Design of encapsulation method for chlorogenic acid and caffeine in coffee waste by-product

IntroductionCoffee silver skin (CSS) is a thin covering over green coffee seeds inside coffee cherry. It is a good source of bioactive compounds like chlorogenic acid and caffeine. It is produced as a by-product of the roasting process. ObjectiveThe goal of this study is to apply spray drying method to encapsulate 5-O-caffeoylquinic acid (chlorogenic acid) and caffeine extracted from CSS. MethodsThe main-plots for optimisation were feed solid concentration (2.5, 5, 10 degrees Bx), and the sub-plots of the whole-plot were carrier material type (maltodextrin, modified starch, arabic gum) and inlet air temperature (130, 160, 190 degrees C). Responses included were drying yield, chlorogenic acid concentration, caffeine content, Carr index, and solubility values. ResultsSuitable conditions were spray drying inlet temperature of 190 degrees C, extract concentration of 10 degrees Bx, and wall material composition [modified starch/arabic gum (MS:AG)] 10.5:9.5. As the feeding CSS extract concentration increased, the amount of chlorogenic acid and caffeine in the final powder increased, while the powder's flow characteristics improved. ConclusionsThe concentration stage might be used to produce free-flowing powdered particles with good bioactive retention for use in the food processing industry.

Automated summary

This study aims to encapsulate 5-O-caffeoylquinic acid (chlorogenic acid) and caffeine extracted from coffee silver skin (CSS) using the spray drying method. Optimized conditions were found to be a spray drying inlet temperature of 190°C, extract concentration of 10 degrees Bx, and a wall material composition of modified starch/arabic gum (MS:AG) 10.5:9.5, which resulted in good drying yield and bioactive retention. The concentration stage could be utilized to produce free-flowing powdered particles for the food processing industry.