Effect of product composition on sensory characteristics of acidified milk products

Abstract

The sensory properties of sour creams with different concentrations of milk fat, solids-not-fat (SNF), and diacetyl were evaluated by consumer taste panel. The data was analyzed by Response Surface Methodology to find combinations of ingredients that produced optimum product scores. Taste, texture, and overall acceptability of the products were significantly (P < .05) affected by the concentration of SNF in the products. Concentration of diacetyl in the headspace of sour creams was determinated by gas chromatography. The concentration of diacetyl, milk fat and the interaction of SNF and diacetyl concentration (P < .05) affected the amount of diacetyl in headspace of sour creams Higher flavor scores were generally obtained for sour creams with 4 ppm diacetyl and higher milk fat content at constant SNF. However, for sour creams with 10-13% milk fat and 11-13% SNF, the products with 12 ppm diacetyl received higher scores than products with 4 or 8 ppm diacetyl. At milk fat concentrations lower than 13% texture scores increased rapidly with increasing SNF. However, in products with more than 16% milk fat, texture scores increased at a slower rate as the concentration of SNF increased. SNF concentrations greater than 13.5% caused texture scores to decrease. Sour creams containing 12.3% SNF had the highest total preference score at all concentrations of milk fat and starter distillate concentrations. Higher levels of milk fat are needed in products with 12 ppm diacetyl in order to achieve scores similar to scores with 8 and 4 ppm diacetyl. Sour cream with 4 ppm diacetyl provides more formulation options for good total preference scores. Flavor scores were highly correlated to total preference scores. Flavor score is a good predictor for total preference of sour creams. There was no relationship between flavor scores and peak area of diacetyl in the headspace of samples. For optimization, combinations with 13-20% milk fat and 8.5-14.5% SNF, 12.5-20% milk fat and 10-14% SNF, and 10-20% milk fat and 11.5-13.5% SNF can meet set criteria (flavor [] 5.5, texture [] 6.6, total preference [] 5.5) and for sour creams with 4, 8 and 12 ppm, respectively.