ASSESSMENT OF SENSORY, MICROBIAL AND PHYSICOCHEMICAL QUALITY OF A FUNCTIONAL BEVERAGE PROCESSED BY ULTRAVIOLET LIGHT (UV-C) ENRICHED WITH YERBA MATE

FERRARIO, MARIANA; GUERRERO, SANDRA; FENOGLIO, DANIELA; SCHENK, MARCELA

Verona

Congreso; Eight European Conference on Sensory Consumer Research; 2018

UV-C treatment under hurdle approach may be a good alternative for turbid juice processing, better preserving bioactive compounds while improving overall quality. Yerba mate (Ilex paraguariensis) is an infusion widely consumed in South America. It has been largely studied due to its multiple health-giving properties, mostly attributed to its phenolic compounds (PC). The objective of this work was to obtain a carrot-orange juice blend (1:1ratio(v/v)/pH:5.0/10.6°Brix/7667NTU) processed by ultraviolet light (UVC) assisted by mild heat (UVC/H) (50°C/2-30W-lamps/1.6L/min/15min/10.6kJ/m2) enriched with yerba mate extract (0.4%YME). For sensory evaluation, 100 volunteers performed a consumer field test (CFT) evaluating overall liking followed by open-ended questions and some juice attributes in acceptability, intensity and/or JAR 5-point scales. Additionally, the check-all-that-apply (CATA) question was performed for which, the used terms were generated in a preliminary round table session. Juice was also examined for native flora, PC, total antioxidant activity (TAA), color, turbidity, °Brix and pH along 24-day storage (4°C). UVC/H+YME was the most effective treatment as it reduced juice native flora by 2.6-5.7 log-cycles. In addition, UVC/H+YME juice exhibited the highest TAA (5.5 mgTroloxEq/mL) and PC (0.7mgGAEEq/mL) values, which increased by 7.2 and 3.5 times, respectively compared with control juice, remaining constant along storage. This juice exhibited the highest turbidity while the other physicochemical parameters remained constant along storage. Regarding CFT, a cluster analysis revealed that one of two groups showed a marked interest in UVC/H+YME juice having an overall liking of 7.0 in 9-point hedonic scale, perceiving bitterness (2.9±1.1) and YME aroma (3.6±0.9), closer to the optimum JAR value. Regarding the CATA question, UVC/H+YME juice was well accepted by a group of consumers interested in the occasional consumption of beverages with herbal taste and strong aroma. Consumer sensory analyses evidenced the most relevant strengths of this novel functional juice to be exploited in the near future.