Evaluación del comportamiento y calidad poscosecha de cuatro materiales genéticos de guayabo del país (Acca sellowiana (Berg) Burret)

The feijoa (Acca sellowiana (Berg) Burret) is a species native to Uruguay, which has aroused interest from producers, researchers, and consumers. In this work, the postharvest behavior of four genetic materials was evaluated by analyzing the physicochemical characteristics of the fruits in refrigerated storage and subsequent shelf life. The guavas were harvested before the moment of "touch picking" in 2021 and stored at a temperature of 5° C and 95% RH. Determinations were made at harvest, 7, 14, and 21 days of conservation, and after 7 days of shelf life (18 °C) after each refrigerated storage period. After harvest, the fruits were characterized by weight and diameter ratio. External and internal color, pulp firmness, weight loss, TSS content, and total polyphenols by the Folin method and antioxidant capacity by the DPPH, FRAP, and ABTS methods, were measured at each evaluation time. The ratio of longitudinal and equatorial diameters marked differences in shape and size, where Artillera and LAF1P3 obtained the highest average fruit weights (82 and 87 g, respectively). Artillera showed the highest firmness at harvest time (28.5 N) and the highest TSS contents together with LAF1P3 (12 and 12.5° Brix, respectively). Regarding the epidermis color, no differences were observed at the time of harvest between materials, but there was an appreciable difference with the course of conservation in Artilera and Cerrillana. Weight loss varied between materials and times, with Artillera having the most significant loss (12%). In all cases, losses were more significant in shelf life, reaching up to 14%. The firmness also decreased with storage and was higher in shelf life. The SST decreased with conservation, being higher in LAF1P3 and Cerrillana. Regarding polyphenols, maintenance of the values ​​was observed. In F1P7, the highest values ​​were obtained on average (120 meq AG/100 g PF). The CAT maintenance of values ​​during the storage period without differences between materials. LAF1P3 and Cerrillana were highlighted by DPPH (1,200 and 1,000 meq Trolox/100 g PF), LMF1P7 and Artillera by FRAP (1,000 and 800 meq Trolox/100 g PF), and LMF1P7 (2,200 meq Trolox/100 g PF) by the method of ABTS. A decrease was observed in the L* parameter except in the LAF1P3 material, while differences were observed throughout the refrigerated storage in the a* and b* parameters. The LAF1P3 and Artillera materials are good alternatives for selling fresh fruit. The LMF1P7 material stood out for its content of polyphenols and CAT, while 154 had a general behavior in conservation, superior to the rest.