New Study Uses Infrared Spectroscopy to Boost Yerba Mate Quality Through Clonal Selection

A recent research collaboration between scientists in Spain and Brazil provided new insight into how to standardize and improve the quality of yerba mate. Yerba mate is a culturally significant plant with expanding potential in the food, pharmaceutical, and cosmetic industries (1). The study, led by Gustavo Galo Marcheafave and Ivar Wendling and published in the journal Food Chemistry, showcased the applicability of using mid-infrared (MIR) and near-infrared (NIR) spectroscopy in identifying key factors that influence the chemical composition of yerba mate leaves (2).

Yerba mate (Ilex paraguariensis) is popular because it contains antioxidant-rich properties and can lower obesity, hypertension, and diabetes (1). However, variations in growing conditions, harvesting seasons, and plant clones can cause significant fluctuations in its chemical profile, leading to inconsistent quality. For producers aiming to supply uniform, high-quality raw materials for various industries, this variability poses a challenge (2).

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What did the research team test in their study?

In their study, the research team investigated how the “spectralprint” of yerba mate leaves are influenced by key cultivation variables. For the variables, the researchers examined growing site, harvest season, and clonal variation. Using both NIR and MIR spectroscopy, combined with a sophisticated multivariate statistical method called ANOVA Common Dimensions (AComDim), they examined samples from nine yerba mate clones cultivated at two geographically distinct sites in Brazil, separated by 413 kilometers, each with different cultivation systems (1).

Ultimately, out of the three variables tested, the location of cultivation and the season of harvest resulted in the largest variance. They accounted for approximately 7% of the variance in the chemical composition of yerba mate leaves, while the interaction between these two factors contributed an additional 5.7% (1). Clonal differences, though smaller in scale, were still significant, representing about 4% of the variance (1). Notably, these clonal variations enabled researchers to pinpoint specific clones with the highest chemical divergence.

The researchers were also able to determine that NIR spectroscopy outperformed MIR spectroscopy in this space, mostly because of the differences in sensitivity. Although MIR spectroscopy was able to determine the main effects of growing site and harvest season, as well as the interaction between the two, it was unable to detect all possible interactions. NIR spectroscopy, on the other hand, proved more comprehensive, identifying every main effect and interaction considered in the study (1). This makes NIR a particularly powerful tool for agricultural and industrial applications where nuanced chemical profiling is required.

One of the most striking technical results came from the MIR spectral region, where researchers identified significant absorption bands linked to carbonyl and nitrile groups, which are chemical signatures that can be used as markers for assessing plant quality (1).

By integrating this type of chemical profiling into agricultural decision-making, producers can select clones and optimize farming practices to consistently achieve desirable chemical characteristics (1). This could lead not only to more reliable flavor and nutritional qualities in consumer products, but also to enhanced raw materials for pharmaceutical and cosmetic applications, where consistency and purity are critical (1).

What are the implications of this study?

Apart from understanding the chemical composition of plants better, this study shows how advanced spectroscopy techniques, along with statistical tools, can improve quality control in agriculture. Similar approaches could be applied to other crops with high commercial and health value, ensuring that natural variability does not compromise product performance (1).

By merging field cultivation insights with laboratory precision, yerba mate may soon reach new heights of quality and consistency, benefiting farmers, manufacturers, and consumers alike.

References

1. Gawron-Gzella, A.; Chanaj-Kaczmarek, J.; Cielecka-Piontek, J. Yerba Mate—A Long but Current History. Nutrients 2021, 13 (11), 3706. DOI: 10.3390/nu13113706
2. De Aguiar, N. S.; Marcheafave, G. G.; Pauli, E. D.; et al. Multiblock NIR and MIR Spectralprint through AComDim to Evaluate the Effects of Growing Site, Harvest Season, and Clone on Yerba Mate Leaves Composition. Food Chem. 2025, 477, 143459. DOI: 10.1016/j.foodchem.2025.143459