Clarification of white-fleshed guava juice by a fixed-angle conical rotor centrifuge laboratory and characterization of continuous disk stack centrifuges

Abstract

The two objectives of this paper were to determine the effect of centrifugation parameters on guava juice physicochemical characteristics and to identify operational characteristics of continuous disc-stack centrifuges based on the performance of a laboratory centrifuge. Effects of g-force (149g – 3731g) and centrifugation time (10 – 40min) on juice physicochemical characteristics (protein, pectin, galacturonic acid, dry matter, total soluble sugars contents; pH; electrical conductivity, clarity and particle size distribution) were assessed. Laboratory centrifuge performance was evaluated for 1343g, 2388g and 3731g. At 1343g, separation limits (xmax), feed flow-rates of disc-stack centrifuges and cut-off sizes (x50) were determined for corresponding laboratory centrifuge operation times. Significant decrease in average particle size, protein and pectin contents was observed, contrary to juice clarity. Similar clarification efficiency was obtained for g-forces ≥ 1343g. xmax were 2669nm, 2200nm and 1783nm, with corresponding x50 for continuous centrifuges, 1887nm, 1556nm, 1261nm, for 20min, 30min and 40min, respectively.