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11.
Genetic Resources and Crop Evolution - The pomegranate fruit is one of the most important horticultural products due to the presence of polyphenols, anti-oxidant and anti-fungal compounds. In the...  相似文献   
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This study evaluated the effects of cultivar and region on the composition of alkylresorcinols (ARs) of 24 wheat bran samples from 6 cultivars grown in four locations (Bath, Nairn, Palmerstone and Ridgetown) in Ontario (ON), Canada, using gas chromatography/mass spectrometry (GC/MS). Total phenolic content (TPC) of wheat bran extracts was determined by the Folin–Ciocalteau method and the antioxidant activity of wheat bran extracts was measured by 2, 2-Dipheny-1-picryhydrazyl radical (DPPH) scavenging activity and oxygen radical absorbance capacity (ORAC). The highest ARs content (μg/g) was found in cultivars Emmit (1522), Harvard (1305), Warthog (1170), and Superior (853), grown in Ridgetown. The relative saturated and unsaturated ARs (%) were 89 and 11, respectively. Total ARs content, their composition, TPC and antioxidant activity of wheat bran extracts were significantly (P < 0.05) affected by location and cultivar and their interaction. TPC, %DPPHdis, and ORAC values for different wheat bran sample extracts ranged from 3 to 58 (mg FAE/g), 5 to 68 (%), and 6 to 94 (μmol TE/g), respectively. Our work provides a detailed examination of region and cultivar effects on potential of ARs in wheat bran and the results can be used for screening and breeding purposes.  相似文献   
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The objectives of this study were to: i) define the optimum concentration of triticale bran (TB) that can be incorporated in yogurt, ii) evaluate the prebiotic effects of TB on microbial viability, pH and total titratable acidity (TTA) in yogurt across 28 days of cold storage, and iii) measure the oxygen radical absorbance capacity (ORAC) of water-extractable polysaccharides (WEP) in TB. Lactobacillus bulgaricus and Streptococcus thermophilus were used as starter cultures. Lactobacillus acidophilus and Bifidobacterium lactis were used as probiotics. A concentration of 4% TB in yogurt was determined to be the maximum amount that could be added without causing synersis. By day 7, the number of bacteria greatly increased in yogurt samples containing TB and maintained higher viable bacteria counts at the end of the cold storage period, in comparison to controls (P ≤ 0.05). Confirming this data was the lower pH levels and higher TTA values of TB yogurt samples exhibited throughout 28 days (P ≤ 0.05). Polysaccharide extracts of TB exhibited strong antioxidant activity with an ORAC value of 33.86 ± 2.30 μmol trolox equivalents (TE)/g of bran. Results of this study suggest that TB may serve as a new prebiotic and antioxidant source for functional foods and nutraceutical applications.  相似文献   
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Germin like proteins (GLPs) are a large group of related and ubiquitous plant proteins which are considered to be involved in different processes important for plant development and defense. Multiple functional copies of this gene family have been reported in a number of species (wheat, barley, rice, soybean mosses and liverwort), and their role is being evaluated by gene regulation studies and transgenic approaches. To analyze the role of a rice (Oryza sativa) root expressed germin like protein1 OsRGLP1, for its antifungal activity, transgenic potato plants were developed. These transgenic potato plants were molecularly characterized and biologically assessed after inoculation with Fusarium oxysporum f. sp. tuberosi. Functional analysis showed high accumulation of H2O2, increased Superoxide Dismutase (SOD) activity and no oxalate oxidase activity (OxO) in transgenics in comparison to nontransformed control. This increased SOD activity, resistance to heat and sensitivity to H2O2 suggest it is a Fe-like SOD. OsRGLP1 expression in potato plants exhibited enhanced resistance in comparison to nontransformed wild type plants suggesting its role in providing protection against Fusarium oxysporum f. sp. tuberosi through elevated SOD level. Overall, results suggest that OsRGLP1 is a candidate for the engineering of potato plants with increased fungal tolerance however, the greater height and tuber number was observed. This phenotype associated with the resistance needs to be evaluated to determine if this is a positive or negative feature.  相似文献   
15.
We evaluated the antifungal and antitermite activities of wood vinegars produced from oil palm trunk. The wood vinegars were produced at three different pyrolysis temperatures, 350, 400, and 450 °C. Antifungal activities of vinegars were evaluated using a Petri dish bioassay with 0.5, 1.0, and 1.5% (v/v) against a white-rot fungus, Trametes versicolor, and a brown-rot fungus, Fomitopsis palustris. Antitermite activities were tested using a no-choice bioassay method for Coptotermes formosanus with 2.5, 5.0, 7.5, and 10.0% (v/v). All the wood vinegars exhibited antifungal activities against T. versicolor. In particular, the wood vinegar produced at 350 °C resulted in complete inhibition of T. versicolor growth at 1.0 and 1.5%. However, higher concentrations were required to obtain growth inhibition of F. palustris. All the wood vinegars exhibited antitermite activity to C. formosanus workers in the no-choice experiment at relatively high concentrations. For instance, 10% concentration was required to achieve 100% mortality against C. formosanus at all production temperatures. The lowest mass loss of the treated filter paper of 11.75% was obtained with a 350 °C—10.0% combination.  相似文献   
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Six Manitoba fruits were analyzed for their phytochemical content and antioxidant activity in order to increase their production and marketability. The major proanthocyanidins (flavanols) present in whole fruit, juice, and pulp of strawberry, Saskatoon berry, raspberry, wild blueberry, chokecherry, and seabuckthorn were measured. The extraction and purification were facilitated using flash column chromatography, while separation and identification were accomplished by using HPLC and LC-MS techniques. The total proanthocyanidin contents varied from 275.55 to 504.77 mg/100 g in the whole fruit samples. Raspberry contained the highest content, and seabuckthorn showed the lowest content of total flavanols. The highest concentration of proanthocyanidin in juice was found in Saskatoon berry (1363.34 mg/100 mL) and the lowest value in strawberry (622.60 mg/100 mL). HPLC and LC-MS results indicated that epicatechin was the most abundant flavanol followed by B2 in the berry samples, while no catechin or B1 was detected in these fruits. A series of oligomers and polymers were detected in all samples. The recovery percentage was obtained from the ratio of the unspiked samples to the area of spiked samples. Monomers, dimers, oligomers, and polymers gave recovery ranges of 83-99%. The lipophilic and hydrophilic antioxidant capacities of whole fruit, juice, and pulp extracts were measured by the oxygen radical absorbance capacity (ORAC) procedure. In whole fruits, the ORAC values varied from 135 to 479 mg/100 g TE in the MeOH fraction. The corresponding ORAC values varied from 115.30 to 733.15 mg/100 g for the acetone fraction. In juice, all berries showed the same antioxidant capacity (P > 0.05) (133.0-312.0 mg/100 g) in the MeOH fraction, with the exception of raspberry (603.0 mg/100 g). Overall, MeOH fractions mainly contained monomers and dimers with smaller amounts of oligomers and polymers when compared to the acetone fractions. Acetone fractions mainly contained polymers and some oligomers. Although acetone fractions contained a higher quantity of total proanthocyanidins, their antioxidant capacities were lower than MeOH fractions.  相似文献   
19.
To investigate the role of antioxidants and cryoprotectants in minimizing protein denaturation in frozen lean fish, cod fillets were treated with either antioxidants (vitamin C (500 mg kg(-1)) or vitamin C (250 mg kg(-1)) + vitamin E (250 mg kg(-1))), antioxidants (vitamins C + E 250 mg kg(-1)each) with citrate (100 mg kg(-1)), cryoprotectants (4% (w/w) sucrose + 4% (w/w) sorbitol), or a mixture of antioxidants (vitamins C + E 250 mg kg(1)), citrate (100 mg kg(-1)), and cryoprotectants (sucrose 40 g kg(-1) + sorbitol 40 g kg(-1)). Untreated and treated fish samples were stored at -10 degrees C; cod fillets stored at -30 degrees C were used as a control. Stored frozen samples were analyzed at intervals for up to 210 days for changes in protein extractability, thermodynamic parameters (transition temperature T(m) and enthalpy DeltaH), structure by FT-Raman spectroscopy, and rheological properties by large and small deformation tests. Results indicated that protein denaturation and texture changes were minimized in the presence of cryoprotectants, as well as in the presence of antioxidants with citrate, antioxidants alone, or the mixture of antioxidants, citrate, and cryoprotectants. In the presence of increased formaldehyde levels in fish treated with vitamin C, toughening was still lower compared to that of the -10 degrees C control due to the antioxidant property of vitamin C. Thus, ice crystal formation and lipid oxidation products are the major factors that cause protein denaturation in lean frozen fish, and antioxidants in addition to cryoprotectants can be used to minimize toughness.  相似文献   
20.
Of all plant constituents, coffee has one of the highest concentrations of chlorogenic acids. When roasting coffee, some of these are transformed into chlorogenic acid lactones (CGL). We have studied the formation of CGL during the roasting of coffee beans in Coffea arabica cv. Bourbon; C. arabicacv. Longberry; and C. canephora cv. Robusta. Individual CGL levels were determined by comparison of HPLC peaks with those of synthetic CGL standards. Seven CGL were identified: 3-caffeoylquinic-1,5-lactone (3-CQL), 4- caffeoylquinic-1,5-lactone (4-CQL), 3-coumaroylquinic-1,5-lactone (3-pCoQL), 4-coumaroylquinic-1,5-lactone (4-pCoQL), 3-feruloylquinic-1,5-lactone (3-FQL), 4-feruloylquinic-1,5-lactone (4-FQL), and 3,4-dicaffeoylquinic-1,5-lactone (3,4-diCQL). 3-CQL was the most abundant lactone in C. arabica and C. canephora, reaching peak values of 230 +/- 9 and 254 +/- 4 mg/100 g (dry weight), respectively, at light medium roast ( approximately 14% weight loss). 4-CQL was the second most abundant lactone (116 +/- 3 and 139 +/- 2 mg/100 g, respectively. The maximum amount of CGL represents approximately 30% of the available precursors. The relative levels of 3-CQL and 4-CQL in roasted coffee were reverse to those of their precursors in green coffee. This suggests that roasting causes isomerization of chlorogenic acids prior to the formation of lactones and that the levels of lactones in roasted coffee do not reflect the levels of precursors in green coffee.  相似文献   
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