Effect of snakehead fish (Channa striata) and sweet potato (Ipomoea batatas L.) flour on the nutritional and physical quality of analog rice

Rice is the major staple food in Indonesia, and its consumption remains high, indicating that daily nutrition largely depends on this grain. However, the nutritional profile of rice contains relatively low levels of protein and antioxidants. Therefore, analog rice has emerged as a potential alternative to enhance its nutritional value. This research was conducted to examine the combined effects of snakehead fish and sweet potato flour on nutritional and physical quality of analog rice. Two species of sweet potato flour —orange and purple—were used, each combined with snakehead fish flour at concentrations of 5% and 10% of the total flour used. Mocaf flour was also included as a variable with concentrations for each treatment, namely purple sweet potato flour: snakehead fish flour: mocaf flour (P1 = 55%: 5%: 40%; P2 = 55%: 10%: 35%) and orange sweet potato flour: snakehead fish flour: mocaf flour (O1 = 55%: 5%: 40%; O2 = 55%: 10%: 35%). The result shows that incorporating snakehead fish flour significantly (p < 0.05) increased the protein content of analog rice by approximately 36–44%. However, higher concentrations of snakehead fish led to reductions in swelling power, water absorption capacity, and texture properties of analog rice. Analog rice formulated with purple sweet potato exhibited higher antioxidant activity (IC50: 7101.4–2798.61 mg/L) compared to orange sweet potato flour (IC5017323.46–9955.59 mg/L). Color analysis further indicated that analog rice produced using orange sweet potato flour exhibited higher lightness (L*) and yellowness (b*) values. Hence, the combination of snakehead fish and sweet potato enhanced the nutritional properties of analog rice, particularly in terms of protein content and antioxidant activity.