Formulation of catechin hydrate nanoemulsion for fortification of yogurt

Catechin hydrate (CH) is a kind of polyphenol present in many plantsincluding green tea, fruits, red wine and cocoa with very good antioxidant effect. The formulation of CH nanoemulsion increased the bioavailability and stability of catechin, allowing for easier food incorporation and faster absorption by the body. The major goal of the current study was to create a nanoemulsion as a reliable delivery mechanism for catechin hydrate and its incorporation into yogurt to increase its antioxidant activity. In this study, ultrasonication method was used for nanoemulsion preparation. The optimized condition for obtaining reduced droplet size includes two-minute ultrasonication time, 40% ultrasonication amplitude and 1.61:1emulsifier to oil ratio. The CH nanoemulsion's spherical droplet shape was confirmed by transmission electron microscopy(TEM). The chemical characteristics of CH nanoemulsion was studied using FTIR and Raman spectroscopy. The zeta potential value of CH nanoemulsion was-57.56 ± 1.35mV and the size was found to be 78.4 nm.Shelf-life analysis was carried out for yogurt incorporated with CH (YCH) and CH nanoemulsion (YCHN). During shelf-life study, YCHN showed better free radical scavenging activity, stability, and higher sensory assessment than YCH. YCHN had a greater Lactobacillus count (9.3 log CFU/mL) than plain yogurt. Hence, the study suggests catechin hydrate nanoemulsion (YCHN)as an effective technique to reduce bitterness and astringency of catechin for food fortification with better antioxidant activity.

The online version contains supplementary material available at 10.1007/s13197-024-06034-9.