Document Type : Complete scientific research article
Authors
1
Associate Professor of Department of Food Science and Technology, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, AREEO, Mashhad, Iran
2
Assistant Professor, Department of Green Technologies in Food Processing, Research Institute of Food Science and Technology (RIFST), Mashhad, Iran
3
MSc of Novel Dairy Products Manufacture, Khorasan Razavi Agricultural and Natural Resources Research and education Center, AREEO, Mashhad, Iran.
Abstract
Background and Objectives: In recent years, with increasing consumer awareness of the relationship between diet and health, demand for low-fat dairy products, particularly yogurt, has significantly increased. Low-fat yogurt is crucial in preventing obesity and cardiovascular diseases due to its low caloric content and favorable nutritional properties. However, reducing fat content in yogurt leads to challenges in texture, flavor, and overall acceptability. The use of functional compounds and fat replacers could provide an appropriate solution to overcome these challenges. Therefore, this study aimed to investigate the potential improvement of physicochemical and sensory properties of low-fat yogurt through the simultaneous incorporation of Aloe vera and beta-glucan as functional ingredients and fat replacers.
Materials and Methods: In this study, low-fat yogurt (1% fat) was produced with varying levels of Aloe vera (0, 0.5, and 1%) and beta-glucan (0, 0.5, and 1%) using a central composite design. The produced samples were evaluated for physicochemical properties including acidity, pH, syneresis, and viscosity. Sensory evaluation of samples, including texture, flavor, and overall acceptance, was conducted by nine trained panelists using a 5-point hedonic scale. The data were analyzed using response surface methodology and principal component analysis (PCA).
Results: Results indicated that the addition of Aloe vera and beta-glucan led to a significant decrease in acidity and increase in pH of the samples (p<0.01). Furthermore, increasing the percentage of these compounds significantly reduced syneresis, indicating enhanced water holding capacity of the product. Sample viscosity increased with increasing concentrations of both compounds due to their hydrocolloid properties and ability to form three-dimensional networks. In sensory evaluation, increasing beta-glucan up to 1% significantly improved texture and flavor scores and overall acceptance, while increasing Aloe vera improved texture scores but negatively impacted flavor and overall acceptance. PCA analysis revealed that the first two principal components explained 74.7% of the total variation. Significant positive correlations were observed between texture, acidity, flavor, and overall acceptance, while negative correlations were found between viscosity and syneresis.
Conclusion: This research demonstrated that the simultaneous use of Aloe vera and beta-glucan could be an effective approach for improving the physicochemical and sensory properties of low-fat yogurt. Numerical optimization showed that formulation containing 0.94% Aloe vera and 0.99% beta-glucan yielded the best characteristics with a desirability of 0.72. This formulation could be introduced to the dairy industry as a functional product with appropriate nutritional and functional properties, offering not only reduced fat content but also the health benefits of Aloe vera and beta-glucan. This product could meet the needs of consumers seeking healthy, low-calorie dairy products with desirable sensory characteristics.
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