Stabilization of Ficus carica L. Drink by utilizing varying levels of ultrasound-assisted moringa extract as a natural preservative

Fig fruit (Ficus carica L.) drink is a source of healthy minerals, vitamins, and bioactive ingredients however to improve the shelf-life of functional drink naturally, moringa leaf extract was compared with optimized concentration of potassium metabisulphite (synthetic preservative). Purposely, fig fruit drink, without preservatives was considered as negative control whereas, 0.2 % potassium metabisulphite-based fig fruit drink was taken as positive control. Further, ultrasound assisted extracts of moringa at varied levels; 5, 10, 15, and 20 % were incorporated in the fig fruit drink as natural preservative to test antioxidant, storage, and sensory quality against control samples. Resultantly, the maximum loss in antioxidant activity (18–38 %) and functional ingredients (24–56 %) was observed in negative control sample, in response to high microbial expansion till the termination of the study. Additionally, acceptability score for negative control sample was maximum at Day 1, that afterwards faced significant decline at 30th Day (6.6 ± 0.3). In contrast, positive control sample demonstrated minimum loss of free radical scavenging ability (7–22 %), polyphenols (11 %) and flavonoids (7 %) thus indicated maximum control on microbes i.e. 61–63 % as compared to negative control. Further, positive control sample indicated optimum consumer preference (7.0 ± 0.3) that remained stable throughout storage. Further, as the concentration of moringa exceeded from 5 to 20 %, the loss of functional ingredients reduced from 13 to 24 to 6–11 % and deterioration in antioxidant capacity suppressed from 14 to 26 to 8–20 %, correspondingly however, the sensory acceptability showed a declining trend, and 20 % moringa based sample portrayed poor consumer response (5.0 ± 0.2). Lastly, it was deduced that control on microbes was directly proportional to the concentration of moringa extract in fig fruit drink, that was poor in 5 % moringa extract concentration; 32–54 %. Conclusively, customer preference was reasonable (6 ± 0) at 15 % moringa extract concentration so this level should be employed in fig fruit drink for realistic control on bacterial (57 %) and fungal (47 %) activities.