Maturação, conservação e capacidade antioxidante em goiabas "paluma".

Abstract

The guava stands out by having excelent nutrional and functional quality. However, due to the intense metabolic activity oh this fruit, postharvest care are essential to reducing losses and conservation its quality. In this context, preservation techniques intended to reduce the metabolic rates, kuping the fruit in preclimateric stage for a intended period. The aim of this work was to evaluate the quality and antioxidant capacity of „Paluma‟ guavas, when submitted to modified atmosphere using edible biofilm based for manioc starch, vacuum polyethylene and control (without coating), it was stored at two temperatures (24 °C and 10 °C). The present study was divided in three experiments, where: Experiment I – were evaluated physical, chemical, bioactive compounds and antioxidant capacity of guava „Paluma‟ at different stages of maturation; Experiment II – the effects were compared in guava „Paluma‟ coated for manioc starch 2% and 4% (BFM 2% e 4%), vacuum polyethylene and control (without coating) in the postharvest fruit store at 24 °C for a period of 10 days and refrigerated temperature of 10 °C for a period of 24 days; Experiment III – were indentified the bioactive compounds and antioxidant capacity of the two best treatments evaluated in the Experiment II (treatments with BFM 2% and vacuum polyethylene stored at 10 °C). The experiments were performed at the Laboratory Technology Products of Plant Origin of UFCG/CCTA/UATA, Campus Pombal – PB. For three experiments, was carried out in complete randomized design. In relation to the first experiment, the effect of the treatments was evaluated through of analysis of variance and comparison of average was done by Tukey test at 5 % probability. For the second experiment, the design was established in a factorial 4 x 6 (4 treatments and modified atmosphere periods of 6 reviews) to 24 °C and 4 x 7 (4 treatments modified atmosphere and periods of 7 reviews) to 10 °C, with three replicates of two fruits/portion. Temperatures were evaluated independent of the applied treatments. From the results of preliminary analyzes of variance, the results were subjected to polynomial regression. Compared to Experiment III was established in a factorial 2 x 7 (first factor corresponds to the two treatments and the second factor corresponds to the evaluation periods), with three replicates of two fruits/portion. From the results of preliminary analyzes of variance, the results were subjected to polynomial regression. The stage IV (predominantly green with yellow pigmentation traits) gathered the best characteristics physical and chemical for postharvest conservation, however stage III (early yellow pigmentation) was recommended for the best the marketing, mainly, targeting distant markets. The guava 'Paluma' showed satisfactory levels for ascorbic acid, carotenoids and phenolic compounds, being potential sources of bioactive compounds for human diet and excellent antioxidant capacity. Modified atmospheres (vacuum and polyethylene biofilm manioc starch 2%) associated with refrigerated temperature preserved the quality and integrity of the fruit, keeping them turgid, attractive appearance for a longer period. 'Paluma' guava has powerful high antioxidant and can be classified, mainly, on the peel and therefore, the consuming fruit should be made in its totality. The pulp of 'Paluma' coated edible biofilm of manioc starch 2% and under refrigeration showed higher antioxidant activity.