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Headspace fingerprinting and sensory evaluation to discriminate between traditional and alternative pasteurization of watermelon juice

Aganovic, Kemal, Grauwet, Tara, Siemer, Claudia, Toepfl, Stefan, Heinz, Volker, Hendrickx, Marc, Van Loey, Ann
European food research & technology 2016 v.242 no.5 pp. 787-803
Maillard reaction, beta oxidation, food research, headspace analysis, high pressure treatment, juice quality, juices, lycopene, pasteurization, pulsed electric fields, sensory evaluation, shelf life, watermelons
The watermelon juice was processed by thermal and large-scale alternative pasteurization technologies, pulsed electric fields (PEF) and high pressure processing (HPP). The watermelon juice was compared and evaluated immediately after the treatment as well as a function of shelf-life. As a basis for the comparison, microbial inactivation was chosen. The watermelon juice quality evaluation was performed by a multivariate quality comparison (headspace fingerprinting), studying volatile fractions of the juice. Control and pasteurized juice was evaluated in terms of sensory at the beginning and the end of the shelf-life. Most of the selected markers in control juice were lower in concentration compared to processed classes. Majority of the compounds detected in higher concentration after processing were C6–C9 carbonyls. Their formation is linked to oxidation of fatty acids. Few degradation products of lycopene have been observed in PEF and HPP class. Compounds selected in higher concentration in thermal class were products linked to the Maillard reaction and Strecker degradation products. All compounds detected in lower concentration in thermal class at day-12 compared to PEF and HPP were linked to lycopene degradation. According to the sensory evaluation, a clear differentiation of control from processed samples as well as among processed samples only after the treatment and at the end of the shelf-life was possible.