Transformation of rice bran into single‐cell protein, extracted protein, soluble and insoluble dietary fiber, and minerals

Abstract

BACKGROUND It is evident that, during the conversion of agricultural sidestreams into valuable substances, a complete utilization is necessary for economic reasons. The present study investigated the transformation of defatted rice bran into proteins (single cell and extracted protein), soluble and insoluble dietary fiber, and minerals. RESULTS In a process chain, starch/glucose was enzymatically extracted and converted into single cell protein (Chlorella sorokiniana). Then, rice bran proteins were extracted and partially precipitated. The remaining liquid was ultrafiltered (3 kDa) to obtain a further protein fraction and minerals. The protein fraction contained a considerable amount of soluble dietary fiber. With these steps, around 69% of the rice bran was transformed, resulting in three protein fractions with an average purity of approximately 45% and minerals with a purity of approximately 63%. In a subsequent process, the remaining cake was disintegrated at 95 °C and pH 2. A further 12% of the rice bran could be liquefied. After centrifugation, the supernatant was subjected to ultrafiltration (3 kDa) to obtain soluble dietary fiber in the retentate and minerals in the permeate. However, only around 2% of the rice bran was converted into soluble dietary fiber, whereas the remainder comprised a mixture of minerals and monomeric sugars. CONCLUSION The process chain can be rearranged and optimized especially to increase the output of soluble dietary fiber and proteins as a result of using the digested monomeric sugars for algae cultivation. At the end of the process, 18% of rice bran remained as an insoluble dietary fiber fraction. © 2019 Society of Chemical Industry

Millets: A Nutritional Powerhouse With Anti-cancer Potential

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“…17 For example, Pruksasri et al investigated the transformation of defatted rice bran into SCP via enzymatic treatment. 18 Hideno et al used wet ball milling and hot-pressed water treatment to increase monosaccharide production without reducing crystallinity. 19 Hua et al adopted a new thermal pretreatment method to oxidize the less polar functional groups on the straw surface into more polar functional groups, thereby enhancing the hydrophilicity of the straw to facilitate contact of the enzymes with the biomass.…”

“…For example, Pruksasri et al . investigated the transformation of defatted rice bran into SCP via enzymatic treatment 18 . Hideno et al .…”