Effect of hydrothermal processing on the proximate composition and organoleptic characteristics of dehulled Moringa oleifera seeds

Abstract

Purpose – This paper aims to investigate the effect of hydrothermal treatment by conventional, microwave and pressure cooking on the cooking properties, proximate composition and organoleptic characteristics of dehulled Moringa oleifera seeds. Design/methodology/approach – Samples of Moringa oleifera seeds were subjected to cooking for the minimum time by each of the methods under study. Cooking properties, proximate composition and organoleptic characteristics were determined following standard analytical procedures. Findings – The results showed that the average cooking time were 25, 30 and 40 mins for conventionally, pressure- and microwave-cooked moringa kernels, respectively. There was no significant difference in cooking weight, moisture absorbed and water uptake ratio of conventionally and pressure-cooked samples. The protein content of moringa kernel reduced from 41.9 for raw kernels to 40.2, 41.2 and 36.9 per cent for conventionally, pressure- and microwave-cooked samples, respectively. Pressure and microwave cooking indicated 40.1 and 39.3 g/100g of crude fat, whereas raw kernels indicated 37.1 g/100g. Conventionally and pressure-cooked kernels had lower fibre content than the raw kernels, but there was no significant difference in the ash contents of the samples. Cooking influenced the proximate composition and colour of moringa kernels. Microwave cooking indicated higher values of cookability than other cooking methods considered in this study, but no significant difference was observed in the organoleptic characteristics of moringa kernels due to the cooking methods. Practical implications – Given the high protein and vital nutrients content which are seldom found in daily diets, moringa kernels may be considered by processors of edible nuts and kernels for food-based applications such as cooked, roasted, mixed or spiced kernels. Originality/value – This work is perhaps the first to document moringa seeds processing by hydrothermal treatment.