The evaluation of probiotic Kashk properties in hot filling condition containing microencapsulated Lactobacillus rhamnosus

Kashk is one of the most popular fermented products in Iran which is produced and packaged in the hot filling mode. Due to the sensitivity of probiotic bacteria to heat, so far, there is no attempt to produce probiotic Kashk. Therefore, in this project, two-layered extrusion microencapsulation technique by alginate and Zedo gum was applied to Lactobacillus rhamnosus. Acidity, color, texture, sensory parameters and bacterial viability were evaluated. The results showed that the acidity was constant during the 60th day of storage time about 211 ° D in the control sample and 193 ° D in the probiotic sample. The free bacteria had not survived after the hot filling process in the Kashk sample, but the probiotic sample had a standard limit for the probiotic product until the 14th day of storage time. On the 60th day, general view, flavor, acceptance, and viscosity as sensory parameters in the control Kashk sample had a higher rating than the probiotic one. ΔE was 4.8 and 2.62 in control and probiotic Kashk, respectively. Except for cohesiveness, the other texture parameters increased at the beginning of the storage period and remained relatively constant during the time in control and probiotic Kashk. Therefore, according to the results of this research, the two-layered microencapsulated L. rhamonosus survived for 14 days as the recommended minimum limit of 6 log CFU/g bacteria for probiotic products and control Kashk had a shelf life of 60 days. Thus, this technique can be used as an effective method for the survival of probiotic bacteria in Kashk.