Effect of Pleurotus tuberregium sclerotium on chemical, antimicrobial and sensory properties of packaged tomato paste
Tomato (Solanum lycopersicum) is one of the most widely consumed fresh vegetables in the world. Due to its low shelf-life, it is processed into paste with added chemical preservatives. Pleurotus tuberregium (P.t.s) is a good source of bioactive compounds effective against microbial growth, in addition to its load of other nutrients. In this study, the physicochemical, microbial, antioxidant activity and sensory properties of packaged tomato paste supplemented with Pleurotus tuberregium sclerotium flour were investigated using standard methods. The tomato pastes and Pleurotus tuberregium sclerotium flour were mixed in ratios of 100:0, 95:5 and 90:10 after which they were stored in low-density polyethylene and plastic containers at ambient temperature. There was a haphazard decrease in the fungal count of the supplemented samples during storage. A progressive increase in antioxidant activity at different inhibition levels was observed, with the samples packaged in plastic having the highest value at 100mg/ml titration. The DPPH value range obtained for (Day 0), (Day 4) and (Day7) were 4.7 - 49.9%, 50.2 -53.8% and 50.0% - 52.2%, respectively. A slight decrease in vitamins and minerals composition of treated samples as compared to the control was evident after storage period. Moderate addition of 5 to 10% Pleurotus tuberregium sclerotium flour is effective in improving the physicochemical properties, vitamins and minerals content, antioxidant activity, sensory properties and microbial stability of the paste stored in plastic container.
Keywords: Tomato paste, Pleurotus tuberregium sclerotium, low density polyethylene, plastic container, chemical composition