Economical substrate formulation for mushroom cultivation and food production of mushroom crackers to reduce postharvest waste

Abstract

Agriculture residues of oil palm waste are a big issue for palm oil producing countries. The residues from oil palm fronds are the most crucial to convert wealth. This study focused on oil palm-related agro biomass for mushroom substrate formulation for grey oyster mushroom cultivation. Mushrooms are a highly perishable vegetable that turn into postharvest waste within 4 to 7 d at normal temperatures. Therefore, in this study, the unsold mushroom was converted as a cracker food product to reduce the postharvest losses, especially for small-scale mushroom growers. The agriculture biomass used for substrate preparation is a combination of oil palm frond (OPF), oil palm empty fruit bunch (EFB), palm pressed fiber (PPF), and sawdust (SD). SD as a commercial substrate was used as a control in this study, and rice bran (RB) and lime (L) were used as supplement ingredients for all the treatments. The treatments were according to mixed formulation with the ratio of T0 (control: 97.2% SD, 0.8% RB + 2% L), T1 as a mixed ratio (60% RS + 22.2% EFB + 15% PPF + 0.8% RB + 2% L) and T2 as a mixed ratio (60% OPF + 22.2% EFB + 15% SD + 0.8% RB + 2% L). The total yield in four cycles showed 1.2 kg in T0 (sawdust), 1.4 kg in T1 (majority of rice straw), and 1.5 kg (majority of oil palm frond) in T3 treated substrate. In this study, the oil palm frond was received free of charge as compared to sawdust and rice straw. Therefore, it showed that using the oil palm frond not only gave a high yield of mushrooms at the same time, it was 100 X lower in cost. Next, the unsold yielded mushrooms were used for cracker preparation. The results obtained from this study indicate that mushroom crackers contain fat (11.34%), protein (2.19%), and carbohydrate (76.55%) while being high in moisture (7.87%) and ash (2.06%) compared to commercial potato crackers. Overall acceptance of sensory evaluation towards mushroom crackers showed a high 'extremely like' percentage, contributing about 66%. Thus, this study found that 66% of participants 'extremely liked' the new innovative mushroom crackers. Overall, the results show that oil palm substrate can be an alternative economical substrate for grey oyster mushroom cultivation and food products from mushrooms will be new items in the snack industry.