Fermentation and Drying Effects on Bioactive Compounds, Vitamin Profile and Antioxidant Activity of Tree Tomato–Crayfish Seasoning Cubes

Seasonings are ingredients used to bring out the natural tastes and flavours in food without significantly altering the basic taste and flavour. This study evaluated the effect of fermentation and drying on the bioactive compounds, vitamins and antioxidant activity of seasoning cubes produced from tree tomato fruit and crayfish. Five (5) samples labelled control salted seasoning (CSS), fermented and dried salted seasoning (FDSS), fermented non-salted seasoning (FNSS), fermented and dried non-salted seasoning (FDNSS), and a commercial control seasoning (CCS) were evaluated for their bioactive compounds, vitamins and antioxidant activity. Results indicated enhanced bioactive compounds in fermented samples, with FDNSS recording the highest β-carotene (0.28 μg/100g), total phenols (0.42 mg/100g), and flavonoids (2.15 mg/100g). FDNSS exhibited the highest anthocyanin content, indicating that the fermentation and drying process enhanced these pigments. Vitamin A content ranged from 0.14 mg/100g (CCS) to 3.50 mg/100g (FNSS), Vitamin C from 0.16 mg/100g in FNSS to 0.04 mg/100g in FDSS, vitamin E from 0.06 to 3.989 mg/100g and vitamin B6 from 0.01 to 0.04 mg/100g. Antioxidant activity results showed a significant difference (p<0.05) between the methods and samples evaluated. The results for DPPH ranged from 12.37% to 83.93%. For FRAP, the fermented and dried salted seasonings showed the highest antioxidant activity, where FDSS scored the highest (10.85 µmolFE2+/100g), followed by the FDNSS with a score of 10.04 µmolFE2+/100g. The CCS scored the lowest antioxidant activity for this method with a value of 1.42 µmolFE2+/100g. For the ABTS method, a significant difference (p<0.05) was recorded between the samples. The antioxidant activity ranged from 2.85% in the CCS to 7.32% in the FDSS. The results showed that combined fermentation and drying at moderate temperatures significantly enhanced the functional properties of the formulated seasonings, making them a more suitable natural option to commercial seasonings with synthetic additives.