Abstract
Soluble coffee offers the combined benefits of high added value and practicality for its consumers. The hydrolysis of coffee polysaccharides by the biochemical route, using enzymes, is an eco-friendly and sustainable way to improve the quality of this product, while contributing to the implementation of industrial processes that have lower energy requirements and can reduce environmental impacts. This work describes the production of hydrolytic enzymes by solid-state fermentation (SSF), cultivating filamentous fungi on waste from the coffee industry, followed by their application in the hydrolysis of waste coffee polysaccharides from soluble coffee processing. Different substrate compositions were studied, an ideal microorganism was selected, and the fermentation conditions were optimized. Cultivations for enzymes production were carried out in flasks and in a packed-bed bioreactor. Higher enzyme yield was achieved in the bioreactor, due to better aeration of the substrate. The best β-mannanase production results were found for a substrate composed of a mixture of coffee waste and wheat bran (1:1 w/w), using Aspergillus niger F12. The enzymatic extract proved to be very stable for 24 h, at 50 °C, and was able to hydrolyze a considerable amount of the carbohydrates in the coffee. The addition of a commercial cellulase cocktail to the crude extract increased the hydrolysis yield by 56%. The production of β-mannanase by SSF and its application in the hydrolysis of coffee polysaccharides showed promise for improving soluble coffee processing, offering an attractive way to assist in closing the loops in the coffee industry and creating a circular economy.
Highlights
Coffee is widely produced and consumed globally
Fungal growth was correlated with enzymes production and the crude enzymatic extracts were applied in the hydrolysis of the coffee polysaccharides, in order to evaluate the ability of these enzymes to solubilize them, with the aim of improving soluble coffee processing, using an eco-friendly and sustainable strategy
In the solid-state fermentations, evaluation was made of the use of coffee waste (CW) as the sole solid substrate, as well as in combination with wheat bran (WB) or sugarcane bagasse (SB), for the production of β-mannanase and β-glycosidase
Summary
Coffee is widely produced and consumed globally. Brazil is the largest producer, followed by Vietnam and Colombia, with these three countries being responsible for more than half of the total supply of coffee. A more eco-friendly and sustainable potential strategy for the hydrolysis and solubilization of coffee polysaccharides is to use an enzymatic route, since enzymes act under moderate process conditions and are highly specific. The residues generated in the coffee industry are potential substrates for the production of β-mannanases [19], since the enzymes produced using such a substrate should be more specific for degradation of this material. Considering the above issues, this work evaluates the use of agro-industrial coffee waste to produce hydrolytic enzymes by SSF, focusing on the production of β-mannanase. Fungal growth was correlated with enzymes production and the crude enzymatic extracts were applied in the hydrolysis of the coffee polysaccharides, in order to evaluate the ability of these enzymes to solubilize them, with the aim of improving soluble coffee processing, using an eco-friendly and sustainable strategy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
