Studying factors affecting the processing of lychee juice (Litchi chinensis S.) supplemented with roselle calyx (Hibiscus sabdariffa L.)

Abstract

This study determined the optimal technical parameters for processing lychee (Litchi chinensis S.) juice supplemented with roselle (Hibiscus sabdariffa L.) calyx extract. The factors investigated included: (i) blending ratios of lychee juice to roselle extract (9:1, 8:2, 7:3, 6:4, v/v); (ii) added sugar levels (12%, 14%, 16%, w/v) and citric acid concentrations (0.15%, 0.2%, 0.25%, w/v); and (iii) pasteurization temperatures (80°C, 85°C, 90°C) and holding times (1, 3, 5 minutes). The results indicated that a blending ratio of 8:2 (lychee juice to roselle extract), with 14% sugar and 0.2% citric acid, pasteurized at 85°C for 3 minutes, achieved a pasteurization value (PU) of 6.99 minutes. This combination effectively eliminated microorganisms, preserved sensory quality, and minimized nutritional loss.