Jojoba albumins and globulins were treated with jojoba tannins to study the protein-tannin complex formation. Trypsin and chymotrypsin were also treated with jojoba tannins to determine the change of enzymatic activity. The treated albumins and globulins were fractionated by gel filtration before and after treatment. Two albumin fractions did not appear after treatment, but a new fraction appeared with a shorter elution time. A precipitate was formed by addition of jojoba tannins to the jojoba globulins, and two globulin fractions did not appear after treatment. Trypsin was completely inhibited by 5.80 μg of tannin/ml. Chymotrypsin was completely inhibited by 36.44 μg of tannin/ml. Seven two-hour successive extractions with methanol were sufficient to obtain a jojoba meal which, when mixed at 15% in a ration with soybean, resulted in excellent growth of mice. Detannification of jojoba meal with methanol and acid methanol extracted other toxicants, because mice fed 15% of this jojoba meal gained more weight than the control. Acid methanol extraction was more effective than methanol or aqueous extraction in removing tannins; water extracted more protein and less tannin.

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Bibliographical references: leaves 162-181. / 181, [64] leaves, [16] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The inhibition of ruminant digestion by dietary tannins is a significant factor limiting livestock production... Characterisation of S. caprinus may provide essential insight into the ability of some ruminants to tolerate tannins. This thesis aims to identify and characterise the mechanism(s) by which Streptococcus caprinus tolerated the presence of tannins in its environment. S. caprinus employs at least two mechanisms to overcome the potential detrimental effects of tannins: degradation of tannic acid and production of a protective exopolysaccharide. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2000

Most of the calories in cereal foods come from starch. Decreasing starch digestibility is fundamental to prevent obesity and diabetes. This study investigated interactions of condensed tannins (proanthocyanidins-PA) and other sorghum phenolic compounds with starch molecules and their effect on in vitro starch digestibility. High tannin (predominant in large molecular weight PA, 80%), black (monomeric polyphenols) and white (low in polyphenols) sorghum phenolic extracts were cooked with starches varying in amylose content. Starch pasting properties, polyphenol profile and in vitro starch digestibility were evaluated. Unlike other treatments, samples with tannin phenolic extracts had significantly (P ≤ 0.05) lower setback in the test using a Rapid Visco Analyser (RVA) compared to control. The same treatments had the least extractable phenol and PA contents after cooking with all starches. These evidences suggest interactions between starch molecules and PA. Furthermore, after mixing tannin phenolic extracts with pure amylose/amylopectin, extractable polymeric PA was in much lower concentration (62% less) in presence of amylose compared to amylopectin. This drop in concentration increased to 85% when purified tannin extract (90% polymeric PA) was used. This indicates a stronger interaction between amylose and large molecular weight PA. When high amylose starch was used in an autoclave cooking/cooling technique, the RS content of control (26.4%) was similar (P > 0.05) to samples with black phenolic extracts (27%); samples with tannin phenolic extracts increased RS to about 40%. The RS increased to 46% when purified tannin extract was used. All these evidences suggest that sorghum condensed tannins, specifically the polymeric PA, directly interacted with amylose, increasing RS content, whereas the monomeric polyphenols did not. This study opens opportunities to use tannin sorghum to develop products for diabetics and weight control, high in dietary fiber and natural dark color. In the other part of this project, polyphenols from black and tannin sorghum bran were extracted using an Accelerated Solvent Extractor (ASE) and eco-friendly solvents such as water, and mixtures ethanol/water. ASE at 120 and 150 degrees C using 50 and 70% ethanol/water was efficient in extracting as much phenols (45 mg GAE/g) and 12% more antioxidants (628 μmol TE/g) from black sorghum compared to conventional methods using aqueous acetone and acidified methanol. Therefore, ASE extracts from black sorghum could be used in beverages and in colorants containing high antioxidant content.

One of the many ways to address health, obesity and hunger issues is genetic bio-fortification, a strategy of breeding or transforming staple crops with micronutrients and vitamins. This dissertation details efforts to bio-fortify bioactive compounds (phenols, antioxidants, condensed tannins, flavonoids and anthocyanins) in Vigna unguiculata, a staple legume grain crop. Approaches included screening of genetic variation in polyphenolic compositions to identify potential varieties and phenotypes, evaluating the impact of environment (drought stress) on these compositions and elucidating the underlying genetics of their inheritance. Our screening showed significant diversity among genotypes for phenols (2.05 –15.48 mg GAE/g), condensed tannin (0.05 -15.29 mg CE/g) and antioxidant activity (4.0 -201.8 µM TE/g). The highest levels of phenols and antioxidant activity were observed in genotypes with light brown, black and red seed coat color, and those with smooth texture and medium maturity (70-90 days). Red and black phenotypes showed the highest content of flavan-3-ols, flavonols and phenolic acids among all color groups, with values of 169 µg CE/g, 26.17 µg QHE/g, 27.14 µg GAE/g for red and 281 µg CE/g, 23 µg QHE/g and 25 GAE/g for black phenotypes. When studying the impact of drought stress, genotypeXtreatment and treatmentXyear interactions for bioactive compounds were significant when tested under irrigated and drought stress conditions. Anthocyanins showed a 14 % decrease under drought stress. The genotypes that were stable to drought stress are favorable for breeding programs in preparation towards climate change. An FTNIR method was established for high-throughput, non-destructive quantification of bioactive compounds. This was used in inheritance studies of bioactive compounds. Phenols, condensed tannins and flavonoids showed heterosis in F1 and exhibit transgressive segregation in F2 populations. The information presented in this manuscript will be useful for nutritional improvement of cowpeas, where potential genotypes and phenotypes with health benefits offered by enhanced contents of bioactive compounds can be improved further upon.

Graduation date: 1971

Thesis (MS)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Mark Jutila. Non-Latin script record Includes bibliographical references (leaves 105-131).

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Nancy M. Targett, College of Marine & Earth Studies. Includes bibliographical references.

Thèse (Ph. D.)--Université Laval, 1996. / Bibliogr.: f. [158]-175. Publié aussi en version électronique.

Four species of acacia of Auatralian origin are associated with the wattle industry in South Africa. Black wattle, Acacia mollissima willd., is the most important of these and is today almost exclusively cultivated. The tree grows successfully only in a limited area of rich soil and high rainfall and is easily affected by adverse conditions caused by insect pests, frost damage and drought. Expansion of the area under cultivation is therefore, not feasible, although the world demand for vegetable extracts far exceeds the available supply. The remaining species such as green (Acacia decurrrens willd.) and silver wattles (Acacia dealbata Link.) possess many desirable characteristics which resist such adverse factors. Their barks, however, give reddish extracts, which are considered unsuitable for tannery usage because of the red colour they impart to the leather. Hybridisation studies, involving the crossing of green and silver wattle with the black, and aimed at produc1ng progenies containing many of the desirable characterlstics of the parent plants, are thus a natural result and have been in progress for a considerable period. Summary, p. i.