SU1698715A1 - Method of determining fat content of milk and milk products - Google Patents

Abstract

This invention relates to dairy production. The purpose of the invention is to accelerate, simplify and improve the accuracy of determination. A sample, an empty cuvette and a fluorescent standard are irradiated with laser radiation and the fat content is determined by a calculation function relating the measured fluorescence values and the milk fat content. 1 il.

Description

The invention relates to milk production and can be used in analyzing the composition and fat content of milk and dairy products.

The known method for determining the fat content of milk and dairy products according to the RozeTotlib method (i.e., the arbitration extraction-weight method).

However, this method is characterized by high laboriousness, the duration of the process of determining the fat content, requires cumbersome equipment, expensive and toxic chemical reagents, and is also subject to the influence of subjective factors.

The closest to the proposed method is the registration of the secondary luminescence of milk and dairy products, carried out as follows.

A dye is added to the test sample, the luminescence of the dye is excited by the radiation of a mercury lamp, the intensity of the luminescence of the dye is recorded. According to the intensity of the luminescence judged on the fat content of milk. The disadvantage of this method is the necessity of introducing a dye into the milk, which excludes the possibility of controlling the milk fat content in the stream. In addition, the introduction of the dye in dense dairy products is difficult.

The purpose of the invention is to accelerate, simplify and improve the accuracy of determining the fat content of milk (both in individual samples and in the stream) and dairy products.

The goal is achieved by the method of spectrofluorimetry that a sample of milk (or milk line) or dairy product is fluorescent standard and empty cell is irradiated with a fluorescence excitation laser with a wavelength of less than 400 nm, which is recorded using a spectrofluorimeter fluorescence spectrum of the sample, fluorescent

with

with

but

About 00 N4

SL

standard and substrate and determine the fat content of Cj by the formula

-will out

Ф А

(one)

where A is a constant;

1F Ic, In - intensely the fluorescence of the sample, standard and empty cell at the wavelength corresponding to the best correlation of this method and the arbitrary extraction-weight method (520 nm);

B is a constant;

F - the signal recorded by the photodetector.

The drawing shows a diagram for implementing the proposed method.

The scheme contains a laser 1, a carriage 2 with three cuvettes (a - with milk; b - with a standard; c - an empty cuvette), a spectral device 3, the dispersion element4 of which is coupled to the engine 5, a photomultiplier 6, an amplifier 7 and a recorder 8.

The laser radiation 1 is directed to one cuvette (a, b or c) located on the carriage 2. The fluorescence radiation is passed through the dispersion element 4, coupled to the engine 5, located in the spectral device 3, after which this radiation is recorded by the photodetector 6, an electrical signal from the output of which is fed to the amplifier 7 and the recorder 8.

The method is carried out as follows.

Three specimen with milk (or milk conduit), a fluorescent standard (fluorescein solution) and an empty glass cuvette are placed on the spectrofluorometer carriage. A fluorescence emission spectrum is prescribed successively when laser radiation with a wavelength of less than 400 nm is applied to the object. The fat content is calculated by the formula (1).

Thus, the proposed method contains the following operations.

Laser 1 radiation with a wavelength of less than 400 nm is guided to one cell of a Carean 2, which is located at an angle of 45 ° to the radiation.

The fluorescence radiation is directed to the entrance slit of the fluorometer 3.

The motor 5 is switched on, coupled with the dispersion element 4.

Register an electrical signal at the output of the photomultiplier 6.

Enhance the electrical signal with the help of amplifier 7.

Write the fluorescence emission spectrum on the recorder 8.

The described operations are repeated for the remaining two positions of the carriage 2. Calibrate the data by comparing the fat content using formula (1) for a specific wavelength and the data obtained by an arbitration extraction-weight method.

By formula (1), the fat content of a milk or milk product is determined.

The proposed method allows, after calibration by the arbitration extraction-weight method, to quickly and accurately determine the fat content in individual samples of milk and in the stream, as well as in dairy products. The use of a serial spectrofluorimeter allows the analysis of milk and dairy products to low-skilled personnel.

Claims (1)

Claims The method of determining the fat content of milk and dairy products, including the initiation and registration of the luminescence of a sample, the intensity of which determines the fat content in milk, characterized in that, in order to speed up, simplify and improve the accuracy of determining the fat content in both individual samples and The sample under study, the fluorescent standard and the empty cell are irradiated with laser radiation with a wavelength from the luminescence excitation region. milk is absent, while fluorescein is used as a fluorescent standard, the fluorescence intensity of sample f, fluorescent standard c and empty cuvette is recorded and determine the fat content of milk by the formula -will out Ф А where Cf is the fat content of a milk or milk product; A and constants; F is a value determined experimentally for calibration samples. g Editor M.Petrova Tehred M. Morgenthal Order 4388 Circulation: Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk nab. Production and Publishing Combine Patent, Uzhgorod, Gagarin st., 101 Proofreader N.Korol