Cheese is a food product which is made by fermenting milk by adding certain starter culture. It is highly proteinaceous and contains high content of fat. It has many flavors but Cheddar Cheese is most popular among all of its kinds. By adding probiotics in cheese it would be added to the group of functional foods.
Probiotics are live micro organisms that are useful for human body if taken in proper amount. There are many food products which contains probiotics like yogurt and fermented milk but the main drawback of these products are their shelf life which is very short and probiotics does not remain viable for longer period of time .
The study was formulated to manufacture probiotic cheddar cheese, chemical and sensory evaluation of probiotic cheese and to check the viability of probiotics. The data was statistically analyzed for the effect of storage and treatment on probiotic viability by using Duncan's test.
The probiotic cheddar cheese was manufactured at Haleeb Foods. Starter culture and rennet was provided by Haleeb foods and probiotic cultures in freeze-died form were obtained from Christian Hansen, Denmark. The starter culture alone and in combination with different concentrations of probiotics were added to milk for cheese making. After completing all the steps involved in its preparation, cheese were removed from mould, packed in vacuum cryovac packaging and were placed for ripening for 90 days at 4ºC.
Sensory evaluation of Cheddar Cheese was done by a team of panelists to check its flavor, colour, taste, texture and overall acceptability at every fifteen days interval during maturation time. There is a significant effect of different levels of probiotics on flavor, color, taste, texture and overall acceptability of Cheddar Cheese. Storage has also shown a significant effect on the sensory parameters of cheese.
Chemical tests like pH, fat, moisture, protein, salt and acidity concentrations were also carried out after fifteen days interval at the laboratory of Department of Food and Nutrition, University of Veterinary and Animal Sciences Lahore. There is a significant effect of pH, acidity, fat and protein on cheddar cheese. As pH lowers with the passage of time its acidity increases. So there is significant effect of storage on different treatment levels. The levels of Lactobacillus acidophilus specifically have shown an increased acidity.
Viability of probiotic bacteria was checked at 15 days interval at the Laboratory of Department of Microbiology, University of Veterinary and Animal Sciences, Lahore. During ripening Bifidobacterium bifidum has shown a good viability level of 107 and 108 cfu/20g of cheese. But on the other hand lactobacillus acidophilus have sustain its numbers for about two weeks and then decreased to a very low level. So there is a significant effect of viability on both strains during the storage. There is non significant effect of levels on viability of probiotics.
The statistical analysis used was two way analysis of variance to check the treatment and storage effect on probiotic cheddar cheese by following the method (Steel et al., 1997). Significance of means was compared by using DUNCAN'S multiple range tests (1955).
The research has enabled us to conclude the outcomes that the Cheddar Cheese is a good vehicle for delivery of probiotics but the lactobacillus strain needs more improvements its viability is concerned.