• Preventive Nutrition and Food Science
• /
• v.20 no.3
• /
• pp.210-214
• /
• 2015

Grape pomace is an abundant source of underutilized winery by-products. Polyphenols were extracted from grape pomace using cellulase and gluco-amylase enzymes. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Folin-Ciocalteu's assays were used to measure antioxidant activity and total polyphenolic contents. Both cellulase, and gluco-amylase digested grape pomace showed efficient radical scavenging activity. In addition, the total polyphenolic contents of cellulase digested grape pomace showed lower concentrations were effective compared to higher concentrations, whereas glucoamylase enzyme did not show remarkable variations. The DPPH radical scavenging activity and total polyphenolic contents were significantly higher in the cellulase digested grape pomace compared to the gluco-amylase digested and the not digested grape pomace. It is notable that enzymatic digestions were efficient for extracting polyphenols from grape pomace. The underutilized grape pomace polyphenols can be further used for food safety as a natural antioxidant.

• Food Science of Animal Resources
• /
• v.37 no.5
• /
• pp.726-734
• /
• 2017

This study investigated the meat quality and storage characteristics of pork loin marinated in grape pomace powder during different storage periods. The experimental design included six treatments : pork loin containing only 100% water (Control, C); pork loin containing a combination of 20% grape pomace and 80% water (T1); pork loin containing a combination of 40% grape pomace and 60% water (T2); pork loin containing a combination of 0.5% grape pomace powder and 95.5% water (T3); pork loin containing a combination of 1.0% grape pomace powder and 99.0% water (T4); and pork loin containing a combination of 2.0% grape pomace powder and 98.0% water (T5). The pork loins aged by grape pomace and grape pomace powder showed decreased crude protein, crude fat, crude ash, pH, redness, and yellowness values; however, their moisture, lightness, and shear force increased significantly. During cold storage, marination with grape pomace and grape pomace powder reduced the 2-thiobarbituric acid value, volatile basic nitrogen value, and total microbial count in pork loin. Thus, marination with grape pomace and grape pomace powder improved the meat quality and storage characteristics, and could be used to improve storage stability of pork loin.

• Journal of Nutrition and Health
• /
• v.36 no.10
• /
• pp.997-1012
• /
• 2003

This study was carried out to investigate the effect of whole grape, grape pomace and grape juice intake on cadmium (Cd) metabolism during aging in thirteen-month-old Sprague-Dawley male rats. One hundred and twenty rats weighing 548.8 $\pm$ 4.3 g were assigned to eight groups according to body weight and were raised for 3, 5 or 7 months on diets containing 2 ％ (w/w) dried powders of three different parts of the grape (Campbell Early) and 0.02 ％ (w/w) CdC12. Food intake tended to decrease with aging, and body weight and epididymal fat pad (EFP) weights of Cd-exposed groups were lower than those of Cd-free groups. Cadmium accumulated in the blood and tissues and Cd concentration was the lowest in the pomace group among Cd-exposed animals. Metallothionein (MT) concentration in the tissues increased through Cd administration. Grape diets, especially grape pomace diets, were effective in decreasing Cd absorption in the tissues by increasing Cd excretion through feces. The intake of grape pomace alleviated the decrease in bone density caused by Cd administration and prevented a decrease in glomerular filtration rates (GFR) with aging. Among the parts of grape, grape pomace, which had highest content of dietary fiber and flavonoids, was the most effective. The results of this study suggest the possibility of using grape pomace as a functional food material, a prospect that previously has been discarded.

• Korean Journal of Organic Agriculture
• /
• v.9 no.3
• /
• pp.73-83
• /
• 2001

The qualities of the rice straw, black locust and orchardgrass silage added with grape pomace were investigated in this study and the amount of grape pomace added in different treatments were 0, 20, 40 and 50%, respectively. Crude protein contents of rice straw(6.5-10.6%) and orchardgrass silage(13.2-14.8%) added with grape pomace were significantly higher(p<0.05) than that of 100% rice straw(5.3%) and orchard grass silage(12.8%), however the crude protein contents(14.9-15.6%) of black locust silage in supplementation were lower than that of 100% black locust silage(16.3%). With higher amount of addition of grape pomade to rice straw, black locust and orchardgrass silages, ADF, NDF and crude ash contents decreased significantly(p<0.75). Moisture contents decreased according to the higher proportion of grape pomace in the rice straw silages, but increased according to the higher proportion of grape pomace in the black locust and orchardgrass silage. Values of pH in 20∼60% addition of grape pomace in rice straw(4.0∼4.2), black locust(4.1∼4.3) and orchardgrass silages(4.2∼4.4) were lower than that of 100% in rice straw(4.6), black locust(5.4) and orchardgrass silages(4.7). The contents of acetic acid and total volatile fatty acid significantly increased according to higher levels of addition of grape pomace compared to the respective values of silage. However the contents of lactic acid in supplementation of grape pomace were lower than that of 100% black locust silage.

• Journal of Nutrition and Health
• /
• v.35 no.7
• /
• pp.713-728
• /
• 2002

This study was performed to see effects of whole grape, grape pomace or grape juice intakes on lipid metabolism during aging in old Sprague-Dawely male rats. One hundred twenty rats of 13 months old Sprague-Dawely were blocked into eight groups according to body weight and raised for 3, 5 or 7 months with diets containing 2% (w/w) dried powders of three different pars of grape and 0.02% (w/w) CdCl₂. Body weights of Cd groups were lower than Cd free groups. Kidney and spleen weights were incre ased with age, and EEP weights of Cd groups were lower than those of Cd free groups. Total lipid, triglyceride and total cholesterol concentration in plasma increased with age. Whole grape, grape pomace or grape juice intake lowered plasma total lipid triglyceride and total cholesterol concentrations, and especially grape pomace lowered them markedly. Whole grape, grape pomace or grape juice intake decreased liver total lipid, triglyceride and total cholesterol concentrations and increased fecal lipid excretion. Grape diets decreased and Cd administration increased TBARS concentration in LDL fraction. In conclusion, grape diets were effective in decreasing lipid levels of liver and plasma, TBARS in LDL, and in increasing HDL cholesterol. The grape pomace was most effective among three grape parts. It is plausible that grape might be recommended for the treatment or prevention of cardiovascular disease and delaying aging. (Korean J Nutrition 35 (7): 713∼728, 2002)

• Journal of Nutrition and Health
• /
• v.42 no.5
• /
• pp.415-422
• /
• 2009

The present study was conducted to investigate the effect of dietary supplementation of grape pomace on lipid peroxidation and related enzyme activities of rats fed high fat diet. Male Sprague-Dawley rats weighing about 90 g were assigned to 4 experimental groups of 8 rats on the basis of their body weight. The high fat diet contained additional 15% lard to AIN 93-based diet. Rats were fed experimental diets containing 5% grape pomace for 4 weeks. Dietary supplementation of grape pomace reduced serum concentration of lipid peroxide in rats fed high fat diet. Hepatic concentration of lipid peroxide tended to be lower by feeding grape pomace. Hepatic total glutathione content and GSH/GSSG ratio were increased by grape pomace feeding in normal or high fat diet groups. Hepatic superoxide dismutase activity of grape pomace group with high fat diet was induced significantly compared with high fat diet group without grape pomace. Hepatic catalase activity of high fat fed rats was induced by feeding grape pomace. Grape pomace diet increased glutathione-S-transferase and glutathione peroxidase activities in rat liver fed high fat. Hepatic glucose-6-phosphatase activity was not affected by dietary supplementation of grape pomace in rats fed high fat. These results suggest that dietary supplementation of grape pomace may alleviate lipid peroxidation through antioxidant effect in rats fed high fat.

• Korean Journal of Plant Resources
• /
• v.27 no.6
• /
• pp.650-659
• /
• 2014

Large quantities of Korean wild grape (Vitis coignetiae, KWG) pomace, a by-product of grape juice and wine manufacture, are generated annually, and disposal cost of KWG pomace is now increasing. Therefore, this study was conducted to determine total polyphenol, flavonoid, and anthocyanin content in whole KWG, KWG skin and KWG pomace and to identify and quantify flavonoids found in whole KWG and KWG pomace using LC/MS/MS. Spectral analysis showed high total polyphenol and flavonoid in KWG skin extracted with 75% ethanol (p < 0.05). KWG pomace had higher amount of total polyphenol, flavonoid and anthocyanin than whole grape (p < 0.05). Sixteen flavonoids were identified, but only 10 flavonoids were quantifiable from whole KWG and KWG pomace. Both epicatechin and rutin were the major flavonoids, and 521 or 147 ng/g of epicatechin (p < 0.05) and 305 or 110 ng/g of rutin (p > 0.05) were found in whole KWG and KWG pomace, respectively. The results show that KWG pomace is a very rich source of flavonoids, thus KWG pomace can be used as a functional food additive. Plans to include KWG pomace in food production are necessary.

• Nutrition Research and Practice
• /
• v.4 no.2
• /
• pp.114-120
• /
• 2010

The effects of grape seeds extract and grape peels extract prepared from grape pomace on the activity of antioxidant enzymes, degree of lipid peroxidation in serum and liver tissue were investigated in rabbits fed on high cholesterol diet. New Zealand white rabbits were divided as follows ; 1) NOR (normal group); 2) CHOL (cholesterol group); 3) GSH (cholesterol + grape seed extract group); 4) GPE (cholesterol + grape peel extract); 5) GSP (cholesterol + grape seed powder); 6) GPP (cholesterol + grape peel powder); 7) GE (cholesterol + grape seed and peel extract); 8) GP (cholesterol + grape seed and peel powder). Eight groups of rabbits were studied for 8 weeks. At the end of the experimental period, rabbits were sacrificed and the liver tissue were removed. Then, GSH, GPx, GST, CAT and MDA in the liver were measured. In liver tissues, total glutathione contents (GSH), glutathione peroxidase (GPx) and catalase (CAT) activity, which was significantly higher by grape seed extract supplementation. The level of malondialdehyde (MDA) was lower in the serum of rabbits fed grape seed extract or grape peel powder plus cholesterol than in the serum of rabbits fed cholesterol alone. It is therefore likely that grape seed extract prepared from grape pomace functioned as antioxidants in vivo, negating the effects of the oxidative stress induced by 1% cholesterol diet. The grape seed extract was found effective in converting the oxidized glutathione into reduced glutathione, and in removing $H_2O_2$ that is created by oxidative stress. The grape peel powder was found to have small influence on reduced glutathione content, CAT and GPX activity, but it increased GST activity in liver tissues, resulting in promoting the combination of lipid peroxide and glutathione (GSH), and further, lowering the formation of lipid peroxide in the serum. Therefore, grape pomace (grape seed extract and grape peel powder) supplementation is considered to activate the antioxidant enzyme system and prevent damage with hypercholesterolemia.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.11
• /
• pp.1595-1603
• /
• 2010

The present study was conducted to investigate the effect of dietary grape pomace on lipid metabolism and hepatic morphology of rats fed a high fat diet. The high fat diet contained additional 15% lard to AIN 93-based diet. Male Sprague-Dawley rats were fed experimental diets containing 5% grape pomace for 4 weeks. Serum activities of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) were not changed by high fat and grape pomace feeding. Serum concentration of triglyceride in rats fed a high fat diet was decreased significantly by dietary grape pomace. Hepatic concentrations of total lipid, total cholesterol and triglyceride were reduced in grape pomace groups with a high fat diet. Fecal concentrations of total cholesterol and triglyceride were increased in grape pomace groups with a high fat diet. The fecal content of coprostanol was not different among the groups. Dietary grape pomace increased the fecal excretion of cholesterol and coprostanone in rats fed a high fat diet. The fecal excretion of bile acid was not affected by feeding grape pomace in rats fed a high fat diet. Light micrographs of liver tissue revealed lipid droplets were increased by a high fat diet, but dietary supplementation of grape pomace tended to alleviate such changes.

• Korean Journal of Environmental Biology
• /
• v.17 no.4
• /
• pp.493-498
• /
• 1999

To verify the usefulness of enzyme activities as a index for the stability or maturity of organic refuse composting such as grape pomace, Vmax of $\beta$-glucosidase, cellobiohydrolase and alkaline phosphatase were measured. The peak values of all measured enzymes at the initial stage of composting were probably associated with easily degradable organic matter in the grape pomace and decreased gradually. But the activities of $\beta$-glucosidase and cellobiohydrolase were increased again rapidly whereas that of alkaline phosphatase remained approximately constant after 60 composting days. These results suggest that the increase of enzyme activities during the later periods of grape pomace composting process could be used as a index for their stability.