초록 ▼

Ⅳ. 연구개발결과
1. 고기능성 쌀 서농 17호, 큰눈자미의 배유 성분(단백질, 지질, 전분질)특성
- 성분조성 특성 ; 전분질 함량은 품종간 차이가 없었고, 거대배아미 품종인 서농 17호, 큰눈자미는 지질함량이 상대적으로 높았으며, 큰눈자미가 서농 17호 보다 불포화 지방산 함량이 더 높았다. 또한 세로토닌의 전구물질인 트립토판 및 NK 세포의 활성화를 통한 면역력 증강에 효과가 기대되는 기능성 아미노산인 알기닌이 거대배아미인 서농 17호에 다량 함유되어 있었고, 성장호르몬의 원료이면서 골다공증 개선에 효능이 있는 라이

Ⅳ. 연구개발결과
1. 고기능성 쌀 서농 17호, 큰눈자미의 배유 성분(단백질, 지질, 전분질)특성
- 성분조성 특성 ; 전분질 함량은 품종간 차이가 없었고, 거대배아미 품종인 서농 17호, 큰눈자미는 지질함량이 상대적으로 높았으며, 큰눈자미가 서농 17호 보다 불포화 지방산 함량이 더 높았다. 또한 세로토닌의 전구물질인 트립토판 및 NK 세포의 활성화를 통한 면역력 증강에 효과가 기대되는 기능성 아미노산인 알기닌이 거대배아미인 서농 17호에 다량 함유되어 있었고, 성장호르몬의 원료이면서 골다공증 개선에 효능이 있는 라이신 함량 및 중추성 피로를 경감시키고 간기능을 강화시켜 신체의 활력 증진 효과가 있는 발린과 이소로이신의 함량이 큰눈자미에 다량 함유되어 있었다.
- 단백질 성분 특성 ; 서농 17호와 큰눈자미 실험군에서만 발현되거나 그 양이 많았던 단백질은 대체로 ROS의 세포내 level을 조절하는 중요 항산화성 단백질인 함황 단백질들이라는 점에서 고 기능성 쌀의 생리활성 기능 특성에 관여하리라 기대되는 단백질들이었다.
2. 고 기능성 쌀 함유 기능성 성분 함량 및 in vitro 항산화 활성
- 총 페놀성 화합물 함량 ; 항산화 활성과 밀접한 연관성을 가지는 기능성 성분인 페놀성 화합물 함량은 큰눈자미가 각각 100 g 당 223.01 mg이었고, 서농 17호도 147.5 mg으로 일반 현미 44.81 mg보다 약 3배 정도 그 함량이 높았다.
- 플라보노이드 함량 ; 총 페놀성 화합물의 함량과 유사한 경향을 나타내어, 큰눈자미 67.65 mg 순이었고, 서농 17호 11.58 mg, 일반현미 9.48 mg 이었다.
- in vitro 항산화활성 ; 총 항산화력은 유색미 계통인 큰눈자미가 360.74 AEAC(5 mg/mL)로서 서농 17호 및 일반현미 보다 월등히 높았다. 이 수치의 의미는 쌀 100 g당 ascorbic acid 360.74 mg과 동일한 항산화력을 나타낸다는 의미로써 항산화용 소재로의 활용이 기대되는 수치라 할 수 있겠다.
3. 고 기능성 쌀 및 햇반 제품의 항 비만, 항 당뇨, 항 고지혈증 중재기작 ; 만성대사성 질환 예방 중재 기전을 검증하기 위하여, 고 지질 식이에 의해서 당뇨가 유도되는 형질전환 마우스(C57BL/6N)에게 고기능성 쌀 및 적용제품(햇반)을 급여함에 따른 바이오마커 분석 및 자궁 적출에 의한 갱년기 유도 흰쥐에게 유색미 미강 보충급여에 따른 바이오마커 분석등을 통하여, 고 지질식이에 의한 당질대사, 지질대사, 항산화 대사 개선 효능을 각각 입증하고, 동시에 비만, 항 당뇨, 항 고지혈증 중재기작을 다음과 같이 검증하였다.
- 당질 대사 개선 효능 ; 식품섭취에 의한 포도당의 항상성 조절과 췌장 β-세포로부터 인슐린분비를 증가시킴으로써 혈당 수준을 일정하게 유지시키는 glucokinase(GK)의 활성이 고 기능성 쌀 급여에 의해서 증가하고, 반면에 당신생에 관여하며, 혈당을 증가시키는 역할을 하는 효소인 glucose-6-phosphatase(G-6-Pase) 및 phosphoenolpyruvate carboxykinase(PEPEK)의 활성은 감소시킴으로서 당질대사를 바람직하게 조절하고 있음을 확인하였다.
- 지질 대사 개선 효능 ; 간조직 및 지방조직에서의 지질대사 관련 효소활성을 측정한 결과, 에너지 생성을 위해서 지방산 산화에 관여하는 효소인 β-oxidation 효소, carnitine palmitoyl transferase(CPT) 활성은 증가하고 있었으며, 반면에 지방산 합성에 관여하는 효소인 fatty acid synthas(FAS), glucose-6-phosphate dehydrogenase(G6PD), malic enzyme(ME) 등의 활성은 감소하고 있어 지질대사를 바람직하게 조절하고 있음을 확인하였다.
- 항산화 대사에 미치는 영향 ; 인체의 항상성을 교란시킴으로써 각종 대사성 질환을 유발하는 생체의 산화적 스트레스는 체내에 생성되었던 활성산소가 세포막에 존재하는 다가 불포화 지방산에 작용하여 지질과산화물을 생성시키고, 동시에 세포의 조직을 변성시키는 것인데, 이들 활성산소는 superoxidedismutase(SOD), catalase(CAT), glutathion peroxidase(GSH-Px)에 의해 최종적으로 분해된다. 고 기능성 쌀, 적용제품 및 미강을 급여하는 경우 실험동물의 혈장 및 간조직에서 이들 항산화 관련 효소의 활성들이 증가하고 있고, 동시에 과산화 지질의 수준은 저하하고 있음을 확인함으로써 항산화 대사를 바람직하게 조절하고 있음을 확인하였다.
- 항 비만 효능(비만 중재 기작) ; 고기능성 쌀 및 적용제품 급여에 의해서 지방조직에서 생성, 분비되어 다양한 신호전달에 관여하는 ‘adipocytokine’들의 혈중 농도를 낮추는 효과가 있음을 확인하였다. 구체적으로는 혈중 leptin 농도를 낮추어 체지방량 저하 효능을 보이고 있었으며, 비만 시 인슐린 저항성을 유발시키는 물질이면서 고지혈증, 당뇨, 고혈압 환자에서 혈중농도가 증가하는 염증성 cytokine인 resistin의 농도, 그리고 인슐린 감수성을 조절하고 항염증 작용을 하는 물질로 지방산 수송 및 열발산을 증가시키는 등 근육의 지질대사를 향상시켜 죽상동맥경화증에 수반되는 염증반응을 억제하는 물질인 adiponectin 및 비만조직에서 발견되는 염증관련 물질로써 비만 지방세포에서 발현이 증가하며 지방세포 분화억제, 지방분해 촉진, 지방세포의 자기사멸을 촉진시키는 기능을 하고, 지방조직과 근육에 있는 인슐린 수용체의 tyrosine kinase에 작용하여 그 활성을 억제시켜 인슐린 저항성을 유도하는 물질인 TNF-α의 혈중 농도들을 낮추는 효과를 나타내면서 결과적으로 체중 감소, 복부 지방량 및 장기조직의 무게를 저하시키는 효과가 나타났음을 확인하였다.
- 항 당뇨 효능(당뇨 중재 기작) ; 당뇨가 유발되면 인슐린 저항성으로 인해 혈중의 높은 glucose 농도 때문에 글리코겐 함량은 감소하고 인슐린 농도는 증가하는 경향을 보인다, 고기능성 쌀 및 햇반을 급여받은 실험동물들은 글리코겐 함량 증가 및 인슐린의 함량 감소 효과가 정상 식이군보다 오히려 높게 나타나는 상당히 고무적인 결과를 얻었다. 이러한 생화학적 지표의 결과를 토대로 정상적인 혈당치로의 회복하는 효과를 확인하였다. 이러한 이유는 지방조직으로부터 분비되는 사이토카인들의 혈중 농도가 고기능성 쌀을 섭취함에 따라 낮아지면서, 인슐린 저항성을 제어하고 있을 것이라 사료된다.
- 항 고지혈증 효능(고지혈증 중재 기작) ; 혈액 내에 중성지방 및 유리지방산 농도의 증가는 간에서 VLDL의 과도한 생성으로 이어져서 고지혈증이나 고 콜레스테롤 혈증을 일으킨다. 이러한 고지혈증은 동맥경화와 당뇨의 주요 원인이 된다. 고기능성 쌀 및 햇반을 급여받은 실험동물들은 식이 기간이 길어질수록 중성지방 및 총 콜레스테롤 수치가 낮아지고 있음을 확인하였고, 총 콜레스테롤에 대한 HDL 콜레스테롤의 비율인 HTR 수준은 증가하고, 동맥경화지수는 유의적으로 낮아지는 효과를 나타내고 있었다. 또한 중성지방의 유화를 돕고 복합 micelle의 용해도를 높여 담석형성을 막고 콜레스테롤의 흡수를 도우며 소장점막의 지질전달 및 흡수를 용이하게 하는 인지질의 혈중 함량이 증가하는 것도 이러한 바람직한 혈중 지질 조성을 뒷받침하는 결과라 사료된다.
4. 고 기능성 쌀 미강 함유 기능성 성분 함량 및 in vitro 항산화 활성
(1) 유색미 미강 성분 조성 변이 및 in vitro 항산화 활성과의 상관성 분석
- 큰눈자미, 대립자미, 슈퍼자미 등 3 품종 유색미 각각에 함유되어 있는 성분 변이를 확인하고자, 미강층으로 70 % 에탄올 추출물을 제조한 후, 핵산, 클로로포름, 에틸아세테이트, 부탄올 그리고 물 분획 등 순차적인 유기용매 분획을 실시하고, 각 분획들의 GC-MS 스펙트럼으로부터 성분 조성 및 함량을 각각 분석한 결과 다음과 같이 품종간에 성분변이가 있었다.
- 항산화 활성과 상관성이 높은 페놀성 화합물 중 일반품종의 쌀에는 함유되어 않으나 유색미에 다량 함유되어 있는 성분은 phrocatecol, protocatechuic acid, Isovanillic acid 등임을 확인하였다.
- 유색미 품종별 phytosterol 종류 및 함량 변이는 다음의 표와 같다.
- DPPH 라디칼 소거능 및 환원력은 총 페놀성 화합물의 양 및 플라보노이드 함량과 유의적인 상관성을 나타내고 있었으며, 금속이온 제거능은 총 페놀성 화합물의 양 및 acetamide, 2-(diethylamino)-N-(2,6-dimethylphenyl)- 등의 양과 정의 상관성을 나타내고 있었다.
- 아질산염 소거능은 페놀성 화합물 중 Pyrocatechol, Isovanillic acid 등의 화합물의 양과 정의 상관 관계가 있었다.
- 또한 xanthine oxidase 저해 활성은 플라보노이드 함량 및 유색미 품종들에만 함유되어 있는 isovanillic acid,e3Ethyl-3,4-dihydroxybenzoate 등의 화합물의 양과 정의 상관관계를 나타내고 있었다.
- 반면, 동물체내의 콜레스테롤 저해 효과를 나타내는 식물성 스테로이드 화합물인 stigmasta-5,23-dien-3β-ol, (23S)-ethylcholest-5-en-3β-ol 등의 함량은 항산화 활성과는 부의 상관성을 나타내고 있었다.
- 그리고 포화 지방산인 팔미트산, 2-hydroxy-1-(hydrpxymethyl)ethyl ester, 9, 12-Octa decadienoic acid (Z,Z)-, 9,12-Octadecadienoic acid (Z,Z)-, 및 1-methylethyl ester (Isopropyl linoleate)등의 지방산 유래 화합물들은 DPPH 라디칼 소거능, 아질산염소거능, 환원력 등의 항산화 활성과 정의 상관관계를 나타내는 물질들임을 확인하였다.

Abstract ▼

The purpose of this study was to evaluate the potential as a health functional food material of new varieties of functional rices, giant embryo rice is a mutant rice with an enlarged embryo and has higher nutritional value compared with the normal embryo rice and is rich in minerals, protein, vitami

The purpose of this study was to evaluate the potential as a health functional food material of new varieties of functional rices, giant embryo rice is a mutant rice with an enlarged embryo and has higher nutritional value compared with the normal embryo rice and is rich in minerals, protein, vitamins, and essential amino acids High amounts of gamma-oryzanol and gamma-aminobutytic acid (GABA) have also been found in giant embryo rice mutants, and colored rice namely "Superjami" and "Daeripjami".
Physicochemical tests, in vitro antioxidant activity and in vivo bioactive efficacy were tested. This thesis was performed to utilize as a basis for certification as health functional materials for metabolic disease prevention. The results were as follows:
1. Physicochemical Characteristics of Giant Embryo Brown Rice "Seonong 17 and Keunnunjami"
1) According to the results of analyzing the physicochemical characteristers of general brown rice, Seonong 17 and Keunnunjami, the cross section of grains and size of starch grain were motsly similar among three cultivars. Mg and K contents were the highest in Seonong17 and Ca too. Protein content by toyo value that Keunnunjami was higher than Seonong17 and Normal brown rice. Three main fatty acid were palmitic acid, oleic acid, and linoleic acid in the rice, oleic acid in Seonong17 was higher than others, but linoleic acid was higher in Keunnunjami. Starch-I2 reaction was somewhat lower in Seonong17. Keunnunjami showed the highest gelatination enthalphy.
The DPPH radical scavenging, reducing power, ABTS of Keunnunjami was significantly increased. Ferrous ion chelating effect and hydroxyl radical scavenging activities were increased. Total phpyphelol contents of Keunnunjami was 223.01 mg/100g and total flavonoid contents was higher than Seonong 17.
2. Effect of giant embryonic rice "Seonong 17 and Keunnunjami" on obesity and diabetes.
1) The effects of giant embryo brown rice Seonong 17 and Keunnunjami, in comparison with that of the ordinary normal brown rice, on the body weight and lipid profile in mice under high fat diet condition were investigated. The animals were fed with experimental diets for eight weeks: normal control (NC), high fat (HF), and high fat supplemented with normal brown rice (HF-NB), Seonong 17 rice (HF-S17) or Keunnujami rice (HF-KJ) powder. A marked increase in the body weight and fat, plasma triglyceride and total cholesterol concentrations, and free fatty acid level were found in HF mice relative to the control group. On the other hand, diet supplementation of rice, particularly the giant embryo rice samples, significantly suppressed this high fat-induced body weight gain and hyperlipidemia via regulation of lipogenesis and adipokine production. Both the Seonong 17 and Keunnunjami exhibited greater hypolipidemic and body fat-lowering effects than the normal brown rice. The results demonstrate that these giant embryo mutants may be beneficial as biomaterials for functional foods with anti-obesity and hypolipidemic effects.
2) The effects of giant embryo rice Seonong 17 and Keunnunjami, in comparison with that of the normal embryo brown rice, on the glucose metabolism and antioxidant defense system in C57BL/6N mice under high fat diet condition were investigated. The animals were randomly divided into five dietary groups: normal control (NC), high fat (HF), and HF supplemented with normal brown rice (HF-NB), Seonong 17 rice (HF-S17) or Keunnunjami rice (HF-KJ) powder. After eight weeks of feeding them with the experimental diets, the HF mice exhibited a significant increase in the blood glucose level, plasma insulin concentration, and lipid peroxidation, accompanied with a substantial decrease in the glycogen level, relative to the NC group. Diet supplementation of the rice powders, however, markedly suppressed this high fat diet-induced hyperglycemia and oxidative stress through regulation of the glucose-regulating enzymes activities and activation of the antioxidant enzymes. Compared with the normal brown rice, Seonong 17 and Keunnunjami exhibited greater hypoglycemic and antioxidative effects in high fat-fed mice. These findings illustrate that these rice mutants may be beneficial as functional foods for the prevention and management of hyperglycemia and oxidative damage.
3. Effect of instant cooked giant embryonic rice "Seonong 17 and Keunnunjami" on obesity and diabetes.
1) The comparative effects of instant cooked rice made from giant embryo mutant or ordinary normal rice on the body weight and lipid profile in high fat-fed mice were investigated. The animals were given experimental diets for seven weeks: normal control (NC), high fat (HF), and HF supplemented with instant normal white (HF-NW), normal brown (HF-NB), giant embryonic white (HF-GW), or giant embryonic brown (HF-GB) rice. The HF group showed markedly higher body weight, body fat, plasma triglyceride and cholesterol concentrations, and atherogenic index relative to NC group. However, instant rice supplementation counteracted this high fat-induced hyperlipidemia through regulation of lipogenesis and adipokine production. The GB rice exhibited greater hypolipidemic and body fat-lowering effects than the GW or NB rice. These findings illustrate that the giant embryo mutant may be useful as functional biomaterial for the development of instant rice with strong preventive action against high fat diet-induced hyperlipidemia and obesity.
2) Results of the present study demonstrated that instant cooked rice made from giant embryo mutant could reduce the blood glucose level and suppress oxidative stress in mice under high fat diet condition through a mechanism involving the regulation of the glucose-regulating enzymes activities and activation of the antioxidant enzymes. The instant giant embryonic brown rice generally exhibited greater hypoglycemic and antioxidative effects compared with the instant giant embryonic white and normal brown rice. These findings illustrate that the giant embryo mutant may be useful as a functional biomaterial in the preparation of instant cooked rice with preventive effect against high fat-induced hyperglycemia and oxidative stress.
4. Physicochemical properties of new colored rice varieties (Superjami, Daeripjami)
Daeripjami crude protein has the largest crude fat content (8.93%) and was not found to have any significant differences between the rice samples. Na, Mg, K, Fe, P content of rice were the largest in Superjami rice. Amount of mineral content among the rice cultivars were P> Na> K> Mg> Fe, respectively. Gelatinization temperature of the starch particles were highest in Superjami (67 ℃). Also, gelatinization temperature peak was also the highest in Superjami. Daeripjami has no significant difference with black rice control Heugjinju.
5. Functional components and antioxidant activity of 70% ethanolic extract of the new colored rice varieties (Superjami, Daeripjami) rice
1) The total polyphenol content of rice in 70% ethanol extract is highest in Superjami.
Flavonoids and anthocyanins content were measured similar to total polyphenolic contents and the order of the content was Superjami>Daeripjami> Heugjinju>Normal brown rice.
2) ABTS radical scavenging of the Superjami showed the highest values as 375.34 AEAC followed by Daeripjami (355.92 AEAC) Heugjinju (274.58 AEAC). Similar trend with other antioxidant activity experiments were found. Also, DPPH radical scavenging activity of Superjami was significantly the highest activity. Therefore, excellent antioxidant effect of the Superjami was confirmed due to invitro free radical scavenging. Inaddition, Hydroxy radical scavenging activity of new colored rice showed excellent activity compared to normal brown rice. However, significant differences were not found in the newly breed colored rice. Also, SOD-like activity was also confirmed that Superjami and Daeripjami have significantly higher activity than both normal brown rice and Heugjinju when compared to other antioxidant capacity measurements.
6. Functional components and antioxidant activity of new colored rice bran varieties(Superjami, Daeripjami) fractionated extracts
1) The yield of 70% ethanol extract was highest in Superjami. The highest yield of hexane fraction is in Daeripjami, yield of chloroform, ethylacetate and butanol fractions are highest in the Superjami and yield of water fraction was the highest in the normal brown rice.
2) Phenolic compounds content of the bran fraction were ethylacetate > n-butanol > water > 70 % ethanol > chloroform > hexane in all cultivars and significant difference was confirmed with each group. Flavonoid content of Daeripjami showed lower amount than Superjami in 70% ethanol extract. The remaining five kinds of the fractions were confirmed that flavonoids were highest in Superjami and the difference between each fraction is similar with the results of the phenol compound.
3) DPPH radical scavenging activity of the extract fraction in accordance with the polarity of the organic solvent showed high activity in Superjami and Daeripjami.
Specifically, activity was highest in the ethylacetate fraction of Superjami and activity of the 2 colored rice butanol and water fractions have similar values. The activity of the polar fraction of hexane and chloroform was low. Similar with DPPH radical scavenging activity, reducing power and nitrite scavenging activity also showed highest activity in the ethylacetate fraction. The order was ethylacetate>butanol>water>chloroform>hexane. Therefore, It is concluded that the material having a high antioxidant activity is soluble in highly polar solution and in return, have a high value as material of functional food.
7. Component analysis of new colored rice bran varieties (Superjami, Daeripjami) fractionated extracts by GC-MS
1) After 70% ethanol extract was analyzed by GC-MS, only the contents with 80% or more have been summarized. Colored rice varieties of Daeripjami and Superjami showed high values over 96% compared to normal brown rice which is about 53% only.
Daeripjami and Superjami have the highest quantity of Octadec-9-enoic acid. Fatty acid derivatives, 9,12-Octadecadienoic acid (Z, Z) - showed the highest content in Daeripjami and Superjami hexane fraction. α-tocopherol were found in both colored rice and campesterol were found in large quantities in Superjami compared to the normal brown rice and Daeripjami. Components of the chloroform fraction,
1,2-Benzenediol(pyrocatechol) was detected in large amounts in both colored rice than in brown rice. Momilactone B and Lupinfolin were found specifically in chloroform fractions of Daeripjami. 4 kinds of materials namely 1, 2-Benzenediol (Pyrocatechol), 3-Hydroxy-4- methoxy benzoic acid (Isovanillic acid), Benzoic acid, 3,4-dihydroxy-, Ethyl3,4-di -hydroxybenzoate are found specifically in ethyl acetate fraction of the colored rice varieties. Therefore, these components are considered to be substances that affect the high antioxidant activity of the ethyl acetate fraction.
2) The amount of phenolic compounds of new varieties analyzed by GC-MS was brown rice (1.32), Daeripjami (26.02), Superjami (34.35 ㎍/g) rice bran. Phytosterols and other components were found to be largest in Daeripjami. Phytochemical which are functional components contained in the cereal plant such as steroid compound was confirmed to be contained in a large amount in colored rice compared with normal brown rice. It was confirmed that the phenolic compounds in Superjami, the phytosterols are highest in Daeripjami. Also, it showed a high content of fatty acids in colored rice varieties. Colored rice varieties were found to have no significant difference.
8. Correlation analysis between invitro antioxidative activities and functional ingredients of colored rice bran
1) DPPH radical scavenging activity and reducing power antioxidant activity showed a significant positive correlation with total phenolic compounds, flavonoids content, 3-Hydroxy-4-methoxybenzoic acid(Isovanillic acid). Metal ion chelating capacity exhibited a positive correlation with total phenolic compounds and acetamide, 2-(diethylamino)-N-(2,6-dimethyl-phenyl)-. Nitrite scavenging ability also showed a significant positive correlation with total phenolic, flavonoid compounds, 1,2-Benzenediol(pyrocatechol) and 3-Hydroxy-4-methoxy benzoic acid (Isovanillic acid). And XO (Xanthine oxidase) inhibitory activity showed positive correlation with flavonoids, isovanillic acid and ethyl-3,4-dihydro -xybenzoate.
2) D-allose and ethyl-α-d-gluco-pyrano-side contained in the rice bran have positive correlation with DPPH radical scavenging activity, reducing power, nitrite scavenging and XOD inhibition activity. Vitamin E has positive correlation with xanthine oxidase inhibitory activity and cyclolaudenol and its derivatives have negative correlation with metal ion chelating capacity, nitrite scavenging and XOD inhibitory activity.
3) A result of examining the correlation between the antioxidant activity and bran-containing fatty acids and their derivatives showed that all five antioxidant activity experiments have negative correlation with tetradecanoic acid and ethyl ester. Hexadecanoic acid, 2,3-dihydroxypropyl ester, Hexadecanoic acid, 1,1-dimethylethyl ester, Octadec-9-enoicacid and 9,12-Octadecadienoic acid(Z,Z)-, 2,3-dihydroxypropyl ester showed a significantly negative correlation with DPPH radical scavenging activity, reducing power, nitrite scavenging and XOD inhibitory activity. Saturated fatty acids, hexadecanoic acid (palmitic acid), XOD inhibitory activity, 9,12-Octadecadienoic acid (Z,Z)-, 1-methylethyl ester(isopropyl linoleate),DPPH radical scavenging activity, reducing power and XOD removal capacity showed significant positive correlation.
9. Effects of new colored rice varieties (Superjami, Daeripjami) on obesity and diabetes.
- Effects on glucose metabolism -
1) Comparison of the change in fasting plasma glucose, blood glucose levels were significantly lower in new varieties colored rice "Superjami" and "Daeripjami" from 4 weeks. Daeripjami and Superjami group showed a lower blood glucose level than normal brown rice and Heugjinju after 8 weeks.
2) Plasma insulin was unable to find a significant difference. Liver glycogen content was shown to significantly lower than the HF content, but the difference between the colored rice was not found.
3) GK activity in liver tissue was significantly higher than NC. And G6pase showed the lowest activity in Superjami diet group. PEPCK activity was not significantly different among all colored rice diet group but, all groups were significantly lower than HF group.
- Effects on lipid Metabolism -
1) Dearipjami and Superjami supplement diets reduced the body fat mass in high fat diet. The plasma triglyceride levels in new cultivars Superjami and Daeripjami were significantly decreased from 2 weeks and showed a significant difference in plasma cholesterol levels from 4 weeks.
2) All rice diet groups include Superjami and Daeripjami showed high HDL-cholesterol and also showed significantly higher values in HTR. Plasma free fatty acid was determined by a slightly lower value in Superjami and Daeripjami compared to the HF group but it is was not significant. Also all colored rice diet group showed a higher phospholipid content than HF and BR gorup.
3) Leptin level of the 2 new cultivals diet group showed lower value than HF, HF-BR and HF-HJ group.
4) FAS, G6PD and ME, hepatic fatty acid synthesis enzymes, activities were lower than HF activity. In contrast, CPT activity was increased in Superjami and Daeripjami diet group.
5) FAS and G6PD of adipose tissue showed no significant difference between the groups. ME activity is decreased in HF group. There were no differences in β-oxidation activity but CPT activity was increased in the colored rice varieties.
- Effect of antioxidant metabolism -
1) As a result of the measurement of antioxidant enzyme activity in liver tissue, SOD activity was the lowest in HF and highest in Superjami diet group. CAT activity also showed a slightly higher activity in Daeripjami and Superjami than in NC. Also GR and PON activity was higher in HF-DJ and HF-SJ than other groups.
2) TBARS levels of erythrocyte and plasma in HF-DJ and HF-SJ showed lower level than the other groups.
In conclusion, dietary feeding of Superjami and Daeripjami rice could inhibit the body weight gain, improve the lipid profile, decrease the blood glucose level, and suppress oxidative stress in mice under high fat diet condition through inhibition of hepatic lipogenesis, modulation of adipokine production, and enhancement of the hepatic antioxidant enzymes activities. Compared with its parental cultivars, Heugjinjubyeo and ordinary brown rice, the Superjami and Daeripjami rice showed greater hypolipidemic, hypoglycemic and antioxidative properties. The present study provides the first evidence of the physiological effect of Superjami and Daeripjami, suggesting that this new pigmented rice cultivar may be useful as a biomaterial in the development of functional food for the prevention and management of high fat diet-induced hyperlipidemia, hyperglycemia, and oxidative stress.