Improving Functional Properties of Not‐From‐Concentrate Apple Juices Through Probiotic Fermentation as Enhancer of Bioactivity and Phenolic Stability

Abstract

The growing demand for non-dairy functional foods makes probiotic-enriched apple juice—a lactose-free, polyphenol-richalternative—an attractive product aligned with contemporary health trends, representing a significant market opportunityfor juice industries. This study evaluated the feasibility of using two commercial Not-From-Concentrate (NFC) apple juices(AJ1, AJ2) as a matrix for four probiotic strains (Lacticaseibacillus casei ATCC 393, Lacticaseibacillus rhamnosus ATCC 53103,Lactobacillus acidophilus ATCC 314, Lactiplantibacillus plantarum ATCC 8014) over four weeks of refrigerated storage. Thestudy monitored bacterial viability, (poly)phenolic content, antioxidant capacity (DPPH, ABTS, FRAP), and anti-inflammatoryactivity (LOX inhibition). Despite a shared origin, the juices exhibited significant initial differences in phenolic profile (primarilyrutin, hydrocaffeic, and caffeic acid) and antioxidant activity, underscoring the impact of specific industrial processing. Probioticsurvival was juice-dependent, with higher viability in AJ2 (89%–100%) than in AJ1 (72%–87%), though both were effectivecarriers. Phenolic losses were minimal (<20%) and not probiotic-dependent. Antioxidant capacity remained stable (AJ1) orincreased post-fermentation (AJ2),withAJ2 exhibiting 100%–300% greater scavenging activity. Furthermore, probiotic enrichmentsignificantly enhanced functional properties, including elevated anti-inflammatory activity that persisted. Correlation analysisrevealed positive relationships between LOX inhibition and specific phenolics, particularly hydroxycaffeic acid, chlorogenic acid,and total polyphenols. These findings confirm that industrial NFC apple juices are robust carriers for diverse probiotics. Theinherent variability of industrial processes allows for the design of tailored functional beverages that synergistically combinenatural bioactives with probiotics, enabling strategic product diversification.