Effect of blueberry flower pulp on sensory, physicochemical properties, lactic acid bacteria, and antioxidant activity of set-type yogurt during refrigeration

Abstract

Blueberry flowers were rich in polyphenols and eight essential amino acids. They were used to prepare blueberry flowers yogurt (BFY) with milk and probiotics. The effects of blueberry flower pulp on sensory and physicochemical properties, lactic acid bacteria, and antioxidant of set-type yogurt were evaluated. Results showed that blueberry flower pulp compatible with yogurt well. Syneresis rate of BFY ranged from 20.7% to 23.9%, and viscosity ranged from 2.5 to 3.8 pa.s. Blueberry flower pulp reduced the rate of syneresis at different degrees and significantly improved the viscosity of yogurt. It could also promote the growth of Lactobacillus plantarum and Streptococcus thermophilus, and the production of amino acids. During the 29 days’ refrigerated storage, the total number of probiotics in BFY was more than 1 × 107 cfu/mL. Compared to the control yogurt, IC50 values of BFY scavenging DPPH (21.06–34.05 mg/ml), ABTS (20.12–34.57 mg/ml), and OH radical (19.87–33.99) reduced at varying degrees. The antioxidant activities of BFY were meaningfully enhanced by blueberry flower pulp and relatively stable. Practical applications In recent years, blueberry flower has been used as a scented tea in China, and it is popular among consumers. In this study, we added 1%–5% of blueberry flower pulp to develop BFY, and its effects on physicochemical properties, probiotics, and antioxidant activity of yogurt were evaluated. Blueberry flower pulp could remarkably improve the quality and antioxidant activities of yogurt.