Avaliação de bagaço de maçã imobilizado e de diferentes madeiras tratadas com ultrassom na extração fenólica durante o envelhecimento de licor de maçã

Abstract

The development of innovative products from apples and their by-products, such as pomace, adds value to this raw material and its production chain. The objective of this work was to evaluate the suitability of immobilized apple pomace as well as different woods treated with an ultrasonic device during the aging of apple liqueur. Chapter 1 contains data and information regarding the apple agroindustry; State of the art on liqueurs and beverage aging and published review article, addressing main aspects of emerging technologies used in the accelerated aging of alcoholic beverages. In chapter 2, liqueurs were produced, varying the formulation using depectinized apple juice, integral apple juice, pectinolytic enzyme and dehydrated apple pomace, all with a final sugar concentration of 100 g/L and an alcohol content of 20 °GL. All received chips (1 cm3) of untoasted oak wood (5 g/L), for maturation for 120 days. Analyzes of acidity, pH, density, total sugar, individual compound profile, total phenols, antioxidant activity and color parameters were carried out. Sensory analysis was applied using the JAR methodology along with acceptability. The results showed that liqueurs made with despectinized juice presented the highest values of total phenols (191.03 mg EAC/L) and antioxidant activity (1001.32 μmol TE/L by DPPH, 1376.70 by FRAP and 1857.41 by ABTS). The compound gallic acid showed a strong correlation with antioxidant activity, and its origin is wooden cubes. Liqueurs that received pomace in the formulation showed an increase in density due to the incorporation of sugars that were transferred to the liqueurs. The compound 5-HMF was identified and quantified with an amount of approximately 370% more in these liquors, when compared to the others. The liqueurs that received pomace, at the end of the maturation period, showed high luminosity (L* = 96.1) and a light yellow tone (b* = 35.31). The other liqueurs presented colorimetric indices with higher values of a* (0.62 and -1.35) and lower values of h° (h° = 89.92). The action of the ultrasonic device under the wood chips was evidenced with a 3% increase in total phenols and a 5% increase in antioxidant activity when compared to the liquor that received chips without ultrasound. The sensory analysis determined the judges' preference for the liqueur that used integral juice and pectinolytic enzyme in the formulation with 75.8% acceptability in contrast to liqueurs formulated with pomace. In chapter 3, wood chips with different botanical origins were tested: European oak, chestnut and jequitibá to aging apple liqueurs. Analyzes of acidity, pH, density, total sugar, individual compound profile, total phenols, antioxidant activity and color parameters were carried out. The liqueur that received untoasted oak presented the highest results in total phenols (244.62 mg EAC/L) and antioxidant activity (1968.38 μmol TE/L by DPPH, 1999.85 by FRAP and 2605.71 by ABTS) and the liqueur with toasted oak showed greater color intensity (C*=52.37). The highest concentration of gallic acid (2.12 mg/L) contributed to the higher values in antioxidant activity in the untoasted oak liqueur. The compounds furfural, syringic acid, syringaldehyde and coniferaldehyde were detected exclusively in the liqueur that received oak toasted. The vanillin compound presented a 72% higher value when compared to liqueurs that received oak toasted and untoasted. Sensory analysis by multiple comparison resulted in the judges not noticing significant differences between the different types of wood. Finally, formulating the liqueurs with depectinized apple juice and aging using untoasted oak chips pre-treated in an ultrasonic device produces an aged apple liqueur with significant values of total phenols and antioxidant activity.