Nutritional and sensory characteristics of tiwul made from different fortified tuber flours

Abstract

Tiwul is a traditional Indonesian food with good functional properties regarding a low glycemic index. However, like other tuber-based products, tiwul also faced nutritional deficiency issues. Therefore, this study aims to optimize the quality of traditional tiwul by modifying the formulation using different tuber flours and adding soybean flour as a fortificant. Three kinds of tuber flour (cassava, sweet potato, and canna) were used as tiwul raw material. These materials were fortified with 10% soybean flour, respectively. Unfortified (native) tuber flours were used as a control treatment. The flours were processed into tiwul with the traditional processing method. The result showed that adding soybean flour as a fortificant of tuber flour significantly improved the nutritional value of tiwul as the end product. Among examined formulations, fortified sweet potato resulted in the highest ash (3.96%), highest protein (8.26%), and lowest carbohydrate (80.23%) of tiwul. The utilization of fortified canna resulted in the highest insoluble fiber (19.01%) of tiwul. Interestingly, the sensory analysis showed that unfortified cassava flour had the highest acceptance for color, taste, and texture of tiwul. This condition indicated that original products still ranked top for local customer preferences.