A systemic review of yak milk and its products on the Qinghai-Tibet Plateau: Unique products, chemical composition, biological activities, and microbial composition

Abstract

Background

In recent years, consumer demand for and interest in specialty milk has increased due to consumers’ taste preferences and health-conscious choices. Yak milk has attracted considerable attention owing to its special environment and nutritional properties and is known as “natural concentrated milk”. Comprehending the derivatives of yak milk, their nutritional profile, possible health advantages, and microbial diversity can aid in creating products with high added value.

Scope and approach

This paper comprehensively reviews the history of yaks and yak milk, yak milk products, chemical composition (volatile and non-volatile components), biological activities, and microbial composition, and proposes opportunities and challenges for further research on yak milk.

Key findings and conclusions

Yak milk and its products have a wide range of bioactive ingredients, including proteins, fats, fatty acids, amino acids, trace elements, and vitamins. In particular, the conjugated linoleic acid and immunoglobulin contents were significantly higher than those in the other animal milk. Its content varies according to species, altitude, and season. Yak milk and its components have demonstrated several potential biological activities in animal and in vitro studies, including antioxidant, antihypertensive, antibacterial, anti-inflammatory, anti-hypoxia, and immunomodulatory activities. Furthermore, understanding the microbial composition of yak milk and its products is crucial for quality control and flavor formation. Currently, the commercialization of yak milk and its products is limited owing to low yak milk production and the production environment, which requires further exploration of unique features and optimization of production process.