Xylooligosaccharides and their chemical stability under high-pressure processing combined with heat treatment

Abstract

Xylooligosaccharides (XOS) are emerging prebiotic ingredients used for enriching food products due to their health-promoting properties. This study investigated XOS chemical stability after high-pressure processing (HPP) combined with heat treatment. First, orange juice was enriched with XOS (xylobiose, xylotriose, xylotetraose, xylopentaose, and xylohexaose), and then HPP-treated at 100, 300, and 600 MPa applying non-thermal (30 °C) and thermal (100 °C) conditions. Ascorbic acid (vitamin C) degradation was monitored to evaluate the extend of the severity of the treatments due to its low stability under high-energy process conditions. Also, quality attributes associated with fruit juices such as physicochemical properties (pH, soluble solid content, and ζ-potential), organic acid content (malic and citric acids), total phenolic content, antioxidant activity, and sugar content (glucose, fructose, and sucrose) were determined. The use of HPP combined with heat treatment degraded ascorbic acid up to 37% and promoted sucrose hydrolysis into glucose and fructose. However, our findings demonstrated that the XOS were chemically stable to HPP in the range of 100–600 MPa even applying thermal treatment. Therefore, XOS are promising ingredients for the formulation of functional plant-based beverages since their integrity was preserved under high mechanical and thermal stress conditions of 600 MPa and 100 °C.