Potential of Zinc Oxide Nanoparticle for Dietary Fortification in Yoghurt: Physicochemical, Microbiological, Rheological and Textural Analysis

Yoghurt is a widely consumed dairy product all over the world. It has been used as an apt fortification and nutrient delivery medium in recent years.

The present study aimed to assess the suitability of zinc oxide (ZnO) nanoparticle as a potential source of fortification of zinc in yoghurt. Three different levels of ZnO nanoparticles, as well as micro-sized ZnO, were added in yoghurt. Physicochemical, sensory, microbiological, rheological and textural characteristics of yoghurt were determined during 7 days of storage at 7±°C.

Significant differences in physicochemical properties were observed in yoghurt samples during storage. All the yoghurt samples showed non-Newtonian characteristics. Zinc oxide nanoparticle added @ 75 ppm was found best for yoghurt fortification and showed advantages over fortification with conventional micro-sized ZnO. In this study, the effects of fortification of yoghurt with zinc oxide nanoparticle during storage were investigated. The FFA content of yoghurt was found to be 0.46% oleic acid and the Peroxide Value was found to be 0.32 Milli equivalent/kg fat, which was found to increase during storage. The tyrosine value at zero day was found to be 2.2 mg/g. The LAB count was 10.59 log 10 CFU/g. Plastic viscosity of yoghurt was found to be 10.8.3 cP. Fortification of yoghurt with zinc oxide nanoparticle proved to be advantageous over fortification with micro-sized zinc oxide in terms of physico-chemical, microbiological, rheological and textural characteristics. Fortification of yoghurt with zinc oxide nanoparticle proved to be highly promising for zinc enrichment in the food system.