Grape juice classification with respect agricultural production system by means of visible spectroscopy chemometrics assisted

Abstract

Grape juice obtained organically is considered to have a higher market value due to the benefits offered to health by not using pesticides and chemical fertilizers, in addition to preserving the environment. It is important to develop an analytical method that enables for the differentiation of the two commercial forms of natural grape juice (organic or conventional) in order to protect the consumers from frauds in its commercialization. In this study, visible spectra combined with chemometric methods were used to discriminate Brazilian grape juices by conventional and organic production systems using a new pH modulation approach to build a more correct classification model based on linear discriminant analysis with variable selection using genetic algorithm. The results showed a hit rate of up to 100 % and 92 % for the training and test sets, respectively. Visible spectroscopy proved to be simple, fast and low-cost instrumentation for evaluating the quality of grape juice.