Teores de polifen\uf3is, antocianas, capacidade antioxidante e intensidade de cor em diferentes cultivares e sele\ue7\uf5es de uva para suco.

Os antioxidantes impedem a reação em cadeia provocada pela ação dos radicais livres, trazendo benefícios à saúde humana. Diminuem a oxidação de lipoproteínas de baixa densidade (LDL) e previnem doenças. Os polifenóis, particularmente os flavonóides, têm-se mostrado potentes antioxidantes em ensaios in vitro. Os flavonóides estão presentes na casca e sementes das uvas. As antocianas, pertencente ao grupo dos flavonóides, são responsáveis pela coloração de sucos de uva e de vinhos tintos

OPTIMIZATION OF SOLVENT-FREE GERANYL BUTANOATE PRODUCTION USING NOVOZYME 435 AND HOMEMADE POLYURETHANE IMMOBILIZED NOVOZYME NZL-102-LYO-HQ AS CATALYSTS

This study reports the optimization of geranyl butanoate production by esterification of geraniol and butanoic acid in a solvent-free system using two immobilized lipases as catalyst. The operating conditions that optimized geranyl butanoate production were determined to be 40 °C, a geraniol to butanoic acid molar ratio of 3:1, 150 rpm, 5 wt% of enzyme, and 1 h of reaction, which resulted in a reaction conversion of about 97% for Novozyme 435. When homemade Novozyme NZL-102-LYO-HQ (Cal-B) immobilized in polyurethane foam was used as catalyst, the experimental conditions of an alcohol to acid molar ratio of 5:1, 70 °C, 150 rpm, 5 wt% of enzyme, and 1 h of reaction gave a conversion of 95%. New experimental data on enzymatic esterification of geraniol and butanoic acid for geranyl butanoate production are reported in this work, showing that the technique is promising for overcoming the well-known drawbacks of the chemical-catalyzed route