Optimized processing method for producing Avocado and Mango seed-based composite flour for functional Foods
Avocado and mango seed kernels are considered as wastes although they are rich in essential nutrients and bioactive compounds for human health. Lack of commercial application, presence of anti-nutrients, difficulty in processing and little information on nutritional and functional values contribute significantly to their underutilization. These factors underscore the need for processing these seeds into consumable products to utilize them as functional foods. The aim of this study was to optimize a processing technique capable of reducing antinutrients to acceptable levels (above 50%), retain nutrients and functional values, and improve sensory qualities of avocado and mango seeds-based composite flour for functional foods. Different processing conditions for probiotic fermentation, boiling and soaking techniques were studied to optimize processing conditions for the seeds. The antinutrients, antioxidant activity, total phenolics and selected nutrients of the seeds were analyzed using standard analytical methods. Furthermore, avocado and mango seeds-based composite flour was formulated using Nutrasheets integrated with the USDA National Nutrient Database for Standard Reference. The formulated composite flour was assessed for safety and quality parameters for a period of 84 days under different storage temperatures. The results showed that all processing techniques significantly (p < 0.05) reduced the antinutrients by over 50% for processed avocado and mango seed kernels. The highest total phenolics and antioxidant activity (IC50) for both seeds were observed at a fermentation temperature of 37oC with Lactobacillus plantarum. Soaking and boiling reduced the analyzed minerals in both avocado and mango seed kernel except for potassium and zinc on soaked mango seeds, whereas probiotic fermentation retained 100 % or increased the concentration of the analyzed minerals, ascorbic acid and α-tocopherol. In contrast, boiling and soaking reduced the contents of ascorbic acid and antioxidant activity of the analyzed samples. The Nutrasheets analysis showed that the formulated composite flour can achieve the nutritional and functional values for the functional foods. The shelf life analysis showed that 115 days (4 months) is the maximum shelf life for the flour where all the assessed safety and quality parameters can still be within the maximum recommended tolerable limits for human consumption. Therefore, the results of this study indicate that unlike boiling and soaking methods, the probiotic fermentation is an optimized processing method which can significantly reduce the antinutrients to acceptable levels, retain nutrients and bioactive compounds, and improved sensory attributes of avocado and mango seeds-based composite flour for functional foods.