This thesis is introducing us theme of the metabolic profile of biologically important compounds in honey. This thesis is devided into two parts. The first part (the literature review) is introducing characteristic of honey, history of a use for medical purposes, honey content, content of biologically active compounds and their positive effects on human health. There are also described methods of determination polyfenolic compounds in honey. The second part of this thesis (practical part) deals with determination of polyfenols in 11 kinds of honey using the high pressure liquid chromatography mass spectrometry (HPLC-MS). Extraction was carried out by using liquid-liguid extraction using ethylacetate and diethylether as a solvent and solid phase extraction using water as a solvent. These methods were then statistically compared.

Few studies in the area of psychodietetics have concentrated upon the relationship between a single dietary nutrient and behavior. However, some vitamins have been shown to be particularly important to central nervous system activity. Among these is Vitamin C (ascorbic acid). Two experiments were done to determine the effects of ascorbic acid deficient diets on a learning task in which guinea pigs were subjects. Learning was defined as acquisition and extinction of shock-escape and shock-avoidance behavior. In Experiment I, twelve adult guinea pigs were fed diets containing two different deficient amounts of ascorbic acid for six weeks. They were then run on shock-escape, shock-avoidance and extinction schedules. No significant differences in behavior among the dietary groups were shown by statistical analysis, either in acquisition or extinction. In Experiment II, three adult guinea pigs were fed the same ascorbic acid-deficient diets as in Experiment I for six weeks after a baseline performance on a shuttlebox shock avoidance schedule was obtained. Performance after dietary treatment among or across subjects was not observably different from the performance prior to treatment. Serum and adrenal protein analysis confirmed that the dietary treatment had lowered the total ascorbic acid content of the serum and adrenals, but behavior did not show a corresponding or consistent change. These results indicate that ascorbic acid deficient diets fed to adult guinea pigs did not result in a change in behavior as observed on shock-escape, shock-avoidance, or extinction schedules.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Nutrition and Food Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Bibliography: leaves 176-193. / by Henry M. Mallek. / Ph.D.

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<p> The research in this thesis investigated the effects of different vitamin C forms [ascorbic acid (Asc), sodium ascorbate, and calcium ascorbate] on gelatinization, pasting, and short-term retrogradation of wheat starch. Vitamin C is the third most supplemented nutrient in the U.S. and necessary for prevention or treatment of many illnesses. Asc is also used in food products as an acidulant that decreases microbial growth and extends shelf-life, flavoring agent that promotes sour taste, and bread improver that increases gluten development and dough strength in wheat doughs. Ascorbate salts are used as vitamin C sources when a sour taste or pH decrease is undesirable. The gelatinization temperature (Tgel) of wheat starch in solutions of the vitamin C forms and related acids and salts at 0.5, 1.0, and 1.5 M concentrations (or equivalent) was measured using a differential scanning calorimeter and, compared to starch in water, was increased by all the salt solutions and decreased only by Asc. Calcium ascorbate increased Tgel more than the other salts due to hydrogen bonds between ascorbate and starch and strong hydration by water of Ca2+ that stabilized the starch-water structure and inhibited gelatinization. Asc decreased starch Tgel while similarly acidic solutions did not because Asc caused more extensive starch hydrolysis, which promoted granule swelling and amylose leaching. The paste viscosity values of wheat starch in solution were measured with a rapid visco analyzer and, compared to starch in water, were increased by all salt solutions except NaCl and increased by all acidic solutions until breakdown, then decreased. Ascorbate salts increased paste viscosities significantly more than chloride salts due to the stabilization effect of ascorbate hydrogen bonds that increased the amount of larger starch structures, which increased the viscosity during pasting and short-term amylose retrogradation. Ascorbate-containing acidic solutions increased starch peak viscosity and decreased trough and final viscosities more than HCl because increased granular swelling and amylose leaching results in a more rapid and greater initial increase in viscosity and subsequent decrease in viscosity when granular breakdown overtakes swelling. The results of this work could be used by food researchers and product developers to supplement or fortify vitamin C in a starch-based food and/or modify the functions of starch within that food.  </p>

<p> Gulonolactone oxidase enzyme is important in the final stage of ascorbic acid biosynthesis. Gulonolactone oxidase is encoded by the Gulo gene. Most animals, such as mice, have the Gulo gene, through which they produce ascorbic acid from glucose, while humans, guinea pigs and primate animals carry a non functional Gulo gene. Ascorbic acid plays an important role in many biological processes. However, it is primarily essential as an antioxidant. Ascorbic acid protects genomic DNA from free radicals resulting from oxidative stress that might otherwise cause a variety of diseases such as cancer or heart disease. This thesis focuses on investigating the role of ascorbic acid in the elimination of oxidative stress-induced mutagenesis.</p> <p> To investigate how vitamin C decreases level of the DNA mutation frequency and protects DNA from free radicals, knockout Gulo and Big Blue mice were used as models to determine the ability of vitamin C to minimize oxidative stress. The Big Blue mice carry the cll gene which is a reporter gene through which DNA mutation rate can be detected in any part of body. Therefore, we generated double transgenic mice which are Gulo deficient or a Big Blue background. Homozygote Gulo cll positive (Gulo-/- cll+) were obtained by crossing heterozygote Gulo cll Positive and homozygote Gulo mice. Five Gulo-/-cll mice were placed under vitamin C deficient diet and another five were supplemented with vitamin C. DNA mutation frequency was analyzed in the two groups. There were no significant differences in mutation frequencies between homozygote Gulo-/- cll mice on vitamin C deficient diet and homozygote Gulo-/- cll+ mice fed vitamin C rich diet. One treatment mouse showed increased frequency in mutations but a second did not. Further tests can be done on other treated knockout mice to identify the mutation types generated by oxidative stress in the absence of vitamin C.</p> / Thesis / Master of Science (MSc)

M.S.

The purposes of this study are (1) to determine the ascorbic acid content of a variety of fruit juices available in Denton, Texas, during March to July, 1943; (2) to ascertain the loss of ascorbic acid when canned grapefruit, orange, pineapple, and apple juices are opened and stored in the home refrigerator for several days' use; and (3) by means of data obtained, to make recommendations as to the most advantageous ways of using one's "points" in purchasing canned fruit juices for their ascorbic acid value.

The purpose of the present study is to determine the ascorbic acid values of orange marmalades made with and without commercial pectin; and to compare these values with those obtained by testing random samples of home and commercial prepared orange marmalades.