Evaluating the effect of fat content on the properties of vanilla ice cream using principal component analysis

In the current study, the effect of fat content on the physicochemical and sensory properties of vanilla ice cream was investigated using principal component analysis (PCA) and quantitative descriptive analysis (QDA). For this purpose low fat, light, reduced fat and full fat ice creams were produced using 2, 5, 7.5 and 10% milk fat respectively. According to the results, reduction of fat in ice cream contributed to a significant decrease in total solid (TS) and caloric value of the samples and increased their protein content and pH value significantly (p < 0.05). The QDA of sensory properties demonstrated that the decreased fat samples had lower viscosity, mouth coating, smoothness and firmness and higher melting rate and coldness sensations in comparison with the full fat ice cream. PCA technique was used to simplify discussion of the obtained results. Two principal components (PC) named as PC1 and PC2 described a total of 96.12% of the variation of the initial variables. PC1 was primarily related to the values of coldness, viscosity, mouth coating, smoothness, firmness, melting rate, overall acceptance, pH, TS, protein and calorie; while PC2 was related to the acidity of the samples. Distribution pattern of the studied attributes showed that the melting rate and coldness sensation discovered in opposite quadrants of other sensory attributes; while, close relations were observed between the smoothness and TS, viscosity and mouth coating and also between the pH value, protein content and melting rate of the ice cream. A comparison between the correlation results of the fat content with the sensory attributes showed that the viscosity of the ice cream samples was more dramatically affected by the fat reduction. Therefore, it is suggested to use a type of fat replacer which can effectively improve the viscosity of low fat ice cream products.