The viability of Lactobacillus rhamnosus in orange juice fortified with nettle (Urtica dioica L.) and bioactive properties of the juice during storage. (January 2020) - Sengun, Ilkin Yucel
Abstract: This study aimed to develop orange juice-based probiotic drink fortified with nettle. The effect of nettle ( Urtica dioica L.) supplementation on the viability of probiotic ( Lactobacillus rhamnosus ATCC 53103), total phenolic content, antioxidant, antimicrobial, microbiological, chemical, physical and sensory properties of the beverages were evaluated during 28 days of storage at 4 °C. The population number of L. rhamnosus was in the range of 6.75–7.33 log cfu.mL −1 during storage period and there was no statistical difference between orange-nettle-probiotic juice (NP) and orange-probiotic juice (OP) (P > 0.05). Total acidic values were ranged independently from the sample formulation between 1.25 and 1.69 citric acid in g.100 mL −1 . The total phenolic contents of the beverages were varied between 715 and 1224.5 gallic acid equivalent in mg.L −1 . Probiotic supplementation also enhanced the antioxidant and antimicrobial activities of the samples. There were no significant differences between the samples in terms of aroma, flavor and overall acceptance (P > 0.05) while OP is the most appreciated sample in terms of color properties (P < 0.05). Although nettle did not improve the growth of L. rhamnosus, the use of this plant improved bioactive properties of the samples. This study showed that NP is a suitable medium for maintaining the viability of L. rhamnosus. Graphical abstract: Image 1 Highlights: The viability of L. rhamnosus in orange-based juices is highly stable. Combined use of nettle and probiotic increased the total phenolic contents. Probiotic supplementation enhanced the antioxidant and antimicrobial activities. Sample including nettle and probiotic is acceptable in terms of sensory properties.