Title: Slowly digestible starch from heat-moisture treated waxy potato starch: preparation, structural characteristics, and glucose response in mice Authors
|Lee, Chang Joo -|
|Choi, Seung Jun -|
|Moon, Tae Wha -|
Submitted to: Journal of Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 25, 2011
Publication Date: N/A
Interpretive Summary: Starch is the main component of digestible carbohydrates in the human diet. Slowly digestible starch (SDS) is a starch fraction digested completely in the small intestine at a low rate. SDS provides a sustained supply of glucose that may help control and prevent hyperglycemia-related diseases such as diabetes. Depending on the temperature and moisture level of treatment, SDS content can be increased in potato starch due to crystalline disruption. In this study, we established the conditions for the maximal formation of SDS by heat moisture treatment (HMT) on waxy potato starch using statistical optimizing technique, investigated the structural characteristics of the SDS produced, and evaluated the blood glucose levels of mice which consumed it. Maximum SDS production was obtained after 5 h 20 min at 120ºC with a 25.7% moisture level and under the condition waxy potato starch with a 41.8% SDS content was produced. HMT significantly decreased the crystalline structure of waxy potato starch and this affected its digestibility and the blood glucose levels of mice fed it.
Technical Abstract: Heat-moisture treatment (HMT) was optimized to increase the formation of slowly digestible starch (SDS) in waxy potato starch, and the structural and physiological properties of this starch were investigated. A maximum SDS content (41.8%) consistent with the expected value (40.1%) was obtained after 5 h 20 min at 120°C with a 25.7% moisture level. Differential scanning calorimetry of HMT starches showed a broadened gelatinization temperature range and a shift in endothermal transition toward higher temperatures. After HMT, relative crystallinity decreased with moisture level and X-ray diffraction patterns changed from B-type to a combination of B- and A-types. Hollow regions were found in the centers of HMT waxy potato starches. HMT intensity significantly influenced SDS level. This study showed that HMT-induced structural changes in waxy potato starch significantly affected its digestibility and the blood glucose levels of mice who consumed it.