The effect of hydrocolloid coating on cheese quality

Semi-hard and dry white brined cheeses were coated with hydrocolloid films based on k-carrageenan, alginate and gellan. The cheeses were immersed in the gum solution followed by cross-linking of the gum solution to produce a coated product.Weight loss, gloss, roughness of surface area, changes in mechanical properties versus time (i.e. stress and strain at failure, stiffness and elastic properties) of the coating film from the cheese and sensory evaluation were studied for each coated system. For the semi-hard cheese, all kinds of coatings reduced weight loss during of storage. The coating contributed to a better color and gloss. The roughness of the coated cheese decreased after coating. Advantages in the textural properties of the coated cheese were observed. Since the coated cheese lost less water by evaporation, a desirable softer and a less brittle texture was detected. The elastic properties of the cheeses were estimated by calculating the recoverable work (the ratio between recoverable and total compressive deformation) of coated and non-coated cheeses. This parameter appeared to decrease from,48 to 34% after 24 days of storage; no advantage of the coated cheese was observed. In the case of the dry white brined cheese, no deliberate drying of the coated film was performed. All coatings reduced weight loss of the cheese with a significant advantage of the k-carrageenan-based coating. The coatings contributed to a lower reduction in pH, thus a higher-quality cheese was obtained. In addition, the coated cheeses were softer and less brittle when compared to the non-coated cheese. The coatings increased the gloss of the cheese fivefold in comparison to the non-coated cheese. In a sensory evaluation, the coated cheese was found to be advantageous over the non-coated system. In general, cheese coating based on hydrocolloid films improved textural and sensorial properties when compared to non-coated cheeses. The coatings did not influence the taste of white brined cheese, and the technology involved is simple and relatively inexpensive.

Keywords:

cheese , physico- chemical properties , coating , hydrocolloid