Influence of Maturity Stage and Postharvest Calcium Chloride Treatment on the Quality and Storage Life of Tomatoes (Lycopersicon esculentum, Mill)
The postharvest quality and storage life of tomato fruits harvested at different maturity stages (breaker, pink and light red stage) and dipped in different concentrations of CaCl2 (2 %, 6 % and 0%) for different dip durations (10, 20 and 30 min.) were studied. The experiment was in 3 phases under ambient conditions with average temperature and relative humidity of 26.85oC and 82.75 % respectively. The first phase was preliminary and was carried out to determine the appropriate dip time to start with. The second phase was carried out to determine the best stage of maturity; which involved treating the 3 stages of maturity with different concentrations of CaCl2 (2 %, 6 % and 0 %). The third phase involved the selection of the best stage of maturity in the second phase and dipping it in different concentrations of CaCl2 for different dip durations. The preliminary study results indicated that, dipping for up to 40 minutes was injurious to the fruits skin. Results from the second phase showed that, fruits harvested at the pink stage recorded significantly (P < 0.05) higher amount of titratable acidity and vitamin C after 10 days of storage. All calcium chloride treated fruits showed a significant (P < 0.05) delay in the changes of weight loss, firmness, decay titratable acidity and vitamin C as compared to the control (0%). Third phase results indicated that, tomato fruit dipped in 6 % CaCl2 was more effective than in the 2 % CaCl2 and the 0 % in maintaining quality. Both 20 and 30 minutes dip time were significantly (P < 0.05) effective in maintaining weight loss, firmness, vitamin C content and also extending storage life as compared to the 10 min dip time. Therefore, tomato fruits harvested at the pink stage and dipped in 6 % CaCl2 for 20 better facilitated the extension of storage life and the preservation of quality.
A Thesis Submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology as a partial fulfillment of the Requirement for the Award of Master of Science Degree in Food Science and Technology, March-2014
Maturity stages, Fruit, Tomato, Dip time, Storage life, Postharvest