Effect of whey protein- and xanthan-based coating on the viability of microencapsulated Lactobacillus acidophilus and physiochemical, textural, and sensorial properties of yogurt

Mina Khorshidi; Ali Heshmati; Mehdi Taheri; Mostafa Karami; Reza Mahjub

doi:10.1002/fsn3.2398

Effect of whey protein- and xanthan-based coating on the viability of microencapsulated Lactobacillus acidophilus and physiochemical, textural, and sensorial properties of yogurt

Food Sci Nutr. 2021 Jun 10;9(7):3942-3953. doi: 10.1002/fsn3.2398. eCollection 2021 Jul.

Authors

Mina Khorshidi¹, Ali Heshmati¹, Mehdi Taheri¹, Mostafa Karami², Reza Mahjub³

Affiliations

¹ Department of Nutrition and Food Safety School of Medicine Nutrition Health Research Center Hamadan University of Medical Sciences Hamadan Iran.
² Faculty of Food Science and Technology Bu-Ali Sina University of Hamedan Hamedan Iran.
³ Department of Pharmacology and Toxicology School of Pharmacy, Medicinal Plants and Natural Products Research Center Hamadan University of Medical Sciences Hamadan Iran.

Abstract

The goal of this study was to investigate the viability of microencapsulated and coated Lactobacillus acidophilus in yogurt during storage in a refrigerator for 28 days and in simulated gastrointestinal conditions. Furthermore, the effect of the microencapsulated and coated L. acidophilus on the physicochemical, textural, and sensory properties of yogurt was assessed. Lactobacillus acidophilus was microencapsulated in sodium alginate and coated with xanthan and/or whey protein. The coating led to the increase in the microcapsule diameter and the microencapsulation yield, while it led to the decreased moisture and water activity (aw) of the microcapsule. The survival of L. acidophilus microcapsule coated with whey protein and xanthan in yogurt during storage and exposure to simulated gastrointestinal conditions was significantly increased. Compared with free bacteria, the L. acidophilus microcapsule coated with whey protein and xanthan had the increased viability in yogurt until 2.16 log CFU/g during storage and 3.52 log CFU/g in simulated gastrointestinal conditions. After the 28th day of storage, a significant difference between the acidity and pH of yogurt containing coated and microencapsulated L. acidophilus and control yogurt was not observed. However, yogurt containing free L. acidophilus had lower pH and higher acidity and showed a significant difference (p < .05) with other samples. Although the coating of L. acidophilus microcapsule did not affect the sensory properties and gumminess of yogurt, it increased the firmness, adhesiveness, and viscosity of this product and caused a significant decrease in syneresis and cohesiveness. In general, the application of whey protein and xanthan coating on L. acidophilus microcapsule surface could increase the viability of this probiotic in yogurt during storage and in simulated gastrointestinal conditions and improve the texture attributes of yogurt.

Keywords: Lactobacillus acidophilus; dairy products; probiotic; viability; yogurt.