Gaseous ozone and ozonized mist in the control of Escherichia coli on 'Rama Forte' persimmon

This study aimed to evaluate the effectiveness of using two ozone applications (gaseous and mist) as a disinfection method for fresh persimmon. To test these sanitizers, in vitro and in vivo assays were performed, and the Escherichia coli was selected because it is a pathogen that causes foodborne diseases in humans. For in vitro experiments, a plate was inoculated with Escherichia coli strain ATCC 25922 and treated. For in vivo assays, persimmon fruit surface was inoculated with the bacteria and treated. For both assays, it was used 10,15,20,30,40 and 50 μL L-1 of gaseous ozone or ozonized mist for five minutes. The results demonstrated that the gas ozone application significantly reduced the growth of E. coli on the plate surface in vitro at doses of 30, 40 and 50 μL L-1 (with 0.83, 0.89 and 0.95 log CFU mL-1, respectively). The application of ozonized mist showed a significant reduction for 50 μL L-1 (with 1.28 log CFU g-1). And, for the in vivo assays, ozonized mist significantly reduced the number of bacteria on the persimmon surface, with a 1.57 log reduction, which was the largest for 40 μL L-1. Therefore, it is possible to conclude that the ozone application can contribute to the control of microorganisms present on fruit surfaces.

Impact of ripening on the health-promoting components from fruta-do-lobo (Solanum lycocarpum St. Hill)

Fruta-do-lobo (Solanum lycocarpum St. Hill) is an underutilized native fruit commonly found in the Brazilian Cerrado, very known due to the presence of glycoalkaloids. In this work we evaluated the biochemical changes on carbohydrates, phenolic and alkaloids during ripening of fruta-do-lobo using chromatographic and spectrometric techniques. During ripening, we observed an increase in glucose, fructose and sucrose, while oligosaccharides levels varied. Chlorogenic acid isomers represented 80% of the identified phenolic compounds in unripe stage, but they reduced during ripening, resulting in predominance of p-coumaroylquinic acid (peel and pulp) and 1-O-sinapoyl-glucoside (seeds). Statistical analysis shows that the unripe fractions were richer in alkaloids compounds, which were the most important for antioxidant activity. Molecular network analysis summarizes the compound changes during ripening, especially regarding the alkaloid compounds, with a reduction of around 85% of solamargine abundance. These data show that fruta-do-lobo can presents different chemical compositions due their ripening stage providing support for future research aimed to the application of these compounds in glycemia control or uses of their extracts with higher content of alkaloids compounds.