Fortification of yogurt with bioactive functional foods and ingredients and associated challenges - A review

Yogurt is one of the nutrient-rich fermented dairy products that support the human gut microbiome. It has also been one of the most consumed dairy products around the globe whose consumption has been progressively increasing. Research has consistently seen that yogurt has been beneficial for humans and helps prevent several gut diseases, which is one of the prominent reasons for its popularity. Moreover, it also helps to reduce cholesterol, thus preventing cardiovascular diseases. Nevertheless, yogurt also provides many essential nutrients to the body. Considering all the benefits of yogurt, the scientific and industrial community has experimented with adding several compounds to enhance its nutrition and marketability further. However, the fortification of compounds other than the primary elements (yogurt cultures, milk) can sufficiently alter the physio-chemical properties of the yogurt, and can equally affect the storage stability of the yogurt. This review focuses on the fortification of functional food products such as fruits, vegetables, cereals, and other compounds to yogurt and how adding these compounds altered the physicochemical properties of yogurt. Moreover, this review only targeted the articles published after 2010 to give recent updates in yogurt technology. It has been noticed that fortifying yogurt with functional food is a challenging aspect of food engineering. Yogurt added with fruits, vegetables, cereals, and other compounds (such as honey, moringa, aloe vera extracts and essential oils etc), improves the nutritional and functional properties of the yogurt, however, the rheological, sensory, microbial characteristics, and shelf life of the resulting yogurt is affected with the addition of these compounds. Stabilization of these properties is important to improve the acceptance and marketability of functional yogurt. Despite the recent improvements in yogurt stability and availability of bioactive functional food ingredients the use of food products should be thoroughly evaluated and modified until a tight balance between safety and efficiency is set in yogurt.