Effect of probiotic cultures on the stability of anthocyanins in blueberry yoghurts

Dependent on anthocyanin pigments, colour is one of the main quality factors of berry products. In this paper we assess the influence of probiotic bacteria on the degradation rate of anthocyanins in yoghurts with a highbush blueberry preparation during storage. Four types of yoghurts were prepared: first with the yoghurt starter culture YC-X16 only (Steptococcus thermophilus and Lactobacilllus delbrueckii subsp. bulgaricus) and three more, each with the starter culture YC-X16 and one of the three probiotic cultures: Bb-12, La-5 and LCP, respectively (Bif. animalis subsp. lactis – Bb-12; Lactobacillus. acidophilus – La-5 and Lactobacillus. paracasei subsp. paracasei – LCP).Derivatives of malvidin were the predominant anthocyanins in the tested yoghurts. Degradation of pigments occurred in accordance with the first-order reaction and its half-life time depended on the bacterial cultures. Anthocyanins in the probiotic yoghurt made with LCP culture were characterized by lower stability than those made with the other bacterial cultures. The impact of lactic bacteria or their metabolic products on the stability of anthocyanins in berry yoghurts shows that an appropriate selection of culture for production of yoghurt is recommended.

► During storage of blueberry yoghurt the content of anthocyanins decreased.
► The lactic bacteria or their metabolism products impact on anthocyanins stability.
► The derivatives of malvidin predominated in blueberry yoghurt.
► The stability of individual pigments are very similar.