Characterization of Conventional, Biodynamic, and Organic Purple Grape Juices by Chemical Markers, Antioxidant Capacity, and Instrumental Taste Profile

Abstract

The objectives of this study were to characterize organic, biodynamic, and conventional purple grape juices (n = 31) produced in Europe based on instrumental taste profile, antioxidant activity, and some chemical markers and to propose a multivariate statistical model to analyze their quality and try to classify the samples from the 3 different crop systems. Results were subjected to ANOVA, correlation, and regression analysis, principal component analysis (PCA), hierarchical cluster analysis (HCA), soft independent modeling of class analogy (SIMCA), and partial least-squares discriminant analysis (PLSDA). No statistical significant differences (P > 0.05) were observed among juices from the 3 crop systems. Using PCA and HCA, no clear separation among crop systems was observed, corroborating the ANOVA data. However, PCA showed that the producing region highly affects the chemical composition, electronic tongue parameters, and bioactivity of grape juices. In this sense, when organic and biodynamic were grouped as "nonconventional" juices, SIMCA model was able to discriminate 12 out of 13 organic/biodynamic juices and 17 out of 18 conventional juices, presenting an efficiency of 93.5%, while 11 out of 13 non-conventional and 100% conventional grape juices were correctly classified using PLSDA. The use of electronic tongue and the determination of antioxidant properties and major phenolic compounds have shown to be a quick and accurate analytical approach to assess the quality of grape juices.

Processing methods with heat increases bioactive phenolic compounds and antioxidant activity in grape juices

“…The differences obtained among the studied juices, through the PCA analysis, corroborate with the results obtained in the ANOVA; demonstrating that PCA analysis is a suitable technique for studies related to the quality of grape juices. In a study by Granato, Margraf, et al () were characterized 31 organic, biodynamic, and conventional grape juice samples in relation to bioactive compounds and antioxidant activity, and the separation obtained in the PCA also corroborated with the ANOVA data.…”

“…The bioactive phenolic compounds of grape juice are mainly flavonoids, stilbenes, and phenolic acids (Dutra, De Souza, et al, 2018a;Lima et al, 2014). Several factors exert influence on the phenolic composition of this beverage (Granato, Margraf, Brotzakis, Capuano, & Ruth, 2015b;Margraf et al, 2016) among them, the method of elaboration (Genova, Tosetti, & Tonutti, 2016;Granato et al, 2016;Lima et al, 2015). There are various methods for commercial processing of grape juices, such as cold pressing (CP) and hot pressing (HP).…”

Assessing the impact of ultra‐sonication and thermo‐ultrasound on antioxidant indices and polyphenolic profile of apple‐grape juice blend

“…Apart from this, grapes have been reported to be abundantly consumed by early Roman and Greek civilizations to obtain health‐related benefits. Nutritionally, grapes have plentiful amounts of phytochemicals, vitamins, edible fibers, carbohydrate, and minerals (Granato, Margraf, Brotzakis, Capuano, & Ruth, ). Juices represent important products of fruits and possess plentiful amounts of antioxidant and phytonutrients together with protective nature against diseases.…”

Multidimensional comparative analysis of phenolic compounds in organic juices with high antioxidant capacity

“…Polyphenols are the predominant group of these compounds, a rich source of which are berries such as chokeberry, acai berry, blueberry, blackberry, blackcurrant and also others fruit, e.g. cranberry, elderberry, pomegranate or grapes . The major polyphenols are flavonoids, especially anthocyanins, flavonols (quercetin derivatives) and flavan‐3‐ols.…”