Food Chemistry Commons^™

Enzymic Milk Coagulation: Casein Micelle Aggregation And Curd Formation, Donald J. Mcmahon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enzymic milk coagulation was monitored by measuring changes in curd firmness and apparent absorbance of undiluted milk. Detection of coagulation, visually or rheologically, occurred after the milk changes from a system of aggregating particles to an extended space network. This change was observed as a shoulder in apparent absorbance plots and coagulation time was defined as the critical point in the aggregation process analogously to non-linear condensation polymerization reactions. It corresponds to the inflexion point during the period when apparent absorbance was rapidly increasing and can be calculated by fitting curd firmness data to an exponential equation.

Addition of calcium …

Quantitation Of Formaldehyde Resulting From Oxidative Deterioration Of Unsaturated Fatty Acids, Stanley J. Andrews

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Derivatives of 3-methyl-1-2-benzothiazolinone hydrazone were formed from the oxidation products of three oxidized unsaturated fatty acids. Aeration with oxygen and heat (65C) was used as a means of accelerating deterioration of lipid samples. Formaldehyde was recovered from oxidized pure standards of oleic, linoleic and linolenic acid methyl esters, and identified using gas chromatography. Formaldehyde was also recovered from oxidized lipid extracts of mechanic ally deboned turkey meat and turkey cluster fat. Gas chromatography was used to measure concentrations of unsaturated fatty acids during the oxidation of extracted lipids. Linoleic and linolenic fatty acids significantly decreased (p < .005) in oxidized lipid extracts from turkey cluster fat stored frozen for six months.

Measurement of the amounts …

Biochemical Investigations Of Black Gram (Phaseolus Mungo L.) And Rice (Oryza Sativa L.) Proteins And Their Improved Nutritional Functionality In The Fermented Product—Idli, Vinodkumar W. Padhye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this investigation have been to characterize black gram (Phaseolus mungo L.) and rice (Oryza sativa L.) proteins and to study changes in their nutritional value due to fermentation. Black gram, the legume chosen for this work, is one of the most important legume crops throughout a large part of the tropics.

The protein content of 60 mesh, dehydrated, defatted black gram meal was 28.5 percent. Sodium carbonate (0.5-1.0 percent), tetra-sodium pyrophosphate (0.5 percent), and sodium dodecyl sulfate (SDS) (0.5-5 percent) proved to be the potential protein solubilizers as they extracted more than 76 grams of …

Quantitation Of Aliphatic Aldehydes In Rancid Turkey Meat Using A Substituted Hydrazone, Stanley J. Andrews

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many objective chemical tests have attempted to correlate with organoleptic evaluation of oxidative rancidity. Major chemical tests used to detect oxidative rancidity of lipids measure nonvolatile high molecular weight carbonylic substances which make no considerable contribution to rancid flavors. High molecular weight carbonyls are present at much greater concentrations than volatile low molecular weight carbonyls. Peroxides and other unknown substances also react in these chemical tests to give at best an empirical evaluation. A 3-methyl-2-benzothiazolinone hydrazone chemical test is proposed which corrected some deficiencies of earlier procedures, and was correlated with organoleptic evaluation of rancid turkey samples. The proposed test …

A Five-Year Follow-Up Study: Relationship Of The High Pufa Diet Used In Original Study Of Middle-Aged Adults To Present Dietary Choices, Rate Of Erythrocyte Hemolysis And Serum Cholesterol And Triglyceride Values, Jeanette Parsons Egan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was a follow-up of the Christiansen study which was completed in 1967. Dr. Christiansen's 26 subjects ranged in age from 33 to 60 years. Ten were designated as controls and the other 16 were placed on a high polyunsaturated fatty acid (PUFA) diet for a period of 26 weeks.

The purpose of doing a follow-up was to determine what effect the study had on present dietary patterns, serum lipid levels and rate of erythrocyte hemolysis.

Eighteen of the original subjects participated in this study. Of these 18, nine were from the control group and nine were from the …

Effect Of Added Calcium Ions On Relative Milk-Clotting Activities Of Commercial Milk Clotting Enzymes, Nuchanart Pavenayotin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effect of added calcium ions on the relative milk clotting activities of porcine pepsin, Mucor miehei protease, Endothia parasitica protease, and Mucor pusillus protease was compared with that of rennin. Skimmilk, maintained at pH 6. 3 with 0.000% to 0.030% added calcium chloride, was used as a substrate. The coagulation activity of Mucor pusillus protease appeared to be most sensitive to calcium ions, followed by Mucor rniehei protease, porcine pepsin, rennin, and Endothia parasitica protease. The clotting activities of Mucor pusillus protease were also more sensitive than rennin to added calcium ions in milk samples maintained at pH values of …

Adaptive Changes Of Some Enzyme Activities In Rats And Humans To Dietary Protein, Jung Ja Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study of the adaptive changes of some enzyme activities to the dietary protein intake was made in the liver, kidney, and pancreas of rats and serum of humans.

The rats fed the 40 per cent casein diet had a higher rate of weight gain and the weights of the liver and kidney were higher than in the rats fed the 10 per cent casein diet.

Three enzymes involved in the elimination of excess nitrogen from the body were found to show a similar response to increased dietary protein intake. These enzymes were: D-amino acid oxidase in the kidneys, arginase …

Influence Of Pre-Fermentation Inoculations With Leuconostoc Mesenteroides And Lactobacillus Plantarum On Physico-Chemical Properties Of Fresh And Dehydrated Sauerkraut, William T. Nabors

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect Leuconostoc mesenteroides and Lactobacillus plantarum has on the physical and chemical properties of fresh and dehydrated sauerkraut was tested. Sauerkraut inoculated with L. plantarum was slower in fermenting and significantly lower in acidity and higher in pH. Dehydration of sauerkraut by freeze-conventional hot-air and micro-wave processes produced a significant loss in volatile components, ascorbic acid , lactic acid and an increase in pH. Each of the dehydration processes caused browning of the sauerkraut . These changes were less with freeze-drying and increased with conventional hot-air drying and microwave drying. Gas-liquid chromatography confirms the loss of volatile components …

Effects Of Ripening Processes On Chemistry Of Tomato Volatiles, Bharat Manu Shah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations were carried out to isolate, identify, and to characterize, major volatile components of tomato fruit. Simultaneously, the confirmation was extended to the reported tomato volatiles. The volatile extracts from field- and artificially-ripe fruits were compared qualitatively as well as quantitatively. The changes which occurred in the volatile components of the fruit at the onset of senescence also were delineated.

A typical chromatogram from field-ripe tomatoes contained 60 peaks. The functional group properties of individual peaks were derived by chemical analysis. The short-chain (C₃-C₆) alcohols represented 10 per cent, aldehydes and ketones 32 per cent, and …

Investigations Into Flavor Chemistry With Special Reference To Synthesis Of Volatiles In Developing Tomato Fruit (Lycopersicon Esculentum Mill.) Under Field And Glass Greenhouse Growing Conditions, K. B. Dalal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The common tomato of our garden belongs to the natural order Solanaceae and the genus Lycopersicum. The name from lykos, a wolf, and persica a peach, is given to it because of the supposed aphrodisiacal qualities, and the beauty of the fruit. By culture and use it is a vegetable, botanically it is a fruit and among the fruits, it is a berry being indehiscent, pulpy, with one or more seeds that are not stones.

Thermal Degradation Of Pigments And Relative Biochemical Changes In Cherries And Apricots, K. B. Dalal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The extent and nature of biochemical changes that take place in canned fruits during storage temperatures above freezing have been reviewed and discussed by Pederson, et al. (1947). These changes include loss in nutritive value, e.g. ascorbic acid, thiamine (Brenner, et al., 1948) and deterioration of color (Tressler, et al., 1955). Bauernfeind (1953) reported that canned peaches, apricots, and sweet cherries, after a few months of storage at 70°F, frequently undergo changes such as destruction of anthocyanin and carotenoid pigments with the subsequent formation of brown colored compounds. Darkening of fruit-color eventually results in their unacceptability at …

The Effect Of Feeding Fluoride On Some Enzymes Of Bovine Tissues, Prasertsri Sitachitt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fluorides are usually found in nature as constituents of soils, water, and the tissues of animals. Fluorite or fluorspar (CaF₂), cryolite (Na₃AlF₆), apatite (3 Ca₃ (PO₄)₂ CaF₂) and sedimentary phosphate rocks are among the principle minerals containing fluorides found in nature. Traces of fluorides also occur in domestic water supplies in nature and also by induction in vegetation and animal feeds. From 0.5 ppm to 1.5 ppm of fluorides in drinking water is the range found to be beneficial in reducing the incidence of tooth decay in man. …

A Survey Of The Literature Dealing With The Calcium-Phosphorus Metabolism Of Normal Children, Albertine Appy Noecker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study is to collect and organize all data available to the investigator on the subject of calcium and phosphorus requirements for normal children. Since it is the business of nutrition to maintain health and prevent disorders, leaving the cure of disorders to the medical profession, this study deals with the calcium and phosphorus metabolism of normal children and avoids going into the pathological phases, taking up rickets and tetany only in so far as prevention is concerned.

If this study has any value it lies in the fact that the findings of investigators seem to be …