Physical, Chemical and Microbiological Changes in Mango Varieties When Cryopreserved Using Solar Energy

Abstract

Fruits and vegetables are highly perishable living tissues that maintain their metabolic activity even after harvest. This study aimed to monitor the changes of physicochemical and microbiological parameters of two varieties of mango (Valencia and Camerounaise) during conservation in a photovoltaic cold room. The mangoes were stored at 10-12°C with a relative humidity of 80-90% for 3 weeks (Valencia) and 7 weeks (Camerounaise). Mango samples were taken every week for analyses. The physicochemical and microbiological parameters of mangoes were determined using standard methods. Results showed an increase in the reduced sugar content of mangoes (3.12±0.01-4.79±0.02 % for the Valencia variety and 3.01±0.08-6.22±0.02 % for the Camerounaise variety). The water content of the mango remained practically constant (85.42 % to 85.40 %) for the Valencia variety. However, an increase was observed for the Camerounaise variety (86.26±0.00-87.29±0.03 %). The titratable acidity of mangoes decreased (1.07±0.03-0.67±0.01 %) and their Brix level increased (9.8±0.01-16.20±0.01 % for the Valencia variety and 8.00±0.00-13.50±0.14 % for the Camerounaise variety). The maximum relative mass loss observed was 8.25 % for the Camerounaise variety. Regarding the microbiological analyses, the results showed a reduction in total flora and yeast and mold loads during storage. Storage in a solar cold room of fresh mangoes picked at physiological maturity and pretreated in accordance with good hygiene practices, delays the ripening process, inhibits the proliferation of surface microorganisms, preserves the physicochemical characteristics and extends the shelf life of the mangoes. Preserved mangoes are of good quality.