Improving Nutritional Qualities of Tomato Pomace by Pleurotus ostreatus and Phanerochaete chrysosporium Fermentation

Abstract

In this study, it was aimed to improve nutrient quality by fermenting tomato pomace with Pleurotus ostreatus (P. ostreatus) and Phanerochaete chrysosporium (P. chrysosporium). Tomato pomace was incubated for 21 days at optimized conditions of pH (3.50-5.50), temperature (24-28 oC), moisture content (68% w w-1), aeration (0,25 L min-1) and stirring rates (10 rpm). Three samples taken at each incubation time were chemically analyzed. The results indicated that fermentation with P. ostreatus and P. chrysosporium significanly increased ash content by 25 and 21%, crude protein content by 16 and 30%, respectively (P<0.05). Fermentation with P. ostreatus decreased ether extract content from 7.22% to 0.29% at 21th day (P<0.05). However, there was an increase of ether extract content with P. chrysosporium fermentation (from 7.22 to 11.62% at 21 day) (P<0.05). Crude fiber of tomato pomace with P. chrysosporium were reduced by 64% (P<0.05). Both fungal fermentations reduced total reducing sugar content by about 30% (P<0.05). Fermentation with P. ostreatus and P. chrysosporium significantly changed tannin and pectin levels (P<0.05). As a result, fungal fermentation caused to nutritionally enriched tomato pomace with added active compounds, and could be used as functional feed in animal nutrition.