RESUMO
The effect of high hydrostatic pressure (HHP) and the proteolytic fraction P1G10 from papaya latex was studied to find out whether a synergy exists in the growth inhibition of Botrytis cinerea in grape juice, contributing to the improvement of conservation techniques and extending the shelf life and quality of food products. Grape juice (GJ) diluted to 16 °Brix with a water activity (aw) of 0.980 was prepared from a concentrated GJ and used in this study. Results indicated a 92% growth inhibition of B. cinerea when exposed to 1 mg/mL of P1G10 and 250 MPa/4 min of pressure treatment. The proximate composition and antioxidant compounds present in the GJ were not significantly affected after the treatments. Eight phenolic compounds and two flavonoids in GJ were identified and quantified, with values fluctuating between 12.77 ± 0.51 and 240.40 ± 20.9 mg/L in the control sample (0.1 MPa). The phenolic compounds showed a significant decrease after the applied treatments, with the HHP sample having a content of 65.4 ± 6.9 mg GAE/100 mL GJ. In conclusion, a synergistic effect at moderate HHP of 250 MPa/4 min with the addition of P1G10 was observed, and the successful development of a stable and acceptable GJ product was possible.
RESUMO
The aim of this study was to determine the antifungal activity of the proteolytic fraction P1G10 from Vasconcellea cundinamarcencis (ex-Carica candamarcensis) against Botrytis cinerea, the causative agent of pre- and postharvest damaging disease in fruit and vegetables. The survival of B. cinerea at different concentrations of P1G10 showed that 1â¯mg/mL inhibited 50% of mycelium growth after 72â¯h incubation. The kinetic of growth inhibition fits the Weibull distribution function, and the data was confirmed by the IC50 survival assay. The study shows that P1G10 inhibits conidia germination and germ tube elongation of B. cinerea relative to untreated conidia. Hypersensitivity to cell wall-perturbing agents (Calcofluor white and Congo red) was observed in mycelium cells treated with P1G10. In addition, P1G10 exhibited inhibitory effect on the adhesion of conidia, provoked alterations in membrane integrity and induced production of reactive oxygen species accompanied by cellular damage. Our results highlight the effect of P1G10 on mycelium growth, cell wall alterations, membrane integrity and adhesion. P1G10 emerges as promising antifungal to control disease causing agents in the food agroindustry.