Nutritional, physicochemical and sensory evaluation of biscuits enriched with Ulva sp. from Gunungkidul coast

Ulva sp. a seaweed commonly found on Gunungkidul coast, had the potential as a source of functional food that contained high antioxidants, protein and dietary fiber. Ulva sp. was developed into biscuits, one of the most popular foods in Indonesia. This study aimed to investigate the physicochemical and sensory evaluation of biscuits enriched with Ulva sp. The nutritional value, antioxidant activity, dietary fiber, texture, color, appearance and sensory evaluation were studied. Ulva sp. was collected from Gunungkidul coast and treated using 5% lime for fishy-smell removal, then dried to produce Ulva sp. powder. The Ulva sp. powder was used for biscuit enrichment with 0% powder (STD), 3% powder (BC3), 5% powder (BC5) and 7% powder (BC7) substitution. Biscuits enriched with Ulva sp. increased the protein, fat, and ash content, while the carbohydrate content decreased (p<0.05). The more Ulva sp. was substituted in biscuits, the higher antioxidant activities and dietary fibers were measured (p<0.05). The crunchiness of BC5 (139.95±28.84 Nmm) was high, and no significant difference with STD (393.05±34.11 Nmm), while the crispiness and the hardness of enriched biscuits were lower than STD. The lightness (L*), redness (a*), and yellowness (b*) of enriched biscuits were lower than STD because the Ulva sp. powder contributed to giving dark-greenish colors. Sensory evaluation showed that BC5 was the most well-liked by the panellist in terms of its appearance, aroma, taste, flavor, texture, aftertaste, and overall (there was no difference with STD). Thus, biscuits enriched with Ulva sp. were confirmed to improve nutritional and physicochemical, and it has sensory evaluation acceptance.