Bruce R Hamaker, Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
J Am Coll Nutr. 2009 Oct;28(5):583-90. doi: 10.1080/07315724.2009.10719790.
With emerging knowledge of the impact of the metabolic quality of glycemic carbohydrates on human health, there is a need for novel carbohydrate ingredients that can be custom-made to deliver controlled amounts of glucose to the body and to test hypotheses on the postprandial metabolic consequences of carbohydrates.
The goal of the present study was to demonstrate the applicability and action of starch-entrapped biopolymer microspheres as customized, novel, slowly digestible carbohydrates to obtain desired glycemic responses.
Starch-entrapped microspheres were developed; and starch digestion and glucose release, subsequent to their cooking (100 degrees C, 20 min) in water, were initially monitored by measuring the rapidly digestible, slowly digestible, and resistant starch fractions using the in vitro Englyst assay. Glycemic and insulinemic responses after consumption of glucose and two different slowly digestible starch microsphere diets were compared using a crossover study in 10 healthy individuals. The mechanism of starch digestion in the microspheres was elucidated from scanning electron microscopic images of the in vitro digested microspheres.
Factors such as biopolymer type and concentration, microsphere size, and starch type were manipulated to obtain starch materials with defined amounts of slowly digestible starch based on in vitro studies. Scanning electron microscopy showed that cooked starch entrapped in the dense biopolymer matrix is digested layer by layer from the outside to the inside of the microsphere. Glycemic and insulinemic responses to microsphere test diets were moderate as compared to a glucose diet, but more important, they showed extended glucose release.
Starch-entrapped microspheres provide a useful tool to study the postprandial metabolic consequences of slowly digestible carbohydrates.
随着人们对血糖碳水化合物代谢质量对人类健康影响的认识不断提高，需要开发新型碳水化合物成分，这些成分可以定制，以向人体提供受控量的葡萄糖，并测试碳水化合物餐后代谢后果的假设。
本研究的目的是展示淀粉包埋生物聚合物微球作为定制的新型缓慢消化碳水化合物的适用性和作用，以获得所需的血糖反应。
开发了淀粉包埋微球；并通过测量体外 Englyst 测定法中的快速消化、缓慢消化和抗性淀粉分数，最初监测淀粉消化和葡萄糖释放，随后在水中进行烹饪（100°C，20 分钟）。使用 10 名健康个体的交叉研究比较了消耗葡萄糖和两种不同缓慢消化淀粉微球饮食后的血糖和胰岛素反应。通过体外消化微球的扫描电子显微镜图像阐明了微球中淀粉消化的机制。
根据体外研究，通过操纵生物聚合物类型和浓度、微球大小和淀粉类型等因素，获得了具有定义量缓慢消化淀粉的淀粉材料。扫描电子显微镜显示，在致密的生物聚合物基质中烹饪的淀粉从微球的外部到内部逐层消化。与葡萄糖饮食相比，微球测试饮食的血糖和胰岛素反应适中，但更重要的是，它们显示出葡萄糖释放的延长。
淀粉包埋微球为研究缓慢消化碳水化合物的餐后代谢后果提供了有用的工具。
