Freeze drying of lactic acid bacteria fermented food prepared from egg white powder and casein supplemented with growth stimulating agent

摘要

Lactic acid bacteria fermemted foods were prepared from egg white powder, casein and growth stimulating agent, pH change and growth of Lactobacillus acidophilus(KCTC 2182) during freeze drying were studied. The effects of freeze drying on sensory evaluation, hardness and volatile aroma compounds in freeze dried sample or reconstituted sample were also studied. Freezing and freeze drying did not affect pH of fermented samples. Number of viable cells in original fermented samples was markedly reduced during freezing or freeze drying. When number of viable cells in original fermented samples was considered as 100%, survival ratio of viable cells after freezing was 72.0-82.4% and that after freeze drying was 10.0-20.4%. When sensory properties of original fermented samples were compared with those of freeze dried/reconstituted samples, sensory properties of original samples were generally better than those of freeze dried/reconstituted samples. However, the reconstitution property and the acceptability of freeze dried samples were good. Volatile aroma compounds in original fermented samples were reduced during freeze drying. The reduction degree of volatile aroma compounds varied with sample.