Exploitation of Plant-Derived Food Waste for Valuable Products Using Bioprocesses: a Narrative Review

Lim, Grace Rong You (2021) Exploitation of Plant-Derived Food Waste for Valuable Products Using Bioprocesses: a Narrative Review. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

Text Grace Lim Rong You_Full Text.pdf Restricted to Registered users only Download (950kB)

Abstract

Globally, million tonnes of plant-derived food waste are generated annually from various cultivation activities and agro-industrial manufacturing. When food waste decomposes, it releases methane gas that causes global warming. Exploitation of food wastes could help reducing environmental impact and for production of valuable products. The project aims (i) to review the exploitation of plant food wastes for valuable products; (ii) to evaluate different bioprocesses for converting plant-derived food wastes into valuable products. This review studies were conducted by using PubMed, ScienceDirect and NCBI electronic databases; more than 100 publications were screened; and papers of high relevance were selected based on inclusion criteria and keywords. Cereal wastes such as wheat straw, rice bran, brewer’s spent grains, corn cobs; root and tuber wastes; fruits and vegetables pomace contribute the most amounts to the total food waste worldwide. These wastes form good substrates for bioactives production. Various fermentation processes using enzymes, yeast or bacteria were used to convert food waste into valuable products including phenolics, flavonoids, dietary fiber, carotenoids, lignocellulose, phytosterols, tocotrienols, coumaric acid, oryzanol, citrulline, vitamins and essential amino acids. Some highlights of the bioprocesses applied for exploitation of plant-derived food wastes and the optimization of process conditions for maximum production yield were reported. In the production of xylitol from corn cobs using yeast (Debaryomyces hansenii), a higher yield (0.216 g-xylitol/g-xylose) was obtained through enzyme hydrolysate fermentation compared to that from acid hydrolysate fermentation (0.100 g-xylitol/g-xylose). In the production of fungal chitosan from food waste using solid-state fermentation, yield of chitosan was more than 3 folds higher (34.4g/kg substrate) when using soybean meals as substrate and Mucor rouxii as fermenting microorganism, as compared to chitosan yield (10.8g/kg substrate) when using potato peels as substrate and Rhizopus oryzae as fermenting microorganism. In summary, plant-derived food waste can be converted to valuable lignocellulosic materials and health-promoting bioactive compounds through various bioprocesses. Different bioprocesses and its optimization for improved yields were evaluated. Exploitation of plant-derived food waste for valuable products have positive implication on environment, public health and economic gain.