Accelerated maturation of processed yerba-mate under the controlled conditions of temperature and humidity

Abstract

Purpose

The purpose of this paper was to assess the changes in secondary metabolites and color during yerba-mate aging under controlled conditions. In Uruguay and Paraguay, the yerba-mate matured, in which chlorophyll degradation occurs, is preferred. For the matured product, the yerba-mate is stored for six months to one year.

Design/methodology/approach

Processed yerba-mate was submitted to 35°C and 80 per cent humidity during 42 days in a climatic chamber. Samples were collected every seven days, and the phenolic compounds/methylxanthines were quantified by ultra-performance liquid chromatography – photodiode array and chlorophylls/phaeophytins by spectrophotometry. L*, a* and b* colorimetric coordinates were measured.

Findings

The most expressive changes in the color occur in the first 14 days. At this time, 23.161 ± 2.984 per cent of total chlorophyll was degraded, considering that in 42 days, 37.458 ± 0.955 per cent is degraded, according to an exponential model. A positive correlation between theobromine amount and maturation time was found. This was verified by an increase in dicaffeoylquinic acid concentrations and small changes in chlorogenic acid isomers.

Practical implications

The results indicate that this is a viable accelerated yerba-mate maturation process according to economics and nutraceutics.

Originality/value

The paper has reported here a novel strategy to promote the yerba-mate maturation using controlled conditions.

Citation

Gonçalves, I.L., Dartora, N., Piovezan Borges, A.C., Picolo, A.P., Dallago, R.M., Mera de Souza, L. and Valduga, A.T. (2015), "Accelerated maturation of processed yerba-mate under the controlled conditions of temperature and humidity", Nutrition & Food Science, Vol. 45 No. 4, pp. 564-573. https://doi.org/10.1108/NFS-12-2014-0105