Effect of lotus ( Nelumbo nucifera ) petals extract on the quality of yogurt and its action mechanism

Abstract

The effect of lotus petals extract (LPE) on the quality of yogurt was investigated and the action mechanism was further observed. With the co-fermentation of LPE, the yogurt showed better quality characteristics, including pH, titratable acidity, microbiological content, texture, color, and chemical composition. The content of Lactobacillus bulgaricus increased from 0.59 × 109 to 1.42 × 109 CFU/ml and the water-holding capacity increased from 50.01% to 55.96%. Moreover, the tertiary structure and secondary structure of casein showed obvious changes in the treatment of LPE according to spectroscopic results. Delphinidin 3-O-glucoside, cyanidin 3-O-glucoside, and malvidin 3-O-glucoside were identified in LPE. Furthermore, with the analysis of molecular docking, LPE could interact with casein by hydrogen bond and promote the folding of its spatial structure. The binding sites were mainly at proline and glutamic acid residues. All present results suggested that LPE had the potential to improve the quality of yogurt in the food industry. Novelty impact statement The quality changes in yogurt may affect its nutrition and sale. In the present study, lotus petals extract (LPE) exhibited the obvious ability to enhance the quality parameters of yogurt such as texture, color, and water-holding capacity, etc., which was attributed to the molecular interaction between casein and phenolic compounds of LPE. The results suggested that LPE had a potential value to improve the quality of yogurt in the food industry.