Influence of Pepper Additive and Packaging Styles on Nutrient, Fungi and Aflatoxin Compositions of Stored ‘Robo’ (Deffatted Melon Snack)

Abstract

Robo, an indigenous defatted melon snack commonly consumed in Nigeria generates a percentage of rural cash earnings for its producers. However, studies on the possible aflatoxin contamination of this product due to associated fungi and their control using cost effective measures are scarce. This study demonstrates the production of Robo, reports its nutrient composition, effects of pepper additive, packaging styles, and its possible fungi/aflatoxin contamination. Powdered chilli pepper was supplemented to paste of melon seed at different concentrations; 50g (T1), 100g (T2), 150g (T3) and 200g (T4) during Robo production while those with no pepper additive were treated as control. Thereafter, they were packaged in sterile polyethylene bag, plastic container and white paper and stored at 28±2°C for 12 weeks. The nutrient, fungi and aflatoxin compositions of fresh and stored Robo samples were determined. The result showed that paper-stored Robo samples had the highest carbohydrate (20.53±4.91), crude protein (40.96±3.79), ash (7.47±0.89), fibre (8.90±1.47) and pH (6.81±0.55) and least moisture (8.14±0.58) contents. Most dominantly associated fungi with this food are Aspergillus flavus, A. parasiticus, Fusarium oxysporium, Penicillium sp, Candida albicans, A. ustus, A. niger, Trichoderma sp, Rhizopus stolonifers and A. oryzae. The polyethylene bag-stored samples record the highest fungal incidence (88) followed by plastic-stored samples (81) while the paper stored samples had the least (76). Plastic-stored samples had the highest aflatoxin content AFB1 of 1.02±0.19 while the polythene stored samples had the highest AFB2 (0.45±0.31), AFG1 (0.02±0.41) and AFG2 (0.02±0.02) respectively. However, paper-stored samples had the least AFB1 (0.52±0.29), AFB2 (0.34±0.09), AFG1 (0.00±0.10) and AFG2 (0.01±0.04). Interestingly, it was observed that increased concentrations of chilli pepper from T1-T4 resulted in the corresponding decrease in their aflatoxin compositions. In addition pepper addition improved the organoleptic properties of the Robo samples as T2 was generally accepted after twelve weeks of storage. The implications of these findings are discussed.