Typescript (photocopy). / Digitized by Kansas Correctional Industries

The vase life of cut flowers is determined by various physiological factors that determine the rate of their senescence. A thorough understanding of these factors is required in order to design treatments that will extend the vase life and delay senescence of cut flowers. Senescence of climacteric flowers such as carnations (Dianthus caryophyllus L. cv. Nordika and cv. Snow White) and freesias (Freesia refracta cv. Athena) is characterized by a climacteric rise in respiration rate and ethylene synthesis during the late stages. The increase in ethylene production is preceded by an increase in the sensitivity of the flowers to ethylene. Pulse treatments with sucrose caused a delay and suppression of the climacteric rise in ethylene synthesis and a delay in the climacteric maximum of the respiration rate. A pulse treatment for 24 hours with a 20% sucrose solution was most effective in extending the longevity of both carnations and freesias. The ability of the receptor molecules to bind ethylene is greatly reduced when flowers are pulse-treated with sucrose. In freesias, the ability to bind ethylene is reduced even further when flowers are treated with STS or 1-MCP. Ethylene synthesis in freesias is suppressed and inhibited when treated with STS or 1-MCP but longevity of the freesias and number of open florets on the stem is not increased. The uptake and distribution of sucrose in the buds of freesias is seen by the distribution of sucrose from the first bud on the stem to the next bud after the bud opens. The distribution of sucrose from one bud to the next results in more buds opening on the stem than that on the stems of STS or 1-MCP treated freesias. It is thus clear from the results of the study, that pulsing senescing climacteric flowers with sucrose increases the vase life of the flowers and suppresses ethylene sensitivity of the flowers, thus delaying the autocatalytic process of ethylene production. It is also evident from the results that the osmolality in the flowers has a direct influence on the metabolic processes of the flowers. In freesias, pulse treatment with sucrose increases the number of open buds on the stem and delays senescence of the florets. / Mr. C.S. Whitehead

Bibliography: leaves 280-300. / xix, 338 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 2000

Advanced research in Controlled/Modified Atmosphere storage systems has shown that open channels of different lengths and cross sectional areas, connected to an air tight storage chamber, are able to maintain variable stable gas concentrations which could be near optimal concentrations for CA/MA storage of various commodities. / This study was geared towards assessing the suitability of the diffusion channels in maintaining a desired gas concentration for CA storage of spinach. Initially, the respiratory behaviour of spinach was studied in gas sealed chambers (replicated four times) stored at four different temperatures, 2$ sp circ$C, 8$ sp circ$C, 15$ sp circ$C and 23$ sp circ$C. The respiration rate of spinach was 20 mgCO$ sb2$/kg.h, 66 mgCO$ sb2$/kg.h, 163 mgCO$ sb2$/kg.h and 271 mgCO$ sb2$/kg.h for 2$ sp circ$C, 8$ sp circ$C, 15$ sp circ$C and 23$ sp circ$C, respectively. A model was developed based on principles of enzymatic kinetics which could reliably predict the respiration rate of spinach at any given storage temperature. / Two other sets of experiments were carried in a cold room set at 2$ sp circ$C. (Abstract shortened by UMI.)

Thesis (MScFoodSc )--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The development of science-based management tools and appropriate postharvest handling protocols are required for the determination of optimal storage performance of pomegranate fruit. The South African pomegranate industry experiences considerable fruit quality losses due to the lack of knowledge on optimal storage and handling practices. The cultivar ‘Wonderful’ is the widely grown in South Africa; however, to date there is currently limited scientific knowledge on the storage requirements. To develop quality standards for the export market, knowledge of optimum storage conditions are required to provide an understanding of postharvest quality attributes and consumer organoleptic perceptions. The overall aim of this research was to provide science-based management tools for the storage performance of pomegranate fruit (cv. Wonderful). The research reported in Chapter 3 focused on the physiological responses of pomegranate fruit at different storage temperatures. Commercially harvested fruit were stored at 5±0.7°C, 7.5±0.3°C and 10±0.5°C with 92±2% RH and at room temperature (21±3°C, 65±6% RH) for 5 months. Fruit respiration and physiological disorders during long term storage were investigated. During storage, low temperatures evidently resulted in lower respiration rates; however, respiration rate increased gradually after 2 months resulting in higher respiration rates at 5°C than 7.5°C after 3 month storage period. Overall, fruit became more susceptible to internal and external disorders as storage period progressed. Storage of fruit longer than 2 months at 5°C resulted in chilling injury and this was observed over the 5 month storage period. Fruit stored at 21°C and 10°C were discarded after 1 and 4 months, respectively, due to complete fruit loss to decay and peel shrinkage. Furthermore, the severity of browning increased with storage temperatures, although this became more severe at 5°C after 3 months. Therefore, to maintain a relatively low respiration rate and minimize physiological disorders, the cv. Wonderful should be stored at 5°C and >92% RH for storage period up to 3 months. In Chapter 4, the effects of temperature and storage duration on pomegranate fruit quality and mechanical properties were conducted. This study revealed that weight loss increased with rise in temperature and storage duration with the primary source of moisture loss being the fruit skin (peel), which resulted in significant reduction in peel thickness with prolonged storage period. The CIE (L*, a*, b* and C*) colour parameters of fruit and arils decreased during storage. However, the hue (hº) for whole fruit increased as a result of browning incidence, and decreased in arils suggesting an increase in redness. Significant increases in total soluble solids (TSS), pH, TSS:TA and BrimA were observed with significant decreases in titratable acidity (TA) occurring throughout the storage period. Storage temperature and duration significantly affected majority of the investigated mechanical properties. Puncture resistance, fruit and aril compression strength decreased with storage temperature and duration. These findings showed that fruit may be stored between 2 to 3 months at 5°C to ensure the best internal and external quality attributes. The studies in Chapter 5 investigated the effects of storage temperature and duration on phytochemical and antioxidant properties. Fresh pomegranate juice was assessed for concentrations of total phenolic compounds, total anthocyanin and ascorbic acid. The antioxidant property of the fruit juice was tested against 2, 2-diphenyl–1–picryl hydrazyl (DPPH). The results showed that total phenolic and total anthocyanin concentration increased up to 3 months of storage at 5°C, 7.5°C, 10°C and 21°C and decreased gradually over time. For antioxidant activity, storage of fruit at 5°C, 7.5°C and 10°C significantly (p< 0.05) reduced the radical scavenging activity of juice by more than 56% when stored beyond 2 months. Furthermore, ascorbic acid concentration gradually declined with increasing storage duration, resulting in reduced juice antioxidant capacity. These findings are beneficial to pomegranate export industries, especially where fruit are stored for long for use in health-promoting purposes. The research conducted in Chapter 6 focused on determining suitable storage conditions based on the combination of instrumental measurements and sensory attributes. During storage, individual fruit were evaluated by trained sensory panel based on the overall appearance, taste and aril texture. Discriminant analysis at different storage temperatures was used to distinguish fruit from each other at 2 months of storage with sensory attributes such as overall pomegranate flavour (R2 = 0.56), total anthocyanin (R2 = 0.46) and Chroma (C*) colour index (R2 = 0.37). Discriminant analysis further showed that storage time rather than storage temperature led to the reduction in overall quality when storing fruit beyond 2 months. Based on sensory attributes, suitable storage temperature and duration were found to be 5°C and 2 months when overall flavor were highly rated; thereafter, significant reductions in overall appearance, aril and kernel texture were observed. Furthermore, the proposed storage conditions were supported with instrumental measurements, which revealed a decline in important fruit attributes such as total phenolics, total anthocyanin, aril colour and aril texture after 2 months of storage. Overall, this study provides science-based tools required for developing cold chain handling protocols needed to manage the long supply chain of ‘Wonderful’ pomegranate fruit grown in South Africa. / AFRIKAANSE OPSOMMING: Die ontwikkeling van wetenskap-baseerde beheerinstrumente en toepaslike na-oes hanteringsmetodes is nodig vir die vasstelling van die optimale stoorprestasie van granate. Die Suid-Afrikaanse granaatindustrie ondervind groot vrug kwaliteit verliese as gevolg van die gebrek aan kennis oor optimale stoor en hantering praktyke. Die kultivar Wonderful is die wyd gegroei in Suid-Afrika, maar tot hede daar is tans beperk wetenskaplike kennis oor die stoor vereistes. Om gehaltestandaarde vir die uitvoermark te ontwikkel word kennis van die optimale stoortoestande benodig sodat ’n begrip van die na-oes gehalte-kenmerke en verbruiker se organoleptiese persepsies gevorm kan word. Die oorhoofse doelwit van die navorsing is om wetenskap-baseerde beheerinstrumente vir die stoor van granate (bv. Wonderful) te verskaf. Die navorsing wat in Hoofstuk 3 beskryf word is gerig op die fisiologiese respons van granate op verskillende bergingtemperatuur. Kommersieel-gekweekte vrugte is by 5±0.7°C, 7.5±0.3°C en 10±0.5°C met 92±2% RH en by kamertemperatuur by (21±3°C, 65±6% RH) vir 5 maande gestoor. Die respirasie van die vrugte en die fisiologiese ongesteldhede gedurende langtermyn stoor word ondersoek. Gedurende stoor het die laer temperature gelei tot laer respirasie koerse; maar respirasie koers het geleidelik na 2 maande verhoog wat lei tot hoër respirasie koerse by 5°C as teen 7.5°C na ’n 3-maande stoorperiode. Algehele, vrugte het egter meer vatbaar geword vir interne en eksterne ongesteldhede hoe langer die stoortydperk geduur het. Die stoor van vrugte langer as 2 maande teen 5°C lei tot skade as gevolg van verkoeling en dit is oor die 5 maande stoor tydperk waargeneem. Vrugte wat teen 21°C en 10°C gestoor is moes na onderskeidelik 1 tot 4 maande as gevolg van verlies wat die gevolg was van swam skade en skil krimping, weggegooi word. Die erns van die verbruining het verhoog toe die stoortemperature verhoog, alhoewel dit meer geraak het teen 5°C na 3 maande. Om dus ’n betreklik lae respirasie koers en min fisiologiese probleme te verseker, moet die kultivaar Wonderful teen 5°C en >92% RH vir 3 maande gestoor word. In Hoofstuk 4 word die effek van temperatuur en die duur van stoor op die gehalte van die granate en die meganiese eienskappe gemeet. Daar is bevind dat gewigsverlies met verhoogte toename in temperatuur en langer stoorperiodes toeneem en dat die hoofbron van verlies aan vog die skil van die vrug is. Die gevolg hiervan is ’n betekenisvolle reduksie in die dikte van die skil na ’n lang stoorperiode. Die CIE (L*, a*, b* and C*) kleur parameters van vrugte en granaatpitte het tydens stoor verminder. Die tint, (hº) van die hele vrug het as gevolg van verbruining, verhoog en het verminder in granaatpitte wat daarop dui vermeerdering in rooiheid. Daar was betekenisvolle verhogings in die totale oplosbare vaste stowwe (TSS), pH, TSS:TA en BrimA is opgemerk met betekenisvolle vermindering in asiditeit waarvan die waarde bepaal kan word (TA) en wat tydens die stoortydperk plaasvind. Stoortemperatuur en die duur van die stoor het ’n groot invloed gehad op die meganiese kenmerke wat ondersoek is. Weerstand teen priken die kompressie krag van die vrugte en die granaatpitte het met verhoogde temperatuur en duur van stoor afgeneem. Hierdie bevindinge het getoon dat vrugte kan gestoor word tussen 2 tot 3 maande by 5°C die beste interne en eksterne kwaliteit eienskappe om te verseker. In hoofstuk 5 is die effek van stoortemperatuur en duur op die fitochemiese en antioksidant kenmerke ondersoek. Vars granaatsap is ondersoek en ramings is gemaak t.o.v. totale konsentrasies van fenoliese samestellings, totale antosianiene en askorbinesuur. Die antioksidant kenmerke van die vrugtesap is getoets vir met 2, 2-diphenyl–1–picryl hydrazyl (DPPH). Daar is bevind dat die totale fenoliese en totale antosianiene konsentrasies tot by 3 maandemaande van stoor teen 5°C, 7.5°C, 10°C and 21°C toegeneem het en toe mettertyd afgeneem het. Wat betref antioksidant aktiwiteit, is daar gevind dat die stoor van vrugte teen 5°C, 7.5°C en 10°C die radikale reinigingsaktiviteite van die sap betekenisvol (p< 0.05) met meer as 56% verminder as dit vir meer as 2 maande gestoor word. Verder, askorbiensuur konsentrasie geleidelik afgeneem met toenemende stoor duur, wat lei tot verlaagde sap antioksidant kapasiteit. Hierdie bevindings is van belang vir die granaatuitvoerindustrie, veral waar vrugte vir 'n lang tydperk gestoor vir gebruik in gesondheids-bevordering doeleindes. Die navorsing wat in hoofstuk 6 beskryf is, het gefokus op die vasstelling van geskikte stoortoestande baseer op ’n kombinasie van instrumentale meting en sensoriese kenmerke. Gedurende stoor word individuele vrugte deur ’n opgeleide panel evalueer t.o.v. voorkoms, smaak en tekstuur van die granaatpitte. Diskriminantontleding teen verskillende stoor temperature is gebruik om vrugte na 2 maande stoor vrugte t.o.v sensoriese kenmerke soos algehele granaat smaak. (R2 = 0.56), totale antosianiene (R2 = 0.46) en Chroma (C*) kleur indeks (R2 = 0.37) te onderskei. Diskriminantontleding het verder getoon dat die duur van die stoor en nie die stoortemperatuur nie, gelei het tot die reduksie in algehele gehalte as die vrugte vir langer as 2 maande gestoor word. Gegrond op sensoriese eienskappe is geskik stoor temperatuur en duur gevind word by 5°C en 2 maande wanneer algehele geur was as hoog beoordeel; en daarna, is aansienlike vermindering in die algehele voorkoms, en die tekstuur van die granaatpitte afgeneem. Hierdie voorgestelde stoortoestande word ook ondersteun deur instrumentele meting, wat ’n afname in belangrike kenmerke soos totale fenologie, totale antosianiene en die kleur en tekstuur van die granaatpitte na ’n 2 maande stoorperiode toon. In die geheel verskaf die bevindinge van hierdie studie wetenskap-baseerde instrumente vir die ontwikkel van koue-ketting hantering protokol vir die bestuur van die lang verskaffingsketting van Wonderful granate wat in Suid-Afrika gekweek word.

Seasonal variations had a great influence on the ripening patterns of banana fruit. Normal ripening was enhanced or delayed by the effect of the maturing season on the fruit. Fruit maturing in summer (harvested in autumn) showed an increase in the rate of ripening, while fruit harvested in winter and spring showed a decrease in the rate of ripening. The banana fruit are sensitive to temperatures outside of their acclimated range. Due to ineffective storage and faulty handling procedures, cold and heat stress is a universal problem in bananas. Large amounts of fruit are lost due to heat and cold stress. Chilling injury occurs when bananas experience or are stored at temperatures below 13C, for a few hours to a few days. Temperatures slightly above 30C may cause extensive heat damage. The three main mechanisms suggested for the prevention of chilling and heat injury are the synthesis of small heat shock proteins, changes in the saturation of fatty acids of the membranes and suppression of the ethylene production and respiration rates. The prevention of cold and heat stress is investigated by monitoring the effect of short-term heat treatment and treatment with ethylene inhibitors on the ripening of the fruit. To determine changes in ripening the following eight ripening parameters are monitored: Yellowing, firmness of the pulp, sugar concentration, starch content, ethylene synthesis, respiration rate, rate of moisture loss and ion leakage. It was found that 1-methylcyclopropene (1-MCP) alleviates the symptoms of heat injury up to a point, but the symptoms of chilling injury were not affected. The effects of the three temperatures investigated: 35°C, 40°C and 45°C for different times. A short pre-heat treatment of 35˚C for 20 minutes proved successful to delay the ripening of the banana fruit, but did not protect the fruit against heat or chilling injury. The results of this study clearly indicate that both chilling and heat injury involve the action of ethylene and suggested that longer exposures to 1-MCP may be effective in preventing both types of injury. / Prof. C.S. Whitehead

No description available.

Thesis (MScAgric)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Red colour development on bi-coloured apples and pears ensures better prices for producers. The use of postharvest irradiation to improve colour has been successful on apples, and the objectives of this thesis were to optimise conditions during irradiation for apples and to evaluate the effects of irradiation on pears. 'Cripp's Pink' apples responded to postharvest irradiation with high-pressure sodium (HPS) lights by developing a red blush, whereas the response to irradiation with UV 8 plus incandescent lights was less effective. '8raeburn' apples held at -0.5°C for 4 or 8 weeks prior to irradiation showed a decrease in hue angle and an increase in anthocyanin concentration after 72 hours of irradiation with HPS lamps. In 'Forelle' pears treated in the same way, neither colour development nor anthocyanin synthesis was affected by irradiation. '8raeburn' and 'Cripp's Pink' apples picked weekly for 5 weeks until the optimum harvest date were irradiated with HPS lights. A significant increase in fruit colour was only measured in mature fruit of both cultivars. 'Cripp's Pink' apples were harvested from two production areas with different microclimates, namely, Ceres and Grabouw, and stored for 0, 2 or 5 days at -0.5 °C before irradiation for 120 hours at either 6°C or 20°C. Fruit from Ceres that were irradiated immediately after harvest developed better colour at 6 °C than at 20°C. The differences between fruit irradiated at the two temperatures were no longer significant after 5 days of cold storage prior to irradiation. Fruit from Grabouw consistently developed better colour when irradiated at 6°C than at 20°C. Colour development slightly after 5 days of cold storage prior to irradiation. In another experiment, fruit from both areas were stored at -0.5°C for 20 days before irradiation at either 6°C or 6/20°C. The fluctuating temperature regime resulted in decreases in hue angle of 70° and 65° for the fruit from Grabouw and Ceres, respectively. The decreases were smaller (±200) when fruit were irradiated at 6°C. The hue angle value of well-coloured 'Cripp's Pink' apples held at 3rC under HPS lights for 144 hours increased from 29.3° to 48.3°, and anthocyanin concentration decreased from 739.9 IJg·g·1to 283.6 IJg·g·1. Control fruit held at the same temperature in the dark did not show any change in hue angle value or anthocyanin concentration. 'Bon Rouge' and 'Red d' Anjou', two full red pear cultivars, irradiated with HPS lights for 72 hours, showed no significant changes in hue angle. 'Forelle' pears, harvested with or without attached leaves, were irradiated with HPS at two temperature regimes, 20°C and 200/6°C. The resulting decreases in hue angle were attributed to yellowing and not red colour formation. In conclusion, the response of apples to postharvest irradiation was affected by maturity and temperature, while pears failed to respond at all. / AFRIKAANSE OPSOMMING: Rooikleurontwikkeling van twee-kleur appels en pere verseker beter pryse vir die produsente. Na-oesbestraling om kleur te verbeter is al suksesvol uitgevoer op appels, en die doelwit van hierdie tesis was om die kondisies vir appels gedurende bestraling te optimaliseer en om die effek van bestraling op pere te evalueer. 'Cripp's Pink' appels het reageer op na-oesbestraling met hoëdruk-natriumligte (HDN) deur 'n rooi blos te ontwikkel, terwyl die reaksie op bestraling met UV-B plus gloeilamplig minder effektief was. 'Braebum' appels opgeberg by -O.5aC vir 4 of 8 weke voor bestraling het 'n afname in die kleurskakeringswaarde getoon, asook 'n toename in antosianienkonsentrasie na 72 uur se bestraling met HDN ligte. 'Forelle' pere wat dieselfde behandeling ontvang het, het geen kleurontwikkeling en geen antosianienontwikkeling getoon na bestraling nie. 'Braebum' en 'Cripp's Pink' appels wat weekliks geoes is vir 5 weke tot die optimum oesdatum is bestraal met HDN ligte. Slegs die volwasse vrugte van beide kultivars het 'n betekenisvolle toename in kleur getoon. 'Cripp's Pink' appels is geoes in twee produksie areas met verskillende mikroklimate, naamlik Ceres en Grabouw. Vrugte is opgeberg vir 0, 2 of 5 dae by -O.5aC voor bestraling vir 120 uur by of 6aC of 20aC. Vrugte van Ceres wat onmiddellik na oes bestraal is het beter kleur ontwikkel by 6aC as by 20aC. Kleurontwikkeling by vrugte bestraal by 6 of 20aC het nie verskil wanneer vrugte vooraf opgeberg was by -~5ac vir 5 dae nie. Vrugte van Grabouw het konstant beter kleur pntwikkel wanneer bestraling by 6°C eerder as 20°C plaasgevind het. In die volgende eksperiment, was beide die vrugte van Ceres en Grabouw vir 20 dae opgeberg by -o.soC voor bestraling by 6°C of 6°/20°C. Die flukturerende temperatuur regime het afnames van 70° en 65° in kleurskakeringswaarde getoon vir die vrugte van Grabouw en Ceres, respektiewelik. Die afname was kleiner (±200)wanneer vrugte by 6°C bestraal is. 'Cripp's Pink' appels wat goed gekleur was en opgeberg is by 3rC terwyl dit blootgestel is aan HDN ligte vir 144 uur, het 'n toename van 29.30 tot 48.3° getoon vir die kleurskakeringswaarde, en antosianienkonsentrasie het afgeneem van 739 I'g.g-1 tot 283.6 I1g.g-1. Die kontrole vrugte opgeberg by dieselfde temperatuur in die donker het geen verandering in beide die kleurskakeringswaarde of die antosianienkonsentrasie getoon nie. 'Bon Rouge' en 'Red d' Anjou', twee volrooi peerkultivars, is bestraal met HDN ligte vir 72 uur en het geen betekenisvolle verandering in kleur getoon nie. 'Forelle' pere, geoes met of sonder 'n aangehegte stingelsegment, is bestraal met HDN ligte by twee verskillende temperatuur regimes, nl. 20°C of 20/6°C. Die afname in kleurskakeringswaarde is aan vergeling toegeskryf eerder as aan rooikleurontwikkeling. Ter opsomming, die reaksie van appels op na-oes bestraling is beïnvloed deur rypheid en temperatuur, terwyl pere geen reaksie getoon het nie.

Choi Yin Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 164-187). / Abstracts in English and Chinese. / List of Abbreviations / List of Tables / List of Figures / Chapter Chapter 1: --- "Background of straw mushroom, Volvariella volvacea" / Chapter 1.1 --- History and economic value of straw mushroom --- p.1 / Chapter 1.2 --- Nutritional value and medical use of straw mushroom --- p.2 / Chapter 1.3 --- Cultivation of straw mushroom --- p.3 / Chapter 1.4 --- Life cycle and developmental stages of straw mushroom --- p.5 / Chapter 1.5 --- Objectives of the research --- p.6 / Chapter Chapter 2: --- Determination of straw mushroom quality during postharvest storage / Chapter 2.1 --- Introduction --- p.18 / Chapter 2.2 --- Materials and methods / Chapter 2.2.1 --- Determination of surface color changes --- p.19 / Chapter 2.2.2 --- Determination of weight loss and dry weight --- p.19 / Chapter 2.2.3 --- Examination of mushroom surface structure --- p.20 / Chapter 2.2.4 --- Statistical analysis --- p.20 / Chapter 2.3 --- Results and discussion / Chapter 2.3.1 --- Browning during postharvest storage --- p.20 / Chapter 2.3.2 --- Weight loss and dry weight changes during storage --- p.22 / Chapter 2.3.3 --- Surface structural changes during postharvest storage --- p.23 / Chapter Chapter 3: --- Physiological studies of straw mushroom during postharvest storage / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Materials and methods / Chapter 3.2.1 --- Materials --- p.33 / Chapter 3.2.2 --- Respiration rates of different produce --- p.34 / Chapter 3.2.3 --- Changes of respiration rate and detection of ethylene production in straw mushroom --- p.34 / Chapter 3.2.4 --- Exogenous ethylene treatment --- p.34 / Chapter 3.3 --- Results and discussion / Chapter 3.3.1 --- Comparative studies of respiration rates between different fresh produce --- p.35 / Chapter 3.3.2 --- Ethylene production and effect of exogenous ethylene effect on straw mushroom --- p.36 / Chapter 3.3.3 --- Change in respiration during postharvest storage --- p.37 / Chapter Chapter 4: --- Biochemical studies of straw mushroom during postharvest storage / Chapter 4.1 --- Introduction / Chapter 4.1.1 --- Hydro lytic enzymes / Chapter 4.1.1.1 --- Protease --- p.43 / Chapter 4.1.1.2 --- Lipase --- p.44 / Chapter 4.1.1.3 --- Chitinase --- p.46 / Chapter 4.1.2 --- Enzymatic browning / Chapter 4.1.2.1 --- Background --- p.48 / Chapter 4.1.2.2 --- Action of polyphenol oxidase --- p.49 / Chapter 4.1.2.3 --- Control of enzymatic browning --- p.50 / Chapter 4.2 --- Materials and methods / Chapter 4.2.1 --- Source --- p.52 / Chapter 4.2.2 --- Enzyme extraction --- p.52 / Chapter 4.2.3 --- Soluble protein determination --- p.52 / Chapter 4.2.4 --- Protease assay --- p.53 / Chapter 4.2.5 --- Lipase assay --- p.53 / Chapter 4.2.6 --- Chitinase assay --- p.54 / Chapter 4.2.7 --- PPO assay --- p.54 / Chapter 4.2.8 --- Optimal pH determination and substrate specificity of PPO --- p.55 / Chapter 4.2.9 --- PPO inhibitors studies --- p.56 / Chapter 4.2.10 --- Localization of PPO in the fruit body of straw mushroom --- p.56 / Chapter 4.3 --- Results and discussion / Chapter 4.3.1 --- Protease activity during postharvest storage --- p.57 / Chapter 4.3.2 --- Lipase activity during postharvest storage --- p.58 / Chapter 4.3.3 --- Chitinase activity during postharvest storage --- p.59 / Chapter 4.3.4 --- pH optimum and substrate specificity of PPO --- p.61 / Chapter 4.3.5 --- PPO activity during postharvest storage --- p.62 / Chapter 4.3.6 --- Effect of various inhibitors on PPO activity --- p.63 / Chapter 4.3.7 --- Localization of PPO in the fruit body of straw mushroom --- p.64 / Chapter Chapter 5: --- Microorganisms in the fruit body of straw mushroom during postharvest storage / Chapter 5.1 --- Introduction --- p.81 / Chapter 5.2 --- Materials and methods / Chapter 5.2.1 --- Evaluation of bacterial population --- p.85 / Chapter 5.2.2 --- Isolation of bacteria --- p.85 / Chapter 5.2.3 --- Treatment of antibacterial agents --- p.87 / Chapter 5.2.4 --- Effect of moisture on bacterial population --- p.87 / Chapter 5.2.5 --- Statistical analysis --- p.87 / Chapter 5.3 --- Results and discussion / Chapter 5.3.1 --- Bacterial population during postharvest storage --- p.88 / Chapter 5.3.2 --- Bacteria growth and mushroom deterioration --- p.89 / Chapter 5.3.3 --- Identification of bacteria isolated from straw mushroom --- p.92 / Chapter 5.3.4 --- Relationship between moisture and bacterial population --- p.95 / Chapter Chapter 6: --- Preservative studies of straw mushroom / Chapter 6.1 --- Introduction --- p.107 / Chapter 6.1.1 --- Chemicals treatment in produce --- p.109 / Chapter 6.1.1.1 --- Application of browning inhibitors --- p.110 / Chapter 6.1.1.2 --- Role of calcium in preservation --- p.111 / Chapter 6.1.2 --- Modified atmosphere technology --- p.114 / Chapter 6.2 --- Materials and methods / Chapter 6.2.1 --- Dipping experiment with browning inhibitors --- p.117 / Chapter 6.2.2 --- Application CaCl2 in straw mushroom cultivation --- p.117 / Chapter 6.2.3 --- Postharvest storage of straw mushroom under modified atmosphere --- p.118 / Chapter 6.2.4 --- Statistical analysis --- p.119 / Chapter 6.3 --- Results and discussion / Chapter 6.3.1 --- Effect of browning inhibitors on mushroom quality --- p.119 / Chapter 6.3.2 --- Effect of calcium chloride on mushroom quality --- p.121 / Chapter 6.3.3 --- Effect of modified atmosphere on mushroom quality --- p.124 / Chapter Chapter 7: --- Conclusion --- p.159 / References --- p.164

Includes bibliographical references (leaves 174-201) / xxii, 201, [20] leaves : ill., photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Wine and Horticulture, 2004