INFLUENCE OF STORAGE CONDITIONS ON SENSORY SHELF LIFE OF YERBA MATE

Abstract

ABSTRACT Samples of yerba mate (YM) manufactured with natural and accelerated processes were stored under constant conditions of temperature (30 and 40C) and relative humidity (75 and 90% RH). Mold and yeast count and changes in sensory attributes, intensity of the flavor, bitterness and humidity flavor were studied. The end of shelf life was determined using the Weibull hazard method, calculated as the time at which 50% of the panelists find the product unacceptable. Conducted tests of acceptability carried out with habitual consumers of YM confirmed results obtained with the trained panel. Similar values of shelf life were found with the high humidity flavor descriptor and with results of acceptance–rejection test. Storage time to which off‐flavor was developed is analogous to the time of fast mold and yeast growth. The RH is the most important variable: sensory shelf life time of 32–44 days at 75% RH and 10–13 days at 90% RH were found at both temperatures of storage. PRACTICAL APPLICATIONSAn important contribution of the present work is the analysis of the influence of storage conditions on the quality loss of yerba mate (YM). Furthermore, the shelf life in unfavorable environmental conditions for the YM storage was determined. This is important because even though the Código Alimentario Argentino establishes an upper limit of moisture in YM, there are no systematic studies about the issue.In addition, sensory parameters of YM quality are associated to the consumer's habits and no standard sensory quality attributes are established. Nevertheless, the consumer expectation is satisfied by preservation of product sensory characteristics. In this sense, from the results of this study, it is possible to establish conditions of humidity and temperature of storage that guarantee the preservation of sensory quality of YM during their commercialization