Food Microstructure Analysis
3.7 OTHER METHODS OF STRUCTURAL ANALYSIS
3.7.4 Optical Coherence Tomography
The emerging technique of optical coherence tomography (OCT) is related to CLSM inas-much as a light source (usually near infrared) penetrates into a sample to create “optical sections.” In OCT the echo time of the reflected light is measured using an interferometer and as such the technique is somewhat analogous to ultrasound imaging. Spatial resolu-tion of a few µm is achievable although a few tens of µm is more usual (Fujimoto aet al.
2000). Depth of penetration is greater than with CLSM (though not so great as ultrasound), typically for plant-based foods being in the order of 1.5 mm (Clements et al. 2004). As with MRI one of the main advantages envisaged for OCT is the ability to image rapidly and noninvasively, therefore with the possibility of in-line sorting and measuring (Meglinski et al. 2010).
Force
Approaching surface
Withdrawing from surface
Z-position
Tip and cantilever
Sample
Figure 3.21 Generating a “force–distance” curve as the AFM tip approaches, and is then with-drawn from, the sample surface gives information about the magnitude of force interactions between the tip and the sample. Tips can be activated by attaching molecules to probe-specific interactions.
3.8 SUMMARY
The influence of microstructure on properties and processes of food-based material has been increasingly recognized in the past few decades, in parallel with the development of tools and techniques that can be used to probe that microstructure. Equally, the materials engi-neering concept of using processing to manipulate structure, to give desirable functional properties is now the basis of a great deal of nutritional research (Morgenstern et al. 2012).
When deciding what techniques to use to quantify the microstructural features of food there are several golden rules, but no silver bullet. Simply put:
• A single technique is highly unlikely to give the complete answer, and in fact might mislead. All structural imaging techniques are complementary and pro-gressing in techniques of increasing spatial resolution is the best approach.
• Sample preparation will alter the sample. The major effort of any microstructural imaging technique is the sample preparation. There are noninvasive techniques (e.g., MRI) that are often limited by resolution but even then image artifacts can be introduced.
• Quantification of microstructure is essential for meaningful interpretation.
Computer-based solutions that allow automated counting and measuring of numerous features are the ideal approach, although outputs should always be checked against an inspection of the structure.
Techniques are developing all the time, at an accelerating rate. Frequently these tech-niques are not developed specifically with food structural analysis in mind, as such may need adapting for appropriate application within food engineering.
REFERENCES
Aguilera JM. 2005. Why food microstructure? Journal of Food engineering, 67, 3–11.
Aguilera JM, Cadoche L, López C, Gutierrez G. 2001. Microstructural changes of potato cells and starch granules heated in oil. Food Research international 34 (10), 939–947.
Aguilera JM, Germain JC. 2007. Advances in image analysis for the study of food microstructure. In:
D. Julian McClements (Ed.) understanding and Controlling the Microstructure of Complex Foods (pp. 261–287). Boca Raton, USA: CRC Press.
Aguilera JM, Stanley DW. 1999. Microstructural Principals of Food engineering. Gaithersburg, USA:
Aspen Publications, Inc.
Amin S, Rega CA, Jankevics H. 2012. Detection of viscoelasticity in aggregating dilute protein solu-tions through dynamic light scattering-based optical microrheology. Rheologica Acta 51 (4), 329–342.
Auty MAE, Twomey M, Guinee TP, Mulvihull DM. 2001. Development and application of confocal scanning laser microscopy methods for studying the distribution of fat and protein in selected dairy products. Journal of dairy Research 68 (3), 417–427.
Bolliger S, Kornbrust B, Goff HD, Tharp BW, Windhab EJ. 2000. Influence of emulsifiers on ice cream produced by conventional freezing and low-temperature extrusion processing. international dairy Journal 10 (7), 497–504.
Braga J, Desterro JMP, Carmo-Fonseca M. 2004. Intracellular macromolecular mobility measured by fluorescence recovery after photobleaching with Confocal Laser Scanning Microscopes.
Molecular Biology of the Cell 15, 4749–4760.
Food MiCRostRuCtuRe AnAlYsis
Brooker BE. 1995. Imaging food systems by Confocal Laser Scanning Microscopy. In: E. Dickinson (Ed.) new Physico-Chemical techniques for the Characterization of Complex Food systems (pp. 53–68).
London: Blackie.
Chen XD, Chiu YL, Lin SX, James B. 2006. in situ ESEM examination of microstructural changes of an apple tissue sample undergoing low-pressure air-drying followed by wetting. drying technology, 24(8), 965–972.
Clayton EG, Hassel AH. 1909. A Compendium of Food-Microscopy with sections on drugs, Water, and tobacco. London: Baillière, Tindall and Cox.
Clements JC, Zvyagin AV, Silva KKMBD, Wanner T, Sampson DD, Cowling WA. 2004. Optical coher-ence tomography as a novel tool for non-destructive measurement of the hull thickness of lupin seeds. Plant Breeding 123, 266–270.
Dalgleish DG, Hallet FR. 1995. Dynamic light scattering: Applications to food systems. Food Research international, Vol. 28, No. 3, pp. 181–193.
Danilatos GD. 1993. Introduction to the ESEM instrument. Microscopy Research and techniques 25, 354–361.
Danilatos GD, Robinson VNE. 1979. Principles of scanning electron microscopy at high specimen pressures. scanning 2, 72–82.
Donald AM. 2003. The use of environmental scanning electron microscopy for imaging wet and insulating materials. nature Materials 2, 511–516.
Donald AM, Baker FS, Smith AC, Waldron KW. 2003. Fracture of plant tissues and walls as visualized by environmental scanning electron microscopy. Annals of Botany 92, 73–77.
Dubochet J, Groom M, Mueeker-Neuteboom S. 1982. Mounting of macromolecules for electron microscopy with particular reference to surface phenomena and treatment of support films by glow discharge. In: R. Barrer and V.E. Cosslett (eds.) Advances in optical and electron Microscopy.
London: Academic Press.
Dürrenberger MB, Handschin S, Conde-Petit B, Escher F. 2001. Visualization of food structure by confocal laser scanning microscopy (CLSM). lWt 34, 11–17.
Eastoe J. 1995. Small-angle neutron scattering and neutron reflection. In: E. Dickinson (Ed.) new Physico-Chemical techniques for the Characterization of Complex Food systems (pp. 268–295).
London: Blackie.
Echlin P. 1992. low temperature Microscopy and Analysis. New York: Plenum Press.
Ferguson LR, Smith BG, James BJ. 2010. Combining nutrition, food science and engineering in devel-oping solutions to inflammatory bowel diseases—Omega-3 polyunsaturated fatty acids as an example. Food and Function 1 (1), 60–72.
Fletcher AL, Thiel BL, Donald AM. 1999. Signal components in the environmental scanning electron microscope. Journal of Microscopy 196(1), 26–34.
Flint O. 1994. Food Microscopy. Oxford, UK: BIOS Scientific Publishers Ltd.
Frisullo P, Conte A, Del Nobile MA. 2010. A novel approach to study biscuits and breadsticks using x-ray computed tomography. Journal of Food science 75, 6, 353–358.
Frisullo P, Licciardello F, Muratore G, Del Nobile MA. 2010. Microstructural characterization of mul-tiphase chocolate using x-ray microtomography. Journal of Food science 75, 7, 469–476.
Fujimoto JG, Pitris C, Boppart SA, Brezinski ME. 2000. Optical coherence tomography: An emerging technology for biomedical imaging and optical biopsy. neoplasia, 2(1–2), 9–25.
Glauert AM, Reid N. 1974. Fixation, dehydrating and embedding of biological specimens and ultra-microtomy. In: AM Glaurt (Ed) Practical Methods in electron Microscopy (Vol. 3, pp. 1–207).
Amsterdam: North-Holland.
Greenish HG. 1923. the Microscopical examination of Foods and drugs: A Practical introduction to the Methods Adopted in the Microscopical examination of Foods and drugs, in the entire, Crushed and Powdered states. London: J & A Churchill.
Gunning AP, Kirby AR, Ridout MJ, Brownsey GJ, Morris VJ. 1996. Investigation of gellan networks and gels by atomic force microscopy. Macromolecules 29 (21), 6791–6796.
Harker FR, White A, Gunson FA, Hallett IC, De Silva HN. 2006. Instrumental measurement of apple texture: A comparison of the single-edge notched bend test and the penetrometer. Postharvest Biology and technology 39, 185–192.
Hassel AH. 1857. Adulterations detected; or, Plain instructions for the discovery of Frauds in Food in Medicine. London: Longman, Green, Longman, and Roberts.
Heertje I. 1993. Microstructural studies in fat research. Food structure 12 (1), 77–94.
Heertje I, Pâques M. 1995. Advances in electron microscopy. In E. Dickinson (Ed) new Physico-Chemical techniques for the Characterization of Complex Food systems (1–52). London: Blackie.
Hermansson A-M, Buchheim W. 1981. Characterization of protein gels by scanning and transmission electron microscopy—A methodology study of soy protein gels. Journal of Colloid and interface science 81 (2), 519–530.
Hills B. 1995. Food processing: An MRI perspective. trends in Food science and technology 6 (4), 111–117.
Hodge SM, Rousseau D. 2002. Fat bloom formation and characterization in milk chocolate observed by atomic force microscopy. JAoCs, Journal of the American oil Chemists’ society 79 (11), 1115–1121.
Holcomb DN. 1990. Food microstructure—Cumulative index. Food structure 9(3), 155–173.
Holcomb DN, Kalab M. 1981. studies of Food Microstructure. O’Hare, USA: Scanning Electron Microscopy, Inc.
Horne DS. 1995. Light scattering of colloid stability and gelation. In E. Dickinson (Ed) new Physico-Chemical techniques for the Characterization of Complex Food systems (240–267). London: Blackie.
Invitrogen. 2013. Fluorescence Spectra Viewer. Retrieved 20/2/2013 from:http://www.invitro- gen.com/site/us/en/home/Products-and-Services/Applications/Cell-Analysis/Labeling-Chemistry/Fluorescence-SpectraViewer.html
James BJ. 2009. Advances in “wet” electron microscopy techniques and their application to the study of food structure. trends in Food science and technology 20, 114–124.
James BJ, Fonseca CA. 2006. Texture studies and compression behaviour of apple flesh. international Journal of Modern Physics B 20, 3993–3998.
James BJ, Yang SW. 2012. Effect of cooking method on the toughness of bovine m. semitendinosus.
international Journal of Food engineering (8) 2, 19.
James BJ, Smith BG. 2009. Surface structure and composition of fresh and bloomed chocolate anal-ysed using x-ray photoelectron spectroscopy, cryo-scanning electron microscopy and environ-mental scanning electron microscopy. lWt Food science and technology, 42 (5), 929–937.
Kiselev NA, Sherman MB, Tsuprun VL. 1990. Negative staining of proteins. electron Microscopy Reviews, 3, 1, 43–72.
Laverse J, Mastromatteo M, Frisullo P, Albenzio M, Gammariello D, Del Nobile MA. 2011. Fat microstructure of yogurt as assessed by x-ray microtomography. Journal of dairy science 94, 668–675.
Lorén N, Langton M, Hermansson A-M. 2007. Confocal fluorescence microscopy (CLSM) for food structure characterisation. In D. Julian McClements (Ed.) understanding and Controlling the Microstructure of Complex Foods (pp. 232–260). Boca Raton, USA: CRC Press.
Ma X, James B, Zhang L, Emanuelsson-Patterson EAC. 2013. Correlating mozzarella cheese proper-ties to its production processes and microstructure quantification. Journal of Food engineering 115 (2), 154–163.
Marchin S, Putaux J-L, Pignon F, Léonil J. 2007. Effects of the environmental factors on the casein micelle structure studied by cryo transmission electron microscopy and small-angle x-ray scat-tering/ultrasmall-angle x-ray scattering. Journal of Chemical Physics 126 (4), art. no. 045101.
McCann TH, Fabre F, Day L. 2011. Microstructure, rheology and storage stability of low-fat yoghurt structured by carrot cell wall particles. Food Research international 44 (4), 884–892.
Meglinski IV, Buranachai C, Terry LA. 2010. Plant photonics: Application of optical coherence tomog-raphy to monitor defects and rots in onion. laser Physics letter 7, No. 4, 307–310.
Mertz J. 2010. introduction to optical Microscopy. Greenwood Village, Colarado USA: Roberts &
Company Publishers.
Food MiCRostRuCtuRe AnAlYsis
Moncrieff DA, Barker PR, Robinson VNE. 1979. Electron scattering by gas in the scanning electron microscope. Journal of Physics 12, 481–488.
Morgernstern M, Foster K, James B. 2012. Food structure breakdown in the mouth to enhance bioac-tivity. Food science and technology, 26, 1, 32–34.
Morris VJ. 2004. Probing molecular interactions in foods. trends in Food science & technology, 15, 6, 291–29.
Morris VJ. 2007. Atomic Force Microscopy (AFM) techniques for characterising food structure. In D.
Julian McClements (Ed.) understanding and Controlling the Microstructure of Complex Foods (pp.
209–231). Boca Raton, USA: CRC Press.
Morris VJ, Kirby AJ, Gunning AP. 1999. Atomic Force Microscopy for Biologists. London: Imperial College Press.
Mousavi R, Miri T, Cox PW, Fryer PJ.. Imaging food freezing using x-ray microtomography.
international Journal of Food science and technology 2007, 42, 714–727.
Nehir El S, Sinsek S. 2012. Food technological applications for optimal nutrition: An overview of oppor-tunities for the food industry. Comprehensive Reviews in Food science and Food safety 11 (1), 2–12.
Nicolai T. 2007. Food characterisation using scattering methods. In D. Julian McClements (Ed.) understanding and Controlling the Microstructure of Complex Foods (pp. 288–310). Boca Raton, USA: CRC Press.
Plucknett KP, Pomfret SJ, Normand V, Ferdinando D, Veerman C, Frith WJ, Norton IT. 2001. Dynamic experimentation on the confocal laser scanning microscope: Application to soft-solid, compos-ite food materials. Journal of Microscopy, 201, 2, 279–290.
Presley JF, Cole NB, Schroer TA, Hirschberg K, Zaal KJM, Lippincott-Schwartz J. 1997. ER-to-Golgi transport visualized in living cells. nature 389, 81–85.
Price RL, Jerome WG. 2011. Basic Confocal Microscopy. New York: Springer.
Ramírez C, Aguilera JM. 2011. Determination of a representative area element (RAE) based on non-parametric statistics in bread. Journal of Food engineering 102 (2), 197–201.
Ramírez C, Germain JC, Aguilera JM. 2009. Image analysis of representative food structures:
Application of the bootstrap method. Journal of Food science 74, 6, 65–72.
Ramírez C, Young A, James B, Aguilera JM. 2010. Determination of a representative volume element based on the variability of mechanical properties with sample size in bread. Journal of Food science 75 (8), 516–521.
Royall CP, Thiel BL, Donald AM. 2001. Radiation damage of water in environmental scanning elec-tron microscopy. Journal of Microscopy 204(3), 185–195.
Russ JC. 2004. image Analysis of Food Microstructure. Boca Raton, USA: CRC Press.
Sargant JA. 1988. The application of cold stage scanning electron microscopy to food research. Food Microstructure 7(2), 123–135.
Sila DN, Duvetter T,De Roeck A, Verlent I, Smout C, Moates GK, Hills BP, Waldron KK, Hendrickx M, Van Loey A. 2008. Texture changes of processed fruits and vegetables: Potential use of high-pressure processing. trends in Food science and technology 19 (6), 309–319.
Smith BG, James BJ, Ho CAL. 2007. Microstructural characteristics of dried carrot pieces and real time observations during their exposure to moisture. international Journal of Food engineering 3(4), Art7.
Sonwai S, Rousseau D. 2010. Controlling fat bloom formation in chocolate—Impact of milk fat on microstructure and fat phase crystallisation. Food Chemistry 119 (1), 286–297.
Stokes DJ. 2003. Recent advances in electron imaging, image interpretation and applications, envi-ronmental scanning electron microscopy. Philosophical transactions of the Royal society A, 361, 2771–2787.
Stokes DJ, Thiel BL, Donald AM. 1998. Direct observation of water-oil emulsion systems in the liquid state by environmental scanning electron microscopy. langmuir 14, 4402–4408.
Stokes DJ, Thiel BL, Donald AM. 2000. Dynamic secondary electron contrast effects in liquid systems studied by environmental scanning electron microscopy. scanning 22, 357–365.
Stokes JR, Telford JH. 2004. Measuring the yield behaviour of structured fluids. Journal of non-newtonian Fluid Mechanics 124 (1–3 SPEC. ISS.), 137–146.
Takata S-I, Norisuye T, Tanaka N, Shibayama M. 2000. Heat-induced gelation of b-lactoglobulin. 1.
Time-resolved dynamic light scattering. Macromolecules 33 (15), 5470–5475.
Tang X, de Rooij MR, de Jong L. 2007. Volume change measurements of rice by environmental scan-ning electron microscopy and stereoscopy. scanscan-ning 29, 197–205.
Tang X, de Rooij MR, van Duynhoven J. 2007. Dynamic volume change measurements of cereal materials by environmental scanning electron microscopy and videomicroscopy. Journal of Microscopy 230(1), 100–107.
Thiel BL, Donald AM. 2000. Microstructural failure mechanisms in cooked and aged carrots. Journal of texture studies 31, 437–455.
Tran ATT, James BJ. 2012. Study of the interaction forces between the bovine serum albumin protein and montmorillonite. surface Colloids And surfaces A, 414, 104–114.
Turgeon SL, Rioux L-E. 2011. Food matrix impact on macronutrients nutritional properties. Food Hydrocolloids 25 (8), 1915–1924.
Verboven P, Kerckhofs G, Mebatsion HK, Ho QT, Temst K, Wevers M, Cloertens P, Nicolaï BM. 2008.
Three-dimensional gas exchange pathways in pome fruit characterized by synchrotron x-ray computed tomography. Plant Physiology 147, 518–527.
Verboven P, Kerckhofs G, Mebatsion HK, Ho QT, Temst K, Wevers M, Cloetens P, Nicolaï BM. 2008.
Three-dimensional gas exchange pathways in pome fruit characterized by synchrotron x-ray computed tomography. Plant Physiology 147, 2, 518–527.
Walther P, Wehrli E, Hermann R, Muller M. 1995. Double-layer coating for high-resolution low-tem-perature scanning electron microscopy. Journal of Microscopy 179 (3), 229–237.
Waninge R, Kalda E, Paulsson M, Nylander T, Bergenståhl B. 2004. Cryo-TEM of isolated milk fat globule membrane structures in cream. Physical Chemistry Chemical Physics, 6, 1518–1523.
Weng J, Song X, Li L, Qian H, Chen K, Xu X, Cao C, Ren J. 2006. Highly luminescent CdTe quantum dots prepared in aqueous phase as an alternative fluorescent probe for cell imaging. talanta 70 (2), 397–402
Zúñiga RN, Tolkach A, Kulozik U, Aguilera JM. 2010. Kinetics of formation and physicochemical characterization of thermally-induced β-lactoglobulin aggregates. Journal of Food science 75 (5), E261–E268.