. Viscosities values (0) obtained according to the Kelvin model, in GA dispersions, they were 0.15 and 0.38 Pas respectively and in SP dispersions they presented values of 0 of 3.45x105 Pas at the maximum concentration of 8%. In the mixtures, when incorporating GA, 0 diminished 106 % presenting values around of 1.3 Pa s, at 15/8 % (w/v). This decrease probably is due to a segregative effect when GA were incorporated.
FP-26 Rheological Properties of Mixture of Crude and Purified Mucins
Delgado-Reyes, V. A., Ramos-Ramírez, E. G., Salazar-Montoya, J. A. Department of Biotechnology and Bioengineering, CINVESTAV-IPN. Av. IPN 2508, P. O. Box 14-740, C. P. 07360 México 14, D. F. México.
Email: [email protected]
The mucins are polymers of proteins and carbohydrates (glycoproteins) where the chain of oligosaccharides is united covalently to a skeleton of peptide nature by bound-ortho. These glycoproteins are secreted by mucosal epithelial, where its protective function it is attributed to the high viscosity that presents; are in the snot of secretions of the gastrointestinal, respiratory and reproductive apparatuses of mammals. In this study the rheological properties of mixture crude and purified mucins were determined. Dispersions of crude and purified mucins at 20% concentration (w/v) and mixtures of crude mucin (25, 50 and 75%) and purified mucin were prepared (75, 50 and 25%). The rheological parameters ???(K, n, ) and the material functions ???(G´, G´´) were obtained using a low stress rheometer LS 100 (Paar Physica, Germany). The model that better represented the experimental results was the Ostwald-de-Waele, the values of the consistency index were 48% bigger in mixtures where the purified mucin ¿this in more? percentage (75%), the flow behavior index is an interval of 0,574 to 0.643. The studied mucins presented a behavior of macromolecular dissolution (G´´> G´). The values of the storage module (G´) were 72% bigger in purified mucin (20%) and 32% in the mixtures with 25% of crude mucin, and 75% of purified mucin.
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FP-27 Microencapsulation of Lactobacillus sp. by Ionic Gelation
Rosas-Flores, W., Ramos-Ramírez, E. G., Salazar-Montoya, J. A.
Department of Biotechnology and Bioengineering, CINVESTAV-IPN. Av. IPN 2508, P. O. Box 14-740, C. P. 07360 México 14, D. F. México. *Email: [email protected]
The ionic gelation is a technique in which divalent and monovalent cations can interact with anionic polysaccharides and it can generate three-dimensional networks. Thus it is possible that these networks can be used to cover and protect an active ingredient, as a flavor or cells of industrial interest. In this research, we pose a technique for microencapsulation of Lactobacillus sp. without changing the viability of the culture using a binary mixture of sodium alginate and gellan gum; thus it was necessary the characterization of flow behavior of dispersions containing biopolymers. The microencapsulation was carried out using ionic gelation through an emulsion W/O at different agitation rates (480, 800, and 1200 rpm). In order to determine the efficiency of microencapsulation it was necessary to count the unit forming colonies before and after microencapsulation process. From the results we can conclude that the flow behavior shown by dispersions studied was non-Newtonian type shear thinning, because the flow behavior index remained below the unit in all cases. Regarding the rates of agitation studied, we noted that the lowest speed of agitation, which affected less the viability of the culture (10%), allowed a 90% efficiency in microencapsulation. While for the other rates of agitation (800, 1200 rpm), the stress generated had a negative effect on efficiency, lowering its value as much as 50%.
FP-28 “Ataulfo” Mango Nectar Stabilized with Polysaccharides
Cruz Juárez, W., Cisneros Martínez, A., Hernández Mondragón, T., Ocadiz García, M., Muñoz Aguilar, P. y Ramírez Ortiz, M.E.
Departamento de Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán-UNAM, Av. 1º de Mayo s/n, Col. Sta. Ma. Las Torres, Cuautitlán Izcalli, Edo. de México, México, C.P. 054740.
e-mail: [email protected]
Mango is a tropical fruit with much acceptance between the consumers, but is a fruit few exploit at industrial level, except the Manila Mango, the other species have not been used more than for direct consumption, for that reason is consider the application of the variety ataulfo for the elaboration of a drink made out of nectar. The main technological preoccupation in this product is the sedimentation of the mango pulp after time preparation, for it is added stabilizers, taking care of that do not modify the characteristics flavor, color and visual appearance. In this work four different polysaccharides were used: Gomar guar, xantana, carboximetilcelulosa (CMC) and pectina, two concentrations in all the cases: 0.075 and 0,1% were used. Flow behavior was evaluated on different nectars by means flow curves in viscometer Haake Viscotester VT550 and MV-DIN from 0,5 to 500 s-1, in ascending and descendent form. Analysis of the relative thixotropic areas calculated by integration. Also, a stability test was realised putting 10 ml of nectar under centrifugation for 20 min. Results were analyzed using analysis of variance (ANOVA) with = 0.05. The following results were obtained, in all the cases the samples adjusted to the Power Law behavior type and concentration of polysaccharide has significant influence on n and K parameters. When polymer concentration was increased the K value was also increased. For n values, it falls generally when the polysaccharide concentration was increased. Stability was increased when polysaccharide concentration increased. Xanthan gum was the polymer that provided more stability to the nectar.
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Polysaccharide Effects on Rheological and Textural Properties in Water Bread Aguirre Ponce, J. D., Herrera Trejo, D. K., Rodríguez Carmona, O. Y., Sampedro Pérez, S. I., Muñoz
Aguilar, P. y Ramírez Ortiz, M.E.
Departamento de Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán-UNAM, Av. 1º de Mayo s/n, Col. Sta. Ma. Las Torres, Cuautitlán Izcalli, Edo. de México, México, C.P. 054740.e-mail:
Nowadays, in the food industry is important to analyze and study both training as the stabilization of solid foam. In bakery products added with hydrocolloids, are modified some rheological and textural properties according to polysaccharide used. However, the results generated add them to reflect better uniformity in crumb and a delay of ageing on the bread, very important factor in the quality of the finished product and therefore the shelf life. This paper describes the behavior of comparative form and functionality, of guar gums, xanthan and mezquite, added in a water bread, each one with three concentrations (0.25, 0.50 and 1% w/w?). We used a rheometer Haake (RM software version 3.11.01), with a plaque rough 35 mm in diameter and 1mm gap, to determinate the linear zone () took place a scanning of 39 to 1000 Pa at 1 Hz; after there was a sweep of frequencies from 0.1 to 100 Hz ( T= 25°C) to establish the viscoelastic behavior. To assess the texture was used a test profile texture with a texturometer (Lloyd TA500 with cell loading 1Kg); took place at 2 different conditions: bread (penetration crust) was assessed with a cone of acrylic, 15 °, crumb was evaluated in a transversal cut, with a cylinder of 1/8 in; parameters considered were hardness and cohesiveness, particularly to chewiness for the crumb and gumminess for the crust (T=25 ° C). To statistical analysis was used an Anova with a = 0.05. The results obtained were as follows: All doughs evaluated showed that G ' (elastic behaviour) was always higher than G'' (viscous behavior) because increasing the concentration. As for the textural properties, the hardness of bread increased proportionately with the concentration of gums. It was noted that the guar gum at low concentrations produced better effects by reducing the hardness. Rather gum xanthan, increasing its concentration retained more water reflected in a high value on the hardness. The mezquite gum introduced a stable behavior to varying concentrations, because it did not have very drastic changes in the assessments made. Based on the analysis showed that the concentration is a significant parameter for the hardness (p <0.005).
FP-30 Mango (Mangifera indica L.) Jam Low in Sugars
Ortiz Melchor, R., Fuentes Romero, M.E. y Ramírez Ortiz, M.E.
Departamento Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán- UNAM, Av. 1º de Mayo s/n, Col. Sta. Ma. Las Torres, Cuautitlán Izcalli, Edo. de México, MéxicoC.P. 54740
* E-mail: [email protected]
The last market tendencies denote an increasing demand of hypocaloric foods by different causes. In first place, the limitation or exclusion of the diet of sugars is for disease reasons, as the diabetes case, that the people have altered the glucose metabolism and therefore limited its consumption of specific form. In addition, they are the injurious effects that on the health have the rich diets in carbohydrates and fats, and finally the aesthetic reasons or fashionable. Mango pulp of Tommy Atkins variety was used it was 14 ºBrix and an acidity of 9 g/L. Also, low methoxyl pectin and two modified starches (a potato starch cross-linked and other stabilized with acetic anhydride), were used. Three concentrations: 3.5, 4,5 and 5.5% for starches and 0.65, 0.75 and 0,8% for pectin were used. To diminish the sugar content, sucralose in a single concentration was used. Textural behavior was evaluated using a texture analyzer TA-XT2 with 2.54 cm cylinder probe. They were obtained from the texture profile, the hardness, adhesiveness, cohesiveness and gumminess like parameters that they describe to this product. Analysis of variance with = 0.05 was employed for data analysis. It was obtained that the hardness, adhesiveness and gumminess of the jam were increased with the increase of polymer concentration in significant form (P < 0.05) Nevertheless, jams made with pectin showed values very superiors respect to the elaborated with starches, this probably is due to the different gel formation mechanisms, that involves in the case of the pectin the formation of ionic and hydrogen bonds, forming therefore one more reinforced three-dimensional network, whereas for starches only hydrogen bonds were involved. A tendency similar is showed for cohesiveness of samples made with starches, the value of this was increased when starch concentration was increased and in the case of samples made with pectin, values were constant, probably because the formation of ionic bonds of this is limited by the ion concentration in the formulation that was constant for the three formulations and in this way the cohesiveness of gel not is modifies.
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Evaluation of Chemical, Physical and Rheological Characteristics of Flours Obtained From Bread Wheat With Different Percentage of the “Yellow Berry
Defect”
López-Ahumada , G.A., Ramírez-Wong, B., Milán-Carrillo, J., Zazueta-Morales, J.J., Garzón-Tiznado, J.A., Figueroa, J.D.
Departamento de Investigación y Posgrado en Alimentos. Universidad de Sonora. Rosales y Blvd.. Luis Encinas s/n. Col. Centro. Tel y fax: 662259-22-07 a 09. Hermosillo, Son., c.p 83000.
Recently, in the State of Sonora Mexico, bread wheat cultivars have been affected by a physiological disorder named “yellow berry”. A research was performed to characterize chemically, physically and rheologically flours obtained from a commercial bread cultivar (Tarachi) with 0, 11, 45, 60 and 100 % of yellow berry. Flours were evaluated for moisture content, ash content, protein content, sedimentation volume, falling number and wet gluten. In addition, rheological determinations were made with the farinograph, alveograph and the rapid viscoamylograph. A completely randomized experiment design was carried out. The percentage of yellow berry in the bread wheat cultivar affected the evaluated characteristics. Include the range values of moisture, ash, protein content, etc obtained Significant differences (p<0.05) were observed in moisture and protein contents, falling number, sedimentation, wet gluten; development time and water absorption measured with the farinograph and tenacitiy, elasticity and dough work deformation measured with the alveograph. Significant differences (p<0.05) also were observed in bread volume. It was concluded that flour obtained from wheat with 11% of “yellow berry” gave still bread with acceptable volume.
FP-32 Rheological Characterization and Texture Profile Analysis of a Squeeze and Low
in Sugar Mango Jam Elaborated with Different Polysaccharides
López-Hernández, G., Hurtado-López, C; Valtierra-Aguilar, M, Ramirez Ortíz María Eugenia; Romero Arreola Verónica .
Departamento de Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán. Universidad Nacional Autónoma de México. Cuautitlan Izcalli, Edo. De México. [email protected]
Mexico counts with a wide variety of tropical fruits such as mango that, in spite of having a great acceptance in the market as raw material, it has not been properly industrialized. In this project the elaboration of a squeeze and sugar reduced “ataulfo” mango jam was proposed. In this project it was established the use of three polysaccharides (low methoxyl amidated pectin =LMP amidated=, propyleneglycol alginate and carrageenan) at three concentrations (0.5%, 0.75% y 1%). Fifty percent of sugar was reduced and replaced by maltodextrin of 20 DE. Flow curves and rheological parameters were obtained using the Haake Viscosimeter VT-550 (𝛾 from 1 to 500 1/s) with SV-DIN, and the Haake Rheometer RT-20 (𝛾 from 1 to 10 1/s) with the serrated platePP35 and a distance of 1 mm. To get TPA curve it was occupied the Lloyd TA500 with a 254 mm cylyndrical geometry, using a load cell of 50 kg m/s2, the sample was placed en petri dishes. The penetration distance was 7 mm at a speed of 0.0016 mm/min. Parameters considered were hardness and adhesiveness. Data were analyzed from ANOVA with a α0.05 in a Minitab software. For the product consistency (kc, τ0, hardness), neither the kind of polysaccharide nor the concentration have a significant influence. However, from Tukey test a 7.2% probability to obtain the same hardness and 14.9% to obtain a similar adhesiveness between each polysaccharide was found. Also a probability of 3.5% was found to get a similar hardness and 0.3% for a similar adhesiveness between each concentration. The kind of polysaccharide and concentration did not affect the model defining the behavior, which is Casson. We conclude that low methoxyl amidated pectin is a gelling polysaccharide suitable for this type of jam , because it confers low viscosity, hardness and adhesiveness, which if higher would not allow flow of the jam from a squeeze bottle.
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Effect of Drying Time, Bean Depth, Temperature and Air Flow on Volatile Acidity, pH and Phenols Totals of Mexican Cocoa Beans.
Barrios Viñas, M.L., and García Alamilla, P.
Universidad Juárez Autónoma de Tabasco (UJAT). División Académica de Ciencias Agropecuarias (DACA). Centro de Investigación en Ciencias Agropecuarias (CICA). Carret. Vhsa – Teapa Km. 25.
Villahermosa, Tabasco, México. E- mail: [email protected] Tel: 993358-1585 fax (142 9151 y 142 91 50) ext 6604
Departamento de Investigación y Postgrado. Instituto Tecnológico de Villahermosa. Villahermosa, Tabasco, México.
Please Include a brief introduction. The drying time (??), bean depth (2.5–7.5 cm.), extraction rate of air flow (0.3–1.2 m/s), and temperature (40–70°C) on volatile acidity, total acidity, pH, phenols totals was studied. The drying process of cocoa beans was realized?? in a tray drier until the moisture content of the beans was reduced to 7.5 %. The samples were dried according to a central composite rotatable design configuration for three factors. The data were analyzed using MATLAB program for statistical analysis. The regression coefficients were then used to plot three dimensional on the response surface methodology. The drying system in trays manifested near levels of volatile acidity to the limits settled down by Augier 1999, however the pH values didn't reach the value of 5.0 recommended in the international level. For the total acidity they were superior values to 3 ml/g under the study conditions. The best drying treatment was obtained at the combination of bean depth 3 cm, extraction rate of air flow of 0.4 m/s and temperatures drops of 50°C.
(key words: cocoa beans drying, response surface methodology, volatile acidity, pH, phenols totals)
FP-34 Evaluation of Fat Pepper (pepper dioica l. merril) Dehydration in Fluid Bed with Tempering Cycles, using the Residual Enzymatic Activity as a Quality Parameter
Flores-Martínez, N.L., Cruz y Victoria, M.T., Anaya-Sosa, I.
Laboratorio de Graduados en Alimentos. Escuela Nacional de Ciencias Biológicas (IPN). Prol. de Carpio y Plan de Ayala s/n. 11340. México D.F.
Fat pepper (Pimenta dioica L. Merril) is a fruit with high moisture content that is dehydrated with commercial purposes. In order to export a high quality product, it is necessary to find a suitable drying technology to maintain the quality of the fruit. Therefore, the aim of this work was to implement the tempering drying technique, which has been proved to be a simple and highly efficient methodology to reduce the moisture content (12% w.b.), to dehydrate fat pepper. The parameters considered to measure the quality of the fruit were peroxidase enzyme (Worthinton manual) and ascorbic acid retention (Xylene extraction method). The experimental design consisted of a 22 factorial where the operation temperatures were 60°, 70° and 80°C, and the tdrying/tcycle ratio was 0.5, 1 and 1.5. The operating conditions were determined according to the minimum fluidizing velocity (Umf), which was 4.75 m·s-1. Thus, the operation velocity (Uop) was 1.2 times the Umf value, and the ratio diameter : length of the drying chamber (L/D) was 0.5.The diameter of the fresh pepper was reduced by 43% (from 7.5 to 4.3 mm) after the drying process. The apparent and packed densities increased after the process; sphericity was taken as the unit because of the geometrical shape of the pepper fruit. For each of the evaluated temperatures, we observed a constant drying rate period ranging from 20 to 55 min, which represents 1/4 to 1/5 of the total drying time without tempering cycles. The use of tempering cycles enabled the removal of 2/3 of the moisture content of the fruit at the same velocity, which means that the amount of removed water can be increased up to three times compared to conventional drying techniques. The values of the diffusion coefficient using the second Fick`s law were found in the range (4.39-6.63) x10-8 m2 s-1. Peroxidase retention increased with the tempering cycles at 70° C compared to the control, while the ascorbic acid retention decreased 50% with batch dryingand tempering drying.
