• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.241-243
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• 1998

The chemical composition of rice germ, a by product of rice milling, was analyzed and its oil stability was evaluated by acid value and Rancimat method during storage. The predominent components of the germ were carbohydrate (36.5%). crude lipid (21.6%) and crude protein (18.7%). The time taken to double the acid value was 2 days for common rice germ, while it took 31 days to increase 1.15 times for rice germ dried at $80^{\circ}C$ for 6 hours. Induction periods of the lipid oxidation from common or dry germ stored at different temperature were not significantly different.

• Journal of Nutrition and Health
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• v.36 no.6
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• pp.543-548
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• 2003

This study was carried out to investigate the effects of rice germ oil supplement on the lipid metabolism of insulin-dependent diabetic mice. Streptozotocin-induced diabetic mice were fed three kinds of experimental diets with 20% lipid, composed of 20% lard (L) : 10% lard and 10% rice germ oil (LRGO) ; and 20% rice germ oil (RBO), respectively, for 7 weeks. Diet intake, body weight, organ weight and lipid levels of serum, liver and feces were measured. There was no significant difference in diet intake, body weight and organ weight among the experimental groups. But the concentrations of serum triglyceride in the LRGO and RGO groups, and of serum total cholesterol in the RGO group, were significantly lower than those of the L group fed the 20% lard diet. The levels of hepatic total lipid of the RGO group, and of hepatic total cholesterol of the LRGO and RGO groups were significantly lower than those of the L group. The contents of total lipid and total cholesterol excreted in the feces of the LRGO and RGO groups were higher than those of the L group. These results suggest that rice germ oil can reduce the levels of total cholesterol concentrations in the serum or livers of insulin-dependent diabetic mice, and that the hypolipidemic effect of rice germ oil may be due to increasing fecal lipid excretion and decreasing lipid absorptivity.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.330-335
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• 2004

Changes in functional constituents of rice germ prepared using three different heat pretreatments: roasting, steaming and microwave heating, were determined and compared with those of non-treated rice germ. The yield of rice germ oil increased generally and then decreased with increasing time for all three heat pretreatments, although the yields of rice germ oil varied among the three heat pretreatments. There were no major differences in fatty acid compositions among the rice germ oils subjected to the three different heat pretreatments. Levels of $\alpha$-tocopherol in rice germ oil increased up to about 1.5 times at 3 min of roasting and microwave heating, compared to control, and then decreased with increasing treatment time, but $\alpha$­tocopherol concentrations in rice germ oil gradually decreased with increasing steaming time. The contents of three phytosterols ($\beta$-sitosterol, stigmasterol and ergosterol) decreased progressively with increases in roasting and steaming time, while concentrations of the three phytosterols increased up to - 15$\%$ with 3 min of microwave process as compared to control, and then decreased thereafter. Levels of $\gamma$-oryzanol in rice germ oil decreased gradually with increasing time during all three different heat pretreatments. However, levels of $\gamma$ -aminobutyric acid (GABA) in rice germ decreased gradually with increasing roasting time, while those of GABA increased greatly up to about 2 times after 10 min of steaming process, and then decreased slowly thereafter. During microwave heating, the contents of GABA increased at 3 min of treatment time and then decreased. These results suggest that microwave heating may be the most suitable processing method to preserve functional constituents in rice germ.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.77-81
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• 1998

Rice germ oils were extracted from common and dried rice germ $(80^{\circ}C,\;6\;hr)$, and their oxidative stabilities were evaluated by measuring acid value, peroxide value and fatty acid composition during storage at $40^{\circ}C\;and\;60^{\circ}C$. The acid values of all lipids were slightly changed during storage, but peroxide values (POV) were greatly dependent on storage temperature. The POVs of the dried germ oil and the refined rice bran oil were 146.2 meq/kg and 15.1 meq/kg, respectively after 31 days storage at $40^{\circ}C$. However after 24 days of storage at $60^{\circ}C$, the POVs of the dried germ oil and the refined rice bran oil were 151.7 meq/kg oil and 219.6 meq/kg oil, respectively. Major fatty acids were linoleic (39.8%) and oleic acid (34.7%) in rice germ oil, and oleic (40.1%) and linoleic acid (38.1%) in rice bran oil. The major fatty acid compositions were not greatly influenced by drying and storage temperature but linoleic acid decreased about half during storage.

• The Korean Journal of Community Living Science
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• v.14 no.3
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• pp.67-73
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• 2003

This study was carried out to investigate the supplementary effects of the rice germ oil compared with soy bean oil on blood glucose level of non-insulin dependent diabetic mice. Forty diabetic KK mice were fed two kinds of experimental diets with 20% lipid from soy bean oil as a control(CO) and rice germ oil(RG) for 8 weeks, respectively. Diet intake, body weight, organs weights and lipids levels of serum, liver and feces were measured. There was no significant difference in food and water intake, body weight gain and organs weights between experimental groups. The concentrations of fasting and random blood glucose were similar between CO and RG groups. There was no significant difference in blood glucose levels after glucose treatment during the glucose tolerance test between two groups. The levels of $HbA_{1c}$ as the index of blood glucose status, and insulin were similar in two groups. These results suggested that rice germ oil can't reduce blood glucose concentration of non-insulin dependent diabetic mice compared with soybean oil. But we need to investigate the hypoglycemic effect of rice germ oil by changing supplementary level and period.

• The Korean Journal of Community Living Science
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• v.14 no.3
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• pp.59-65
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• 2003

This study was carried out to investigate the supplementary effects of the rice germ oil compared with soy bean oil on lipid metabolism of non-insulin dependent diabetic mice. Forty diabetic KK mice were fed two kinds of experimental diets with 20% lipid from soy bean oil as a control(CO) and rice germ oil(RG) for 8 weeks, respectively. Diet intake, body weight, organs weights and lipids levels of serum, liver and feces were measured. There was no significant difference in food and water intake, body weight gain and organs weights between experimental groups. But the concentrations of serum total cholesterol and LDL-cholesterol were lower in RG group than in CO group. The hepatic total lipid and total cholesterol levels of RG group were significantly lower than those of CO group. The contents of total lipid, triglyceride and total cholesterol excreted in feces of RG group were higher than those of CO group. These results suggested that rice germ oil can reduce serum total cholesterol and LDL-cholesterol and hepatic total lipid concentration of non-insulin dependent diabetic mice compared with soybean oil due to increasing fecal lipid excretion. But we need to investigate the hypolipidemic effect of this oil by supplementary level and period.

• The Korean Journal of Community Living Science
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• v.14 no.2
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• pp.83-92
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• 2003

This study was carried out to investigate the supplementary effects of soybean oil and rice gem oil compared with lard on lipid metabolism of insulin dependent diabetic mice. Streptozotocin-induced diabetic mice were fed three kinds of experimental diets with 20% lipid from lard(L), soy bean oil(SBO) and rice gem oil(RGO) for 7 weeks, respectively. Diet intake, body weight, organs weights and lipids levels of serum, liver and feces were measured. There was no significant difference in diet intake, body and organs weights among experimental groups. But the concentrations of serum triglyceride of SBO and RGO groups, and of serum total cholesterol were lower in RGO group than in the other groups. The hepatic total lipid and total cholesterol levels of RGO group were significantly lower than those of the other groups. The contents of total lipid and total cholesterol excreted in feces of SBO and RGO groups were higher than those of L group, and the significance was shown only in RGO group. These results suggested that soy bean oil and rice germ oil can reduce serum triglyceride and total cholesterol levels and hepatic total lipid concentration of insulin dependent diabetic mice compared with lard as a animal fat source by increasing fecal lipid excretion of these groups. But the significant reducing effects on serum and liver lipid levels were shown only in RGO group, and we need to investigate the hypolipidemic effect of this oil by supplementary level and period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.710-714
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• 2003

This study was carried out to compare the effects of different plant oil sources on lipid metabolism of insulin dependent diabetic mice. Streptozotocin-induced (65 mg/kg B.W.) diabetic mice were fed four kinds of experimental diets with 20% lipid, which composed of 10% lard, and 10% soy bean oil (SBO), 10% rice germ oil (RGO), 10% rice brab oil (RBO) and 10% sesame oil (SSO) respectively, for 7 weeks. Diet intake, body weight, organs weights and lipids levels of serum, liver and feces were measured. There was no significant difference in diet intake and body weight among experimental groups. But the concentrations of serum triglyceride of RGO and RBO groups, and of serum total cholesterol of RGO and SSO groups were lower than those of the others. The hepatic total cholesterol level was the lowest in RGO group. The contents of total lipid and total cholesterol excreted in feces of RGO and RBO groups were higher than those of SBO and SSO groups. These results suggested that rice germ oil can effectively reduce serum triglyceride level and hepatic total cholesterol concentration of insulin dependent diabetic mice than rice bran oil, soy bean oil and sesame oil, and hypolipidemic effect of rice germ oil be due to increasing fecal lipid excretion. But we need to investigate the more detailed factors on lipid reducing effect in rice germ oil and rice bran oil.

• Proceedings of the KSCN Conference
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• 2000.11a
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• pp.104-104
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• 2000

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2002.08a
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• pp.64-71
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• 2002

Rice(Oryza stiva L.) is a major cereal food providing nourishment to over half of the world's populations and was considered only as a source of energy. However, The recent many researches have been made to suggest that rice may relate to prevention chronic disease and health-promoting properties such as postprandial glucose response, hypocholesterolemic effect and blood pressure-lowering effect. There has been numerous observation supporting that rice has hypocholesterolemic effect. Rice, rice bran, rice bran oil and unsaponifiable matter of rice bran oil reduced plasma cholesterol in rat, hamster as well as human. Components of rice showing hypocholesterolemic effect include dietary fiber(hemicellulose, phytic acid). protein, ${\gamma}$-oryzanol, $\beta$-sitosterol, and tocotrienols. Crapo et al has been studied that the effect of various of starchy foods on the postprandial blood glucose and insulin responses in healthy and diabetic humans. The results showed that rice had lower blood glucose and insulin responses compared to potato, bread and dextrose. The different physical forms in the same starch also produce the different postprandial glucose and insulin responses. In recent years, several studies have shown that some components of rice have potent antioxidant activity against Fe$^{2+}$ -ascorbate induced lipid peroxidation in rat liver microsomal membranes. Cell culture and animal studies have shown that some components of rice have inhibitory effect on the growth and proliferation of several types of human cancer cell. It was also reported that the methanol extract of brown rice has antimutagenic activity against various mutagens. In addition, the pepsine hydrolysate from rice protein is reported to inhibit angiotensin converting enzyme activity. GABA (${\gamma}$ - aminobutyric acid) and GABA enriched rice germ is also effective for lowering blood pressure and triglyceride levels.s.