Relationship between the physicochemical properties of starches and the glycemic indices of some Jamaican yams (Dioscorea spp.)

Starch granules from round leaf yellow yam (RY), Lucea yam (LY), white yam (WY), and Chinese yam (CY) grown in Jamaica were isolated and the relationship between starch amylose content, crystallinity, microscopic properties, in vitro digestibility, and the glycemic index (GI) of the tubers was investigated. The results indicate that RY had the highest amylose content (265.30 +/- 0.09 g/kg starch) while CY the lowest (111.44 +/- 0.03 g/kg starch). A corresponding variation in starch digestibility and GI was also observed, as CY which had the highest in vitro digestibility had the highest GI (21.27 +/- 0.01 and 97.42 +/- 0.62%, respectively), while RY, LY, and WY starches with low digestibility had lowest GI. Differences in the crystalline pattern of the different starches were observed, where RY, LY, and WY displayed the type B crystalline pattern while CY had the intermediate crystallite (type C).     

血糖生成指数、血糖负荷与人类疾病

该文介绍血糖指数(GI)和血糖负荷(GL)概念,影响GI、GL测定因素,及高低GI、GL食物对肥胖、糖尿病影响,指出GI、GL意义及应用前景。     

血糖生成指数研究进展

近年来的研究显示,食物血糖生成指数可以控制和影响慢性病的发生、发展,促进人类健康。本文从血糖生成指数的定义、测定方法、影响因素、与人类健康关系和国内外研究现状等方面对其进行展开概述,并展望其未来发展前景。     

Determination of glycemic index for some breads

Glucose-responses and glycemic indices of standard bread, rye bread and mixed bread were studied with 10 healthy subjects. Incremental areas of blood glucose (above fasting levels) were calculated as 81, 58 and 46 mmol/liter×120 min GI values determined as 100, 72, 57 for standard bread, rye bread and mixed bread, respectively. The area under the glucose-response curve and GI value of standard bread were significantly higher than rye bread and mixed bread (p<0.05).     

Food status peculiarities, anthropometric, clinica and biochemical indices at professional sportsmen

Under steady state conditions in 66 athletes involved in weightlifting, bodybuilding, judo and taekwondo have studied features of the metabolic status. Data on matter-of-fact nutrition, body weight content within the inter-competition period, energy exchange, clinical and biochemical indices and physical acceptability indices were analyzed. As a result, the decrease indexes of metabolism at all the sportsmen and high-level caloric value at sportsmen who are engaged in weightlifting, which corresponds their energy expenditures, was revealed.     

A comparison of satiety, glycemic index, and insulinemic index of wheat-derived soft pretzels with or without soy

The consumption of nutrient-poor snack foods in Western diets is thought to be contributing to the increasing prevalence of obesity and diabetes. Soy offers unique potential to provide high quality protein, dietary fiber, and phytochemicals to snack foods to produce a more healthful nutritional profile. In this study, 27.3% of wheat flour was replaced with soy ingredients in a soft pretzel and evaluated for impact on satiety, glycemic index (GI), and insulinemic index (II). We first tested the soy pretzel for consumer acceptability by 51 untrained sensory panelists on a 9-point hedonic scale. Second, in a crossover trial, 20 healthy adults consumed soy and traditional pretzels (1000 kJ or 239 kcal each) after an overnight fast. They reported their levels of satiety on a 10 cm visual analog scale (VAS) for 2 h postprandially. Third, 12 healthy, non-diabetic subjects consumed soy or traditional pretzels (50 ± 2 g available carbohydrates) to determine the GI and II of both products. Blood glucose and insulin responses were monitored for 2 h after consumption and compared to a glucose reference. It was found that a consumer-acceptable soy soft pretzel had a lower mean (±SD) GI than its traditional counterpart: 39.1 (±20.4) for soy and 66.4 (±15.3) for wheat, (p = 0.002). However, soy addition did not statistically affect II (p = 0.15), or satiety (p = 0.91). In conclusion, a nutrient-dense soy pretzel formulation with 27.3% of wheat flour replaced by soy ingredients had attenuated postprandial glycemia without significantly affecting insulinemia or satiety in healthy adults.     

Dietary-resistant starch improves maternal glycemic control in Goto-Kakizaki rat

Scope: Dietary prebiotics show potential in anti‐diabetes. Dietary resistant starch (RS) has a favorable impact on gut hormone profiles, including glucagon‐like peptide‐1 (GLP‐1) consistently released, a potent anti‐diabetic incretin. Also RS reduced body fat and improved glucose tolerance in rats and mice. In the current project, we hypothesize that dietary‐resistant starch can improve insulin sensitivity and pancreatic β cell mass in a type 2 diabetic rat model. Altered gut fermentation and microbiota are the initial mechanisms, and enhancement in serum GLP‐1 is the secondary mechanism. Methods and results: In this study, GK rats were fed an RS diet with 30% RS and an energy control diet. After 10 wk, these rats were mated and went through pregnancy and lactation. At the end of the study, pancreatic β cell mass, insulin sensitivity, pancreatic insulin content, total GLP‐1 levels, cecal short‐chain fatty acid concentrations and butyrate producing bacteria in cecal contents were greatly improved by RS feeding. The offspring of RS‐fed dams showed improved fasting glucose levels and normal growth curves. Conclusion: Dietary RS is potentially of great therapeutic importance in the treatment of diabetes and improvement in outcomes of pregnancy complicated by diabetes.     

马铃薯食物血糖指数与慢性疾病风险

马铃薯含有较多淀粉,被西方国家认为是高血糖指数食物。有流行病学研究提示增加马铃薯食物摄入可能影响慢性疾病风险,而这种作用与其提升膳食整体的血糖指数和血糖负荷有关。本文综述了马铃薯与慢性疾病风险的研究证据,以及影响马铃薯血糖指数的品种和烹调加工方法等因素。