IN-VITRO DIGESTIBILITY AND GLYCEMIC INDEX OF EXTRUDED SNACKS PRODUCED FROM FLOUR BLENDS

Abstract

BACKGROUND AND OBJECTIVES: Extrusion cooking is a promising technology that provides a convenient, inexpensive and efficient manufacturing process to obtained snacks (1). Development of snacks using locally under-utilized crops such as orange fleshed sweet potatoes (OFSP) and Bambara groundnut is crucial for alleviating under-nutrition among the population through food-based approach. Therefore, the study examined the in-vitro digestibility and glycemic index of extruded snacks produced from OFSP and Bambara groundnut protein concentrate. MATERIALS AND METHOD: Raw materials were procured from Kure Ultra-Modern Market, Minna, Niger State. The OFSP was washed, peeled, sliced, surphited by soaking in water containing sodium meta-bisulphite for 30mins, drained and solar dried for 48hrs. The dried OFSP was milled into flour as described by (Olatunde et al.,). The bambara seeds were cleaned and then soaked in distilled water for six hours, at ambient temperature. The soaked bambara seeds were spread on jute bags and allowed to germinate for 48 hours with sprinkling of water at intervals. The germinated bambara seeds were dried using solar drier for 48 hours and then milled. The protein extraction was carried out as described by (Chandi and Sogi), with minor alterations. In-vitro starch digestibility was determined using the method of (Chung et al.,). The analyses were conducted in triplicates and data were subjected to one-way analysis of variance. RESULTS AND DISCUSSION: Table 1 shows all parameters measured were significantly. However, the variation in the in-vitro starch digestibility may be attributed to formation of protein starch complexes that alters starch gelatinization behaviour. The relatively high values of Slow digestible starch (SDS), Resistance starch (RS), Total glucose (TG), may be as a result of the destruction of double helix structure of starch during extrusion. (Kamble et al., 2019) Also, as the protein proportion increases, Resistance starch show a constant decrease. CONCLUSION AND RECOMMENDATİON(S): There were significantly difference in the in-vitro starch digestibility and glycemic index of the flour blends. It is also recommended that the flour blends storage stability should be determine.