Estabilidade de néctar de ameixa tratado termicamente e armazenado a temperatura ambiente

Abstract

The objective of the present work was to evaluate the physical-chemical, antioxidant and microbiological stability of plum nectar submitted to pasteurization (75 ° C / 5 minutes) and hot filling (90° C / 1 minute) for 45 days storage , Packed in PET packaging and kept at room temperature. The product was evaluated at zero and every 15 days, in three replicates, for the parameters: total acidity, pH and total soluble solids, total phenolic compounds, antioxidant activity by ABTS (2,2-azinobis-3-ethylbenzthiazoline- 6- sulfonated) and FRAP (Antioxidant Power of Reduction of Iron) and total counts of molds and yeasts. At the end of the study, it was possible to verify that the applied thermal treatments did not influence, statistically, the parameters evaluated during the 45 days of storage. The same was not observed for the storage time parameter, since the acidity increased at the end of the experiment and the pH decreased. No significant difference (p> 0.05) was observed for total soluble solids contents. As for total phenolic compounds, there was a significant variation (p <0.05) only in the first fifteen days, with an increase of the same at the end of 45 days compared to the initial time. The antioxidant capacity by the ABTS method decreased steadily whereas by the FRAP method decreased and increased alternately throughout the experiment. Regarding the microbiological evaluation, it was observed that on the 15th day the product already had mold and yeast counts above that allowed by Brazilian legislation. The results showed that the limiting factor on nectar stability was storage time. At the end of storage time, the nectar did not present good microbiological quality, since the total counts of molds and yeasts were higher than allowed by the legislation.