SU1377721A1 - Quantitative method of determining non-dairy fats in dairy products - Google Patents

Abstract

The invention relates to milk production and can be used to quantify fats of non-dairy origin in dairy products. The aim of the invention is to improve the accuracy, the sensitivity of the method and the reduction of its duration. To prepare the sample, either lard oil, or sunflower oil, or beef tallow, or mixtures thereof are used as fats of non-dairy origin: after which the prepared sample is filtered, thermostatic at 59-6 l C. within 9-11 minutes and determine its optical density at a wavelength of 430-450 nm, which is used as the main output parameter, and then using the constructed calibration graph of the dependence of optical density on the content of beef or pork fat, or sunflower oil, or their mixtures in the sample with milk fat determine the content. non-dairy fat in dairy product by the found value of optical density. 6 ill., 2 tab. with $ (L

Description

The invention relates to the food industry and can be used in the dairy industry to control the amount of fat in the mixture in the production of fat-containing products with a balanced fat basis.

The purpose of the invention is to improve the accuracy and sensitivity of the method and to shorten the time it is spent.

A sample of milk fat is prepared with non-dairy fats, for example, with swine or beef tallow, sunflower oil, or a mixture thereof. The melted, filtered mixture of the sample of the fat mixture is placed in a cell with a photoelectric colorimeter and thermostatic for 9–11 min at 59–61 s. The optical density is determined at a wavelength of 430-450 mm, which is used as the main output parameter. Build a calibration graph of the dependence of optical density on the content of goat or ground fat, sunflower oil, or their mixtures in a sample with milk fat, determine the content of non-dairy fat in a milk product based on the found optical density.

The temperature of 59–61 ° C is necessary to maintain the mixture in the molten state for 4–5 measurements for each sample during colorimetry. When the fat cools below 50-55 C, the fat becomes cloudy, and this makes it difficult to colorize it and leads to incorrect measurement results. Increasing the temperature of thermostating above 61 ° C and keeping the sample in time can contribute to the onset of intense oxidation processes in it, which result in a change in the physicochemical parameters of the sample, which can also lead to incorrect data.

The thermostating time of 9-11 minutes is optimal for uniform and complete heating of the fat mixture to a transparent state. Reducing the time of delivery is not acceptable in order to avoid incomplete melting of the fat mixture, and the increase is not rational, since it does not affect the indicators, but only increases the time of analysis.

Jq

5 20 25 30

5 0 5

0

five

The wavelength of 430-450 nm, when determining the optical density, corresponds to the maximum transmission with respect to distilled water. For each sample, 4-5 measurements are taken and the arithmetic average is calculated.

Knowing the value of D for the studied fat mixture according to the calibration curve, find the corresponding percentage of non-dairy fat in the mixture with milk fat.

Example. A melt of a fat sample of a filtered test sample (milk fat with pork or beef or sunflower oil) or with their mixture is placed in a PEC-56M photoelectric colorimeter cuvette. The absolute error of optical density measurement on this device does not exceed 1%. However, the relative error of determination will be different when working on different parts of the scale and reaches a minimum at an optical density of 0.4. Therefore, in order to work close to this optical density and preferably not higher, animal fats and vegetable oils are best used with cuvettes with a working length of 0.5 cm. This ensures sufficient accuracy of definitions and good reproducibility of the results.

 I

Then the fat in a cuvette thermostatic

10 min at 60 ° C. Exactly after the indicated time has elapsed, the optical density (D) is determined using a photoelectric colorimeter. The wavelength of the wave corresponds to the maximum transmission of 440 + 10 nm (light filter No. 4). Colorimetry is carried out with respect to distilled water. For each sample, up to 4-5 measurements of optical density are taken on the instrument and the arithmetic average is calculated. However, it is not allowed to cool the fat below 50 ° C. Otherwise, the fat becomes cloudy, which makes it difficult to colorize it and leads to incorrect measurement results. Knowing the value of D for the studied fat mixture, according to the grading curve, the corresponding percentage of non-dairy fat in the mixture with dairy one is found.

The calibration curve is constructed as follows. Preparing by a gravimetric method (with an accuracy of 0.01 g) a series of modeltps of milk fat systems with fats of non-dairy origin or with their compositions at concentrations of 10, 20, 30 ... 90%, as well as using the original milk and non-dairy fats.

For each model system, the optical density is measured at the same light filter and calibration curves are plotted according to D f (C,%) by plotting known concentrations (C) of the model systems on the horizontal axis, and corresponding optical density values on the vertical axis. (D)

The calibration curve is then used to determine the unknown concentration of non-dairy fat in the fat mixture studied, and the molten fat mixture is poured into the same cuvette for which the calibration curve is constructed.

The absolute error of the method for mixtures of milk fat with sunflower oil or its composites with animal fats does not exceed 1.5-2%, for mixtures of milk fat with animal fats - 2-3.5% depending on the amount and the type of fat added to the mix.

 Samples of dairy, pork, beef tallow and sunflower oil were used as an object of research. In addition, three compositions of chemical composition similar to milk fat in the following proportions, g, were made from beef, pork fat, and sunflower oil:

1-2 3

Beef tallow 7 9 45

Pork fat 88 70 43

Sunflower

butter

On their basis, model milk fat systems with vegetable oil, animal fats, and compositions No. 1, 2, 3 were prepared using the above method.

For each model system and initial fats and oils, they are determined in four-, fivefold repetitions of the optical density according to the described method. The data obtained are presented in Table 1, on a basis of Q), 15 20

25, 30, 5 IQ

45

50

55

the average data which graphs are built (figure 1-6).

As can be seen from Figs. 1-6, between the optical density (D) of the fat mixture and the percentage (C,%) of non-dairy fat additives mixed with milk fat, linear dependence is clearly observed for all model systems. Therefore, the graphs in figure 1-6 can be used as a calibration. Knowing the value of optical density (D) for the fat mixture according to the calibration graphs of FIGS. 1-6, the percentage of fat additives mixed with milk fat is found. The irradiated data found on the calibration graphs (figure 1-6) are presented in table 2.

Claims (1)

Invention Formula A method for quantitative determination of non-dairy fats in dairy products, which involves preparing a sample of milk fat with non-dairy origin, determining the main output parameter and building a calibration graph of the main output parameter versus the percentage of pig fat or sunflower oil in the sample with milk fat, characterized in that , in order to increase the accuracy, sensitivity of the method and reduce the time it takes to prepare the sample as non-dairy fats, use either pork fat, or sunflower oil, or beef tallow, or mixtures thereof, after which the prepared sample is filtered, thermostatic, at 59-6l C for 9-11 minutes and its optical density is determined at a wavelength of 430–450 nm, which is used as the main output parameter, and then, based on the calibration curve plotted, the dependence of optical density on the content of beef or pork fat, or sunflower oil, or their mixtures in a sample with milk fat neighing of a non-dairy fat in the dairy product according to the optical density value found. Table I Continuation of table 1377721 ten Continuation of table 1 Continuation of table 2 Seri,  payment order Dtp. conv. units The content of non-dairy fat in a mixture with milk fat,% Deviation SpecifiedFound 50,306 50.0 49,50,5 60,274, 60,060,00,0 70.245 70.071, 01.0 8, 0.226 80.079.01.0 ABOUT YOU 30 fiQ 50 60 70 80 90 100 SIERD) non-dairy) Kira 8 mixture with dairy (s), / o FIG. one Deviation, About Yu 20 30 W 50 60 70 WEEE JOO Non-dairy Codepft oHue / kira Blend with dairy (C), / About Yu 20 30 0 50 60 70 80 90 100 Non Milk Fat Content in a mixture with milk (C), o. , Fi & .3 OL50 O. Azo. § 0,300 , § C1250 I0.20 I I.0,150 I IO.WO "§0,050 o 10 20 30 lO 50 ba 70 30 SOW Content of cement fat of 8 mixture with milk (from J, / Fig.Ch Oh for uobotoduyuo Content of Henofoviozo fat in a mixture with milk (s),% Phi & .5 ( O Yu 20 30 40 50 60 70 80 90 TOO The content of non-fatty fat in mixture with micron (s),% FIG 6