Impact of coffee preparation on total phenolic content in brewed coffee extracts and their contribution to the body’s antioxidant status

Food Science and Biotechnology - Although coffee has been reported as a major contributor to antioxidants in the diet, there are limited studies assessing how brewing methods and types of coffee...     

Short-term synergistic effect of fruit extracts with red-ginseng on forced swimming endurance capacity in ICR mice

This study was designed to evaluate the effect of the oral administration of fruit extracts (lemon and Japanese apricot) combined with red-ginseng on the endurance and availability of metabolic substrates in ICR mice. Administration of the fruit extracts and red-ginseng (RG) (1:1) significantly increased swimming capacity, by 40%, with increased expenditures of non-esterified fatty acids and triglycerides in the plasma of the mice after 1 week of feeding. There was no significant increase in swimming capacity with the fruit extract alone. These results suggest that the fruit extract could synergistically elevate the effects of red-ginseng on swimming capacity in the mice by increasing fat utilization and reducing the consumption of stored glucose.     

Neuronal cell protective and antioxidant effects of phenolics obtained from Zanthoxylum piperitum leaf using in vitro model system

In order to obtain basic data for the utilisation of Zanthoxylum piperitum leaf as a functional substance in the food industry, the antioxidative and neuronal cell protective effects of silica-gel open column chromatographic fractions, obtained from Z. piperitum leaf, were examined. ABTS and FRAP assays indicated that the ZP4 fraction (eluted with methanol/chloroform, 1:4, v/v) of Z. piperitum leaf was a more potent radical-scavenger and reducing agent than the other five fractions. The ZP4 fraction also presented protective effects against H₂O₂-induced neurotoxicity in a dose-dependent manner. Therefore, our study verified that the ZP4 fraction has strong antioxidative and neuronal protective effects which are correlated with its high level of phenolics, particularly quercitrin, afzelin, and hyperoside. These phenolics of Z. piperitum leaf can be utilised as effective and safe functional food substances, i.e., natural antioxidants, and may reduce the risk of neurodegenerative disorders.     

Changes in phenolics,soluble solids,vitamin C,and antioxidant capacity of various cultivars of hardy kiwifruits during cold storage

Food Science and Biotechnology - Hardy kiwifruits (Actinidia arguta) contain various bioactive compounds such as vitamin C and phenolics and can withstand cold temperatures. Changes in soluble...     

Antioxidant capacities of individual and combined phenolics in a model system

In order to understand how interaction of individual phenolics contributes to the total antioxidant capacity, we quantitatively measured antioxidant capacity of various phenolics in different combinations, using ABTS radical-scavenging ability in a model system. Selected phenolics included in this study were those often found in fruits and vegetables, such as catechin, chlorogenic acid, cyanidin, cyanidin 3-glucoside, cyanidin 3-rutinoside, epicatechin, peonidin, peonidin 3-glucoside, quercetin, quercetin 3-glucoside, quercetin 3-galactoside and quercetin 3-rutinoside. Individual phenolics showed their characteristic antioxidant capacities, while the mixtures, with two or three phenolics combined revealed that the summation of antioxidant capacities of individual phenolics led to total antioxidant capacity. Therefore, it can be concluded that there was no synergistic effect among the phenolics studied. Only an additive effect of antioxidant capacity was observed.     

Protective effects of aqueous extract from Cudrania tricuspidata on oxidative stress-induced neurotoxicity

Total phenolics and flavonols of aqueous extract from different parts of Cudrania tricuspidata (fruit, root, leaf, and stem) and neuronal cell protective effects against oxidative stress-induced cytotoxicity were investigated. The neuronal cell protective effects of aqueous extract from different parts of C. Tricuspidata was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction, lactate dehydrogenase (LDH) release, and neutral red uptake assay. The overall relative neuronal cell protective effects of C. tricuspidata root by 3 assays were much higher than those of leaf, stem, and fruit. The aqueous extract of C. Tricuspidata root also showed higher total phenolics than those of different parts. Therefore, our study suggested that the aqueous extract of root has strong protective effect on oxidative stress-induced neurotoxicity which is correlated with its high level of phenolics, particularly kaempferol, quercetin, and myricetin.