A Systematic Review of Edible Swiftlet's Nest (ESN): Nutritional bioactive compounds, health benefits as functional food, and recent development as bioactive ESN glycopeptide hydrolysate

Edible swiftlet's nest (ESN) is dried gelatinized saliva secreted by swiftlets during the breeding season. The ESN has been widely consumed as a food and medicine since the ancient dynasty of China, particularly in the practice of Traditional Chinese Medicine (TCM). As a food with health-promoting effects, this made ESN a potential functional food. Whereby, functional food is food that can be consumed in the daily diet which then enhanced human health through nutritional aspect, but not as the cure of a disease. In this review, we discussed ESN as a potential functional food through the bioactive nutritional components and health benefits of ESN in promoting good health. Scientific evidence has proven that ESN consists of the unique glycoprotein of great value which provides high nutritional and functional properties for human health benefits. These include anti-ageing, anti-hypertension, immunity and neurological enhancement contributed by not only the unique glycoprotein but also sialic acid, epidermal growth factor (EGF) and other bioactive compounds. The ESN appeared to be categorized as a functional food, with various functionality, applications, nutritional composition and therapeutic benefits committed by its components. This review also pronounces recent development of ESN as hydrolysate in the form of bioactive glycopeptide with improvements in terms of solubility, functional and nutritional benefits that broaden its applications in various industries.