Proximate Composition of Packaged Freeze Dried Cheeses in Storage
Keywords:Cheese, freeze drying, proximate composition, packaging materials, storage duration, milk, Nigeria
The proximate composition of packaged freeze dried cow milk cheese and soy cheese in storage were investigated. Fresh cow milk cheese and soy milk cheese of 600g each was prepared and cut into sizes of 3x3cm dimension and a thickness of 0.3cm. 100g each of the fresh cheese samples was used to determine the initial propertieswhile the remaining 500g were freeze dried. The initial properties of the freeze dried samples were determined using a portion of each of the samples. A randomized experimental block design was adopted. The freeze dried samples were packaged in sterile tightly covered glass jar, sterile tightly covered plastic container and a sterile polythene film while the unpackaged sample was used as the control sample. The samples were stored at 35– 40oC and 90 - 95% RH for 3 months. Samples were analyzed for its proximate qualities monthly during the storage period. Data obtained were analyzed statistically to determine the effect of the packaging materials and storage durations on the proximate composition of freeze dried cheese samples. Result of the mineral composition for the fresh cow milk and soy cheese for moisture content (%), ash (%), protein (%), fat (%), and carbohydrate (%) were 54.02±0.10, 6.40±0.32, 20.34±0.50, 18.11±0.06, 4.25±0.20 and 50.89±0.12, 6.31±0.31, 22.05±0.02, 19.02±0.58, 4.06±0.10 respectively while the result for the freeze dried cow milk and soy cheese before storage were 4.28±0.10, 32.72±0.12, 32.24±0.28, 4.05±0.98, 26.86±0.90 and 4.19±0.46, 30.98±0.55, 34.84±0.31, 4.30±0.29, 24.72±0.01 respectively. The packaging material type used and storage duration have no significant effect on the proximate composition (moisture, carbohydrate, protein, ash and fat) of the cow milk and soy milk cheeses after 3 months of storage. This indicates that all the packaging material types used can adequately retain the proximate composition of freeze dried cheese. It is therefore concluded that freeze drying increases some proximate composition (carbohydrate, protein and ash) of cheeses and appropriate packaging enhances and extend the shelf life of cheeses.