Prospects of using sweet clover extracts in yogurt production

Abstract

Yogurt fortification with herbal extracts is a promising strategy for developing functional fermented dairy products. This study investigated the effect of sweet clover (Melilotus officinalis) extract on the physico‑chemical composition, phenolic profile and vitamin content of yogurt. Yogurt was produced according to a traditional procedure, and sweet clover extract was added at a level of 0.5% after fermentation. The fortified yogurt showed a slight increase in protein (from 4.51 ± 0.03% to 4.89 ± 0.05%) and dry matter (from 14.75 ± 0.01% to 15.28 ± 0.02%), while fat content remained practically unchanged, indicating good technological compatibility of the extract with the dairy matrix. Total phenolic content increased from 1.28 ± 0.05 to 1.34 ± 0.05 mg GAE/g, and total flavonoid content from 0.53 ± 0.03 to 0.59 ± 0.02 mg QE/g, confirming the contribution of sweet clover–derived bioactive compounds. In addition, small but consistent increases (approximately 5–10%) were observed for vitamins B1, B2, B5, B6, B9 and C in the fortified samples, whereas vitamin B3 remained unchanged. Overall, the results demonstrate that sweet clover extract can be effectively used as a natural fortifying ingredient to obtain yogurt with slightly improved nutritional value and enhanced levels of phenolic compounds and vitamins, supporting its classification as a promising functional dairy product.