• 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.

• The Korean Journal of Food And Nutrition
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• v.34 no.3
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• pp.302-309
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• 2021

This study examined the quality characteristics of yanggaeng with rice germ; it was incorporated into yanggaeng at different levels (containing 5% rice germ, 10% rice germ, 15% rice germ, and 20% rice germ) based on the total weight of red bean extracts. For analyzing the quality characteristics of yanggaeng, moisture content, hardness, color, antioxidant activity, total polyphenol content, reducing sugar, and vitamin E were determined. There was no significant difference in the moisture content and hardness except in the control. For color, lightness and yellowness of yanggaeng increased as the concentration of the powder was increased, whereas there was no significant difference in redness. As the rice germ powder was increased, total polyphenol content and antioxidant activity increased significantly, whereas reducing sugar decreased. Especially, total vitamin E, including isomers, increased as the concentration of the powder increased from 0.41 mg/100 g to 4.03 mg/100 g. Therefore, it could be possible to develop processed products with functional snack for yanggaeng prepared by adding 10% rice germ.

• 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 the Korean Society of Food Culture
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• v.33 no.1
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• pp.62-69
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• 2018

The purpose of this study was to investigate the antioxidative and physical properties of finger food type rice snacks and pumpkin rice snacks for infants aged 6 to 12 months old. The addition of rice germ did not affect density or porosity, and there was no significant difference when compared with commercial products. The addition of rice germ to the rice snack group did not reduce the longitudinal expansion quality of the rice snack. The WAI of RW and SW values were 9.83 and 8.93, respectively, which were significantly higher than those of other samples (p<0.05). The results of this study show that the addition of rice germ to rice snack resulted in reduced density and porosity of rice snacks and maintenance of a high water absorption index, which are more desirable characteristics for products. The products with rice germ showed significantly higher antioxidative activities among all samples (p<0.05).

• Biomolecules & Therapeutics
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• v.23 no.3
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• pp.268-274
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• 2015

${\gamma}$-Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the mammalian central nervous system, is involved in sleep physiology. Caffeine is widely used psychoactive substance known to induce wakefulness and insomnia to its consumers. This study was performed to examine whether GABA extracts from fermented rice germ ameliorates caffeine-induced sleep disturbance in mice, without affecting spontaneous locomotor activity and motor coordination. Indeed, caffeine (10 mg/kg, i.p.) delayed sleep onset and reduced sleep duration of mice. Conversely, rice germ ferment extracts-GABA treatment (10, 30, or 100 mg/kg, p.o.), especially at 100 mg/kg, normalized the sleep disturbance induced by caffeine. In locomotor tests, rice germ ferment extracts-GABA slightly but not significantly reduced the caffeine-induced increase in locomotor activity without affecting motor coordination. Additionally, rice germ ferment extracts-GABA per se did not affect the spontaneous locomotor activity and motor coordination of mice. In conclusion, rice germ ferment extracts-GABA supplementation can counter the sleep disturbance induced by caffeine, without affecting the general locomotor activities of mice.

• 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.

• 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.

• Journal of Biosystems Engineering
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• v.29 no.2
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• pp.121-130
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• 2004

This study was carried out to develop a miller to produce white embryo rice with functional nutrients by improving the conventional vertical miller. The effects of rice moisture content and the shaft revolution speed of the miller on germ(embryo) adherence rate, whiteness, broken rice rate, and cracked rice rate were investigated. Also, the effect of the mesh size of emery stones on the germ adherence rate was investigated. The vertical prototype miller was improved with the increasement of about 42% in producing white embryo rice at proper conditions(shaft revolution speed of 900 rpm, emery stones of mesh ＃50, processing capacity of 2.3t/h, zero outlet resistance, rice moisture content of 16.2%). The results were as follows: 1. The germ adherence rate of white rice was significantly influenced by the moisture content of brown rice. The germ adherence rate of white rice decreased rapidly with the increase of the moisture content of brown rice. When brown rice with moisture content of 13.2%, 14.5%, 15.2%, 15.4% was milled by the prototype with emery stones of mesh ＃35 and shaft speed of 900(1,100) rpm, rpm adherence rate of milled rice was 76.2%(70%), 69.2%(66%), 45.9(38%), 13.0(9%), respectively. 2. The whiteness of white rice milled by the prototype with emery stones of mesh ＃35 and shaft speed of 1,100(900)rpm increased from 27(23) to about 40, respectively, as the moisture content of brown rice increased from 13.2% to 17.2%. 3. The rate of broken rice of white rice milled at 900rpm decreased by 0.6∼1.0% compared with that at 1,100rpm when the moisture content of brown rice was less than 15.2%. 4. The germ adherence rate was increased by 10.3% and 11.0%, respectively when brown rice with moisture content of 16.2% and 15.5% was milled by the prototype miller with shaft speed of 900rpm and emery stones of mesh ＃50 instead of mesh ＃35. 5. Considering the germ adherence rate, broken rice rate, and whiteness of milled rice, the proper milling conditions of the prototype miller for producing embryo rice were the moisture content of about 15%, the processing capacity of 2.3t/h and minimum outlet resistance of 0Nㆍm with shaft speed of 900rpm and emery stones of mesh ＃50.

• Journal of the Korean Society of Food Culture
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• v.15 no.4
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• pp.253-258
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• 2000

The chemical components of Korean rice germ were analyzed. Proximate compositions of rice germ were as follows; crude lipid 21.18%, crude protein 16.50%, crude fiber 2.95%, crude ash 6.23% and carbohydrate 44.45%. Free sugar compositions were as follows; fructose 50.20mg/100g, glucose 68.80mg/100g, maltose 569.00mg/100g. Major amino acids of rice germ are glutamic acid (1920.9mg/100g), arginine (1503.7mg/100g), aspartic acid(1208.7mg/100g) and leucine (1039.7mg/100g). Fatty acid compositions of rice germ lipid extracted by chloroform-methanol (2:1) were palmitic (22.2%), linoleic acid (38.9%), oleic acid (24.7%) and palmitic acid (22.2%). Mineral elements were phosphorus (1766.22mg/100g) and potassium (1217.80mg/100g). Vitamins were composed of Vit E (11.96mg/100g) Vit B1 (5.69mg/100g) and niacin (2.96mg/100g). 16 flavonoids and 9 phenolic acids in rice germ were not detected. Above the chemical components of rice germ were compared with that of rice endosperm and wheat germ.