Analysis of Techno-Functional Properties of Fermented and Non-Fermented Buttermilk-Containing Ice Creams

The aim of this study was to investigate the utilization of buttermilk, a by-product of butter production, in ice cream. Butterfly pea flower, which provides natural coloring and antioxidant properties, was added to buttermilk for investigating its improving effect on the techno-functional and sensory attributes of ice cream. Ice cream mixes were prepared with varying buttermilk concentrations (0%, 20%, 40%, 60%, 80%, 100%) as the first factor of the research. In addition, the effect of fermentation was also investigated as the second factor of the experiment. The ingredients included buttermilk, milk, cream, sucrose, dextrose, locust bean gum, butterfly pea flowers, and vanilla extract. The preparation involved the extraction of the butterfly flowers, fermentation in case of the fermented samples, homogenization, pasteurization, freezing, and hardening. Quality attributes such as dry matter content, pH, color, rheological properties of the ice cream mixes, overrun, melting properties, and ice cream hardness were analyzed to determine the maximal substitution level of milk by buttermilk without compromising ice cream quality. Our results explore the impact of buttermilk content and fermentation on the techno-functional properties of ice cream. As buttermilk concentration increased, dry matter content decreased, ranging from 34.4 g/100 g at 0% buttermilk to 31.9 g/100 g at 100% buttermilk. pH levels were lower in the fermented samples, decreasing from 6.5 in the non-fermented to 4.6 in the fermented samples. L* decreased with higher buttermilk content, while a* and b* values increased slightly. The butterfly pea flower provided a blue hue across all samples; the blue hue increased by 20% with a higher buttermilk content. Increasing the buttermilk concentration led to a 40% decrease in the yield stress and consistency coefficient, indicating a less viscous mix. The flow behavior index slightly increased, suggesting a more Newtonian-like flow at higher buttermilk levels. Overrun decreased with a higher buttermilk content, from 45% at 0% buttermilk to 30% at 100% buttermilk, indicating reduced air incorporation. The meltdown rate increased with a higher buttermilk content, meaning the ice cream melted more rapidly. The hardness of the ice cream decreased as buttermilk concentration increased, from 15 N at 0% buttermilk to 10 N at 100% buttermilk. The fermented sample groups were on average 44% harder than the non-fermented sample groups. The findings suggest that up to 100% of buttermilk can effectively replace milk in ice cream formulations without compromising quality, providing a sustainable and health-beneficial use for this dairy by-product.