The objective of the research was to carry out the biogeneration of lipophenols by enzymatic esterification of tricaprylin and caprylic acid with catechin and catechol in a model hexane system. Commercial lipases, including Lipase N from Rhizopus niveus, Lipozyme IM from Mucor miehei and Novozym 435 from Candida antarctica were used throughout this study. The effects of reaction time, incubation temperatures and agitation speeds on enzymatic hydrolytic activity were investigated to determine the optimal conditions for biocatalysis. The optimal temperatures for biocatalysis were determined to be 37.5°C for Lipase N, and 55°C for Lipozyme IM and Novozym 435; the optimum agitation speed was 100 rpm. Using Lipase N, maximum hydrolysis of 1.66 mumol free fatty acids/mL was obtained after 1.5 days of incubation, while with Lipozyme IM, maximum hydrolysis of 8.1 and 8.5 mumol free fatty acids/mL was obtained after 1 and 4 days, respectively. With Novozym 435, the highest hydrolysis of 4.0 and 6.1 mumol free fatty acids/mL were found after 2 and 9 days, respectively.

Recent preliminary data have suggested that microbe-to-plant signals, and plant internal signals elicited by microbial signals, affect aspects of plant physiology, development and growth. The reported research investigated the responses of plants to signal compounds of microbial and plant origin, such as lipo-chitooligosaccharides (LCOs - signal molecules in rhizobia-legume associations), chitin and chitosan (present in fungal cell walls), and phenolic compounds (salicylic acid, acetylsalicylic acid and gentisic acid - internal signals in plants, often affected by signals from microbes). Phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) are key enzymes of the phenylpropanoid pathway. Oligomers of chitin and chitosan increased the activities of both PAL and TAL in soybean leaves. The degree of increase was dependent on oligomer chain length and time after treatment. LCO [Nod Bj V (C18:1 , MeFuc)] was isolated from Bradyrhizobium japonicum strain 532C. When Arabidopsis thaliana plants were grown for two weeks on agar containing this LCO (10-8M) or chitin pentamer (10-4 M), they had greater root length, root diameter, root surface area and number of root tips than control plants. Chitosan (tetramer and pentamer) did not have this effect. Chitin and chitosan were also tested for effects on corn and soybean photosynthetic rates and growth. High molecular weight chitosan generally reduced photosynthetic rates, but did not reduce the growth of corn or soybean. However, foliar application of 10-6 M LCO to corn leaves increased photosynthetic rates (up to 36%). Foliar application of lumichrome (10-5 and 10-6 M), a breakdown product of riboflavin produced by some rhizosphere bacteria, to corn (C4 plant) and soybean (C3 plant) increased photosynthetic rates (up to 6%). Foliar application of lumichrome (10-5 M) increased soybean leaf area and shoot dry weight. Foliar application of SA, acetyl salicylic acid (ASA) and gentisic acid (GT

The distribution of total phenolics, antioxidant capacity, monomeric anthocyanin, and ascorbic acid contents in the peel and flesh of Red Delicious, Granny Smith, and Fuji apples during a six-month storage period were determined. In addition, the effect of 1-MCP (1-Methyl cyclopropene) on these parameters of the edible portion of apples during storage was also investigated. Two different assays were employed to determine antioxidant activities: the spectrofluorometric-based Oxygen Radical absorbing Capacity (ORAC) and the spectrophotometric-based Ferric Reducing Antioxidant Power (FRAP). Total phenolics were measured using the Folin-Ciocalteau method. A determination of monomeric anthocyanin content was also performed using the pH-differential method for Red Delicious and Fuji apples. Antioxidant activity was predominantly observed in the aqueous fraction and was attributed to polyphenolics. Antioxidant activities were highest in the peel, with Red Delicious peel having the highest values, presumably due to anthocyanin pigments. At zero time month storage, the ORAC, FRAP, total phenolics, and total monomeric anthocyanin contents of Red Delicious peel were: 37.7 μmol T.E./g, 62.7 μmol T.E./g, 6.63 mg/g GAE, and 26.4 mg/100g, respectively. The three tested cultivars were significantly different with respect to ORAC, FRAP, total phenolics, and monomeric anthocyanin contents. 1-MCP treatment did not have a significant influence on antioxidant activities and monomeric anthocyanin contents of the three cultivars during storage. Storage did not have significant influence on ORAC values of the edible portion of apple, however it had significant influence on the FRAP values. The contribution of ascorbic acid to the total antioxidant capacity was small. / Graduation date: 2003

Lic.-avh. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 2 uppsatser.

Thesis (M. Ag. Sc.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1997. / Includes bibliographical references (leaves 87-96).

Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 71-74). Also available in electronic format on the Internet.

Thesis (PH. D.)--University of Nebraska, 1931. / eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 24.

Thesis (M.S.)--University of Michigan, 1949.

Thesis (PH. D.)--University of Nebraska, 1931. / eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 24.

Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 58-64).