Development of low aflatoxin soycorn milk: optimisation of soybean and sweet corn ratio and its stability during storage

Abstract

A nutritious soycorn milk can be produced by combining soybean and corn. The beverage offers dual nutritional advantages for public health in combating protein and Vitamin A deficiency. However, many studies have shown high level aflatoxin contamination in corn and corn foods. The high content of aflatoxin in food become a public health problem throughout the world. In this research, soybean and sweet corn blend have been used to produce low level aflatoxin soycorn milk. Ratio of soybean and sweet corn affected the physicochemical and sensory properties of the soycorn milk. Ratio of soybean and sweet corn of 70:30 produced soycorn milk with the highest consumer acceptance, total protein of 1.12%, total solid of 11.5%, viscosity of 179.10 cP and colour of 0.60 Orange/4.63 Yellow. Aflatoxin B1 was detected in soycorn milk at a low level of 0.24 ng/ml, while aflatoxin B2, G1 and G2 were not detected by High Performance Liquid Chromatography (HPLC). The aflatoxin content in the soycorn milk was below the maximum limit regulated by European Union and USA Food and Drug Administration. Based on the tolerable daily intake set by WHO, it could be calculated the maximum daily consumption of the soycorn milk to control the aflatoxin exposure concerning public health. Further researches to produce soycorn milk with lower content of aflatoxin, even no aflatoxin, are needed. Bacteria growth was found in the soycorn milk during cold storage in refrigerator, with containing bacteria of 4.07 × 102 cfu/ml after three days. Slightly declining of colloidal stability was found during storage. Efforts to extend the shelf life of the soycorn milk are also needed.