Dairy protein stabilizers affect both rheological properties and growth of Zygosaccharomyces parabailii in lite salad dressings

Abstract

Lite salad dressings were evaluated for the effects of dairy protein stabilizers on Zygosaccharomyces parabailii (Z. parabailii) growth and rheological properties. Salad dressing formulations were prepared with 12.5% w/w milk protein isolate, whey protein isolate, or micellular casein. Formulations were inoculated with Z. parabailii (104 CFU/ml) and stored at 4, 10, or 25°C for 45 days. The viscosity and small- and large-strain viscoelastic properties of the formulations were determined via rheometry. Formulations containing milk proteins were compared to a control lite salad dressing containing 4.2% (w/w) starch. Formulations containing a milk protein stabilizer and acidified with acetic acid showed no detectable Z. parabailii growth after 5 days of storage at any storage temperature. While milk protein-stabilized lite salad dressings showed significantly reduced Z. parabailii growth compared to the control, the changes in viscosity and viscoelastic properties of these dressings indicated destabilization of the dressing over time. Practical applications The information from this study can be used as a starting point to reduce Zygosaccharomyces parabailii growth in salad dressing products. Additionally, the data from this study gives insight into a dairy protein-stabilized salad dressing and its effectiveness for preventing/reducing Zygosaccharomyces parabailii growth. Rheological findings in this study can be used to predict potential flow behaviors for lite salad dressings made with a dairy protein stabilizer.