Skim milk Mozzarella cheeses (negligible fat) were made using two maltodextrins (Maltrin M1 and M2) and a modified potato starch (StaSlim S1) fat replacers. A control cheese was made with skim milk without any fat replacer. The texture characteristics of the cheeses were measured with an Instron Universal Testing Machine and the microstructure examined using scanning electron microscopy. The moisture contents of the skim milk and maltodextrin based cheeses were similar, while modified potato starch-based cheeses showed significantly lower moisture levels. The protein contents of the cheeses made with fat replacers were significantly lower than for the control cheeses. The hardness values for Maltrin M1 and M2 cheeses were lower at 5, 10 and 18 d of storage while StaSlim S1 cheeses were similar to those of control during storage. In general, all the cheeses made using fat replacers showed less cohesiveness and springiness than the control cheeses, while adhesiveness was higher. The Maltrin M1 and M2 cheeses showed lower values of gumminess and chewiness; however, StaSlim S1 cheeses showed higher values, compared to control, at 5, 10 and 18 d of storage. Incorporation of fat replacers resulted in an increased openness in cheeses, and large serum channels (up to 0.1 mm diameter) were noticeable. The maltodextrin-based cheeses showed more openness than the modified potato starch-based cheeses.

R K Bhaskaracharya and N P Shah studied the characteristics of low fat Mozzarella made using exopolysaccharide and non-exopolysaccharide producing starter cultures.

Three batches of mozzarella cheese were prepared using skim milk (< 0.1% fat), each with exopolysaccharide (EPS)or non-exopolysaccharide (non-EPS)-producing starter cultures consisting of S. thermophilus and L. delbrueckii ssp. bulgaricus. The cheeses were analysed for moisture, protein and fat contents and for texture characteristics such as hardness, cohesiveness, adhesiveness, springiness, chewiness and gumminess. An Instron Universal Testing Machine was used to measure the texture characteristics while the microstructure of the cheeses was examined using a scanning electron microscope. The EPS cheeses showed 1.7% higher moisture content ton total cheese weight) than non-EPS cheeses. Both types of cheeses had similar protein content (43%). Most of the texture measurements decreased during storage for both types of cheese; however, adhesiveness at 50% compression increased during storage. Both types of cheese showed similar hardness and springiness values during storage; the EPS cheeses showed lower values of cohesiveness and adhesiveness during storage. The microstructure of the cheeses showed large and small voids representing the location of the serum and fat phases. The starter bacteria were located in serum channels. The exopolysaccharide was in the form of filaments, which extended from the protein matrix, probably as a result of dehydration of the EPS during SEM sample preparation. The EPS was primarily produced by S. themnophilus which was found in abundance, but not L. delbrueckii ssp. bulgaricus. The EPS cheeses were more open and porous compared to the non-EPS cheeses which could have decreased the cohesiveness and adhesiveness of the product.

The microstructure of mozzarella cheeses was studied using a simplified method of specimen preparation for imaging. Mozzarella cheeses were prepared each with and without exopolysaccharide-producing Streptococcus thermophilus and Lactobacillus delbruckeii ssp. bulgaricus. Samples were obtained from the cheeses to study their microstructure. Specimens were cut from the cheese samples, fixed in 2% glutaraldehyde, dehydrated and impregnated using 1.5% osmium tetroxide. The specimens were dried in a critical point drying apparatus, fractured at room temperature (similar to 20 degrees C), sputter coated with gold, and images of the cheese specimens taken using a scanning electron microscope. The images showed clear internal structures of the specimens. The compact protein structure of cheeses interspersed with small and large voids representing locations of the fat and serum phases, respectively, was seen. The exopolysaccharide produced by the streptococci appeared to be delicate and filamentous. The lactobacilli seemed to produce the exopolysaccharide in meagre amounts. The micro-organisms were found in serum channels.

This study aimed to examine the textural characteristics such as hardness, springiness, cohesiveness, chewiness and gumminess of four brands of commercial mozzarella cheeses in order to develop a product made with fat replacers with similar characteristics to these cheeses. These textural characteristics were analysed using an Instron Universal Testing Machine. A non-stretching cheddar cheese was used as a standard. The moisture, fat and protein contents of the cheeses were also analysed. The hardness and springiness were significantly higher with increased compression, while cohesiveness was reduced. Chewiness and gumminess initially increased and then decreased. The cheddar cheese exhibited higher hardness compared to mozzarella cheeses and slightly lower springiness. There was a drastic decrease in chewiness and gumminess with increased compression in all the mozzarella cheeses. The cheddar cheese showed significantly lower cohesiveness, which decreased with increased compression. In general, the hardness decreased with increase in moisture content. The springiness increased significantly with increase in fat content while the cohesiveness increased with increase in protein content in the mozzarella cheeses. This study shows the effect of moisture, fat and protein on the textural characteristics of the commercial mozzarella cheeses. One of the mozzarella cheeses showed the textural characteristics of the typical full-fat mozzarella cheese and will be used as a reference for further studies in developing a mozzarella pheese made with fat replacers.