Investigating the hydrogen peroxide quenching capacity of proteins in polyphenol-rich foods     

Zhou L  Elias RJ 《Journal of agricultural and food chemistry》2011,59(16):8915-8922

Polyphenols are widely regarded as antioxidants, due in large part to their free radical scavenging activities and their ability to disrupt radical chain propagation. However, recent studies have demonstrated that the oxidation of some polyphenolic compounds, such as the tea-derived compound (-)-epigallocatechin-3-gallate (EGCG), results in the generation of reactive oxygen species that can potentially compromise the oxidative stability of food lipids under some conditions. In this present study, the rate of hydrogen peroxide (H(2)O(2)) generation and its stability, resulting from EGCG oxidation in Tween 80- and sodium caseinate-stabilized oil-in-water (O/W) emulsions in the presence of iron (25 μM Fe(3+) from FeCl(3)), were examined. Observed H(2)O(2) levels in protein-stabilized emulsions were significantly lower across all treatments as compared to surfactant-stabilized emulsions. The lower observed H(2)O(2) concentrations seen in the protein system are likely due to the antioxidant effects of the added proteins, which either prevented the generation of or more likely scavenged the peroxide. All protein-stabilized emulsions containing EGCG showed increases in carbonyl concentrations, a marker of protein oxidation, throughout the study. The H(2)O(2) scavenging activity of aqueous phase and interfacial caseinate and whey protein isolate (WPI) was also evaluated. Both proteins showed concentration-dependent scavenging of H(2)O(2) with caseinate displaying significantly higher scavenging abilities at all concentrations. These results suggest that food proteins may play an important role in mitigating the pro-oxidant effects of polyphenols.  相似文献   

中国-波利维亚经济发展的参照案例     

Elias J.Chalup Zaconeta 《山东饲料》2011,(2)

波利维亚是一个具有中等人类发展指数的发展中国家,贫困程度大约为60%.其主要的经济活动包括农业、林业、渔业和矿业.制造品主要有纺织品、服装、冶炼金属以及成品油.  相似文献   

Timing of Nitrogen Application to Enhance Corn (Zea mays, L.) Yields in a Desert Climate     

H. A. Esechie  S. Elias  J. Magpantay 《Journal of Agronomy and Crop Science》1995,175(4):271-278

Experiments were conducted in two consecutive years to investigate the response of two corn (Zea mays, L.) cultivars, Eperon and Challenger, to timing of N fertilizer in a desert climate. Fertilizer was applied three times (at planting, 6 weeks after sowing (6WAS) and at 9WAS) to give a seasonal total of 180 kg N ha^-1 The N treatments were N_ooo (control), N_LOH (60 kg N ha^-1 at planting, none at 6WAS and 120 kg N ha^-1 at 9WAS), N_LLL (60 kg N ha^-1 at sowing, 6WAS and at 9WAS) and N_LOH, (60 kgN ha^-1 at planting, 120 kg N ha^-1 at 6WAS and none at 9WAS). Generally, N ha^-1 was associated with the highest grain and dry matter yields. Plants in N treated plots had significantly larger number of leaves and ear leaf N contents than the control at mid-silk. High ear leaf N was associated with high leaf area index and dry matter yield. Based on these results, it would appear that the application of 60 kg N ha^-1 at planting, followed by 120 kg N ha at 6WAS (N_LHO) is the most suitable for enhancing corn yields in the desert climate.  相似文献   

Pancreatic Degenerative Atrophy and Chronic Pancreatitis in Dogs a Comparative Study of 60 Cases     

Eija Rimaila-Prnnen  Elias Westermarck 《Acta veterinaria Scandinavica》1982,23(3):400

During the years 1977–1980 60 cases of non-neoplastic chronic exocrine pancreatic disease in dogs were investigated clinically and pathologically. The disorders were clinically divided into pancreatic degenerative atrophy (PDA) and chronic pancreatitis. Fifty dogs had PDA and 45 of them were German shepherd dogs. The PDA cases formed both clinically and pathologically a homogeneous group except for 1 case. All the dogs had maldigestion and protease activity was absent from the faeces. General inanition and highly atrophic pancreas were the most typical macroscopic findings. Histologically the exocrine pancreas contained atypical acinar tissue and mononuclear cell infiltrations. Five of the dogs died spontaneously, 4 of them had intestinal torsion and 1 had paralytic ileus.There were 10 dogs with chronic pancreatitis. This group was rather heterogeneous both clinically and pathologically. The pancreas was slightly enlarged and the consistency was firm. The histologic picture was one of fibrous tissue proliferation and inflammatory cell infiltrations in the interstitium. The dogs nutritional state as well as faecal protease activity were normal.  相似文献   

Tissue-culture propagation of banana     

R.Dore Swamy  N.K.Srinivasa Rao  Elias K. Chacko 《Scientia Horticulturae》1983,18(3):247-252

The possibility of clonal propagation of banana through tissue culture was explored. Shoot tips isolated from the rhizomes were found to be suitable material for plantlet production in vitro. Excised shoot tips with the youngest leaves produced only one plantlet. However, shoot tips with several older sheathing leaf bases enclosing the axilary buds regenerated multiple plantlets. Individual shootlets, when separated and sub-cultured, produced a new crop of multiple shoots. The plantlets obtained from both types of explants have been successfully transplanted to soil and grown to maturity.  相似文献   

Intake,performance, and efficiency of nutrient utilization in Saanen goat kids fed diets containing calcium salts of fatty acids     

Possamai  Ana Paula Silva  Alcalde  Claudete Regina  de Souza  Rodrigo  Gomes  Ludmila Couto  de Macedo  Francisco de Assis Fonseca  Martins  Elias Nunes 《Tropical animal health and production》2015,47(1):259-263

Tropical Animal Health and Production - The objective of this study was to evaluate the effect of feeding Saanen goat kids with calcium salts of fatty acids (CSFA) in diet, on intake, performance,...  相似文献   

The source of Saturn's G ring     

Hedman MM  Burns JA  Tiscareno MS  Porco CC  Jones GH  Roussos E  Krupp N  Paranicas C  Kempf S 《Science (New York, N.Y.)》2007,317(5838):653-656

The origin of Saturn's narrow G ring has been unclear. We show that it contains a bright arc located 167,495.6 +/- 1.3 km from Saturn's center. This longitudinally localized material is trapped in a 7:6 corotation eccentricity resonance with the satellite Mimas. The cameras aboard the Cassini spacecraft mainly observe small (1 to 10 micrometers) dust grains in this region, but a sharp decrease in the flux of energetic electrons measured near this arc requires that it also contain larger (centimeter- to meter-sized) bodies whose total mass is equivalent to that of a approximately 100-meter-wide ice-rich moonlet. Collisions into these bodies may generate dust, which subsequently drifts outward to populate the rest of the G ring. Thus, the entire G ring could be derived from an arc of debris held in a resonance with Mimas.  相似文献   

Changes in chemical and selected biochemical components,protein quality,and digestibility of mung bean (Vigna radiata) during gemination and cooking     

Mohd I. Noor  Dr. R. Bressani  L. G. Elias 《Plant foods for human nutrition (Dordrecht, Netherlands)》1980,30(2):135-144

The effect of germination on the nutritive value of mung beans (Vigna radiata) was studied in raw and cooked samples after 0, 2 and 4 days of germination. Water content increased, but crude protein, lipids, crude fiber, ash and carbohydrates decreased with germination. Trypsin inhibitor activity did not change significantly while hemagglutinins were absent. Essential amino acids (methionine, tyrptophan and lysine) decreased with germination.Net protein ratio (NPR) and protein efficiency ratio (PER) in rats decreased with germination especially in cooked sprouts. True digestibility did not change consistently due to germination or cooking. In conclusion, loss of protein quality in mung beans occurs upon germination and cooking.Publication INCAP/UNU-4.  相似文献   

Limiting amino acids in raw and processed amaranth grain protein from biological tests   总被引：1，自引：0，他引：1  

Ricardo Bressani  Luiz G. Elias  Arnoldo Garcia-Soto 《Plant foods for human nutrition (Dordrecht, Netherlands)》1989,39(3):223-234

Amino acid supplementation studies with young rats were carried out using raw and processed amaranth grain (A. cruentus) of dark- and cream- or light-colored seeds. The results of various studies repeatedly indicated that threonine is the most limiting amino acid in raw and processed, dark and cream-colored grain. Protein quality as measured either as NPR or PER was improved by threonine addition alone or with other amino acids and decreased liver fat to values similar to those measured with casein. This finding contradicts the reports that state that leucine, determined by chemical score, is the most limiting amino acid. Leucine addition alone or with other amino acids did not improve protein quality. The study confirmed cream-colored grain to be nutritionally superior to dark grain and that properly processed grain, light- or dark-colored, has higher protein quality than raw grain.INCAP Publication I-1525  相似文献   

Antioxidant activity of cysteine, tryptophan, and methionine residues in continuous phase beta-lactoglobulin in oil-in-water emulsions   总被引：1，自引：0，他引：1  

Elias RJ  McClements DJ  Decker EA 《Journal of agricultural and food chemistry》2005,53(26):10248-10253

Proteins dispersed in the continuous phase of oil-in-water emulsions are capable of inhibiting lipid oxidation reactions. The antioxidant activity of these proteins is thought to encompass both free radical scavenging by amino acid residues and chelation of prooxidative transition metals; however, the precise mechanism by which this occurs remains unclear. In this study, the oxidative stability of cysteine, tryptophan, and methionine residues in continuous phase beta-lactoglobulin (beta-Lg) in a Brij-stabilized menhaden oil-in-water emulsion was determined. The presence of low concentrations of continuous phase beta-Lg (250 and 750 microg/mL) significantly inhibited lipid oxidation as determined by lipid hydroperoxides and thiobarbituric acid reactive substances analysis. It was observed that cysteine oxidized before tryptophan in beta-Lg, and both residues oxidized before lipid oxidation could be detected. No oxidation of the methionine residues of beta-Lg was observed despite its reported high oxidative susceptibility. It is conceivable that surface exposure of amino acid residues greatly affects their oxidation kinetics, which may explain why some residues are preferentially oxidized relative to others. Further elucidation of the mechanisms governing free radical scavenging of amino acids could lead to more effective applications of proteins as antioxidants within oil-in-water food emulsions.  相似文献