Volatile Fingerprinting and Sensory Profiles of Coffee Cascara Teas Produced in Latin American Countries

Abstract

Coffee is one of the most produced and consumed food products worldwide. Its production generates a large amount of byproducts with bioactive potential, like the fruit skin and pulp, popularly called cascara. This study aimed to evaluate the volatile and sensory profiles and the consumption potential of commercial Coffea arabica cascara teas by Rio de Janeiro consumers. Analyses of volatile organic compounds in unfermented (n = 2) and fermented (n = 4) cascara tea infusions were performed by GC-MS. RATA and acceptance sensory tests were performed with untrained assessors (n = 100). Fifty-three volatile organic compounds distributed in 9 classes were identified in different samples. Aldehydes, acids, alcohols, esters, and ketones prevailed in order of abundance. With mild intensity, the most cited aroma and flavor attributes were sweet, herbal, woody, prune, fruity, honey, toasted maté and black tea for unfermented teas. For the fermented teas, sweet, woody, black tea, prune, herbal, citric, fruity, honey, raisin, peach, toasted maté, tamarind, and hibiscus were rated as intense. A good association between the attributes selected by the assessors and the volatile compounds was observed. Unfermented teas, with a mild flavor and traditional characteristics, showed better mean acceptance (6.0−5.9 points) when compared to fermented teas (6.0−5.3 points), with exotic and complex attributes. These were well accepted (>8.0 points) by only about 20% of the assessors, a niche of consumers that appreciate gourmet foods.

Keywords: coffee cherry tea; coffee fruit; coffee husk; fermentation; infusion; volatile compounds.

Figure 1

Transverse cut of a Coffea arabica fruit, reproduced with permission from the Royal Society of Chemistry.

Figure 2

Infusions of commercial coffee cascara teas from Latin American countries. (A): sample 3—El Salvador (F); (B): sample 1—Brazil (F); (C): sample 4—Nicaragua (F); (D): sample 5—Brazil (UF); (E): sample 6—Nicaragua (UF); (F): sample 2—Bolivia (F). Note: F–fermented; UF—unfermented.

Figure 3

Mean acceptance (A) and purchase intention (B) scores given for coffee cascara infusions by Brazilian consumers living in Rio de Janeiro. Different letters over the bars indicate statistical differences among samples by ANOVA (p ≤ 0.05) (n = 100 assessors). Samples: 1—Brazil (F); 2—Bolivia (F); 3—El Salvador (F); 4—Nicaragua (F); 5—Brazil (UF); 6—Nicaragua (UF). F—fermented; UF—Unfermented.

Figure 4

Main aroma (A), flavor (B) and taste (C) attributes selected for all coffee cascara infusions by the assessors.

Figure 5

Principal component analysis (PCA): bi-dimensional plot of samples of cascara coffee tea infusions (n = 6) (A) and sensory characteristics attributed by consumers (n = 100) through RATA sensory test, distributing volatile compounds and attributes that make up the best acceptance of samples among consumers (B). Overall liking and the volatile compounds were considered as supplementary variables. Samples: 1—Brazilfermented (F); 2—Bolivia (F); 3—El Salvador (F); 4—Nicaragua (F); 5—Brazilunfermented (UF); 6—Nicaragua (UF).