Synergising tradition and innovation: Fortification of milk kefir with date syrup, a novel functional beverage

Abstract

AbstractMilk kefir is gaining popularity due to its high probiotic content. This study focuses on fortifying milk kefir with date syrup to enhance its sensory attributes, with the goal of encouraging consumption among the younger generation. Date syrup was added to milk kefir in specific proportions (2, 4, 6, 8, and 10% per 100 mL of milk). The selection of the most suitable percentage (10%, 74 °Bx) was determined based on sensory preferences indicated by the panellists. The newly developed fermented beverage underwent physicochemical and biochemical analyses over a 14-day fermentation period. Results revealed that the addition of date syrup led to a significant (P ≤ 0.001) decrease in pH and total soluble solids (TSS) content, accompanied by a noteworthy increase in total phenolic, flavonoids, condensed tannins contents and antioxidant activity (almost 2-fold). Liquid chromatography - heated electrospray ionisation - mass spectrometry (LC-HESI-MS/MS) results identified the presence of a newly formed and important antifungal compound, p-hydroxyphenyllactic acid (HPLA), showing a progressive increase in quantity during the fermentation process (13.8-fold on the 14th day of fermentation). Hence, the outcomes of this study offer compelling evidence that a novel category of functional beverage can be developed by employing milk kefir as an appropriate starter with the incorporation of date syrup.