Thesis (Sc.D.) Massachusetts Institute of Technology. Dept. of Food Technology, 1950. / Bibliography: leaves 234-245. / by Darshan Singh Bhatia. / Sc.D.

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.

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.

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.

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).

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.

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.

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.

Levulose (D-fructose, fruit sugar), C6H12O6 is a white crystalline ketohexose. This sugar has distinctive properties which make it of commercial interest. It is more costly than ordinary table sugar (sucrose). Levulose is characterized by a high degree of sweetness (6), great solubility (20), and medical usefulness when administered intravenously. Joslin (21) and Root and Baker (32) found levulose to be of great value in the treatment of diabetes. According to Daniel (8), it is assimilated and oxidized more quickly than sucrose, supplying the necessary energy requirements for the human system. Additional uses of levulose have been reported by McGlumphy and Eichinger (27), which include its application to improve the quality and the flavor of jams, jellies, marmalades, canned fruits, carbonated beverages, and corn sugar. Plants of the family compositae contain large amounts of levulose polymers, but the dahlia, chicory, and Jerusalem artichoke are the most promising sources because of the high levulose content and the ease of production (13). The tubers of Jerusalem artichoke were used in this study because they offer an inexpensive and prolific source from which levulose can be extracted. Since most of the levulose units in the artichoke tubers are linked together to form inulin or carbohydrate intermediate compounds between inulin and levulose, it is necessary to hydrolyze the material in order to free the levulose. Several investigators have reported the use of acid compounds. Anderson and Greaves (1) used H2SO4 for hydrolysis, while Yamasaki (41) used HC1 for the same purpose. Kleiderer and Englis (23) obtained complete hydrolysis of inulin by use of CO2 and SO2 at a pressure of 1000 pounds per square inch at 150o C. for 60 minutes. As fare as can be determined from the literature, little work was done prior to 1953 using radioactive material to study peaceful uses of atomic energy. Since that time, a law was passed by the United States Congress authorizing the use of radioactive material for peaceful purposes, thereby making it possible to use atomic energy for this study. Since previous work has shown that gamma rays can convert starch to simple sugar (33), it was therefore, assumed that the inulin and other carbohydrate intermediates of Jerusalem artichoke upon hydrolysis by beta or gamma rays might yield fructose (35). The primary purpose of this study was to determine the effects of beta and gamma rays on inulin and other carbohydrate intermediate compounds present in the Jerusalem artichoke tubers and to compare the results with those obtained by hydrolysis with radiation plus hydrochloric acid.

This study was designed to answer a three-fold purpose. Primarily, it has endeavored to measure the inhibitory effect of three antibiotics (potassium pencillin, dihydrostreptomycin, and oxytetracycline) on lactic acid producing organisms. The lactic acid-producing organisms include Streptococcus lactis, Streptococcus thermophilis, and Lactobacillus bulgaricus. The determination of an effective dose of a given antibiotic which will inhibit 50 percent of the lactic acid-producing organism (E.D.50) will be established. A 50 percent cut in acid development will certainly lead to an inferior product. The secondary purpose has related to the detection of inhibitory substances (antibiotics) in milk. What is the possibility of detecting the concentration of antibiotic which correlates to the E.D.50 established in the first phase of the problem? The third purpose embraces a study of the sensitivity of tests for detecting inhibitory substances.