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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.
1

Product Development Considerations for a Nutrient Rich Bar Using Cricket (Acheta domesticus) Protein

Zhong, Amy 28 April 2017 (has links)
<p> Insect protein has recently gained attention as an alternate protein source for humans as it is regarded as a sustainable source of protein that is nutritionally comparable to traditional livestock. The objective of this study was to assess the acceptability of a protein bar supplemented with cricket protein. A bar composed of 7.5% cricket powder was compared against a market alternative in a evaluation, food action rating scale (FACT), paired-preference test, and a triangle test. Subjects rated the market bar higher than the cricket bar for appearance (6.59&plusmn;1.92; 6.32&plusmn;2.05), color (6.37&plusmn;1.92; 6.22&plusmn;1.84), flavor (6.41&plusmn;1.86; 5.46&plusmn;2.53), aroma (6.25&plusmn;1.50; 5.75&plusmn;1.82), texture (6.79&plusmn;1.65; 5.95&plusmn;1.93), and overall acceptability (6.67&plusmn;1.67; 5.75&plusmn;2.07). Flavor (<i>p</i>=0.16), texture (<i>p</i>=0.003), and overall acceptability (<i>p</i>=0.004) were rated significantly lower in the cricket bar. Moreover, more subjects indicated in their scores that they would eat the market bar (5.70&plusmn;1.64) more frequently than the insect bar (4.66&plusmn;2.14). Texture, appearance, aroma, and flavor were all significantly associated (<i>p</i>&lt;0.05) with overall acceptability. The majority (61%) of subjects preferred the market bar to the insect alternative. Additionally, 84% of the subjects were able to distinguish the cricket bar from the market alternative. This suggests that products developed using cricket protein powder will need to modify the sensory attributes accordingly to successfully integrate edible insects in the diet of the western society.</p>
2

Crystallization behavior of waxes

Jana, Sarbojeet 31 December 2016 (has links)
<p> Crystallization behavior of different waxes such as beeswax (BW), paraffin wax (PW), ricebran wax (RBW), sunflower wax (SFW) was studied individually and in different oil solutions. Binary mixture at various proportions of the individual waxes was also explored in this study. Soybean oil is used in most of the study but olive, corn, sunflower, safflower, and canola oils were also explored. Lipid crystalline networks were characterized by several physical properties such as melting profile, solid fat content, viscoelastic parameters, cooling rate, phase behavior, crystal morphology. High intensity ultrasound (HIU) was used to change processing conditions of lipid crystallization. Instruments used to analyze the physical characteristics were differential scanning calorimeter, nuclear magnetic resonance spectroscopy, rheometer, temperature controlled water-bath, turbiscan light scattering device, and polarized light microscopy. The use of high intensity ultrasound showed that HIU technology can be used to delay the phase separation in beeswax/ oil system (canola, corn, olive, safflower, sunflower and soybean oil). Crystal sizes were reduced in beeswax/oil system at 0.5 and 1% concentration with the application of HIU technology. A study on binary waxes showed different phase behavior: eutectic behavior in BW/PW, SFW/PW, SFW/ BW, and RBW/BW; monotectic behavior in RBW/PW and continuous solid solution in RBW/SFW. Binary waxes in oil system (2.5% binary waxes) showed different physical properties when a range of binary blends were analyzed. Phase diagrams using iso-solid lines in binary wax/oil study show similarity when binary waxes without oil were studied using melting profile data. From all the above study it is understood that the physical properties of wax/oil systems are affected not only by the concentration and type of wax used, but also by the type of oil and application of HIU which induces wax crystallization and retards phase separation in wax/oil systems. Studies performed on all the topics suggest that understanding wax crystallization could help develop product formulation in food, pharmaceuticals, cosmetics, medicine and other industries.</p>
3

Analysis of Frozen Desserts Using Low-Temperature Scanning Electron Microscopy (LT-SEM)

MacDonald, Kinsey Elizabeth 21 February 2019 (has links)
<p> Commercial vanilla ice cream and other frozen desserts from the United States were analyzed for ice crystal length using low-temperature scanning electron microscopy (LT-SEM). Average ice crystal length was determined using multiple micrographs of each sample/product. Out of the products tested, 11 out of 15 samples had an average ice crystal length above the consumer sensory threshold limit of 55 &micro;m. Products containing stabilizers tended to have smaller average ice crystal lengths than products without stabilizers. With a few exceptions, lower fat products tended to have larger ice crystals because there was less fat to stabilize the ice crystals. Four brands of frozen dessert were studied in detail: a super-premium ice cream (Brand P), a regular ice cream (Brand R), a dietary high protein ice cream (Brand D), and a non-dairy coconut-based frozen dessert (Brand ND). All brands were purchased from two separate supermarket supply chains (Store I and Store P) and analyzed for ice crystal size, weight loss/shrinkage, melting rate, texture, and sensory characteristics before and after being heat-shocked (HS). Brand P, R, and ND all had mean ice crystal sizes that were not significantly different when purchased from either Store I and Store P. The mean ice crystal size increased after HS for all brands except Brand ND. Brand D and Brand P had the highest melting rates, while Brand ND had a much lower melting rate than the other brands tested. Brand ND had a slight decrease in the average ice crystal size and had a decrease in peak force/hardness after HS, while all other brands had an increase in average ice crystal size and an increase in peak force/hardness after HS. Significance was determined using &alpha; = 0.05 for all sensory data. The iciness attribute was found to be significantly affected by both brand and HS and an increase in ice crystal size corresponded with an increase in iciness for most samples. The use of stabilizers and emulsifiers in the brands affected various melting characteristics. Additional research is needed on non-dairy frozen desserts and how their physical and sensorial properties are affected by heat-shock.</p><p>
4

Improving food allergen management in small food service businesses serving loose food

Schembri, Paulino January 2017 (has links)
Food allergens, a concern for an increasing number of people, are common food ingredients found in most kitchens. For the majority of the population these ingredients are harmless yet for about 2% of the global adult population, these ingredients pose a health risk and at times could also be life threatening. There is no known cure for food allergies; therefore abstinence from consumption is the only assurance of food safety which means that controls of ingredients and preparation practices are imperative. This becomes more complex when the food is not prepared by the sensitive individual. To date, literature on food allergens has not sufficiently engaged in the management of allergens in the food service industry. The food service industry, irrelevant to size, is legally obliged since 2014, to inform the food allergy sufferers of food allergens present in the food served. This requires staff to be knowledgeable of the food allergens. The practices of producing safe food for allergy sufferers are hindered by barriers which are synonymous with the nature of the business and compounded in small food service businesses, however food allergy sufferers trust small business more when eating out. Understanding key factors in the preparation and serving of food to sensitive individuals required this research to adopt a mixed-method approach in analysing the procedures required in food production and preparation. Initially four allergy sufferers drew attention to their concerns of the practices in the food service industry during a focus group discussion held in Malta. This was followed by investigating the proper management of food by observing current practices in preparation, identifying gaps in training and discussing behavioural change. This thesis introduces an innovative multi-faceted toolkit which was developed to manage food allergens and tested in three small food businesses. Taking into account the literature review, the innovative toolkit provides a system which logs ingredients for recipe building through matrices, meets the sufferers’ requirements to be informed about the food through QR codes, and overcomes the barriers the food industry has to produce allergen free food. The research identifies lack of understanding of food allergens and their consequences by the food service staff and the influence this has on the quality of life, as contributors to the lack of trust the allergy sufferers have in the industry. Seventeen staff were trained in food allergen management. The participants’ knowledge was evaluated pre and post training. It was determined that the required change in behaviour to prepare safe food for allergy sufferers requires external drivers, as traditional classroom training alone failed to entrench better practices. The work provides a holistic understanding of the requirements of food allergens management and the improvements required to achieve effective allergen management training programmes in small food services businesses.
5

Effects of Gamma Radiation on Asparagus and Tomatoes

Rivers, Arthur L. 01 May 1959 (has links)
Since growers are generally unable to produce food the year-round, preservation of available food by the growers and processors has continued to challenge the minds of these men and their scientific cohorts. Even the consumer is subject to this problem and mist rely on those from. whoa he receives food as to its present and eventual condition. Many methods of preservation have been used such as pickling, drying, smoking, canning, and freezing. Most of these preservation methods require excessive handling and/or extensive storage facilities.
6

A Study of Hot Brine Treatment in Making Cheese from Antibiotic Milk

Howe, Robert E. 01 May 1960 (has links)
The cheddar cheese industry is continually confronted with the problem of manufacturing cheese from milk in which tile acid development is slow or non-existent. In recent years, many antibiotics have been used as a treatment for mastitis. Penicillin, streptomycin, and aureomycin are some of the more prominent antibiotics used for this purpose.
7

Influence of Temperature on Protein, Moisture and Fat and Some Other Factors in Charcoal Broiled Meats

Savage, Ilene C. 01 May 1964 (has links)
Due to the increasing popularity of outdoor cooking of meat, there is interest in determining the chemical and physical changes that occur during the charcoal broiling process. Of particular interest is the effect of these changes upon the quality of the broiled meat. Although broiling is not a new method of cooking meat, a review of the literature revealed few reports of scientific work on broiled meats. Some work has been done on the effect of different cooking methods on weight losses, tenderness, palatability, thiamine, protein content, but no reports were found relating surface temperature and cooking time to rate of heat transfer and to final internal temperature. Little research has been done in this area because there has been no means available for measuring surface temperature during broiling. The investigation and results reported in this study were made possible by the development of an experimental model of a coil type thermometer, developed by the Taylor Instrument Company, and an Electronic Universal Nine Point Strip Chart Recorder were used to record temperatures in this study. The thermometer determined the surface temperature of the grill and thermocouples attached to the meat and connected tot he recorder determined the top, internal, and bottom temperatures of the samples. This preliminary study was conducted on beef using charcoal as the source of heat, since the heat from the charcoal could be controlled at an approximately constant temperature. Studies by Salvosa (1963) and Irvine (1963) showed the interrelationships of surface temperature to cooking time and degree of doneness. One grade (Good) Sirloin, two grades (Good and Choice) Porterhouse steaks and ground beef patties were broiled in this study. The steaks were cut in two thicknesses, 1 and 1/12 inches, and were broiled at three different cooking temperatures (400o, 350o, and 300o Fahrenheit) to three degrees of doneness. Statistical analysis using these variables produced a change of only two minutes in predicted cooking time. The current study, a continuation of the previous studies, was made to determine the relationships of surface temperature, cooking temperature, cooking time, and degree of doneness, to moisture, protein, and fat content of broiled beef. This study also included a compilation of thiamine and soluble protein results of the previous studies (Salvosa, 1963; and Irvine, 1963).
8

A Method for Determining Proteinase Activity

Randeria, Bhupendra V. 01 May 1959 (has links)
Enzymes play a very important role during the ripening process of the cheese. Enzymes are important in producing the body, texture, and flavor of the cheese. The breakdown of carbohydrates, fats, and proteins by added enzymes into different end products during the ripening of the cheese aids the process and may reduce time. The characteristic flavors of different varieties of cheeses are influenced by enzyme action. Some enzyme like proteinase s can be used to improve the body, texture, and the flavor of the cheddar cheese. Addition of these enzymes during cheddar cheese making may shorten the ripening period. In order to use some specific amount of the enzyme to bring about desirable changes, it is desirable to determine the activity of that enzyme.
9

Effects of Gamma Radiation in Concurrence with Certain Environmental Conditions on Lethal and Physio-chemical Responses of Penicillium expansum L.

Chou, Tsong-Wen 01 May 1969 (has links)
In vitro investigations were conducted to study the lethal effect of gamma radiation on the fruit spoilage fungus Penicillium expansum under certain environmental conditions, and to study some physio-chemical changes in the fungus induced by the radiation which may be related to the death of the fungus or its ability to invade fruits. The radiation sensitivity of P. expansum conidia was influenced by such factors as nutritional condition of the post-irradiation media, age of the spores, delayed plating, heat treatment, and chemical sensitizers. Higher survival was obtained when irradiated conidia were plated on Czapek solution agar (sugar-salts medium) than on potato dextrose agar; yeast extract added in Czapek's medium hastened colony growth but reduced survival. The 6-month-old conidia were more radiation sensitive than the 1-week-old conidia. Recovery from the radiation injuries was observed when irradiated spores were held in the suspension for several days at 23o C. No recovery was found at 1o C. Heat treatment (58o C; 4 minutes) before or after irradiation increased the radiation effect. Difolatan (10 ppm), iodacetic acid (50 ppm), and secondary butylamine (500 ppm) were effective radiation sensitizers to P. expansum. The colony growths were inhibited for various periods following irradiation of the mycelia. The duration of inhibition was influenced by the dose applied and the nutrient of the medium tested. Irradiation of the Czapek solution agar slowed the initial growth of unirradiated fungus. No such effects were found with the other media tested. From these results, it can be concluded that under proper conditions, the fungus can be effectively inactivated by low doses of gamma radiation and thus retain the quality of fresh fruit with a minimum irradiation cost. Abnormal colonies and mutants were induced by the radiation. Some mutants were no more radiation resistant than the normal strain. The culture grown from irradiated conidia produced more of pectolytic enzyme than did the control after 3 days of post-irradiation incubation. The enzyme production was stimulated by the irradiation. Nucleic acid content of the mycelia grown from irradiated spores was related to the growth stage of the fungus and not directly influenced by the irradiation. The slowed growth rate of the irradiated fungus indirectly influenced the nucleic acid content. When isotope labeled mycelia were irradiated, no radiation induced degradation of nucleic acid was detected in the fungus during 8 hours of post-irradiation incubation, either by chemical or isotopic analysis.
10

Evaluation of a Vapor Pressure Osmometer for Determination of Added Water in Milk

Pensiripun, Kietipong 01 May 1975 (has links)
A Wescor Vapor Pressure Osmometer measured the osmolality of a solution by sensing the vapor pressure above the solution in a closed chamber. The instrument sensing element comprised a precision thermocouple which measured the dew point temperature depression, a function of the water vapor pressure in the chamber. It used approximately 5-7 microliter samples to saturate a 0.64 cm filter paper disc. The instrument fixed a milliosmolal digital reading and signaled test completion in 110 seconds. The instrument weighed approximately 3. 62 kilograms, was 26. 7 x 24. 1 x 10. 2 cms in size and had a range of 0 to 1999 milliosmolal. The modular solid state osmometer contained no mechanical moving parts, required no refrigerated components, sample pipetting, sample tube, and no operator attention following sample insertion. Cleaning the sample chamber pocket between tests with an acetone impregnated tissue improved repeatability of the osmometer and reduced the coefficient of variability from O. 76% to 0. 70% on a raw milk sample. Two hundred individual cow milk samples from 20 herds were run in February, 1974, to establish a mean freezing point in Cache Valley herds for that period. The mean and standard deviation was 280±3.0 millisomolal. Results of milk samples containing 0 to 25% added water measured by the osmometer were compared to those obtained from an Advanced thermistor cryoscope. The coefficient of correlation was 0.991. A collaborative study was conducted involving eight hospitals and industry laboratories. When the results of two laboratories were discarded, due to instrument maintenance problems, there were no significant differences among the laboratories in their abilities to quantitate added water. Proper maintenance of the osmometer in order to keep the thermocouple clean and frequent calibration checks are recommended.

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