Chemical and sensory evaluations of energy bar made from purple sweet potatoes and tapioca flour with the addition of Sidempuan salak fruit

Sidempuan salak is a local fruit originating from South Tapanuli, North Sumatra. This fruit has a unique taste of sweet, sour and slightly astringent. This fruit can be consumed fresh or processed into several products, such as flour, drinks and sweets. This study aimed to develop a food-based energy bar from Sidempuan salak fruit (Salacca sumatrana (Becc.)). Energy bar formulation was done by blending purple sweet potato flour, tapioca flour, glucose syrup, egg albumen, coconut oil, salt, and dried salak fruit powder at 0 g as the control, 100 g (bar 1), 150 g (bar 2) and 200 g (bar 3). The chemical characteristic analysis showed that the control energy bars (CEB) per 100 g consisted of 63.17 g of carbohydrates, 1.95 g of protein, 13.42 g of fat, 6.40 mg of vitamin C, 248.05 mg of potassium and 381.24 kcal. Energy bar salak 1 (EBS1) had 377.44 kcal with a composition of 68.34 g carbohydrates, 1.71 g protein, 10.81 g fat, 8.00 mg vitamin C and 347.05 mg potassium. Energy bar salak 2 (EBS2) contained 375.49 kcal with 71.48 g carbohydrate, 1.84 g protein, 9.12 g fat, 5.77 mg vitamin C and 368.42 mg potassium. Energy bar salak 3 (EBS3) showed 369.40 kcal with 74.54 g carbohydrates, 1.92 g protein, 7.07 g fat, 9.96 mg vitamin C and 410.24 mg potassium. Based on sensory evaluation, the untrained panellists indicated that ESB3 was the most preferred, even though EBS1 and EBS2 were also very much acceptable. In conclusion, energy bars containing salak (EBS1, EBS2, EBS3) were lower in calories than the control energy bars due to the lower addition of flour. From the data obtained, salak has a good potential to be used as an additional ingredient to develop energy bars.