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Sensory analysis of acidified dairy products using response surface methodology
Abstract
Modified processing techniques to reduce the time required to manufacture and to improve the general characteristics of dairy products have been developed. Direct acidification is a method to produce acidified milk products. The objective of this study was to determine the influence of diacetyl concentration on the sensory characteristics of a directly acidified low fat sour cream. The flavor added to the product was a natural starter distillate obtained from lactic acid cultures. Diacetyi was the principal component. A commercial conditioner was used to enhance the texture and an acidulant to adjust the samples to the desired pH. The milk product was prepared with selected concentrations of milk fat, solids-not-fat, and diacetyl as a starter distillate. A response surface experimental design was used for the experiment. Flavor, texture and total preference of the milk samples were evaluated by an untrained panel of consumers from Texas A&M University. Concentration of diacetyl in the head space of sour cream samples was determined by gas chromatography. The results of the analysis of variance indicated that milk fat and milk solids-not-fat significantly affected the flavor scores (p<.05). However, the scores assigned by the consumer panel were very low. Similar results were obtained for texture, and total preference. Milk fat was the most important component that affected sensory scores in the sour cream. The highest scores were obtained when milk fat concentrations were approximately 8%. Further increases in milk fat content decreased the sensory attributes, independent of NFS and diacetyl values. There was a high correlation between the panelist scores for flavor and total preference, emphasizing the importance of flavor for the acceptance of this product. The effect of the starter distillate concentration was significant (p<.05) only in the gas chromatography analysis. The consumers did not detect variations in diacetyl concentrations unless the milk fat concentration was less than 2%. The optimum values of the variables were a combination of 8.1% milk fat, 14.26% SNF, and 14.52 ppm of starter distillate. The scores assigned by the panelists indicated that low fat sour cream samples in this study were of minimum acceptability.
Description
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references: p. 53-55.
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Citation
Rocha, Maria de Guadalupe (1997). Sensory analysis of acidified dairy products using response surface methodology. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1997 -THESIS -R63.
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