Effect of Sucrose on the Production of Acetaldehyde and Acids by Yogurt Culture Bacteria

Abstract

Yogurt cultures were grown in homogenized milk containing 2% fat, 12% solidsnot-fat, and 0, 4, 8, 12, and 16% sucrose. Following incubation, the pH, titratable acidity, acetaldehyde and cell numbers of Lactobacillus bulgaricus and Streptococcus thermophilus were determined. In general, growth and acid production were inhibited in media containing 4% or more sucrose. Acetaldehyde production was decreased in media containing 8% or more sucrose. The flavor thresholds determined for acetaldehyde in milk, milk plus 8% sucrose, and milk plus 8% sucrose plus strawberry flavoring were .8, 1.0, and 11.7 ppm, respectively. The masking effect of the flavoring was judged to be of greater importance to the perceived acetaldehyde note than the influence of sucrose on bacterial growth in fruit-flavored yogurt. © 1972, American Dairy Science Association. All rights reserved.