Production and nutritional composition of juice powder from oyster mushroom Pleurotus ostreatus (Jacq.) Kummer

Abstract

Background: Mushrooms have been used as functional foods, nutraceuticals and medicines for decades in Asian countries. Because of their vital roles in human health, nutrition, and well-being, they are described as treasures in the wild and have served as food supplements. In regard to their nutritional composition, they are relatively low in total fat, vitamins, minerals, and fiber, but rich in high quality proteins and polyunsaturated fatty acids.

Objective: To determine the nutritional value and proximate analysis of the oyster mushroom Pleurotus ostreatus, formulate mushroom juice powder, and determine its nutritional composition of the powder

Methods: Optimization of the processing condition of the mushroom Pleurotus ostreatus (Jacq.) Kummer was first conducted using four different drying temperatures; 55^oC, 60^oC, 65^oC and 70^oC hourly for  3 hours to determine the best drying temperature. The temperatures at which the juice retained 5-10% moisture were selected for preparation of condensate and analysis because they had the best nutrient composition. Stevia (plant sugar) was used as a sweetener and ginger as the flavor for the formulation of the juice powder. A nutritional composition analysis of the juice powder was also carried out.

Results: The nutritional composition of dried P. ostreatus at the chosen drying temperature (55 ^oC) were (8.71, 9.45, 7.07, 9.38, 51.81 and 13.3 mg/g) for iron, manganese, copper, zinc, magnesium and calcium respectively. Nutritional values Fe, Mn, Cu, Zn, Mg and Ca for the juice powder were 8.96 mg/g, 12.1mg/g, 7.94 mg/g, 11.88 mg/g, 59.0 mg/g and 42.0 mg/g respectively. The vitamin content of initial P. ostreatus raw material were Vitamin B1 (4.99) and B6 (0.74) while for the juice powder B1, B6 and C were 0.78mg/g, 0.035mg/g and 0.21mg/g respectively. Proximate analysis showed that the mushroom contained moisture (11.20±0.47%), fat (0.55±0.07%), protein (39.75±0.53%), fiber (3.30±1.04%), ash (8.65±0.52%) and carbohydrate (36.54±0.50%) while juice powder contained moisture (5.0%), fat (1.0%), protein(27.13%), fiber (16.00±2.52%), ash (2.83±0.12%) and carbohydrate(48.04±2.58%).

Conclusion: This work demonstrated that the nutrient composition of the mushroom improved when formulated into juice powder. The quantity of Zn and Ca significantly increased in the juice powder at p<0.05 and reached the recommended daily dietary allowances and adequate intakes.

Keywords: Pleurotus ostreatus, Juice powder, Nutritional value, formulation