Sensory and chemical analyses of spontaneously fermented coffees

Abstract

Coffee fermentation has emerged as an innovative post-harvest process in recent years. The effectiveness of this process is in conferring sensory notes to the coffee that would please the consumer and allow for the positive differentiation of the coffees. This is achieved by monitoring the different parameters of the procedure of coffee fermentation. In this regard, the present study aimed to conduct a natural fermentation of the coffee fruit for up to 96 hours followed by the sensory (sensory characteristics for aroma, flavor, acidity, body and overall score of the 0 to 100) and chemical analyses (bioactive compounds, volatiles, organics, and fatty acids) to evaluate the influence of fermentation on sensory quality and on chemical compounds. The coffee (Coffeea arabica L.) samples for the study were collected from Presidente Olegário – MG (Harvest 2018/19) in the cerrado of Minas Gerais. The effects of fermentation and fermentation duration on the sensory quality and chemistry of coffee were evaluated. It was observed that after 48 h of fermentation, significant sensorial differentiation occurs, including an increase of the approximately two points in the final grade. In addition, time was revealed as the most relevant factor in the chemical analyses for the categorization of samples into different groups. Accordingly, it was concluded since coffees with subjected to 48, 72, and 96 h of fermentation got higher final grades, higher levels of palmitic fatty acid and characteristic compounds of fermented coffees (1,3-dioxolane 2,4,5-trimethyl, 2-furan methanol acetate, and butanoic acid) checking out the coffees wine-like notes and sweet notes to the beverage.