On fat destabilization and composition of the air interface in ice cream containing saturated and unsaturated monoglyceride

The influence of glycerol monostearate (GMS, saturated), glycerol monooleate (GMO, unsaturated) and type of milk proteins on fat destabilization and the composition of the air interface in ice cream was investigated by particle size distribution, de-emulsified fat content and immuno-gold labelled transmission electron microscopy . When ice cream was made from skim milk powder and GMS, casein micelles, β-casein and β-lactoglobulin were all detected at the air interface. Fat was also found adsorbed or residing at the air interface. GMO strongly displaced caseins from the fat interface, introduced more partially coalesced fat adsorbed to the air interface and seemed to displace more proteins from the air interface. However, GMO was slightly less effective at displacing β-lactoglobulin from the fat interface than GMS. Fat globules were seldom found adsorbed to the air interface when whey protein was used as the only source of protein because ice cream emulsions were too stable to undergo desirable fat destabilization. In this case, the air interface predominantly comprised β-lactoglobulin, regardless of emulsifier type.