نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشگاه علوم کشاورزی و منابع طبیعی گرگان
2 استاد دانشکده علوم و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان
3 دانشیاردانشکده علوم و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: With increasing consumer awareness of nutritional, environmental, and ethical issues, the demand for plant-based milks as alternatives to cow’s milk has been growing. Quinoa-based plant milk, due to its high protein content, unsaturated fatty acids, dietary fiber, and gluten-free nature, is considered a nutritious and functional option in this field. One of the main challenges in producing plant-based milks is their physical and chemical instability during storage, caused by the density difference between the continuous and dispersed phases as well as the high content of unsaturated fatty acids. To overcome this problem, it is necessary to use additives such as stabilizers and fat phases with a high saturated fatty acid content in the formulation of plant-based milks, aiming to achieve a product with physical and chemical stability during storage and characteristics similar to dairy milk.
Materials and Methods: This study investigated the effects of soy protein isolate and xanthan gum, two common stabilizers in the food industry, on the physical stability of quinoa-based plant milk containing coconut oil. To eliminate the variable effect of fat content, the concentration of coconut oil was kept constant at 2% (w/w) in all treatments, while only the type and concentration of stabilizer were varied. Soy protein isolate was tested at three levels (1, 2, and 3% w/w), and xanthan gum at three levels (0.05, 0.1, and 0.2% w/w). Physicochemical properties of the samples—including particle size, zeta potential, apparent viscosity, physical stability, sensory evaluation, and microbial tests—were measured over 7 days of storage.
Results: The results showed that adding both stabilizers significantly improved stability parameters. Increasing soy protein isolate and xanthan gum to 2% and 0.1%, respectively, significantly increased viscosity and zeta potential while reducing particle size (P < 0.05). These changes were more pronounced in treatments containing xanthan gum than those with soy protein isolate. The improvement in stability simultaneously enhanced both the physical and microbial stability of the quinoa-based plant milk during 7 days of storage. However, at concentrations above the optimal level, a reverse trend was observed, leading to product instability. Color analysis showed that increasing soy protein isolate concentration decreased the L* value and increased the b* value, while xanthan gum addition caused minimal changes in a* and b*; however, at 0.2%, xanthan gum slightly reduced L*, likely due to increased viscosity limiting light transmission and causing turbidity, without xanthan gum itself having a significant color effect. Additionally, sensory evaluation indicated that increasing soy protein isolate and xanthan gum concentrations up to the optimal levels (2% and 0.1%, respectively) significantly improved texture, taste, and overall acceptance. Concentrations above these levels caused particle sedimentation and precipitation, resulting in undesirable texture and unpleasant mouthfeel.
Conclusion: Overall, the findings demonstrate that both soy protein isolate (optimal at 2%) and xanthan gum (optimal at 0.1%) can effectively improve the physical stability of quinoa-based plant milk, with xanthan gum having a greater effect than soy protein isolate. The targeted use of these stabilizers can play a key role in stabilizing emulsion-based products with acceptable sensory properties.
کلیدواژه‌ها [English]
)