식용유 함량을 달리한 마요네즈의 유변학적 특성

The steady shear flow and the small-amplitude dynamic viscoelastic properties of mayonnaises with different oil contents (75-85%) have been studied over a wide range of shear rates and angular frequencies by using a cone-plate rheometer. Yield stress was determined by Casson model. The fluid consistency coefficient (K) and flow behavior index (n) were determined by Herschel-Bulkley model. The volume-weighted average diameters of oil droplets for mayonnaises with 75, 80 and 85% oil contents were 3.89, 3.04 and 3.15 μm, respectively. All of the mayonnaises had yield stress, shear-thinning behavior and thixotropy. These properties were fortified as the oil content in the mayonnaise increased. The magnitude of storage modulus and complex viscosity increased with the increase of oil contents. Over a wide range of angular frequencies, the value of storage modulus (G') for mayonnaise was much higher than that of loss modulus (G"). Both G' and G" increased with increasing angular frequency but they had slight dependency on angular frequency. Parameters, n' and n" were 0.10 and 0.20, respectively, meaning that frequency dependency of G' was smaller than that of G". The mayonnaise with higher oil content had more pronounced gel-like characteristics than that with lower oil content.