Micronutrient stability in soy-moringa beverage processing

This work aimed at developing a soy-moringa beverage rich in micronutrients particularly vitamin A and iron from soybean and Moringa oleifera, which could contribute to the daily recommended requirements of these nutrients to children, pregnant and lactating women. Two methods were employed in the course of developing soy-moringa beverage; method 1 (mixing of soymilk and moringa juice) and method 2 (co-grinding of blanched moringa leaves with soymilk) at a content of 10%, 20%, 30%, 40% and 50% moringa. Optimal processing temperature and time for stability of iron and β-carotene were established. Blanching of Moringa oleifera leaves at 100°C for 3 minutes, soybean at 100°C for 5 minutes and pasteurization at 65°C for 20 minutes gave the highest retention of iron and β-carotene. Samples were stored for two weeks in refrigerator at 4 ± 2°C and protein, pH of samples and β-carotene was determined. Proximate composition of method 2 samples was significantly (p < 0.05) higher than method 1 samples. Method 2 was more suitable in processing soy-moringa beverage. Method 2 samples contained significantly (p < 0.05) higher amounts of iron and β-carotene. Results showed that 30% soy-moringa beverage was suitable for providing significant amounts of iron (0.79 mg/100g) and vitamin A in the form of β-carotene (2.24 mg/100g) to children, pregnant and lactating women. During storage pH dropped significantly (p > 0.05) with increase of time but it was within the range at which β-carotene is stable. Further research is required to study bioavailability of vitamin A and iron, rheological properties of the product and to carry out feasibility study for production of the developed beverage at pilot and factory production conditions.