Pulsed light treatment of water enriched with short‐chain fructooligosaccharides

Abstract

Short‐chain fructooligosaccharides (sc‐FOS) are a soluble dietary fiber with a low calorific value and a sweet taste. The beverage industry is leveraging sc‐FOS in a variety of innovative functional drinks. However, sc‐FOS drinks are vulnerable to microbial spoilage due to the presence of free sugars and high water activity. This study explored the potential of pulsed light (PL) technology to pasteurize water enriched with sc‐FOS at 3% and 6% levels of usage. PL treatments were carried out at 1.7, 1.9, and 2.1 kV for 120, 180, and 240 s, corresponding to fluence ranging between 0.28 and 1.03 J/cm2. The microbial inactivation (of Saccharomyces cerevisiae, Escherichia coli, and Listeria monocytogenes), pH, titratable acidity (TA), total soluble solids (TSS), color profile, and sc‐FOS integrity were investigated. A 5‐log10 inactivation in the microbial populations was obtained at 1.9 kV/ 240 s (equivalent to 0.85 J/cm2 fluence). Of the log‐linear and Weibull models evaluated, Weibull model was found to best‐fit the inactivation kinetics. Insignificant effects of PL were observed on pH, TA, TSS, and color. More than 98% sc‐FOS content was retained in all samples after PL flashing. Therefore, PL technology can be explored as an industrial antimicrobial intervention for functional beverages, including water enriched with sc‐FOS.Practical applicationsShort‐chain fructooligosaccharides (sc‐FOS) are a soluble dietary fiber with a low calorific value and a sweet taste. This study explored the potential of pulsed light (PL) technology to pasteurize water enriched with sc‐FOS at 3% and 6% levels of usage. The study establishes that pulsed light (PL) treatment can be an effective nonthermal pasteurization condition for functional water enriched with short‐chain fructooligosaccharides (sc‐FOS). A PL fluence of 0.85 J/cm2 can be employed for the pasteurization of a 3% sc‐FOS drink (considered a source of dietary fiber) and a drink with 6% sc‐FOS (considered a fiber‐enriched drink). PL fluence up to 1.03 J/cm2 has no concerning effect on the total sugars or sc‐FOS content of the water enriched with FOS after PL treatment, thus making it suitable for an industrial application.