Spray drying conditions of lime juice prepared by freeze-concentration

Abstract

Lime (Citrus latifolia) juice concentrate is rich in vitamin C and phenolic compounds exerting a range of health benefits. Spray drying converts fruit juice into powder and offers convenience for industrial applications. The appropriate spray drying conditions for lime juice prepared by freeze concentration are rarely reported. Thus, this study aimed to investigate the effects of inlet temperature (130-170°C) and feed flow rate (20-40 mL/min) on drying yield, total ascorbic and phenolic contents (TPC) of the dried lime powder from spray drying of freeze-concentrate lime juice (containing 22% solid). The inlet drying temperature influenced the yield, total ascorbic acid and phenolic contents of the lime powders. The drying using an inlet temperature of 130°C resulted in the dried lime powder with ascorbic acid and phenolic contents of 113.1 mg/100 g and 1268 mgGAE/100 g, respectively and an acceptable yield (90.1%). The most appropriate feed flow rate was 30 mL/min which resulted in lime powder with high yield, total ascorbic acid and phenolic content. In conclusion, the high-quality spray-dried powder can be processed at the 130°C inlet temperature and 30 mL/min of feed flow rate. At these conditions, the obtained powder had a 45% lime solid and suitable moisture content (4.5%) and water activity (< 0.25) that would be stable for storage.