Method of research the quality of animal meat during storage
The invention relates to biotechnology and can be used in meat processing industry. Method of research the quality of animal meat during storage change microbial contamination includes: sampling the sample of meat, sample preparation, sowing and determination of the total microbial numbers. Studies lead to a model sample of meat cooked impregnated sponge material cold water, obtained from a sample of the meat. Inoculation onto culture media lead from samples obtained by keeping the model sample of meat in sterile water not less than 30 min, or flush with the surface, or flush with prints of the model sample. The invention improves the accuracy and reproducibility of the research quality of the meat during storage, in particular when determining retention periods, to simplify and reduce the cost of their implementation. 1 PL.
The invention relates to methods of animal products and can be used in the meat processing industry the food industry.
The quality and durability of the meat to change properties during storage associated with the quantitative content of Mikri meat and deterioration of its quality.
There is a method of research of the quality of animal meat during storage, its freshness and suitability for processing and consumption on the change in microbial contamination of the samples of meat taken from prepared for storage of carcasses or cuts .
According to the method of microbial seeding is determined by the number of bacterial colonies that grow on the appropriate nutrient medium, for example on mesopatamia agar, planting substrate and culturing at a temperature favorable for the reproduction of the main causative agents of spoilage of meat - saprophytic microflora (putrefactive bacteria a group of bacteria Escherichia coli, Salmonella, mold spores, yeast, coccoid bacteria and other).
There is a method of study of meat quality during storage has significant drawbacks. For analysis requires a sample of meat taken from the carcass or cuts weighing not less than 200, it is necessary to take samples from several locations carcasses (at least three). During storage and especially in studies to determine the shelf life of meat and effectiveness of preservatives required multiple sampling and analysis. Moreover, in accordance with the General requirements for accuracy ek is when storing meat need a significant amount of meat for test to 2-10 kg, which increases the cost and however, complicates research. In addition, the reproducibility of the experiments with natural meat is not high enough and does not provide the necessary accuracy because of the heterogeneity of the samples of meat. This is due to the fact that the samples each time taken from different places of the carcass (cuts), as each subsequent sample, in principle, cannot take the place of the previous selection. Therefore, seeding samples will not reflect the real condition of the meat quality.
The technical result of the invention is to improve accuracy and reproducibility, simplification and cheapening of the research quality of animal meat during storage.
This is achieved by the fact that the study of the quality of animal meat during storage change microbial contamination, including identification of microbial seeding of the sample on a nutrient medium, carried out on a model sample of meat, made of spongy material such as foam rubber, saturated aqueous extract of the studied meat, and inoculation of microbes on nutrient medium are from the sample obtained by washing the sample model meat water or from its surface.
The method is of retention, the storage conditions change, assessment of the actions of preservatives and other) selected samples of meat from one or more of the most vulnerable places for the propagation of microorganisms on the carcass (cuts). When this is examined each sample of the meat, the results of analyses which conclude about the state and changes the quality of the meat, its freshness.
A sample of meat free from bones, tendons, ligaments, and fat, ground in a meat grinder in the meat. Pour the stuffing double quantity of water (sterile) and insist in a cool place at a temperature of 6-10°C (e.g. in a refrigerator) for 24 hours. Then the meat sucks drained, squeezed it minced and filtered through a gauze filter.
In the filtered supernatant determine the specific flora (bacterial count, coliform bacteria coli, Salmonella, cocci and others), pH, redox potential, and other relevant indicators. The presence of microbes in meat water is determined by known methods of analysis of contamination of liquid media (water, milk, and others). The obtained data analyses contamination of meat water used for primary reference quality investigated meat.
A model sample of meat made it hot (95-100°C) water, dried, and then impregnated with cooked meat is resting for at least 30 minutes, If necessary, research the quality of the meat multiple times within a certain time preparing several samples of the model. Parallel definitions cook for 2-3 sample.
Prepared to study the model samples of meat is placed in a thermostat for storage at a given temperature (typically at 0-4°C). After a certain period of time (few days) sample (samples) taken out of the fridge and it determines the desired microflora by known methods.
One variant of the test sample prepared from the wash water obtained by placing the samples in sterile tap water and keeping it at least 30 minutes, which makes the inoculation onto culture media. Microorganisms define as the original meat water, according to the method for liquid media. In another embodiment, the inoculation of microbes made from swabs taken from the surface of the sample, as in the case of solid culture media, for example, agar - prints caused by lateral surfaces of the sample to the cooled medium. Analysis of swabs and fingerprints spend as solid is in this case the number of microbes (colonies) in 1 g of meat - in the first embodiment or on 1 cm2the surface of the carcass by the second. The first option is somewhat more precisely due to the possible infiltration of a certain amount of germs inside the sample and leaching during sample preparation, the second is simpler in design by eliminating the flushing of the sample. However, given the complexity of the techniques associated with the preparation of nutrient media, dilution of samples, by colonies of microbes, etc. and the number of microorganisms, in some cases reaching as high as 103-1010differences in accuracy can be neglected. This applies to cases of short-term storage of meat, when the microbes have not yet penetrated into the thickness of the meat and when it is known that the microorganisms grow on the surface.
The model samples of meat, analyzed in further studies do not use.
Examples of application of the method.
To evaluate the effectiveness of the proposed method studies the quality of beef during storage at refrigerated largest total microbial contamination and changes in hydrogen ion exponent (pH). Meat (carcass) were stored in the refrigeration compartment slaughterhouse slaughterhouse at a temperature of 1°C and humid the activated water - the anolyte (preservative), and the other composition of bischofite in the anolyte (preservative B); control group half-carcasses of preservative were not processed. The experiments were conducted on model samples of meat soaked in sludge from the originally selected sample of meat from the carcasses used by a known method.
Total microbial colonization was determined by the value of the total microbial number (TBC), is numerically equal to the number of microbial colonies in the seeding of the substrate on medium - mastopathy agar, MPA - after incubation of the sample in the Petri dish in an incubator at 30°C for 72 hours. Counting the number of microbes was done on the device for counting bacterial colonies. In the first experiment (experiment 1) inoculation of microbes were from samples obtained by washing the sample model meat, in experiment 2 the seeding was made flush with the surface of the sample model and in experiment 3 with the fingerprint side surface of the sample cooled MPA in a Petri dish (the samples were size 25×25×25 mm). Control experiments (tests by a known method) made from non-uniform samples taken that course, from different, albeit closely-spaced seats of meat on the carcass.
The research results are summarized in the table. All values given in TBC one of edenized of assumptions the whole microflora is focused on the sample surface of the meat or the model sample of the meat, and the density of ground beef (which is determined TBC) is 1.5 g/cm3.
As can be seen from the table, the values of TBC, some different techniques for the proposed method (experiments 1-3), differ slightly from each other: the coefficient of variation (standard deviation divided by mean value) between them is within 3-10%, and the difference between the data on known and proposed method reaches 75%. This indicates a higher accuracy of the proposed method. Above here and vosproizvodimosti: scattering values TBC along the curve over time in all three experiments is less than in the control.
In General, the proposed method of determination of meat quality during storage has a higher accuracy and reproducibility of measurements, it is much easier to use and cheaper in comparison with the known.
The method of study of meat quality during storage for modifying microbial contamination, including the selection of the sample of meat, preparation of samples analyzed meat, planting material from the sample on a nutrient medium and the determined impregnated sponge material of a size not less than 25×25×25 mm cold water, obtained from a sample of the meat and planting material are from samples obtained by keeping the model sample of meat in sterile water not less than 30 min, or from flushing, or fingerprints from the surface of the model sample.