Effects of spans on whipping capabilities of aerated emulsions: Reinforcement of fat crystal-membrane interactions

Poor whipping capabilities of anhydrous milkfat based aerated emulsions pose a fresh challenge to food industrial production, limiting their potential applications in tea drinks, coffee, cakes, and desserts. In this study, the effects of high melting- and low melting-Spans on whipping compatibilities of the aerated emulsions were investigated from view of fat crystal-membrane interactions. With an increase in Spans concentration, there was a corresponding decrease in both fat globule size and interfacial protein. However, in comparison with low melting-Span 20 and Span 80, Span 40 and Span 60 with higher melting points have been found to improve anhydrous milkfat crystal matrix in terms of dense (D f  > 1.8) and spot-like crystals (5–10 μm). The interfacial film strength was reduced in this case as both long chain-saturated Spans competitively absorb at the membrane, and elasticity-dominant interfacial membrane was further obtained as their crystallization effects. Occurrence and development of partial coalescence of fat globules (>80% at more than 0.5% addition) were therefore promoted with such fat crystal-membrane interactions during whipping, contributing to a significant improvement in whipping capabilities and heat-stable stabilities of foam structures. A mechanism on the effects of Spans on improving whipping capabilities of aerated emulsions was therefore proposed based on the fat crystal-membrane interactions, which will provide guidance to produce high-quality whipped structures for aerated emulsions.