Variabilité du contenu en lova statine durant la production et la conservation de pleurotus ostreatus et évaluation de son activite hypocholesterolemiante

Abstract

The increase in the production of edible mushrooms is important because they are considered as foods with high protein content and several medicinal properties including their cholesterol-lowering activities. Among edible mushrooms, Pleurotus ostreatus is the second most commercialized in the world. However, it has been shown that the different substrates used in its culture have an impact on its functional and organoleptic properties. Also, its nutrient and bioactive content are affected by current preservation techniques (drying, cooling and canning). This work was carried out to determine the effect of different growth substrates and preservation methods on the hypocholesterolemic activity of Pleurotus ostreatus. To do this, the culture of Pleurotus ostreatus was done on maize and sorghum grains to obtain pure mycelium and on maize cobs and rice hulls for fruiting and obtaining carpophores. At the end of the production of the mushrooms, some macroscopic parameters and the concentration of lovastatin were determined. The production protocol that gave the best lovastatin concentration was adopted. The mushrooms from this protocol were used for further work where the effect of drying and canning on lovastatin and the stability of the mushroom was evaluated over 20 months. Subsequently, the cholesterol-lowering activity of Pleurotus ostreatus was evaluated in rats following a preventive and curative approach after induction of hypercholesterolemia by a high-fat diet. The results showed that the best production yields (532.1 g/bundle) were obtained with the mushrooms produced on the corn cobs/rice hulls mixture combined with the seeds obtained on corn seeds while the mushrooms produced on the corn cobs with the seeds obtained on corn seeds presented the best lovastatin concentrations (676.2 μg/g). Oven drying at 80°C and appertization at 110 and 121°C resulted in a 45.4%, 52.2%, and 48.9% reduction in lovastatin content, respectively. Daily administration of Pleurotus ostreatus at the dose of 0.67 mg/kg body weight resulted in weight loss in rats and a significant reduction in LDL cholesterol (79.1-4.7 mg/dL) concentrations similar to that obtained using the standard lovastatin (65.6-26.3 mg/dL). The adopted production protocol, solar drying, oven drying at less than 80°C, and appertizing at 100°C can ensure the use of Pleurotus ostreatus as a functional food.