Progress in the preparation, identification and biological activity of walnut peptides

Walnuts are rich in protein and are a high-quality plant protein resource. In recent years, with the growth of consumer demand for functional food and food for special medical purpose, the use of walnut protein for the preparation of functional walnut peptide ingredients or additives and other compositions has received increasing attention. However, the improvement of the yield of walnut peptides and the clarification of their functional activities are the bottlenecks that limit the development of these peptides. To this end, this article reviews the pretreatment, preparation, purification and identification processes of walnut peptides, as well as their biological activities such as antioxidant activity, antitumour activity, improvement of memory, antihypertension and regulation of metabolic disorders are elaborated to provide a reference for the industrial development of walnut peptides.