Top PDF Accelerated fruit libraries to predict storage potential of 'Hayward' kiwifruit grower lines : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, New Zealand

I would like to say special thanks to Peter Jeffery for his always ready to help attitude. No matter when and what kind of help you need from him, he is continually willing to offer his expertise. Many thanks to Sue Nicholson for her extremely valuable suggestions and continues assistance in experiment planning and during my time working in laboratory. I am thankful to Byron McKillop for technical support. I appreciate Peter Jones (Zespri International Ltd.), and Geoff Wheldon and other people at East Pack (Te Puke) for their efforts to organise in time delivery of fruit lots to Massey University over three years.

Fresh kiwifruit seldom are marketed immediately after harvest. Most of the fruit is usually warehoused for up to 4 - 6 months at 0 °C, with relative humidity 90 - 95% and no ethylene, during the storage (Harvey et al., 1983; McDonald, 1990; Ritenour et al., 1999; Burdon and Lallu, 2011). Kiwifruit slowly deteriorate over time even in cool store with softening being the major limiting factor of storage life (Feng et al., 2001). Immense losses occur if fruit soften prematurely in storage. Kiwifruit are very susceptible to small concentrations of ethylene (i.e. 0.01 - 0.03 ppm) during storage (Ben-Arie and Sonego, 1985; Mitchell, 1990; Hewett et al., 1999). So, one of the most important concerns for kiwifruit storage is management of ethylene in the atmosphere (Section 2.3.2.3). Factors such as frequency of opening the doors, location of storage facility, nearby roads and presence of decaying fruit in the vicinity of store rooms, all influences the concentration of ethylene in the atmosphere (Rushing, 2004). Rot incidence (Section 2.4.2) and low temperature breakdown (Section 2.3.2.2) are also important problems of kiwifruit and contribute to losses during storage (Hewett et al., 1999; Kim, 1999). Therefore, it is necessary to ensure correct temperatures with no accumulation of ethylene during storage (Mills, 2006; Burdon and Lallu, 2011). For successful management, application of strict regimes (temperature and humidity in an ethylene free environment) is needed to ensure fruit storage for long periods while maintaining good flavour and appearance. Effects of these factors may vary among different cultivars, orchards and seasons (Hopkirk and Clark, 1991; Benge, 1999).

Seasonal variation in the average concentrations, on a dry weight basis, of calcium Ca, magnesium Mg, potassium K, nitrogen N and phosphorous P in the leaves petioles included of kiwifru[r]

Kluge et al., (2003a) also reported that the occurrence of CI symptoms was reduced to 12.5-20% by their IW treatments but all their fruit showed CI after 90 days of storage. They also found no differences in physicochemical characteristics between the fruit stored at 5°C continuously and the fruit stored under IW treatments (IW-1 and IW-2). The more extreme IW-3 treatment led to adverse effects on fruit quality such as a reduction in acidity (TA, % citric acid) during storage and also loss of ascorbic acid content, with declines of approximately 30 and 50% at 30 and 60 days, respectively. In addition, a significantly higher respiration rate and production of ethanol and acetaldehyde were observed under IW-3 compared to constant temperature storage at 5°C and the other IW conditions. Thus Kluge et al. (2003)’s IW regimes were able to achieve gains with respect to improved colour but overall were not really successful in providing high levels of acceptable fruit. From my results, I concluded that the correct selection of the number of cycles and duration of warming was very important. I could not retain quality of fruit by only using 1-cycle IW, but I could retain quality better using only a 2-cycle regime. Quality retention was the best when the 6-cycle IW was used. This I hypothesise to be associated with tissue repair processes facilitated during warming periods during IW storage.

Starch degradation during ripening potentially affects cell turgor pressure. Turgor pressure contributes to the cell and tissue strength by providing the hydrostatic pressure within the cell and therefore influences textural properties (De Belie et al., 2000). Having a low turgor pressure will cause the cell to collapse while too high in turgor pressure leads the cell to be brittle and likely to rupture (Lin & Pitt, 1986; Jackman & Stanley, 1992). An increase in soluble solids content during ripening will result in an increase in turgor pressure and thus an increase in firmness is expected. However, no distinct pattern of change in cell turgor has been observed during kiwifruit ripening (Harker & Hallett, 1994). Harker and Hallett (1994) proposed the cell wall of ripened kiwifruit cell became more plastic and elastic and thus resulted in a cell expansion rather than an increase in turgor pressure when placed in a hypotonic solution. Another possibility is solute accumulation may occur in both apoplast and symplast and thus maintaining a constant turgor pressure. Turgor pressure in beetroot tissue was found to remain unchanged even after an increase in osmotic pressure due to sucrose accumulation (Tomos et al., 1992). Turgor pressure in tomato was found to be lower than expected from the osmotic potential, which may be due to the presence of solutes in the apoplast (Schackel et al., 1991). Overall, these findings point out the possible reasons why no association between change in turgor pressure and starch breakdown was observed in kiwifruit ripening.

All the staff and students at Riddet Institute are very much appreciated. The inspirations from the nice and diversity environment are very important to my journey of study. I also thank all professors, staff and students at Massey University who have helped me during my study.

xiii Figure 6.5: Experimental data and modelled average firmness of fruit exposed to high temperature conditions after 10 weeks of storage ......................................................... 132 Figure 6.6: Experimental data points and modelled average firmness of fruit with chilling injury development........................................................................................................ 133 Figure 6.7: Scatter plots of initial fruit firmness (F 0 ), soluble solids (B 0 ) and dry matter

that purified native actinidin from Hayward kiwifruit ran at the same molecular weight of 25 kDa in both SDS-PAGE and Western blot analysis. The identification of this 25 kDa protein was confirmed by LC-MS showing identical fragments derived from recombinant acidic actinidin protein. However, for recombinant proteins, both 25 kDa and 30 kDa bands were observed on SDS-PAGE, but only the predominant protein produced at 30 kDa reacted with the polyclonal actinidin antibody. It was suggested that recombinant acid and basic forms of actinidin had a 6 x Histidine tag attached at the N-terminus that added approximately 5 kDa to the size of mature protein. Moreover, Western blot results showed antibodies also positively recognize a protein with a molecular weight around 38 kDa. But this protein was not detected on 2D gels by silver staining. The reason of this was unexplained. Another study reported that two-dimensional PAGE showed fragmentation of the 30 kDa protein, pI 3.6 into a 26 kDa protein with a pI value of 3.2, and both the protein and protein fragment showed actinidin proteolytic activity in a zymogram (Gavrovic-Jankulovic et al., 2005).

Summer defoliation reduced fruit Ca concentrations as much as spring defoliation . Within 20 days of applying the summer defoliation treatment fruit Ca concentrations had decreased by 27% compared to the control . In addition, the Ca content of fruit from the summer defoliation treatment decreased by nearly 2mg/fruit between January and April. This was unexpected because by 5 January 2002 (7 WAFB) it was anticipated that about 75% of the Ca would have accumulated in the fruit (Clark and Smith, 1 988) and that fruit Ca concentrations would have been reduced only slightly by defoliation at this time. Instead it appears that only about 60% of the Ca h ad accumulated in fruit by 5 January 2002. This indicates that, contrary to previously published information (Clarkson, 1 984; Clark and Smith, 1 988; Xiloyannis et al., 200 I ), significant amounts of Ca were accumulated late in the season despite the decrease in water accumulation in fruit as they mature. An alternative explanation for this unexpected result is that summer defol iation may have caused Ca to be remobi lised out of fruit. In apple (Lang, 1 990) and grape (Lang and Thorpe, 1 989), sap may flow out of fruit along a water potential gradient during periods of high potential evapotranspiration. This reduces the likelihood of leaves becoming water-stressed and photosynthetic efficiency being reduced, but may affect the mineral composition in fruit. However this latter explanation, does not seem likely gi ven that : (a) \eaves were removed, so that a water potential gradient between leaves and fruit could not be established, and (b) xylem tissues In defoliated fruit were largely dysfunctional, thereby preventing xylem sap outflow from fruit.

The effect of storage temperature on casein properties was studied in more detail. High and low moisture samples were exposed at storage temperatures of 1 400e, 1 200C and l OOoe for 2 hours. The 1 400C temperatu re was repeated to c h e c k the earlier observations . Figure 1 0.2 shows the plots of the solubility index against the moisture content of s ample s stored at different high storage temperature s for 2 hours . The solubility index for the high and low moisture samples stored at 1 400e for 2 hours from the first tes t is also plotted in Figure 1 0.2 for comparison. At 1 000C there was little change i n the solubility index with moisture content. At the low moisture content, the solubility index rose sharply with an increase in storage temperature, while at the high moisture content, increasing the temperature reduced the solubility index, the effect being most noticeable at 1 400C. Figure 1 0.3 shows the appearance of the ground s amples stored at different high storage temperatures for 2 hours. The results indicate that severe colour changes occurred on all the samples at 1 200e and 1 400C but there w as only a slight change on the samples at l OOoe. It seems also that the high moisture s amples had more severe colour changes than the low moisture samples at 1 200C and 1 40°C. S pellacy ( 1 953) pointed out that temperatures employed in the drying process will not materially affect the solubility of casein, provided they are not excessive and are properly c orrel ated with air volume s . B urnt or scorched casein i s rendered i n soluble. The res ults have shown that this is the case for low moisture samples. However the re sults for the high moisture samples were surprising. The thermal denaturation reaction seems to be different because of the presence of a large amount of moisture which c annot evaporate during the heating process. Therefore these conditions are different from the drying of wet curd since the moisture will evaporate l eaving the dehydrated casein solids. Hence 1000C was used as the high level storage temperature for the succeeding factorial experiments on casein because the trend of the results was similar to those found at 60°C.

It is recognised that heat alters the flavour of milk with the type and intensity of the flavour changes being dependent on the temperature and the duration of the heat treatment. Therefore the flavour of whole milk powder will be influenced by the degree of heat treatment that the milk receives during the evaporative and drying stages of the manufacture of whole milk powder. Scanlan et al. ( 1968) examined the effects of heat treatment on the volatile compounds from milk and found a variety of volatile compounds to be heat induced: C3-5,7-1 1,13 n-methyl ketones, C 8,10,12 o-lactones, benzaldehyde, furfural, phenylacetaldehyde, vanillin, oct- l -en-3-01, heptan ol, 2-butoxy- ethanol, maltol, acetophenone, benzonitrile, benzothiazo1e and diacetyl. It was also suggested that because of the increase in the level of diacety1 from 5 ppb (raw milk) to 3 8 ppb (heated milk) , which is above the average flavour threshold for diacetyl in milk, that this could be contributing to the rich heated flavour of heat treated milk.

The complete data set is a 3D image (Fig. 4.5) consisting of 512 two- dimensional (2D) vertical slices at 5.9 μm spacing. However, for the purpose of ease of demonstration, 2D slices of the data set are presented in this chapter. Several layers of sub-surface structures were observed in the raw images (Fig. 4.1 and 4.2). These structures include: (a) the suberised periderm layer (the ‘skin’), (b) a layer of homogeneous small cells, intermingling with (c) elongated black voids (large cells) located in the sub-surface region. In addition, some image artefacts are present as a result of: (d) shadowing effect caused by lenticels observed as grey spaces throughout the tissue underneath without detailed texture boundaries, (e) shadowing effects caused by trichomes observed as “black streaks” underneath the hair throughout the tissue, and (f) direct reflection of light back into the sensor from the surface observed as “white streaks” in the vertical direction (Fig. 4.1). Lenticels were a common issue for all the cultivars, whereas trichomes were a significant issue for the hairy green-fleshed ‘G14’ (Fig. 4.2d) and ‘Hayward’ (Fig. 4.2e). This can be more clearly observed in Fig. 4.3 where shadows of lenticels and trichomes were manually selected on cross-sectional slices and then visualised in 3D images. Details of any cellular structures within the shadowed volumes were unable to be observed or extracted. The fraction of volume being affected by these artefacts of the assessed image region varied between cultivars, with 9-13% losses for all three yellow cultivars (‘G3’, ‘G9’ and ‘Hort16A’; Fig. 4.3a-c) and 25-29% for the hairy green cultivars (‘G14’ and ‘Hayward’; Fig. 4.3d-e).

Hu x l ey-Wi l berforce debate as the ir mod e l , ha v e been tr iumpha l i st , pos iti v istic , and mi l itaristic. The b l oody 'batt l e' between science and r e l ig ion , accord ing to the se rece i v ed v iews , resu l ted in the ov erwhe lming v ictory of science , truth , and progress o v er r e l i gion , ignorance , and superstition. This mod e l i s inapp l i cab l e in the New Zea l and context. Generations of reconci l ing Genesis with geo l ogy had prepared the Chr istian mind we l l for coming to terms with scientific disco v eries , and adjusting interpretations o f Scripture accord ing l y. After an initi a l per iod of caution and d e l iber ation , churchmen within the major denominations came to terms with �io logica l e v o l ution as read i l y as they had earl ier accepted the findings of geo l ogy and p a l aeonto l ogy. By the 1 8 80's e v o l ution became acceptab l e to most educated Chr istians. Scientists too,quick l y accepted bio l ogical

Ten t rays of commerc ia l l y packed 'Hayward ' k iw i fru it ( count 36) fro m each of the n ine grower lines were sampled during the main harvest seasons of year 2000 (9 M ay to 23 M ay) at week ly i ntervals ( three grower l ines per week) fro m pack houses in t he Bay of P lenty. Fruit were cool stored at 0.5°C in po ly l ined single- layered t rays w it h 5 g per tray o f ethylene absorbent ( Purafi l, Papworth E ngineering Ltd., New Zealand) a fter two days for t ransportat ion and labo ratory measurements. A fter 2-8 days cool storage and 1 2 hours temperature equ i l i bration, 20 fru it fro m each grower l ine were taken out of storage for VNI R measurement i n re flectance mode using a com mercial N I R system (Co mpac Sorti ng Equipment Ltd, New Zealand). Fru it carried by a conveyer belt w ith stem-calyx axis horizontal passed t hrough the N I R scann in g c hamber where a cont i nuous beam of l ight generated fro m a halogen lamp was f(Jeu sed on moving fru it and the reflected l ight from the fru it measured ten t imes. Two separate spectral measurements were made on each k iw i fru it, on opposite sides o f the med ian equator. T he 20 VNI R spectra recorded for each fru it were averaged after subt racti ng the dark reference and d iv id ing by a white reference ( materials and methods u sed to obtain reference spectra are confi dent ial to the Compac Sort ing Equipment Ltd). The averaged spectra were then smoothed u sing in-house software. S pectra were col lected w ithi n a wave length range of 300- 1 200 nm at 3 . 50-3.56 nm i ntervals (256 po ints). Fruit attributes such as L , C H, FL, FC, FH, C F, FF, SSC, O M and m inera l concentrations were measured on the fo l lowing day.

I would like to offer special thanks to Dr. Pieter Verboven and Prof. Bart Nicolaï from Katholieke Universiteit de Leuven, Belgium, for hosting me as a visiting scholar there for two months and for their excellent input towards the OCT work. I would also like to mention Dennis Cantre from KU Leuven for providing training on OCT image analysis, and Dr. Andreas Buchsbaum from the Research Centre for Non Destructive Testing (RECENDT), Austria for his help with the OCT instrument and image capture. Many thanks should go to Dr. Alistair Mowat for his help and suggestions for the orchard manipulation trial, and Dr. Thamarath (An) Pranamornkith for setting up the light manipulation trial and collecting NIR data. In addition, both Prof. Ian Hallett and Dr. Jinquan (Ringo) Feng from Plant and Food Research, Auckland should be accredited for providing insights on topics relating to plant cell structures and NIR grading. I would also like to acknowledge Assoc. Prof. Kelvin Goh for his help and support during my Honours degree, which eventually led to a PhD opportunity for me.

The dwindling i n fluence of the Soc ial Developmen t Counc i l i n the cons t ruc t i on o f social ind i ca t ors was apparen t by 1974 , when t he Soc ial Ind i ca t ors Un i t was es tabli shed wi thin the Department of S ta t i s t i cs . In Augus t 1975 this Un i t repo r ted to the S t anding Commi t t ee on Soc ial Obj ec t ives and Social ind i ca t ors . ( 1 1 8 ) The i r repo r t canvassed t hree maj or approaches to the es tabli shmen t of In terna t ional Indicator Sys t ems and summari sed '' progress " wi thin New Zealand . In d i s cuss ion , Mrs . Shields saw the prior i t ies of t he Uni t being set largely by wha t could be " prac t i cally managed '' ra ther than wha t was '' theore t i cally poss i b le " , and i n agreeing wi th t he New Zealand approach , the mee t ing cons idered tha t "goals should be poli t i cally neu t ral . '' ( 1 1 9 ) There was also general agreemen t tha t Uni t pub l i ca t ions should be aimed "at the publ i c at large " , al though i t was acknowledged that d i f fe ren t individuals and organisa t i ons m igh t wan t informa t ion in d i f feren t forms . The Uni t ' s short t e rm plans revealed t ha t the depar tmen t would be concen t ra t ing o� two areas of concern to be selec t ed from t he ca t egories of heal t h , educa t i on , labour , income and leisure , and t hese p r i o r i t ies were unanimously endorsed . A fur t her mee t i ng o f t he S t and ing Commi t t ee was scheduled for March 197 6 .

FOR the peoples of the Pacific Islands the nineteenth century was a period of bewildering and demoralising change. The islands had received occasional visits from mariners and explorers before the beginning of the century/ but while these visits excited the cupidity and wonder of the islanders they had little effect on their lives. But from about 1800 expanding Western civilisation forced itself upon the island world, and successive waves of Europeans began rapidly eroding traditional societies. First came the beachcombers bringing new technologies. They were followed by whalers bringing alcohol and new diseases, by missionaries with their new beliefs, by traders introducing new patterns of economic activity and by planters insisting on new attitudes to property. Native societies underwent revolutionary changes within a short space of time in an attempt to adjust to the new demands being made upon them, but in almost every case their responses were inadequate. Unable to come to terms with the new dispensation, one by one the island polities succumbed .and were absorbed into one or other

A thesis submitted in partial fulfilment of the requirements of Birmingham City University for the degree of Doctor of.. Philosophy.[r]

Patients with the l ate infantile and juvenile forms o f NCL develop motor d i sturbances varying from an initial partial loss o f abil i ty to per form coordinated movements to a terminal incapacitating r i gidity with flexion contracture s o f neck , trunk and extremitie s . Often an initial clumsiness develops into an incoordination o f gai t with ataxia o f the l egs . Patients may show di fficulty in initiating movement , but succeed i n carrying out a movement once s tarted . The upper extremities re tain the i r use longe r , despite abnormal po stur ing and hyperkine s i a . Mastication and gluti t io n are impeded and there i s imperfect articulation o f speech ( Zeman and Dyken , 19691.

Storage material apparently free in the cytoplasm o f a men inge al capil lary endothelial cell . Short arrow points to a five - layered membrane , which a t long a rrow seems to b e formed b y the fu sion o f two tr iparti te membrane s .