Structural changes in sweetened condensed milk during storage: an electron microscopy study

Abstract

SummaryThis work aimed to relate changes in rheological behaviour with structural details of different sweetened condensed milk samples as well as to clarify the role of additives in delaying gelation. To study the process of gelation, rheological techniques were applied to fresh and stored condensed milk samples for times and at temperatures known to favour gelation (45 d at 37 °C). Electron microscopy techniques were used to relate the rheological changes with observed structural details. Examination by electron microscopy showed that micellar aggregation and association of casein micelles with fat globules increased during storage. The whey proteins appeared to play an important role in the thickening process.