In recent years, milk and milk protein-containing products have been marketed as nutraceutical supplements and gained support from the general public.¹ Milk proteins can be separated into two principle fractions: caseins and whey proteins. Casein proteins are predominantly responsible for providing nutrients for the new-born, and have been shown to be an important contributor of biologically active peptides in bovine milk.² Whey is a by-product of cheese manufacturing which was historically considered as waste. However, more recently, whey proteins are increasingly being recognised as functional food. Bovine whey has been demonstrated in the literature to have potentials for development of valuable bioactive elements with emerging therapeutic benefits.³ Bioactive peptides have been well documented in exerting a wide range of physiological effects in many animal models and in human intervention studies.⁴

Cow milk has attracted extensive research over the last few decades due to its commercial availability and popularity. On the other hand, small ruminant milk which has a significant production and been documented to have health advantages over cow milk, has not been studied to any great extent.

This current study aims to fractionate and characterise whey proteins and peptides from sheep, goats and deer, and compare with those of cows, which have been well studied. Sweet whey was made from milk of the aforementioned species and depleted of α-lactalbumin and β-lactoglobulin to allow access to lower abundant proteins which were sub-fractionated by ion-exchange chromatography, separated on SDS-PAGE and analysed with MALDI-TOF MS to identify protein components, prior to the establishment of protein hydrolysates using GRAS proteases and analysis of bioactivities in the future.