Executive Summary : | Starch is the most fundamental energy source for the human diet, and it is widely used as a functional ingredient in food industry applications. Starch is homo α-glucan consisting of only glucose molecules via α-1,4 and α-1,6 linkages, which is a key molecule to initiate various biochemical reactions. The WHO declared that obesity is a serious metabolic disease with type 2 diabetes, and one of the reasons is the high intake of glycemic carbohydrates. These metabolic diseases can be initiated by the rapid increase of post-prandial glycemic response and high stress on the regulatory system of glucose homeostasis. Therefore, research has focused on the limited intake of starchy-based glycemic foods in regular diets to prevent these metabolic errors. However, there is a risk of causing nutritional and physiological imbalances, such as the depletion of essential nutrients. Thus, there is a lot of interest in producing slowly digestible carbohydrates that regulate the postprandial-blood glucose spike with an extended glucose delivery into the body to prevent and/or control the incidence of metabolic disorders. Elephant foot yam (EFY) is an underutilized tuber crop known as the ‘King of Tuber Crops’ due to its high yield of starch. Starch is the basic energy source, and it is widely used in the food industry. However, consuming native starches instantly raises blood glucose levels, which is unfavorable for diabetic and obese peoples. To defeat these limitations, starch has been modified further to improve its use in the food industry. Several practices (physical, chemical, and enzymatic treatments) have been used to prepare the slowly digestible carbohydrates from the starch matrix, and these can be used as a low-calorie ingredient in the formulation of functional foods. In this study, native EFY starch-matrix will be treated with 4,6-α-glucanotransferase to the production of α-limit dextrin. After enzymatic treatment, the α-limit dextrin was isolated and characterized using conventional techniques, including HPSEC, SEM, TG-DSC, XRD, RVA, TPA and FTIR, to determine molecular structure, morphology, thermal properties, crystalline pattern, Viscosity, and Texture profile. Besides, to produce resistant starch, the native EFY starch matrix will be treated with pullulanase, followed by ultrasonication and microwave treatments to enhance the production of resistant starch. After treatments, the resistant starch was isolated and characterized using conventional techniques. To understand the digestibility rate and glycemic response of the α-limit dextrin and resistant starch will be analyzed using in vitro assays. Finally, these samples will be used for the development of functional food. Overall, these slowly digestible α-limit dextrins and resistant starches may utilize as starch alternatives in food formulations, especially for consumers requiring lower insulin response. |