Comparison on Sterilization Effect and Quality Change of Passion Fruit Pulp Prepared by Different Non-thermal Processing Technologies
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
To evaluate the influences of different non-thermal methods on the sterilization effectiveness and quality of raw fruit and vegetable materials, high hydrostatic pressure (HHP) technology, cold plasma (CP) technology, and irradiation technology were applied to sterilize freshly pressed passion fruit pulp. The results indicated that the three non-thermal treatments could inhibit and kill to certain extents the microorganisms in the pulp (2.15 lg(CFU/g), 2.44 lg(CFU/g), 2.34 lg(CFU/g), respectively). The number of colonies in the pulp was lower than 1 lg (CFU/g) after the treatment at a pressure of 300 MPa and above and the treatment with an irradiation dose of 3 kGy, indicating that both methods had a good sterilizing effect on passion fruit pulp. In order to explore further the effect of HHP treatment on the storage period of fruit pulp, this study also investigated the changes in the microbial contents of fruit pulps with and without a high hydrostatic pressure treatment during the storage at -18 °C for 9 months. The experiments showed that the microbial contents of the passion fruit pulps treated at 500 MPa and 600 MPa were still in compliance with the National Safety Regulation after being stored at -20 °C for 9 months (both<2 lg (CFU/g)). In terms of physico-chemical characteristics, the HHP technology and CP technoldogy coul effectively retain the color (ΔE<2) and flavor (p>0.05) of the fruit pulp, and exerted certain inhibitory effects on the activities of POD and PPO enzymes, although the irradiation treatment could not inactivate the PPO enzyme. In summary, the HHP technology can effectively kill the microbiam colonies in the passion fruit pulp while retaining better the quality of the pulp. Therefore, HHP technology has good commercial application prospects in processing passion fruit pulp.
