Postharvest Quality of 'Prata Anã' Bananas Treated with Microalgae Coating

Aims: Biodegradable technologies comprise an innovative tool in the post-harvest treatment of fruits. They can maintain the food quality without harming consumer health and environment. This study tests the efficiency of microalgae as a coating for bananas of the 'Prata Anã' cultivar.

Study Design: We carried out a completely randomized experimental design with plots subdivided over time.

Place and Duration of Study: The experiment occurred in the Laboratory of Fruit Postharvest Technology of the Federal University of Campina Grande (UFCG), Pombal, Paraíba, Brazil, during 10 days of storage.

Methodology: The following coatings were applied to the banana fruits: 0% (no coating); 2% of Chlorellasp.; 2% of Scenedesmus sp.; and 2% Spirulina platensis. After application of treatments, the fruits were stored at 25 ±2°C and 65 ±5% RH and analysed every two days for 10 days.

Results: The characteristics of bananas differed among treatments at the sixth and eighth days of storage. The colour of bark and pulp showed an increase of the parameter a* and reduction in brightness and hue angle over time. At the sixth day, fruits covered with Chlorella sp. showed 5.89% of mass loss of, firmness of 65.24 N, 0.60% of malic acid, 25.50% of soluble solids, 21.73 SS/TA ratio, and 8.27% of total sugars, showing retardation fruit ripening.

Conclusion: The microalgae Spirulina platensis, Chlorella sp., and Scenedesmus sp. used at 2% in the coating of 'Prata Anã' bananas delayed ripening, maintained pulp firmness, and decreased fresh mass loss, extending fruit conservation to eight days. Untreated fruits ripened fast, lost significant fresh weight, and softened.