Inoculation of Saccharomyces cerevisiae with sugar cane juice as a starter culture in coffee (Coffea arabica) fermentation ¹

Inoculação de Saccharomyces cerevisiae com caldo de cana-de-açúcar como cultura iniciadora na fermentação do café (Coffea arabica)

HIGHLIGHTS:

Yeast from wine production is an alternative to inoculation as a starter in coffee fermentation chaptalized with sugar cane.

Treatments with sugar cane and S. cerevisiae are a proposal that contributes to the production of specialty coffee.

The incorporation of additives such as sugar can favor the metabolism of yeast because it is a source of carbohydrates.

ABSTRACT

This study aims to evaluate the effect of sugarcane juice and the addition of commercial yeast Saccharomyces cerevisiae var. bayanus (≥ 1 × 1010 cfu/g) during the fermentation of coffee to the beverage’s sensory characteristics and the coffee bean’s chemical composition. A completely randomized experimental design with two replicates is carried out for four treatments, distributed as follows: i) water addition (0.78 kg), ii) sugar cane juice addition (0.78 kg), iii) sugar cane juice addition (0.78 kg) combined with yeast Oenoferm® Freddo (0.12 g) and iv) sugar cane juice addition (0.78 kg) combined with yeast Oenoferm® Color (0.12 g). After fermentation and drying, the samples were subjected to medium roasting and analyzed using infrared spectroscopy and sensory analysis according to the methodology of the Specialty Coffee Association. The implementation of organic additives directly affected the attributes and sensory notes, allowing coffee to be classified as a specialty coffee with a score above 80 points. Adding sugar cane juice or a combination of sugar cane juice and Saccharomyces cerevisiae showed promising results in improving coffee beverage quality. Additionally, chemometric analysis of the infrared spectrum showed that the chemical characteristics of roasted coffee were affected, which correlated with the sensory results. The addition of cane juice only (T2) and the Oenoferm® Freddo yeast strain (T3) presented the best sensory quality.

Key words:
Guarapo; coffee postharvest; yeast inoculation; infrared spectroscopy