A comparative study to develop calcium, zinc, and antioxidant rich drinking yoghurt products using plant and pharmaceutical ingredients

Abstract

Today, people in the world hungers natural foods. This study is an attempt taken to investigate the compatibility of utilizing plant sources in fortification rather than pharmaceutical sources. Two sets of drinking yoghurt products were prepared using cow's milk and fortified using selected plant and pharmaceutical sources of Ca and Zn separately; as they fulfil 1/3, 1/2 and 2/3 of Reference Dietary Intakes (RDI) of Ca and Zn. Drinking yoghurt fortified at 50% RDI of Ca with plant extracts elicited best sensory properties among all products. Incorporation of Moringa oleifera dried leaf powder extract and Phyllanthus emblica fruit extract had significantly increased the mineral composition compared to plain drinking yoghurt (p <0.05). All drinking yoghurts incorporated with plant ingredients had significantly higher (p<0.05) antioxidant activity (Range: 52.08+0.02-91.69+0.00%) and total phenolic contents (2.29-3.60 mg GAE/g) than the control. All products fortified with Ca and Zn using pharmaceutical sources showed significantly lower (p<0.05) antioxidant activity. Microbiological evaluation did not elicit any significant difference (p>0.05) after subjected to mineral fortification from either plant or pharmaceutical sources. During the shelf life evaluation, quick increment in pH was observed in products with pharmaceutical ingredients than the control. Syneresis was higher in samples with plant ingredients than the control and pharmaceutical ingredient added products but was not greatly affecting the product stability during two weeks of shelf life period. Overall, the incorporation of M. oleifera and P. emblica can be concluded as reliable option for dairy products such as drinking yoghurts; to fortify them with high Ca and Zn, to enhance antioxidant properties as well as to maintain product stability and organoleptic properties.