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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

The selective value of modifiers of the eyeless locus in Drosophila melanogaster

Wills, Christopher James January 1962 (has links)
The reactions of a spectrum of eyeless phenotypes of Drosophila melanogaster, ranging from complete eyelessness to overlapping of the wild type, were examined with respect to the action of modifiers of the ey locus. Flies with less than 1/3 of a compound eye were found to show no response to light. Modifiers of eyeless could be selected for and against under constant environmental conditions. The continuous range of variation exhibited by the locus indicates that a large number of modifiers are involved. Under laboratory conditions, the effect of light alone was shown to have no influence on the rate of accumulation of modifiers in large populations, in spite of the fact that the absence of eyes was demonstrated to exert a great effect on the photokinetic response of the flies. This indicates that under the conditions found in population cages the absence or reduction of compound eyes and optic lobes is not detectably disadvantageous to the flies. Three sampling techniques were used to determine the phenotypic distribution of the flies in the cages. Mass culturing of egg samples produced great variability in the phenotypic means of the adult flies, due to crowding and the variable number of flies which emerged. Suction samples of flies taken directly from the cages were biased towards those flies which were most normal and vigorous and therefore most likely to be trapped by the suction device. The method which introduced the least variability involved isolating a small known number of eggs from the cages and culturing them under uncrowded conditions. / Science, Faculty of / Botany, Department of / Graduate
32

Studies on refrigerated fruit products in flexible pouches

Speers, Robert Alexander January 1982 (has links)
Selected cultivars of apples, peaches, and cherries were prepared as edible fruit portions, and preserved in flexible pouches under refrigeration. Preserving adjuncts such as sucrose, potassium sorbate, calcium chloride, citric acid and ascorbic acid were added as concentrated solutions to apple slices, peach slices or pitted cherries in Polyester/Polyethylene or Polyester/ Al foil/Polypropylene pouches that were evacuated and nitrogen-flushed prior to sealing. Some of the pouches were placed directly in 4°C storage whereas others were heated in steam or water to provide various blanching treatments prior to refrigerated storage. At various times up to 12 weeks after processing, the fruits were examined for physical, chemical, microbiological and sensory quality. Of the two package structures studied the aluminum foil-containing pouch proved superior to the Polyester/Polyethylene laminate in preserving fruit quality. Results for a series of mild thermal blanch treatments varied with fruit type in terms of microbial stability and sensory quality attributes. For apples, blanching to a center temperature of 80°C proved to be the most satisfactory, whereas 70°C was optimal for peach quality. Cherries, blanched to a center temperature of 80°C, were of good microbial stability. Both. Golden Delicious and Spartan cultivars prepared as apple slices were found to have good flavor, color and textural characteristics after 12 weeks of refrigerated storage. Of the three peach cultivars examined, Fairhaven and Redhaven freestone peaches produced slices of good quality after processing and refrigerated storage of 12 weeks. Fortuna, a clingstone cultivar, had an unsuitable rubbery texture after the storage period. Lambert sweet cherries and Montmorency sour cherries proved to be unsuitable because of problems arising from microbial growth and loss of textural quality. In summary, it was determined that Golden Delicious and Spartan apple cultivars and Fairhaven and Redhaven peach cultivars can be processed into high quality refrigerated fruit products suitable for storage in aluminum foil-containing flexible pouches at 4°C for up to 12 weeks. / Land and Food Systems, Faculty of / Graduate
33

Studies on the canning of apples in syrup.

McCornack, Andrew A. 01 January 1939 (has links) (PDF)
No description available.
34

Technical and nutritional investigations on canned baked apples.

Ruffley, John 01 January 1938 (has links) (PDF)
No description available.
35

The effect of fruits in the diet of rats on calcium retention.

Mindell, Abraham. 01 January 1938 (has links) (PDF)
No description available.
36

Impact of Marine Extracts Applications on cv. Syrah Grape (Vitis vinifera L.) Yield Components, Harvest Juice Quality Parameters, and Nutrient Uptake

Martin, Jonathan 01 March 2011 (has links) (PDF)
Vineyard management practices have an impact on grape berry development in ways that influence the quality of wine made from those grapes. The goal of this study was to determine whether exogenous applications of marine extracts on Syrah grapes can influence yield components, harvest juice quality parameters, and nutrient uptake. From 2009 to 2011, Syrah grape vines at the Trestle Vineyard on the California Polytechnic State University, San Luis Obispo campus received individual doses of marine extract via fertigation at berry set and veraison proportional to the amount they would receive on an annual per-acre basis based on the extract manufacturer’s recommended rate of application. In a separate experiment conducted in 2011, marine extracts were applied as foliar treatments. Treatments were analyzed for their effects on berry juice TSS, pH, TA, anthocyanins, tannins, and fruit yield per vine, clusters per vine, average berry weight, cluster weight, berries per cluster, vegetative yield, and foliar nutrient concentration. The marine extracts did not have any significant effects on yield components, harvest juice quality, or foliar nutrient concentration at any point in this experiment, except for a marginally significant increase in copper uptake with seaweed extract application as compared to the untreated control. Seaweed extract fertigation did result in a significant decline in net photosynthesis shortly after application as compared to control, while fish/seaweed extract blend fertigation resulted in a significant increase in net photosynthesis after application as compared to control. Though some minor effects of marine extracts were detected, there appears to be no benefit or drawback to applying these products in Syrah grapes growing in heavy clay soil in cool-climate conditions.
37

Diffusion of sugar, acids and pigments during processing and storage of canned berries

Boziotis, Constantinos Andreas 08 March 1963 (has links)
Processing and storage of berry fruits is accompanied by various changes, the important ones being the changes in the soluble solids content, titratable acidity, pH, pigments, and texture. A study was made of these changes in processed strawberries, raspberries, blackberries and blueberries, still cooked and stored at 78°F for one and six months in No. 10 cans. Three samples of the above four berries were analyzed before processing, immediately after processing and after one and six months of storage at 78°F. Five samples of syrups were collected from both center and side of the cans by means of 50 ml pipettes. These five samples were from top, 1 3/4", 3 l/2", and 5 1/4" from the top and from the bottom and a mean sample was taken from the drained syrup. The cans were then drained on an 8 mesh 10" screen. 100 gram samples of the drained solids from top, middle and bottom were collected for texture measurements. The results indicated the following: 1. There is a decrease in soluble solids of the syrup and drained weight of the fruit immediately after processing. Softening of berries progresses with storage. 2. There is an increase in titratable acidity, pH and pigments of the syrup immediately after processing. Titratable acidity and pigments increase with storage and pH values were lower. 3. There is a tendency to reach an equilibrium in the can with regards to soluble solids in all berries and pigments in case of strawberries with a lower tendency for raspberries. In the case of titratable acidity equilibrium was almost realized in strawberries and blueberries. All berry packs showed no equilibrium in the pH value after six months. 4. No noticeable differences between samples collected from centers and side of the can. / Graduation date: 1963
38

Changes in raspberry pigments during processing and storage

Daravingas, George Vasilios 14 May 1963 (has links)
The retention of pigments in processed raspberries is a function of the process method and conditions of subsequent storage. The presence of sucrose and the nature of the headspace gas also influences the retention of the pigment. The effect of some of the above variables on the pigments was investigated. Variables imposed were: (1) concentration of syrup, (2) headspace gas atmosphere, (3) temperature, and (4) time of storage. Separation of the pigment of Willamette red raspberries and black raspberries was made by column chromatography and the pigments were analyzed. spectrophotometrically. The results showed the following: 1. The pigments of Willamette red raspberries consisted of four separate cyanins as based on the R [subscript f] values and characteristic wavelengths of maximum absorption. The pigments of black raspberries consisted of three fractions. 2. On the basis of R [subscript f] values and wavelengths of maximum absorption only two of the constituent fractions were the same. 3. The wavelength of maximum absorption of all the anthocyanins shifted towards shorter wavelengths after the first month of storage. 4. Time and temperature of storage and their interaction each contributed significantly to the destruction of the cyanin pigments. An increase in either variable resulted in a greater destruction of the pigments. 5. As the concentration of the ingoing syrup was increased, the amount of individual cyanins decreased. 6. Oxygen in the headspace gas was shown to be detrimental to the retention of the cyanins I, II, and IV of the Willamette raspberries and to cyanins II and III of the black raspberries. 7. Changes in the total pigment concentration were greatly influenced by the cyanin in greatest concentration in the species. 8. Heat processing destroyed approximately 20 percent of the pigments of the raspberries. / Graduation date: 1963
39

Physiological and biochemical changes of litchi fruit during development and postharvest storage.

January 1990 (has links)
by Huanpu Jun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 122-136. / Acknowledgement --- p.iii / Abstract --- p.V / Introduction --- p.1 / Literatiure review --- p.3 / Chapter A. --- "The changes of fruit during development, maturation, senescence" --- p.3 / Chapter 1. --- Fruit --- p.3 / Chapter 2. --- Fruit cell --- p.6 / Chapter 3. --- Respiration and ethylene --- p.18 / Chapter 4. --- Other oxidative reaction --- p.21 / Chapter 5. --- Control of ripening --- p.22 / Chapter B. --- In period of harvest and storage --- p.23 / Chapter 1. --- After harvest --- p.24 / Chapter 2. --- Postharvest technology procedures --- p.25 / Chapter C. --- Litchi --- p.28 / Chapter 1. --- Morphology and embryology --- p.28 / Chapter 2. --- Composition --- p.30 / Material and methods --- p.33 / Chapter A. --- "Morphological , anatomical and physical studies" --- p.33 / Chapter B. --- Biochemi cal studiets --- p.34 / Chapter 1. --- Starch content --- p.34 / Chapter 2. --- Soluble protein content --- p.35 / Chapter 3. --- Sugar component separated by thin layer chromatography --- p.36 / Chapter 4. --- Reducing sugar content --- p.36 / Chapter 5. --- Total sugars --- p.37 / Chapter 6. --- Acid content --- p.37 / Chapter 7. --- Chlorophyll contents --- p.37 / Chapter 8. --- Anthocyanin contents --- p.38 / Chapter 9. --- Phenolic compound content --- p.33 / Chapter 10. --- Peroxidase activity --- p.39 / Chapter 11. --- Superoxide dismutase activity --- p.39 / Chapter 12. --- Vitamin C content --- p.40 / Chapter C. --- Preliminary study on storage --- p.41 / Results --- p.43 / Chapter A. --- Development period --- p.43 / Chapter 1. --- "Morphological , anatomical and physical changes" --- p.43 / Chapter i. --- Whole Fruit --- p.43 / Chapter ii. --- Seed --- p.43 / Chapter iii. --- Aril --- p.44 / Chapter 2. --- Rhysio1ogica1 and biochemical changes --- p.47 / Chapter i. --- Weight and water content --- p.47 / Chapter ii. --- Soluble protein content --- p.52 / Chapter iii. --- Starch content --- p.52 / Chapter iv. --- Acidity --- p.52 / Chapter v. --- Sugar content --- p.61 / Chapter vi. --- Change in pericarp --- p.68 / Chapter B. --- Storage period --- p.63 / Chapter 1. --- Fruit without any treatment stored at 5°C and 10°C --- p.63 / Chapter 2. --- Fruit was treated and packed with different methods and then stored at 10°C and room temperature respectively --- p.75 / Chapter i. --- Change in Fresh weight of stored Fruit --- p.75 / Chapter ii. --- Rate of rotting --- p.78 / Chapter iii. --- Rate of darkening --- p.78 / Chapter iv. --- Anthocyanin --- p.87 / Chapter v. --- Phenolic compound --- p.87 / Chapter vi. --- Chlorophyll --- p.88 / Chapter vii. --- Acidity --- p.88 / Chapter viii. --- Total sugar --- p.101 / Chapter ix. --- Reducing sugar --- p.101 / Chapter x. --- Ascorbic acid --- p.106 / Chapter xi. --- Peroxidase activity --- p.106 / Chapter xii. --- Superoxide dismutase --- p.107 / Discussion --- p.114 / Reference --- p.122
40

Co-operative and other organized methods of marketing California horticultural products

Lloyd, John William, January 1900 (has links)
Issued also as Thesis (Ph. D.)--University of California. / Cover title. Bibliography: p. 133-137.

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