Efeito da secagem do bagaço de maçã na extração de compostos fenólicos e sua influência na composição aromática de bebida fermentada

Abstract

The apple (Malus domestica) is one of the most widely known and consumed fruits globally, rich in vitamins, fiber, and bioactive compounds such as phenolics. These compounds provide various health benefits, can enhance the shelf life of food and beverages, and influence sensory characteristics such as aroma, color, and flavor. Among the diverse apple-derived products, apple juice retains some of the fruit’s nutritional properties and helps combat free radicals, contributing, for example, to cardiovascular health. Another important product is cider, a fermented beverage made from apple juice or must, whose aroma plays a key role in determining its quality, identity, and consumer acceptance. During the production of apples juice and cider, a significant amount of pomace is generated. Although commonly discarded, this by-product is rich in phenolic compounds with potential applications in the aromatic enhancement of beverages. To better utilize these compounds, drying the pomace is an essential step, as it ensures microbiological stability and facilitates the extraction of bioactive compounds. This study began with a comprehensive literature review, collecting relevant data on apples, phenolic compounds, the use of apple by-products and their industrial applications, as well as drying techniques and beverage aromas. In order to maximize the utility of apple pomace, three drying techniques were evaluated: freeze-drying, microwave drying, and hot-air oven drying. Freeze-drying was the most effective in preserving phenolic compounds and antioxidant capacity, despite being time-consuming. Microwave drying, on the other hand, offered a balance between speed and preservation of the compounds, while oven drying resulted in greater degradation of the phenolic content. Phenolic extracts obtained from freeze-dried pomace were added to beverages to assess their influence on fermentation and the formation of aromatic compounds. An artificial must formulation was used to allow controlled analysis of how these compounds effect the development of volatile compounds in cider. The results indicated that both musts and ciders enriched with phenolic extracts exhibited positive changes in their volatile profile, with yeasts interacting with the added compounds, thus altering the aromatic characteristics of the final beverage. The addition of the extracts also influenced the fermentation kinetics, bioactive properties, and volatile compound formation, resulting in more efficient fermentation and the preservation of antioxidant activity, although some phenolic and aromatic compounds were reduced throughout the process. Sensory analysis of the cider made from apple must revealed distinct aromatic profiles, ranging from an intense apple aroma in the cider with added chlorogenic acid to a milder aroma, but with a greater addition of phenolic extract. Among the tested formulations, the cider with 25% phenolic compounds stood out for its balance and aromatic intensity. These findings demonstrate that incorporating phenolic compounds extracted from apple pomace can enhance both the sensory and functional qualities of fermented beverages, offering health benefits and contributing to a more complex aromatic profile. These results demonstrate that the addition of phenolic compounds extracted from pomace can enhance the sensory and functional quality of beverages, providing health benefits and promoting a more complex aromatic profile. Furthermore, the use of these extracts supports the valorization of agro-industrial by-products, fostering sustainable and innovative practices in the fermented beverage sector.