In a recent study published in PLOS ONE, researchers assessed the suitability of mare milk in manufacturing yogurt-based and probiotic ice creams.
Study: The use of mare’s milk for yogurt ice cream and synbiotic ice cream production. Image Credit: Radoxist studio/Shutterstock.com
Introduction
Consumers are becoming more interested in functional food items, particularly dairy products. Mare milk, like human milk, has a significant potential for functional food production due to its low casein-to-whey protein ratio, low mineral content, high lactose concentration, and polyunsaturated fatty acid composition.
It includes bioactive compounds and has medicinal properties, which might help cure or prevent gastrointestinal and respiratory disorders.
Dairy products such as yogurt, kefir, and probiotic fermented beverages contain traditional fermented drinks from mare milk.
About the study
In the present study, researchers investigated the use of mare milk to make yogurt ice creams and synbiotic ice creams containing probiotic microorganisms and inulin.
The researchers developed four mare milk-containing ice cream variants: ice creams with yogurt bacterial microbes with 2.0% inulin (YO+I) and without inulin (YO), synbiotic ice creams with 2.0% inulin, Lacticaseibacillus rhamnosus (LCR+I), and Lactiplantibacillus plantarum (LP+I).
They obtained mare milk from Poland during the summer and pasteurized it at 65°C for 0.5 hours, dividing it into two batches, the first to prepare ice cream and the other to produce fermented milk.
After pasteurization, researchers cooled milk to fermentation temperatures of 34 °C for 10 hours (pH 4.2). They divided fermented milk into three parts, one inoculated with YO-122 yogurt culture comprising Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, and incubated for four hours at 42°C until pH 4.4.
They inoculated the second part with LCR monocultures comprising probiotic Lacticaseibacillus rhamnosus strains and incubated for 10 hours at 37°C till pH 4.4.
They inoculated the third part with probiotic monocultures comprising Lactiplantibacillus plantarum strain at 34°C for 10 hours. They added 0.10 g/L of freeze-dried cultures to the milk.
Researchers cooled the milk to 5°C and added pasteurized mare milk, cow cream, and sugar with or without inulin. Yogurt ice creams without inulin comprised 12% (weight by weight) of sugar, whereas yogurt and synbiotic ice creams with inulin comprised 2.0% inulin and 10% sugar.
Researchers blended the ice creams and subjected them to maturation procedures at 4.0°C for two hours, followed by freezing in ice cream machines until -10°C for an hour. They hardened the ice creams at -18°C for 24 hours and stored them in containers.
The researchers prepared 60 ice cream samples, 50 g each. They performed sensory, physicochemical, and textural analyses a day after production. In mare milk, they tested protein, fat, total solids content, and titratable acidity expressed as lactic acid percentage.
They evaluated overrun percentages, meltdown rates, texture (hardness and adhesiveness), and color. Sensory analyses included consistency, taste, flavor, appearance, color uniformity, creaminess, smoothness, presence of granules and lumps, cream aroma, bitterness, acidity, and foreign aroma. Microbiological analyses included the evaluation of viable lactic acid bacteria (LAB).
Results
Mare milk contained 0.5% fat, 2.4% protein, and 8.2% total solids, with 6.7 pH, 1.0 g/cm density, and 0.1% titratable acidity.
The ice creams were not significantly different in their total solid, fat, and protein content (25% to 27%, 7.3% to 7.6%, and 1.9 to 2.0%, respectively) but varied in acidity. Likewise, the overall sensory quality of the samples was similar, ranging from 17 to 18 points.
YO ice cream without inulin was the most acidic, while LCR+I showed the lowest acidity, indicating that inulin decreases acidity.
Irrespective of LAB culture type and inulin content, samples showed similar overrun (35% to 44%) and melting rates (74% to 80%). High melting rates may be associated with low-fat content since this ice cream component positively affects the melting resistance of the product.
However, the ice cream variant influenced texture and color. All ice creams prepared from mare milk showed high sensory quality.
Ice creams containing inulin had a higher LAB count [above 7 log colony forming units (CFU) per gram] than those not containing inulin (above 6 log colony forming units per gram). Sample YO, the one without 2.0% inulin, contained the lowest LAB. Probiotic milk ice creams were more adhesive and harder than yogurt ice creams.
All ice cream samples were creamy white and uniform with a greenish-yellowish hue. Ice cream YO without inulin addition was the brightest.
All samples had a soft, quite creamy, slightly coarse texture and a pleasant, creamy taste. The LP+I ice cream containing L. plantarum and inulin had considerably more acid flavor than other samples.
Conclusion
Based on the study findings, mare milk might be a viable raw food ingredient for making yogurt and probiotic ice creams better for the gut.
Novel mare milk products show promise in bringing this type of milk to Western customers who are unfamiliar with it, potentially increasing supply and processing.
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