Evaluation of the Mycochemical and Proximate Composition of Oyster Mushrooms (Pleurotus ostreatus VAR Florida, (MONT) Singer. and P. pulmonarius (FR) QUEL) Grown on Bark of Gmelina arborea Roxb., Straw of Saccharum officinarum L. and Pods of Delonix regia

Abstract

Mushrooms are fungal fruit-bodies which have over successive years served as suitable source of protein, carbohydrates, minerals and vitamins. The fruit-bodies derive their nutrients from varieties of substrates including agro-wastes. This study was conducted to evaluate the potentials of using the pods of Delonix regia, straws of Saccharum officinarum and bark of Gmelina arborea in the production of nutritionally-rich edible oyster mushrooms, Pleurotus ostreatus and Pleurotus pulmonarius. The experiment was carried out in three replicates in the Department of Plant Science and Biotechnology, Michael Okpara University of Agriculture, Umudike. The results of the investigations were analysed using Analysis of variance (ANOVA), and the means were separated using Least Significant Different (LSD) tool. The result of the myco-chemical analysis shows that fruit-bodies of P. ostreatus var florida, produced in Saccharum officinale straw, yielded the higher alkaloids (3.93±0.010g/100g) than those produced in Gmelina+Delonix (3.84±0.025g/100g) and S. officinale+D. regia , (3.77±0.03g/100g). The trend was the same with Flavonoids, tannins, saponins and phenols from S. officinale, G. aborea + D. regia and S. officinale + D. regia, and D. regia. Pleurotus pulmonarius from the substrates contained low concentration of alkaloids but higher concentration of flavonoids, tannins, saponins and phenols. Generally the substrates yielded fruit-bodies that are rich in protein. However those from S. officinale + D. regia appeared richer in protein (28.44±0.03g/100g). The substrates showed encouraging potentials for use in the production of nutritionally-rich edible P. ostreatus and P. pulmonarius, with S. officinale + D. regia standing out as a more likely preferred substrates. There appears to be a synergism between the substrates of S. officinale and D. regia, since the mean of their individual performance is less than their performance when combined.

Nutritional value and safety of castor bean (Ricinus communis) seeds detoxified in solid-state fermentation by Pleurotus ostreatus

“…Saponin was reduced in 'Ogiri', a locally made condiment from castor seeds (CSF), while CPF has the highest concentration. Research carried out by Okwulehie et al (2018) revealed that Pleurotus ostreatus has a higher content of saponin, which could have led to the high saponin content of CPF. The reduction observed in CSF may be as a result of long boiling time and fermentation.…”

“…Fermented castor seeds (CPF and CSF) had higher alkaloid content than the raw castor seeds. Research carried out by Okwulehie et al (2018) revealed that Pleurotus ostreatus has high alkaloid content, which may probably be responsible for the increase alkaloid concentration of CPF.…”