Desenvolvimento de revestimento à base de concentrado protéico de soro de leite e óleo essencial de erva doce e sua eficiência na vida pós-colheita de mamão "Golden"

Abstract

Papaya (Carica papaya L.) is a climacteric fruit, has high transpiration rates and due to the intense metabolism during ripening, senesce quickly, making it difficult to store for long periods and consequently generating high rates of post harvest losses, which may be aggravated by the action of Colletotrichum gloeosporioides. In view of extending the useful life of the papaya'Golden' this study aimed to develop a coating using a combination of protein whey concentrate (WPC), essential oil of fennel (OED), calcium chloride (CC) and glycerol (G). Evaluations were carried out in vitro effect of different concentrations of OED reduction in mycelial growth of C. gloesporioides as were tested in vitro fungitoxic capacity of the O ED. Using the two most efficient concentrations of OED togethe r with different concentrations of WPC (10, 12, 14%), DC (1%) and G (5%) were formulated nine coatings, which have had their stability evaluated using the analysis contact angle, average particle diameter, zeta potential and microscopy. Possession of the most promising coatings were started three experiments in parallel. In the first, papayas artificially inoculated with C. gloesporiodes were submitted to coatings, to assess the incidence and severity of the pathogen. The second and third experiments, sound papayas were coated and subjected to analysis of survival and quality respectively. In vitro tests showed a positive potential in use of the fennel oil on mycelial growth of the fungus C. gloesporioides with minimal inhibitory concentration (MIC) and mini mum fungicidal concentration of 2000 ppm. The set of analyzes used to assess the stability of the formulated coatings indicated that those containing a lower percentage of WPC (10%) and the OED higher concentrations (0.2% and 0.4%) provided the formation of more stable coatings. In the experiment using papayas inoculated with C. gloeosporioides, we observed a lower incidence and severity of disease in non - inoculated points of the coated papayas Coatings tested in survival analysis were able to slow the ripening process of papayas, and the treatment consists of: 10% of CPSL, 0.4% O ED, 1% and 5% CC G was the most effective in controlling the incidence of C. gloeosporioides and the extension of postharvest life of these fruits.