Effect of Quince (Cydonia Oblonga) and Balangu (Lallemantia) Native Gums on Sensory Properties of Low-Fat Milky Dessert Using Principal Component Analysis (PCA)

Abstract
Introduction: Production of low-fat or high-fat products in order to reduce the amount of calories in excess of the body's consumption needs, is one of the developing circles in the food industry. Hydrocolloids are among the compounds that can be used to improve the properties of these low-fat products. Hydrocolloids extracted from the native seeds of Iran, such as Cydonia Oblonga and seed gum Lallemantia, have a good ability to be used in these cases. Therefore, without the use of data analysis methods, it is not possible to fully understand these studies and achieve practical results. Sensory evaluation and consumer play an important role in the development of food science and industry. Sensory evaluation studies provide extensive data. In sensory evaluation of food, the analysis of the main components provides a way to visualize the relationship between the product or sample and its sensory characteristics or traits. In fact, the analysis of the main components is used to create a simplified view of the multidimensional data set. The data set becomes smaller data due to the correlation of the main variables, and as a result, the main components are formed. Each major component is a linear combination of the main variables. Analyzing the main components is a useful way to evaluate data, as many researchers have used this method to analyze the results of sensory evaluation. In fact, the application of this method has been measured for a large number of the main variables (called the main components) are obtained, which include the highest varians of the observed variables. Therefore, with this method, the number of the main variable is reduced, and a smaller number of artificial variables (called the main components) are obtained, which include the highest variance of the observed variables. However, the effect of Cydonia Oblonga and Lallemantia native gums on the sensory properties of low- fat milky dessert has not been studied. Therefore, this study was conducted to investigate the effect of different levels of two types of grain gum Cydonia Oblonga and seed gum Lallemantia as a tissue healing agent and fat replacement on the sensory characteristics of low-fat milk dessert and another goal was to determine the correlation coefficient between sensory parameters so that the factors that had the greatest impact on overall acceptance were identified.
Material and methods: In this study, native gums of Cydonia Oblonga and Lallemantia in the from of a completely radomized design at the levels 0.1, 0.2 and 0.3% gums concentrations were used as the low-fat milky dessert as a textur improver and fat replacer. Then, the method of analying the main components was used to determine the relation ships of sensory parameters and to obtain the main components.
Results and discussion: The results of comparing the mean related to sensory testing showed that the amount of Scent and Taste and softness in different samples did not differ much (P <0.05). However, sensory evaluators were more interested in softness in samples containing 0.3 ,0.2 Lallemantia gum. The lowest amount of softness was related to the full fat control sample. The degree of porosity in different samples did not differ significantly (P <0.05). Congelation in the full fat control sample was more appropriate. Samples containing 0.3 Lallemantia gum and 0.3 Cydonia Oblonga gum were the best in terms of jelly. The being oily in the full fat control samplewas more adeguate. Scent and Taste were best in samples containing 0.3 Lallemantia gum and 0.3 Cydonia Oblonga gum. In general, overall acceptance on the amount of gum, sensory evaluators liked the samples with more Lallemantia and Cydonia Oblonga gums. Also, the results of the analysis of the main components showed that the highest correlation was between the general acceptance with the color parameter, which showed a correlation coefficient of 0.702. Softness with a coefficient of 0.659 and being jelly with a coefficient of 0.560 were also closely related to general acceptance. The Selection of the main components based on the specific value showed that the slope of the line is higher in the first 3 components (scent and taste, sweetness, softness) than the other components. The higher the absolute value of these coefficients, the more important the measured properties in the construction of the main component. Therefore, color is the most important component in the first factor, being oily and sweet are the most important components in the second and third factors, respectively. The product coordinates in PCA indicate the relevance of the parameters. For example, pastry and scent and taste were located in close proximity to each other, indicating a close connection between these parameters.
Conclusion: In sensory evaluation of food, principal component analysis provides a way to visualize the relationship between sample and sensory characteristics. In this study, in order to achieve a product withe a suitable structure in different amounts of 0.1, 0.2 and 0.3 gums concentrations were used as the low fat milky dessert, as a texture improver and fat replacer. In the production of samples, low fat milky dessert samples containing 0.3 Lallemantia native gum and 0.3 Cydonia Oblong native gum had the highest rate of sensory acceptance among the evaluators. Also, using principal component analysis, it was found that the overall acceptance of the samples had high correlation with color, softness and gel content. This study showed that Cydonia Oblonga and Lallemantia native gums could be used as a fat replacer and also as a dessert texture improver.