Formulation of Protective Agents for Improvement of Lactobacillus salivarius I 24 Survival Rate Subjected to Freeze Drying for Production of Live Cells in Powderized Form

Abstract

The effectiveness of formulations using different protective agents to maintain viability of Lactobacillus salivarius I 24 during freeze drying for production of live cell in powdered form was investigated. The influence of prefreezing and cultivation conditions on viability of cells after freeze drying was also studied. Surface methodology was used to determine the most suitable combination of the protective agents. Concentrations of skim milk, sucrose, glycerol, and calcium carbonate were selected as operating variables, and survivals of cultures after freeze drying were used as results. Skim milk and sucrose were better protective agents than glycerol and calcium carbonate when used individually for preserving L. salivarius I 24 during freeze drying. Their protective abilities could be enhanced significantly when using them as a mixture (9.85% w/v skim milk and 10.65% w/v sucrose). Prefreezing of the cells at −80°C for 5 h prior to freeze drying and cultivation with regulated pH and temperature gave the highest cell viability.

Ultrasound assisted nucleation of some liquid and solid model foods during freezing

“…As a result, ultrasound can be used to improve the quality of the frozen product by controlling nucleation. In the freezing of tissue foods, formation of large ice crystals which are mostly extracellular, results in significant damages to the tissue (Ahmad, Yaghmaee, & Durance, 2010;Delgado, Zheng, & Sun, 2009;Kiani & Sun, 2011;Ming, Rahim, Wan, & Ariff, 2009;Streit, Corrieu, & Béal, 2010;Yu, Ma, Zheng, Liu, & Sun, 2011). On the other hand, formation of fine crystals that are evenly distributed both inside and outside the cells, leads to the quality of the final product to be better preserved due to less damages to the tissue .…”

Evaluation of Lactobacillus paracasei subsp. tolerans isolated from Jenyn's sprat (Ramnogaster arcuata ) as probiotic for juvenile rainbow trout Oncorhynchus mykiss (Walbaum, 1792)

“…The suspension was frozen at −70°C and lyophilized (Rificor Mod. L‐A‐B4, Argentina) (Berner and Viernstein, ; Kŏs et al., ; Ming et al., ). The viable cell number was monitored periodically by plate counting on MRS agar under reduced oxygen tension.…”

Optimization of Protective Agents for The Freeze-Drying of Paenibacillus polymyxa Kp10 as a Potential Biofungicide

“…The first is where the cells are frozen and water molecules in the cells are disabled followed by a drying stage where water molecules are removed [15]. Ice formation in the cells during the freezing phase could cause damage to the cells due to membrane rupture [16]. To overcome these effects, protective agents are usually added before freezing or freeze-drying stage [17,18].…”