Impact of pineapple (Ananas comosus [L.] Merr.) processing under low oxygen conditions using an innovative spiral filter press on juice physical characteristics and phytochemical composition

Abstract

This study compared pineapple (Ananas comosus ‘MD2’) juices produced using either a vacuum-driven spiral filter press (SFP) or a conventional rack-and-cloth press (RCP). To our knowledge, this represents the first systematic evaluation of SFP-based dejuicing applied to pineapple. SFP extraction under low-oxygen conditions produced juices with higher turbidity (~760 to ~2075 FNU), cloud, and viscosity (from ~3.0 to ~5.1 mPa·s), but lower titratable acidity, and slightly higher total soluble solids. Dissolved oxygen levels were lower after SFP processing (~0.27 vs 0.34 mg/L). Although total vitamin C content was similar between the two methods, SFP juices exhibited significantly higher levels of α-tocopherol (~294 vs 60 µg/L) and total provitamin A carotenoids (~124 vs 33 µg/L). Several phenolic compounds were more abundant after SFP processing, and the total phenolic compounds detected by high-performance liquid chromatography exceeded those in the RCP juices. Very low levels of ethanol and lactic acid in both juices are consistent with good microbiological quality. Overall, the application of SFP for pineapple processing resulted in matrix-specific improvements, yielding a visually attractive, bright yellow juice with enhanced retention of oxidation-sensitive phytochemicals and distinct physical properties compared to RCP.