Optimization of moromi fermentation parameters to nutritional content of oyster mushrooms sauce (Pleurotus spp.) by using response surface methodology

N.T.N Giang,T.V Khai,N.M Thuy

doi:10.26656/fr.2017.5(5).097

Abstract

Oyster mushrooms are used as raw materials for sauce because of their enhanced nutritious and sensory flavour. The study was aimed to select the optimal parameters of moromi fermentation of oyster mushrooms sauce. Optimizing moromi fermentation from oyster mushrooms by response surface method (RSM) was conducted with 3 factors including salt concentration (15-25% w/v), the brine ratio [150-250% (compared to raw materials, v/w)] and fermentation time (50-70 days). The central composite design used for optimizing the effect of salt concentration, amount of brine and fermentation time showed that the parameters were in agreement with the quadratic regression models well with R2 >0.95. Based on the response surface plots, the optimal parameters of moromi fermentation were salt concentration 20% (w/v), brine ratio 190% (compared to raw materials, v/w) and 60 days of fermentation time. In the optimized condition, the chemical composition (reducing sugar, amino protein, total acids) and the bioactive compounds (βglucan, total phenolic, total flavonoid) (per kg of dry matter) of fermentation sauce were 258.94 g, 204.76 g, 99.06 g, 86.57 g, 108.32 mg TAE and 93.78 mg QE, respectively

Highlights

Soy sauce is a widely used product because it is suitable for everyone, especially vegetarians
The sauce is produced by the fermentation method because it does not have 3-monochloropropane-1,2-diol (3-MCPD) which is formed by the combination of amino acids, glycerin and fatty acids at high temperature in the presence of HCl
The scientific basis of the hydrolysis process is the use of amylase and protease produced by Aspergillus oryzae to break down starch into saccharose, maltose, glucose and protein into polypeptides, peptides and amino acids

Summary

Introduction

Soy sauce is a widely used product because it is suitable for everyone, especially vegetarians. There are two main methods to produce soy sauce that are chemical hydrolysis and fermentation. The soy sauce process consisted of an established two-step fermentation method, namely Koji and moromi (Yang et al, 2017) and Aspergillus oryzae is the main fermenting agent in the production of soy sauce (Yokosuka and Sasaki, 1998). The scientific basis of the hydrolysis process is the use of amylase and protease produced by Aspergillus oryzae to break down starch into saccharose, maltose, glucose and protein into polypeptides, peptides and amino acids. Oyster mushrooms are very helpful for vegetarians because of essential amino acids found in animal proteins such as lysine, methionine, tryptophan (Verma et al, 1987). The study was to select the optimal parameters of the moromi fermentation of oyster mushrooms sauce

Methods

Results

Conclusion