Effect of Solid-State Fermentation on Phytochemical and Proximate Composition of Millet Bran Meal

Abstract

The majority of a fish farm's overall operating expenses involve costs related to feeds. Commercial feeds are often too expensive for fish farmers. Consequently, farmers do use agricultural by-products and locally available fish feed ingredients to improve pond productivity and minimise cost. This study was aimed at evaluating the effects of solid-state fermentation on phytochemical components and proximate composition of millet bran meal for possible incorporation in fish feed production. Millet bran was collected in three different bowls, ground to powder, and then sieved and fermented using a solid-state fermentation procedure. Each sample was fermented (wet at 10% moisture and kept in a container at ambient temperature) for 24 hours (1 day), 96 hours (4 days), and 168 hours (7 days). Afterwards, the fermented samples were sun-dried for 94 hours (4 days approximately). Quantitative phytochemical screening was carried out on the samples which were analysed for proximate composition. The results revealed that fermenting millet bran for seven days (168hrs) using solid-state fermentation method reduced the alkaloid content from 14.69±1.24 to 10.12±0.16, phytate from 5.73±1.32 to 3.25±0.73, tannins from 6.62±0.53 to 4.62±0.84, oxalate from 17.78±1.65 to 13.82±0.53. However, it increases flavonoids from 11.95±1.82 to 13.08±1.35 and phenols from 23.78±1.65 to 31.71±0.62. The study also elucidates an increase in crude protein from 9.23±0.64 to 19.77±0.53 and a reduction in crude fibre from 7.41±0.52 to 6.02±1.14. This study demonstrates that solid-state fermented millet bran meal can be incorporated as an essential part of feed production.