Atuação de extratos naturais com efeito antimicrobiano sobre a conservação de pães do tipo integral

Abstract

Nos comentários do painel sensorial observou-se que os extratos foram detectados sensorialmente. Conclusões -Nas concentrações aplicadas nos pães integrais, os extratos não alcançaram todas as características de conservantes naturais para serem considerados substitutos de conservantes químicos. O pão com própolis apresentou maior tempo de armazenamento aceitável do que o pão com mix de OE, corroborando com os resultados dos testes realizados nos extratos e indicando maior potencial antioxidante e antimicrobiano para o extrato de própolis. As três amostras de pães obtiveram boa aceitação sensorial e com potencial para aquisição.Descritores: Óleos essenciais; Própolis; Antimicrobianos; Aditivos alimentares; Pão.MOTA, E. B. F. Performance of natural extracts with antimicrobial effect on the conservation of whole-grain breads. ABSTRACTIntroduction -Essential oils (OE) and propolis have antimicrobial properties, which generate interest in the production of food to replace chemical preservatives, which can cause damage to the body with its frequent exposure. Bread, a food of high consumption in Brazil, generally has chemical preservatives among its ingredients when it is industrialized, even if it is of the integral type. Replacing these additives with natural preservatives becomes a strategy for health promotion. Purpose -Evaluate the preservative action of natural extracts in whole grains. Methods -A mix of OE (thyme, oregano and basil) and an alcoholic extract of propolis were used, which were analyzed for antioxidant and antibacterial activities. These extracts were added to the whole loaves formulation, being macroscopically verified for the appearance of signs of deterioration in two periods of the year and physico-chemically analyzed for pH, water activity (aw), color and instrumental texture during the first , the fourth and the seventh day of storage. A sensorial acceptance test was performed by hedonic scale and by intention of purchase test. Data were analyzed through analysis of variance (ANOVA) and Tukey test. Results -Antioxidant and antibacterial tests revealed lower values of EC50 (amount of antioxidant needed to decrease the concentration of the radical by 50%) and MIC50 (lower concentration of an antimicrobial agent that prevents visible growth of a microorganism by 50%) for propolis. In the period of the year with lower average temperature, the control loaves and with OE mix presented visual deteriorations in the seventh day of storage, whereas in this day no deteriorations in the bread with propolis were observed. The pH and aw measurements of the breads met the standard for these products. The color of the breads presented L * color intervals from 57.11 to 63.50, a * from 0.20 to 1.79 and b * from 22.83 to 25.50 and the maximum shear force variation of 9.1 N to 50.2 N. For the sensorial analysis 103 individuals participated with frequent consumption of breads. The hedonic scale test revealed mean scores ranging from "slightly liked" to "moderately liked". The IA indicated that the control bread was...