Microstructure of some dairy foods and food protein gels

An important factor influencing texture of a food product is its microstructure. The objectives of these investigations were to study the effect of fat replacers on the microstructure of low fat Cheddar cheese and impact of maturation on the microstructures of Vallegret and Edam cheeses to understand the effects of concentration of some food proteins on the microstructure of their respective gels to study the impact of ions on Bovine serum albumin (BSA) gel microstructure and to understand the effect of sweeteners on the microstructure of yogurt.Transmission and Scanning electron microscopic techniques were used for these ultrastructural investigations. Microstructure of low fat Cheddar cheese was found to be affected by fat replacers, particularly Simplesse which imparted discontinuity to the protein matrix. Layers were seen in the protein matrix of matured cheese. Fiber formations were also noted in the protein phase of mature Vallegret cheese. Presence of microscopic inclusions (voids) were markedly reduced in mature cheese. In immature (day 1) Vallegret cheese calcium phosphate associated mainly with the fat phase. On the other hand, in mature cheese these associations were mostly seen with the protein phase. The BSA gels were most compact compared to gels of other protein sources in this study, viz., whey protein concentrate (WPC) and egg white (EW). Most open matrices were seen in case of WPC gels. Gels became more open (less dense) as the protein concentration decreased. Ions profoundly impacted BSA gel microstructure, individual aggregates became significantly larger with the use of CuSO...