红小豆-粳米混合食物的碳水化合物体外消化速度研究

碳水化合物的消化速度直接影响着淀粉类主食的餐后血糖反应,因此可利用碳水化合物的体外模拟消化预测淀粉类主食品的血糖反应。用胰酶模拟小肠消化测定了几种烹调方法下红豆-粳米混合膳食中碳水化合物的消化速度,并探讨了其中快速消化淀粉(RDS)、慢速消化淀粉(SDS)和抗性淀粉(RS)相对含量的变化,结果表明:高压烹调显著提高了整豆-粳米混合食物的水解率和RDS含量,但豆粉-米混合食物在不同烹调压力下的差异不显著。整豆和大米分别烹调后再混合的食物与豆谷共同烹调食物相比,抗性淀粉的含量较高,且淀粉消化指数较低。红小豆-粳米混合食物的消化速度与精白粳米的消化速度呈显著性差异(p<0.05)。烹调方法对食物中碳水化合物的消化速度有很大影响。血糖调节异常的人群适合在主食原料中添加整豆类食物,以帮助稳定餐后血糖反应。     

食物血糖应答测试方法研究进展

血糖应答是指食物对血糖水平变化的影响，能够反映食物中的碳水化合物在体内的消化代谢状态，因此食物血糖应答的测定对于糖尿病患者的膳食指导以及低血糖生成指数产品的研发过程等均有着非常重要的意义。目前最权威的测试食物血糖应答的方法是人体测试。此外，动物试验和体外消化模型由于具有简便易行、成本较低以及可大量测试食物原料等优势，也逐渐成为研究的热点。本文主要对血糖应答测试的方法包括人体测试、动物试验以及体外消化模型的研究现状进行综述，以期为后续的相关研究提供一定的指导和帮助。     

混合膳食组成对体外消化过程中GI与食物消解的影响

对14种单品食物与8种混合膳食展开了体外消化实验,测定了消化过程中GI的变化过程,研究膳食中不同成分对血糖生成指数的影响,并通过显微镜观察食物在不同消化过程中结构和形貌变化,研究不同成分对食物消解过程的影响。根据食物碳水化合物的含量计算含有50 g碳水化合物的食物量,用50 g葡萄糖作为参照物,利用烧杯或者锥形瓶模拟人体食用食物后在胃部和小肠的4 h消化过程中葡萄糖变化情况。相对于单独的主食来说,加入蔬菜、肉类、蛋类或水果后的混合膳食出现明显的GI下降。研究食物消解过程也发现,混合膳食中米饭的形貌与结构变化会显著慢于单独米饭的外形变化;而挂面的消解趋势与其相反。结果证实了膳食纤维、脂肪和蛋白质会抑制淀粉类食物的消化过程,减缓葡萄糖释放速率。     

淀粉类干豆的血糖反应与消化速度

淀粉类干豆具有较低的血糖指数和消化速度,对于预防和辅助治疗多种慢性疾病,特别是控制血糖和体重具有重要的价值。这种健康作用可能部分被归因为豆类的低血糖指数和缓慢消化速度。本文综述了这方面的研究,并分析了影响淀粉豆类消化速度和血糖反应的因素,包括物理特性、非淀粉多糖和抗营养因素等的影响。     

稻米碳水化合物消化速度影响因素的研究进展

体外模拟碳水化合物消化速度的方法可以很好地预测食物的血糖反应,本文对有关研究的数据加以总结,并分析了影响稻米碳水化合物消化速度的因素,包括稻米的淀粉组成、理化特性以及品种和加工、储藏等方面.     

几种糯性食物的淀粉消化特性

为了研究糯性食物的消化特性,选择大米(Oryza sativa L.)、小米(Setaria italica L.)、大黄米(Panicum miliaceumL.)相对应的糯性和非糯性品种进行体外模拟消化实验,测定鲜热、回热、冷藏样品的体外消化速度,并测定市售糯米制品的淀粉组分。结果表明：糯性品种消化速度显著高于非糯性品种,但粗杂粮的糯性品种消化速度仍然略低于精白大米;圆粒糯米与长粒糯米在冷藏后有明显差异;对于糯性品种来说,再次加热时的消化速度可能比新鲜烹调时更高;糯米加工食品均属于高消化速度食品。结论：无论新鲜烹调或冷藏,糯性淀粉食物消化速度均较快,需要控制血糖者和控制体质量者应谨慎食用。     

加工方法对红小豆碳水化合物消化速度的影响

运用体外模拟消化方法探讨了不同加工方法对红小豆中碳水化合物的消化速度和淀粉组分中快速消化淀粉(RDS)、慢速消化淀粉(SDS)和抗性淀粉(RS)含量的影响。结果表明,烹调压力和颗粒大小对红小豆中淀粉消化率及淀粉组分有较大影响。高压烹调水解率高于常压烹调,烹调前粉碎处理显著提高RDS和淀粉水解指数(SDI),但烹调压力对豆粉的消化速度指标无影响;煮熟的豆在冷藏前后碳水化合物水解率的差异不显著。     

慢消化淀粉的结构基础和机理

葡萄糖是食品营养中重要的能量物质,维持血糖水平的平衡对于正常的生理活动,特别是中枢神经系统的正常运转至关重要。淀粉是食品中葡萄糖的重要来源,但是不同来源的淀粉以及食品加工方式的不同都会影响淀粉的消化性能而导致淀粉具有快消化、慢消化和抗性之不同。近来有关碳水化合物的营养研究表明,快消化淀粉由于其对血糖调节系统的胁迫可以引起许多疾病的发生,而慢消化淀粉则比较温和而有助于疾病的预防。抗性淀粉不能被人体吸收利用,但对于大肠的健康具有重要功能。相对而言,慢消化淀粉的机制以及制作方法还很缺乏了解,本文将侧重慢消化淀粉的结构基础和机理做比较全面的综述,以促进此领域的进一步发展。     

压力烹调对五种食材中淀粉消化性的影响

目的:探讨不同烹调方法对红小豆、莲子、山药片、芡实、薏米5种富含淀粉的保健食材的碳水化合物消化特性的影响,为科学食用传统食材提供依据。方法:体外模拟消化方法测定各时间点的水解率、快消化淀粉、慢消化淀粉和抗性淀粉等指标。结果:压力烹调显著影响样品的水解速率和淀粉类型,水解指数增大,快消化淀粉含量增加,抗性淀粉含量减少。但所有样品的预期血糖负荷均显著低于粳米样品。红小豆和莲子经过压力烹调仍保持低消化速度和低EGL特性。结论:压力烹调对提高难烹煮碳水化合物消化率有利,需要控制血糖的人可以通过选择慢消化食材和烹调参数来控制淀粉类型和EGL的变化。     

香菇β-葡聚糖的提取及其对淀粉消化性的影响

从香菇子实体中提取的香菇β-葡聚糖（Lentinus edodes β-glucan,LEBG）,重均分子质量为1.868×106?Da;其单糖组成为阿拉伯糖、木糖、甘露糖、葡萄糖、半乳糖物质的量之比为0.72∶1.61∶2.61∶92.75∶2.34;通过红外图谱判断其为β-吡喃多糖。分别向小麦淀粉、玉米淀粉添加LEBG,两种淀粉的损耗模量和储能模量均增加,动态流变学揭示了LEBG与淀粉之间有相互作用的存在。体外消化结果显示,与未添加LEBG?相比,添加LEBG的淀粉酶解速率显著降低。这可能是因为LEBG和淀粉之间相互缠绕,凝胶网络结构增强;同时,添加了LEBG的两种淀粉均为较低水平的快速消化淀粉和血糖指数预测值以及较高含量的缓慢消化淀粉和抗性淀粉,说明LEBG对淀粉体外消化具有一定的抑制作用。在可视化实验结果进一步说明LEBG与淀粉相互作用的具体方式为包裹作用。将含有LEBG的香菇超微粉加入淀粉,结果表明超微粉也对淀粉体外消化具有一定抑制效果。该研究表明LEBG可用于研发低血糖指数的淀粉类食品。     

Reducing the glycemic impact of carbohydrates on foods and meals: Strategies for the food industry and consumers with special focus on Asia

Type 2 diabetes is increasingly prevalent in Asia, which can be attributed to a carbohydrate‐rich diet, consisting of foods in the form of grains, for example, rice, or a food product made from flours or isolated starch, for example, noodles. Carbohydrates become a health issue when they are digested and absorbed rapidly (high glycemic index), and more so when they are consumed in large quantities (high glycemic load). The principal strategies of glycemic control should thus aim to reduce the amount of carbohydrate available for digestion, reduce the rate of digestion of the food, reduce the rate of glucose absorption, and increase the rate of glucose removal from blood. From a food perspective, the composition and structure of the food can be modified to reduce the amount of carbohydrates or alter starch digestibility and glucose absorption rates via using different food ingredients and processing methods. From a human perspective, eating behavior and food choices surrounding a meal can also affect glycemic response. This review therefore identifies actionable strategies and opportunities across foods and meals that can be considered by food manufacturers or consumers. They are (a) using alternative ingredients, (b) adding functional ingredients, and (c) changing processing methods and parameters for foods, and optimizing (a) eating behavior, (b) preloading or co‐ingestion of other macronutrients, and (c) meal sequence and history. The effectiveness of a strategy would depend on consumer acceptance, compatibility of the strategy with an existing food product, and whether it is economically or technologically feasible. A combination of two or more strategies is recommended for greater effectiveness and flexibility.     

Increasing the fat content of pancakes augments the digestibility of starch in-vitro

Carbohydrate foods that breakdown rapidly during digestion are known to have the highest glycemic index (GI) values. It is known that lipid-starch complexes can form in foods; however how this may enhance the resistance of starch to enzyme hydrolysis is unknown. The aim of this study was to examine the effect of adding different fats to a carbohydrate rich food on the digestibility of starch in-vitro. Three sets of carbohydrate-lipid emulsion (CLE) batters in the form of pancakes were prepared as 1) low fat (20.3% mass as fat), 2) medium fat (32.7% mass as fat) and 3) high fat (45.1% mass as fat). For each set of CLE a control (containing no added fat), saturated fat (butter), polyunsaturated fat (sunflower oil), monounsaturated fat (olive oil) and medium chain triglyceride saturated fat (MCT oil) was prepared. The CLEs were digested in-vitro and sugars released measured. The results indicated that increasing the concentrations of fat in the CLE augmented sugar release (p < 0.001). The results also showed that there were differences between the different types of fats in the CLE (p < 0.001). The primary differences existed between the control and all the other CLEs, as well as between the MCT CLE and all other CLEs. Correlation analysis showed an inverse relationship between the amount of remnants remaining after digestion and the sugars released from the CLE (p = 0.004 and p = 0.014). This research indicates that adding fat to a carbohydrate food will increase the digestibility of starch and release of sugars from the food which may impact on glycemic response.     

Interactions between Starch,Lipids, and Proteins in Foods: Microstructure Control for Glycemic Response Modulation

In real food, starch is usually forming part of a matrix with lipids and proteins. However, research on this ternary system and interactions between such food components has been scarce so far. The control of food microstructure is crucial to determine the product properties, including sensorial and nutritionals ones. This paper reviews the microstructural principles of interactions between starch, lipids, and proteins in foods as well as their effect on postprandial glycemic response, considering human intrinsic differences on postprandial glycemic responses. Several lines of research support the hypothesis that foods without rapidly digestible starch will not mandatorily generate the lowest postprandial glycemic response, highlighting that the full understanding of food microstructure, which modulates starch digestion, plays a key role on food design from a nutritional viewpoint.     

藜麦石头饼的工艺及消化特性

研究藜麦粉、酵母、棕榈油的添加量对藜麦石头饼感官品质的影响并对其消化特性进行初步的探讨。通过单因素实验和响应面法优化出藜麦石头饼的最优配方,并根据Eylnst的方法研究最优配方藜麦石头饼的淀粉消化特性。结果表明:藜麦石头饼的最优配方是藜麦添加量为14%,酵母添加量为1%,棕榈油的添加量为17%,此时的感官评价得分为83.95,藜麦石头饼的口感最佳。测定其淀粉总含量为38.08 g/100 g,其中快消化淀粉(RDS)占19.25%,较对照组石头饼降低了40.6%,慢消化淀粉(SDS)占18.52%,抗性淀粉(RS)占62.23%,较对照组石头饼分别升高了41.2%和14.3%。通过淀粉水解率的一级动力学拟合方程预测藜麦石头饼的血糖生成指数(GI)为69.95,低于对照石头饼,属于中等血糖生成指数食品。     

Mangiferin nanoparticles fortified dairy beverage as a low glycemic food product: its quality attributes and antioxidant properties

Mangiferin-encapsulated β-lactoglobulin–chitosan (mangiferin/βLG-CS) nanoparticles were fortified in milk to obtain a low glycemic index (GI) food product with high antioxidant capacity. The present study evaluated the bioaccessibility and bioavailability of mangiferin in milk fortified with nanoparticles. Fortification reduced the GI of milk by 34.5%. A mathematical model was developed to evaluate the lactose digestion, in terms of reducing sugar formed in milk by determining the digestion rate (k), and a significant reduction in k was observed. The bioaccessibility of mangiferin was enhanced by fortification. Fortified milk showed good antioxidant, lipid peroxidation inhibition and protein oxidation inhibition properties. Mangiferin nanoparticles fortified dairy beverage as an ideal food product with high antioxidant capacity and can inhibit lipid peroxidation and protein oxidation. It may be used as a low GI food product.     

菊粉改善酥性饼干的品质及降低消化速率

可溶性膳食纤维可以抑制淀粉的水解消化,为研究菊粉对饼干品质的影响,通过均匀设计法优化菊粉饼干的配方工艺,并通过模拟人体胃肠道消化过程研究菊粉对饼干消化的影响。结果表明;最佳配方为低筋粉100 g,水20 g,木糖醇15.05 g,菊粉12.60g,油脂(黄油:玉米油=1:1)31 g,小苏打0.5 g,食盐0.5 g。另外,测得菊粉饼干脂肪含量为16.54%,蛋白质3.33%,膳食纤维6.87%,碳水化合物56.63%。通过体外消化模拟结果表明加入菊粉之后,饼干的快消化淀粉含量从14.51%下降到3.06%,慢消化淀粉和抗性淀粉的含量分别增加了3.67%和0.20%,且菊粉饼干的体外消化率低于空白饼干,预测菊粉饼干血糖指数为68.36,属于中等血糖指数食品。故对于高油脂饼干而言,菊粉可以抑制其淀粉的水解消化,降低其血糖指数,菊粉的应用对于开发中低血糖指数产品具有重要意义。