Original Article | 2003, Vol.25, No.6, pp. 791-797
Evidence of association of milk fat globule membrane with protein matrix in dairy gels as revealed by confocal microscopy
Nathanon Trachoo
pp. 791 - 797
Abstract
Consumer needs for low caloric and reduced fat foods has increased in Thailand. Cholesterol in milk fat has been a drawback for milk products. Reduction of fat results in undesirable effects in some products. To reduce fat in yogurt, total solid is lowered to 9-10%. This adversely affects physical and sensory properties of yogurt. Syneresis, weak body, lack of flavor and poor texture and mouthfeel are common defects of nonfat and lowfat yogurt. Our previous study has shown that yogurt made from milk with high milk fat globule membrane (FGM) had less whey separation. The objective of this study was to investigate the association of FGM on protein matrix in dairy gels using confocal microscopy. Sweet buttermilk contains a large amount of FGM. A model system was used by addition of glucono-δ-lactone into yogurt mixes. When directly acidified, membrane-like materials were observed under the microscope. They functioned as bridges linking protein matrices together resulting in a more defined protein network. This suggested that FGM has a potential to improve textural properties of yogurt.
