Microfluidization of Ginger Rhizome (Zingiber officinale Roscoe) Juice: Impact of Pressure and Cycles on Physicochemical Attributes, Antioxidant, Microbial, and Enzymatic Activity

The aim of this study was to investigate the effects of high-pressure microfluidization on the physicochemical attributes, antioxidant, enzymatic, and microbiological activity of ginger rhizome (Zingiber officinale Roscoe) juice at different microfluidization pressures (68.94, 103.42, and 137.89 MPa) and cycles (1, 2, and 3). An important physical attribute, the mean particle size of ginger rhizome juice, was significantly (p < 0.05) decreased from 15.85 (control) to 12.86 µm at 137.89 MPa and 1 cycle, which was further supported by microscopic inspection revealing cell disintegration. Due to the release of phenolic compounds and pigments brought on by cell disruption, total phenolic content, antioxidant activity assay DPPH, and ABTS values increased from 56.79 to 65.28 mg GAE/100 mL, 69.99 to 77.51% inhibition, and 74.61 to 84.74% inhibition, respectively, at 103.42 MPa and 3 cycles. The polyphenol oxidase (PPO) enzyme was shown to be baroresistant because microfluidization had no noticeable impact on its relative activity. A higher microfluidization pressure of 137.89 MPa resulted in the complete reduction of aerobic bacteria, yeast, and molds. Due to its solvent-free nature and success in microbial reduction, microfluidization may aid in the delivery of high quality clean-labeled ginger juice. The findings demonstrated that microfluidization treatment has the potential to produce clean-labeled, safe ginger juice with improved overall quality. This study provides useful information to industries for the commercialization of ginger juice and will assist in promoting the usage of undervalued rhizome species.