Active packaging using Scenedesmus sp. and agar delays maturity and maintains post-harvest quality of 'Paluma' guavas

The use of new technologies is important for the preservation of guava, especially in reaching long-distance markets, being indispensable to associate storage techniques to increase the durability of fresh fruit. We evaluated the efficiency of edible coatings based on agar and Scenedemus sp. on the quality and post-harvest conservation of 'Paluma' guava. The experiment consisted of a randomized design with four replicates. The treatments (T) were composed of mixing concentrations between agar and Scenedesmus sp.: A: (0% + 0%); B: (0% + 0.5%); C: (0% + 1%); D: (0% + 2%); E: (3% + 0%); F: (3% + 0.5%); G: (4% + 0%) and H: (4% + 0.5%) applied by immersion. At the end of 11 days of storage at 10 °C ± 2ºC and 65% ± 5% RH, the fruit was analyzed. There was a significant effect (P < 0.05) of the coating based on Scenedesmus sp. on the brightness (L*) of the peel and pulp of guava, hue (°h) and chromaticity (C*) of the peel, loss of fresh mass, firmness of the pulp, ascorbic acid, titratable acidity, pH, SS/AT ratio, and total sugars. We observed a lower maturation and maintenance of the post-harvest quality of 'Paluma' guava with the active packages corresponding to treatments F and H. This included the maintenance of the indexes L*, C* and h of peel color, retention in the loss of fresh mass, in the firmness and maintenance of organic acids