Compostos fenólicos de maçãs comerciais, polinizadoras e silvestres como agentes antibacterianos e antioxidantes em alimentos

Abstract

Apples and apple pomace (by-product generated during juice and must processing) present a wide range of phenolic compounds, which are investigated for numerous actions, including antioxidant, anti-glycemic and antibacterial activity. The objective of this study was to evaluate the properties mentioned above in cultivars of commercial, pollinating and wild apples (fruit and pomace) for future application in food. The extraction of phenolic compounds with antibacterial activity in apple pomace was optimized using different extraction solvents (ethanol, acetone and methanol), was optimized using Box-Behnken design. Acetone showed the highest extraction of individual phenolic compounds and the highest percentage of inhibition for the bacterial strains tested: Staphylococcus aureus (ATCC 25923 and ATCC 6538), Salmonella enterica sub enterica (ATCC 13076) and Escherichia coli (ATCC 25922). Chemical hydrolysis method for extraction of bound phenolic compounds in apple pomace from Gala, Fuji, Red Delicious and Granny Smith cultivars to evaluate individual phenolic compounds (HPLC), antioxidant (FRAP, ABTS, DPPH) and antibacterial activity. (micro dilution in broth) under Escherichia coli (ATCC 25922); Staphylococcus aureus (ATCC 25923) and Salmonella enterica spp enterica (ATCC 13076) strains. Fruit and pomace of 34 apple cultivars were analyzed to verify the antioxidant and antibacterial activity, correlating with the phenolic compounds present in the samples. The antiglycemic activity was analyzed in commercial cultivars. Among all the cultivars analyzed, the wild ones were those that presented higher levels of total phenols and flavonoids, as well as greater antioxidant and antibacterial activity, both in fruit and in pomace. However, none of the samples had a bactericidal effect. Apples demonstrated greater inhibitory activity of α-glycosidase in relation to its respective pomace. The results obtained allow us to conclude that both the fruit and the pomace of the wild cultivars present potential for application in foods, being able to act as possible antioxidant and natural antibacterials. Thus, Malus platicarpa wild apple pomace, added in pork hamburger, in proportions of 0.2 and the 2 % (w/w), aiming at antioxidant and antibacterial action under Escherichia coli strain (ATCC 25922). and enumeration of total mesophiles. The pomace incorporation promoted stability of the oxidative and antimicrobial process, under conditions and storage days analyzed. Based on the results obtained, this study provides relevant information that may contribute to the use of apples and/or apple pomace as a raw material for the use of phenolic compounds such as antioxidants, antibacterial and antiglycemic agents, that can be used in the food industry in the future.