Coffee husks are a major by-product of coffee production and are currently being underutilized. The aim of this work was to chemically characterize coffee husks to allow for an adequate evaluation of their potential for valorization. Blanched and non-blanched coffee husks were characterized for extractable and non-extractable phenolics, caffeine, trigonelline content, and for their polysaccharide and proximal composition. The total, soluble and insoluble fiber contents were determined, together with the husks’ technological properties. Antioxidant activity and bioaccessibility of phenolic compounds of coffee husks were evaluated. Two types of husk were studied: one comprised mostly of outer skin and pulp (CH1); and other comprised mostly of parchment (CH2). Blanching had positive effects on non-extractable phenolics, chlorogenic acid and on the bioaccessibility of phenolics, promoting small reductions in extractable phenolics, protocathecuic acid, caffeine and trigonelline contents. Blanched CH1 presented more appropriate properties than CH2 for potential applications in food. It also presented better antioxidant, hydration, and oil holding properties than those of other agri-food by-products. Tentatively identified polysaccharides included galactomannans, arabinogalactans type II, pectin and cellulose.

Umbu, a common fruit from the northeastern region of Brazil, contains many bioactive compounds not yet exploited. Thus, this study evaluated the potential of pulps and peels of mature and semi-mature umbu as a source of bioactive compounds. Trigonelline contents ranged from 1.75 to 6.14 mg/100 g, values higher than those of many vegetables described in the literature, such as corn and barley. The contents of extractable and non-extractable phenolic compounds were also higher than those of other vegetables. Bioaccessibility of total extractable phenolics, flavonoids, and tannins was determined (15.67–37.73%, 31.87–39.10% and 18.81–114.27%, respectively). The constituent polysaccharides of the pulp and peel were tentatively chemically characterized as arabinoxylans, arabinogalactans, rhamnoarabinogalactans, xyloglucans, and pectin of the rhamnogalacturonan type. The technological potential of peel flours was evaluated. The maturation advancement showed no significant changes in the technological properties of the flours, except for color and water solubility index. Results indicated excellent prospects for future research on umbu pulps and peels as potential sources of natural bioactive compounds.

Projective mapping: potential tool for sensory evaluation of coffees for industrial application

O Brasil é um país de grande atividade agrícola, resultando em elevada produção de resíduos agroindustriais. Estes resíduos, na maioria das vezes, não apresentam aplicação industrial, podendo transformar-se em fonte de poluição ambiental. Esse estudo tem como objetivo revisar os compostos bioativos presentes em resíduos de frutos tropicais e verificar seu potencial para aproveitamento na produção de Pós Ricos em Fibras (PRF). Utilizou-se como metodologia uma revisão bibliográfica qualitativa. Os compostos com efetivos efeitos benéficos à saúde revisados foram os compostos fenólicos, carotenóides, vitaminas (C, E e A) e alcalóides (trigonelina e cafeína). Os dados encontrados para os PRF apontam boas propriedades funcionais e alto teor de compostos antioxidantes e fibras dietéticas, permitindo que esses materiais sejam usados na elaboração de novos produtos. Além disso, verificamos que poucos são os estudos que abordam a bioacessibilidade de pós produzidos a partir de resíduos de frutos tropicais, o que confirma a necessidade de mais estudos com essa temática. Ressaltamos que além dos benefícios a saúde, a produção de pós ricos em fibras é uma alternativa importante para reduzir impactos gerados ao ambiente pelo descarte incorreto de resíduos agroindustriais.