Discerning the proximate composition, anti-oxidative and prebiotic properties of de-oiled meals: Mustard and Rice-bran

The de-oiled meals are the less economically viable counterparts obtained from post oil-extraction process. These de-oiled meals are extremely rich constituents of various nutrients such as carbohydrate, protein, dietary fibre and minerals. However, in addition to the nutrition, it also has a significant content of various anti-nutritional factors that can be removed by simple processing methods. These de-oiled meals are largely discarded and disposed of as waste, leaving only a small portion to be used for feeding animals. The progressively increasing demand for alternative sources of naturally occurring feed stuffs necessitates utilisation of de-oiled meals to its full potential for feeding animals and fishes that are being raised/cultured for commercial objectives. In this paper, we have analysed the nutrient, anti-oxidants, as well as anti-nutritional composition of the two de-oiled meals mustard and rice-bran, followed by evaluation of their prebiotic properties with respect of Lactobacillus acidophilus bacteria. The de-oiled meals were good sources of protein, carbohydrate crude fibre, polyphenols and flavonoid. They were found to contain low amounts of phytates and tannates and demonstrated prebiotic activities comparable to that of commercial inulin. The de-oiled meals also inhibited amylase enzyme activity. The mustard meal had the highest amylase inhibitory activity i.e., 49.75%. Therefore, these edible oil industry wastes have a great potential to serve as a nutrient dense food for animals and their utilisation will help to reduce the burden on environment as well as meet the ensuing demand gap.