優化體外消化方法學並據此開發改善代謝症候群之薏仁產品

Abstract

近十年來，由於生活品質提升及生活型態的改變，全球的代謝症候群之盛行率皆有逐年上升的趨勢，而台灣男性罹患代謝症候群之盛行率從13.6%上升至25.5%，女性則從26.4%上升至31.5%，並隨著年齡增長，盛行率亦有增加的趨勢，且罹患代謝症候群會使罹患者罹患第二型糖尿病的風險增加五倍、罹患心血管疾病的風險增加兩倍。目前代謝症候群主要治療方式是透過生活型態的改變，其中尤以飲食最為重要。研究顯示，長期的低GI飲食能改善代謝症候群；而澱粉類的主食中慢性消化澱粉(slowly digestible starch, SDS)便具有低GI的特性，也已有研究證實慢性消化澱粉能有效控制餐後血糖，並降低膽固醇。因澱粉質食品之GI值可透過澱粉體外消化性試驗得知，故此本實驗第一部分為依據國人之體內GI測定，以口腔模擬期之破碎程度、腸模擬期之反應速度及用以模擬腸道分散樣品之玻璃珠加入數目為變因，優化體外之澱粉消化試驗，第二部分則為薏仁即食產品之開發，利用已知具有降血脂、降血糖、降膽固醇等活性的台灣糙薏仁台中選育4號為材料進行擠壓加工，發現當螺旋轉速越低及水份含量越高時，快速消化澱粉含量越高、慢速消化澱粉含量越低，預估升糖指數也就越低，且慢速消化澱粉含量和硬度、膨發率及水溶性指標呈高度相關。

In recent years, better life quality has caused an increase of the global prevalence of metabolic syndrome year by year. In Taiwan, the prevalence of metabolic syndrome (MetS) is 25.5% in males as well as 32.6% in females, and increases with age. MetS has been shown to increase 5-fold risk for diabetes and 2-fold risk for cardiovascular disease. The major treatment for MetS is through lifestyle changes, and diet control is especially important. The long-term effect of low glycemic index (GI) diet has been approved to improve metabolic syndrome. Sowly digestible starch (SDS) exhibits the characteristic of low GI, thus it can attenuate hyperglycemia and hyperinsulinermia after meal to improve metabolic syndrome. In vitro starch digestibility tests are useful for the prediction of GI. Hence, the first aim of this study is to optimize the condition regarding in-vitro digestibility of starch based on the in-vivo GI value. The in-vitro digestibility of starch was optimized by the degree of grinding in the oral phase, the reaction speed in the small intestine phase, and the number of glass balls used to simulate the intestinal dispersal sample. The second aim of this study is to explore the effect of different processing conditions on GI using response surface methodology, and choose the best condition to develop ready-to-eat products with low GI using Taichung number four dehulled adlay, which exhibits some medical properties, such as hypolipidemic, hypoglycemic and cholesterol lowering abilities. In this study, we find as screw speed decreased and feed moisture content increased, RDS contents decreased, SDS contents increased and GI decreased. And the correlation coefficients between SDS and hardness, expansion rate, water solubility index are highly correlated.