Effect of Post-harvest Quality Parameters on Ultra-Sonication Treatment ofKhoonphal (Haematocarpus validus) of Meghalaya, North-East India

摘要

Freshly harvested khoonphal (Haematocarpus validus) were surface cleansed with ultrasonic treatment. The process variables i.e., ultrasonic amplitude, treatment time and temperature selected were optimized using response surface methodology (RSM) by three factor three level Box-Behnken design. Horn type ultra-sonicator with a power density of 460 W/cm2 with a constant frequency of 30 Hz was used for all the 17 experiments. Optimum independent variables selected by RSM were ultrasonic amplitude (100%), treatment time (5.10 min) and solvent temperature (25°C). The corresponding optimum values for dependent variables obtained were total plate count (2.94 log CFU/cm2), firmness (66.67 N) and respiration rate (42.32 N). Linear terms for all the dependent variables were found to be significant (p<0.05). Similarly, the interaction terms between ultrasonic amplitude and treatment time had showed significant negative effect on total plate count (p<0.001) and firmness (p<0.05). But significant positive effect was obtained for respiration rate (p<0.100). Therefore, from this study it was concluded that the ultra-sonication was found to be an effective technology in reducing surface microbial load. Hence, this may be used for extending the shelf-life and maintaining the quality of freshly harvested khoonphal, while RSM was proven to be an effective technique in controlling and optimizing the factors responsible for ultrasonic treatment.