Effect of Thermal and Chemical Pre-treatments on Shelf Life and Quality of Egyptian Pomegranate Arils

Document Type : Original Article

Authors

1 National Research Centre

2 Food Technology Department National Research Centre

3 Food Tech. Dep. NRC

Abstract

This investigation was carried out to study the preserving of Egyptian pomegranate aril with different thermal and chemical pre-treatments to increase shelf life and maintain quality of Arils. TSS, pH, acidity, vitamin C, T. Phenol, antioxidant activity color characteristics, microbiological and sensory evaluation were determined for the different thermal and chemical pre-treatments of on Egyptian pomegranate aril for 21 days. All untreated and treated samples were storage at 4 oC for 21 days and the previous parameters were analyzed after zero, 7, 14 and 21 days. Results evidenced that it was found that the Total soluble solids (TSS) content, titratable acidity and pH decreased during storage of pomegranate arils in pre-treated samples through 21 days storage at 4 oC. During successive storage period the Hunter color Lab* value and parameters (L*, a*, b*, ΔE, C*, H* and BI) of arils decreased, showing a decrease in brightness (L*), redness (a*) & yellowness (b*). On 21th day of storage the least microbial count was observed for samples thermal pre-treated with SB and WB, then chemical pre-treated with SO2 and PS. The results showed that the non-enzymatic browning and the concentration of total anthocyanine (TACN) were low in SO2 and PS pre-treatment pomegranate arils samples compared with un-treatment samples. However, all pretreatments did not effect on total phenol contents. The sensory score revealed that there was not much variation in color scores over the storage period. On 21th day of storage highest sensory score was observed for arils treated with SO2 and PS pre-treated pomegranate arils. The present study exposed that the thermal and chemical pre-treatments such as water blanching (WB), steam blanching (SB), sodium metabisulfite (SO2) and potassium sorbate (PS) can be applied for increasing shelf life of pomegranate arils maintaining the functional compounds during storage at 4 oC.

Keywords