Antioxidant activity, anthocyanins and organic acids content of grape juices produced in Southwest of Minas Gerais, Brazil

Abstract

Phenolic compounds and anthocyanins content in grape juices varies in the cultivar, ripening and climate characteristics. The objective of this work was to characterize and evaluate antioxidant activity of grape juices produced in southwestern Minas Gerais. Grapes were harvested, sanitized and the juices from cultivars 'Bordô', 'Isabel Precoce', 'BRS Violeta' and 'BRS Rúbea' were produced in artisanal equipment by steam extraction and stored for 120 days. The following analyzes were performed during storage: color (L *), pH, soluble solids, titratable acidity, anthocyanins, antioxidant activity (DPPH and β-caroteno/linoleic acid), total phenolics, vitamin C and organic acids. Among the cultivars evaluated, the consumption of grape juice from cultivar 'BRS Violeta' is suggested due to its higher content of vitamin C, antioxidant activity, total phenolics, anthocyanins, and also due to a better physicochemical characteristic showed, when compared to the juices of the other cultivars.Index terms: Vitis labrusca, phenolics, vitamin C, organic acids. RESUMOO teor de compostos fenólicos e antocianinas em sucos de uva varia de acordo com a cultivar, maturidade e características climáticas. Neste trabalho, objetivou-se a caracterização e a avaliação da atividade antioxidante de sucos de uvas americanas produzidas no sudoeste de Minas Gerais. As uvas foram colhidas, sanitizadas, sendo as grainhas e demais partes dos cachos descartadas. Então, os sucos das cultivares Bordô (Vitis labrusca), Isabel Precoce (Vitis labrusca), BRS Violeta (híbrida) e BRS Rúbea (híbrida) foram produzidos em equipamento artesanal por extração em vapor de água, acondicionados em frascos de vidro e armazenados a 18ºC±2ºC por 120 dias. As seguintes análises foram realizadas ao longo do armazenamento: cor (L*), pH, sólidos solúveis totais, acidez titulável, , antocianinas, atividade antioxidante (DPPH e β-caroteno/ácido linoléico), fenólicos totais, vitamina C e ácidos orgânicos. Entre as cultivares avaliadas, sugere-se o consumo do suco de uva da cultivar BRS Violeta, pelos maiores valores de vitamina C, atividade antioxidante, fenólicos totais, antocianinas, além de apresentar melhores características físico-químicas quando comparada ao suco das demais cultivares. Termos para indexação:Vitis labrusca, fenólicos, vitamina C, ácidos orgânicos.

Bioactive Properties of Different Parts of Vitis labrusca L. Fruit

“…Studies have shown an inverse relationship between agerelated diseases and fruit and vegetable consumption due to antioxidants and especially phenolics in fruits and vegetables (Boas et al, 2014).…”

Efektifitas Frekuensi Ekstraksi Serta Pengaruh Suhu dan Cahaya Terhadap Antosianin dan Daya Antioksidan Ekstrak Kelopak Rosella (Hibiscus sabdariffa L.)

“…. Antosianin adalah pigmen larut dalam air (Delgado-Vargas et al, 2003;Boas, 2014), selanjutnya Delgado-Vargas (2003) juga menyebutkan bahwa antosianin besifat vakoular yang berada dalam sel epidermis pada bunga tetapi juga terdapat dalam sel mesofil yaitu pada daun gandum (Secale cereale) dan dapat ditemukan dalam kelopak rosela yang dapat menyebabkan warna merah keunguan. Senyawa utama yang ditemukan dalam kelopak rosela adalah asam organik, terutama asam sitrat, asam malat, dan antosianin, juga ditemukan flavonoid dan glikosida, serta serat (Ali et al, 2005;Sayago-Ayerdi et al, 2007).…”

“…Antosianin biasa digunakan dalam industri makanan sebagai bahan antioksidan dan pengganti pewarna sintetis karena warnanya yang cerah dan menarik serta kelarutan yang tinggi dalam air, sehingga memungkinkan untuk diaplikasikan ke dalam sistem pangan (Castaneda-Ovando et al, 2009;Cissé, 2012;Boas, 2014;Inggrid et al, 2017). Selain warna merahnya yang menarik, antosianin terasa asam dan menyegarkan.…”