- 學位論文
乳酸菌發酵之山苦瓜牛奶豆漿與枸杞牛奶豆漿預防動脈粥狀硬化之評估
Atherosclerosis preventing effect assessment of lactic acid bacteria fermented soymilk supplement with Momordica charantia or Lycium chinense Miller
摘要
黃豆為傳統中國飲食中常用之豆科植物，含有豐富的蛋白質及大豆異黃酮。黃豆中之大豆異黃酮主要為與醣基連結之形式，進入人體後可被腸道菌所分解成去醣基化形式以利吸收。本研究所使用之兩株乳酸菌皆具有將金雀素黃酮 (genistein) 之醣基化形式轉化成利於人體吸收之去醣基化形式。山苦瓜為亞洲常見之蔬菜且具有多種藥性。枸杞為常見之中藥材，現今普遍作為保健食品，具有多種對人體有益的功效。本研究使用乳酸菌發酵不同添加物之牛奶豆漿進行預防動脈粥狀硬化之評估。結果顯示，未發酵牛奶豆漿及發酵牛奶豆漿皆具有降低膽固醇的功效，顯示牛奶豆漿本身即具有降膽固醇功效。發酵之後的牛奶豆漿皆具有降低體內脂質過氧化程度能力，顯示牛奶豆漿以乳酸菌發酵之後可以顯著提升抗氧化力。以Lactobacillus paracasei subsp. paracasei NTU 101發酵則能增加由糞便排出的膽固醇量。而 L. plantarum NTU 102 發酵組可降低低密度脂蛋白膽固醇 (low density lipoprotein cholesterol, LDL-C)，並且高密度脂蛋白膽固醇 (high density lipoprotein cholesterol, HDL-C) 不致下降，降低 LDL-C/HDL-C 比值。發酵枸杞牛奶豆漿可降低高膽固醇倉鼠血清中三酸甘油酯、LDL-C、及LDL-C/-HDL-C 比值。發酵山苦瓜牛奶豆漿組可顯著提升抗氧化酵素活性如超氧歧化酶及過氧化氫酶等，以提升血漿總抗氧化力，並減少動脈脂肪斑塊形成。根據本研究結果，添加山苦瓜並以L. plantarum NTU 102 發酵的牛奶豆漿具有較佳預防動脈粥狀硬化的功效。
並列摘要
Soybean, the most important legume in the traditional Chinese diet, was found rich in high-quality protein and isoflavones. Isoflavones were constitutively presented at large quantities in soybean, and existed primarily as glucoside forms. Isoflavone aglycones were extensively degraded, probably by human intestinal bacteria. In this study, two lactic acid bacteria presented the ability of transforming genistin to genistein. Momordica charantia, a common oriental vegetable possesses medicinal activities. Fruits of Lycium chinense were well-known as traditional Chinese herbal medicine, which nowadays widely used as a popular functional food. Its large variety of beneficial effects were found. The objective of this research was to evaluate the effect of fermented soymilk of two local Lactobacillus strains with different subjoinder on preventing atherosclerosis in hyperlipidemic hamsters. Unfermented and fermented soymilk were both resulted in lowering serum cholesterol, indicated that the benefit came from soybean. Fermentation of Lactobacillus species would assist soymilk repress lipid peroxidation via inhibiting lipoxygenase by genstein. The egested cholesterols in stool of hyperlipidemic hamsters were increased by feeding soymilk fermented by L. paracasei subsp. paracasei NTU 101. However, soymilk fermented by L. plantarum NTU 102 was able to maintain high density lipoprotein cholesterol (HDL-C) level and decrease low density lipoprotein cholesterol (LDL-C) level and LDL-C/HDL-C ratio. L. chinense soymilk was the only group which presented the ability to lower serum triglyceride level of hyperlipidemic hamsters. Furthermore, L. chinense soymilk was able to decrease liver cholesterol level, LDL-C level and LDL-C/HDL-C ratio. However, supplementing M. charantia extract into soymilk would result in higher superoxide dismutase and catalase activity. Therefore, adding M. charantia extract to soymilk would increase total antioxidant status level of hyperlipidemic hamsters and decrease aorta lipid plaque formation. L. plantarum NTU 102 fermented M. charantia-soymilk exhibited potent hypolipidemic effect and antioxidant ability, therefore presented more preventing atherosclerosis efficiency.