The Effect of Addition of Different Amounts of Chitosan Powder to the Batter and Chitosan Coating of Tea Sausage (Dry-Fermented Sausage) on the Physico-Chemical, Sensory and Microbiological Quality.

The effect of chitosan addition at amounts of 0, 0.25 and 0.50% and chitosan coating on pH, instrumental surface and cut cross-section colour (L*-lightness, a*-redness, b*-yellowness, h-hue angle, C*-chroma-saturation index and λ-dominant wavelength) and texture (hardness, springiness, cohesiveness and chewiness) parameters, and overall sensory and microbiological (TPC-total plate count and LAB-lactic acid bacteria) quality of dry-fermented sausages (tea sausage) were investigated. The addition of chitosan increased the pH, surface λ and cut cross-section h (0.50%), and decreased surface b*, C* (0.50%) and h, and cut cross-section a* (0.50%) and λ (0.50%), while chitosan coating increased surface L* and h, and decreased surface a*, b*, C* and λ, and cut cross-section L*. Hardness (0.50%), springiness, cohesiveness and chewiness were lower in the sausages with chitosan. The chitosan coating also led to a decrease in hardness, but at the same time increased springiness and cohesiveness. The chitosan addition improved the overall sensory quality, while the chitosan coating had the opposite trend. The microbiological results indicated that addition of chitosan had reduced TPC (0.50%), while chitosan coating had reduced LAB. In addition, the adding of chitosan did not affect surface L* and a*, cut cross-section L*, b* and C*, and LAB, while pH, cut cross-section a*, b*, C*, h and λ, chewiness and TPC were not affected by the chitosan coating. The two-way interaction between amount of chitosan and the chitosan coating had a significant (p = 0.038-<0.001) effect on the pH, surface a*, h and λ, cut cross-section L*, a*, C*, h and λ, hardness and overall sensory and microbiological (TPC and LAB) quality. In practice, chitosan can be applied as a food additive to control and improve the quality of dry-fermented pork sausages.