Extração de composto fenólicos da casca do café por diferentes métodos

Abstract

The coffee is a fruit of the coffee, is that is plant of approximately 4 meters of height, that belongs family of the Rubeáceas of the genus Coffea. There are hundreds of species of coffee, but the most produced in Brazil has been Coffeaarabica and Coffeacanefora (Robusta), having cultivated in places where it has milder climates. The coffee culture in Brazil is very strong, making the country the largest producer and exporter of coffee, occupying the second place in the consumption of this product. The country has 2.21 million hectares of coffee, in which it produced more than one billion kg of fruit in the first half of 2017. The coffee crop is characterized by the generation of a large amount of agro-industrial waste, which has been applied as fertilizer and in the feed of ruminants, but in the barks are toxic substances (caffeine and tannins), that in excess causes damages to the health of the animals. The coffee husk represents 40% of the fruit, and has several types of phenolic compounds, and the most common are chlorogenic acids (ACG), which can have a weight-loss effect. Given the need for an appropriate destination of post-harvest residues to reduce environmental impacts, along with the potential economic benefits, further studies in this area are needed. The objective of this research was to find the best method of extracting the phenolic compounds from the coffee husks in order to isolate them. The coffee husk of the Coffea Arabica species purchased in Cássia dos Coqueiros - SP was ground in a knife mill to reduce the contact surface, improving extraction. Approximately 5 g of sample were added in 200 ml of two different solvents, methyl alcohol and water. In order to evaluate the efficiency of the extraction, four equipments were used in comparison: shaker incubator/shaker, soxhlet extractor, plate with magnetic stirrer and Ultrasonic bath, at predetermined temperatures and times according to the area literature. This sample was then filtered and oven dried at 105 ° C for 4 hours, then the yield of each method was calculated. By analyzing the four extraction methods, only in the soxhlet solvent methyl alcohol (0.50 ± 0.05 g extract ˖100 g-1 methanol) was more efficient than water. In other equipment the water was more efficient. The results of extractions ranged from 0.20 ± 0.01 g extract˖100 g-1 water to the shaker method up to 9.00 ± 1.60 g extract˖100 g-1 water to the shaker shaker. Thus, the Shaker incubator / shaker extraction method was the most effective of all methods tested.