METHOD FOR DETERMINING WEIGHT FRACTION OF FAT IN MILK Russian patent published in 2021 - IPC G01N5/00 

FIELD: food industry.

SUBSTANCE: invention relates to dairy industry, namely, to the field of technical control, and can be used for determination of fat weight fraction in milk or in milk-based liquid products by direct method without oil hydrolysis. Method for determination of weight fraction of fat in milk or in milk-based liquid products, including extraction of fat with petroleum ether and calculation of percentage of fat in milk by formula, characterized by that weighed portion of milk with weight "a" is held for three hours in a freezing chamber, then subjected to lyophilic drying in weighing pans of weight M₁ at minus 40 °C and 0.02 Bar for not less than 8 hours, after reaching the dry milk remainder portion of the constant weight weighing M₂, method includes extracting fats at room temperature by placing a dry residue from a weighed portion of milk into a porcelain mortar, pouring the weight portion with petroleum ether in portions of 10 ml five times, the mixture is thoroughly ground with a porcelain pestle, settled and the extract is separated from the sediment by means of a syringe, after which all 5 successively obtained extracts are combined in one flask with weight M₃ with volume of 100 cm³, removing petroleum ether on vacuum rotary evaporator and weight of bulb with fat M₄ is determined, and weight fraction of free fat and water fraction is calculated by formulas:

where M_F is mass fraction of fat in product, %; the M_w is mass fraction of water in the product,%; M₁ is mass of initial bucks, g; M₂ is weight of weighing bottles with dry milk sample, g; M₃ is mass flask of 100 cm³g; M₄ is bulb weight with fat, g; a is weight of a portion of milk, g; 100 is conversion coefficient of fat weight fraction per 100 g of product.

EFFECT: technical result is a wider range of methods for determining fat in milk.

1 cl, 3 ex, 1 tbl