STUDY OF PHYSICOCHEMICAL PROPERTIES OF COFFEE BEANS FROM DIFFERENT PROCESSING METHODS

Abstract

Fully ripened coffee beans of species Coffea Arabica from Kakakelia farm of Dadabazar-3 Dhankuta, Nepal, were subjected to different processing methods with the aim of studying physicochemical properties of coffee beans with 6 different processing method which were wet fermentation, semi-dry fermentation, and fermentation with yeast strain, 0.25%, 0.5% and 1% concentration of Polygalacturonase (PG) enzymes. Different physical parameters (length, breadth, l/b ratio, bulk density) and chemical (caffeine, total phenolic content, DPPH, flavonoids and tannin) parameters were studied. Physical properties of samples with different methods of processing had no significant difference. Caffeine, antioxidants, flavonoids, total polyphenols of samples were measured and found high in samples treated with 0.25% PG. There is no significant difference in tannin and caffeine content among different processing methods, but DPPH, total phenolic content, flavonoids were found significantly different (p˂0.05) between samples. From Principal Component Analysis (PCA), it shows that 0.25% PG, 0.5% PG and yeast samples were best in terms of chemical properties and correlation plot shows that strong positive correlation between Total Phenolic Content (TPC) and DPPH, DPPH and flavonoids. This findings indicates that it is possible to improve quality of green beans by optimizing the enzyme concentration and methods of processing