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IDENTIFICATION OF AROMATIC SUBSTANCES WHEN ESTIMATING QUALITY OF MEAT PRODUCTS AND COMPONENTS

The quality of meat products is largely depending on the organoleptic properties, including aroma which specificity is connected with various additives and their ratio in the formula.

Spices have a stable aroma of a different degree of poignancy and partly smack.
Due to availability and some combination of substances of various chemical nature, most of which are known, the dishes and products have specific aroma.

Up-to-date experience of industrial production of sausage and other meat products shows that dry ground spices have a number of essential disadvantages negatively influenced the quality of the products.
First of all this is a high germ semination and loss of volatile aromatic substances during storage.

The stability of aromatic substances is achieved by keeping spices in a gas-tight packing at low temperatures (2 - 4°С). Besides, ground spices degrade colour and pattern of sausage products at a section. It is connected with the fact that tannin contained in some widely used spices, for example in black pepper, can react with iron of the haemo group of meat proteins and give sausage a grey-and-black shade. In addition spices are often struck with vermin, mould and littered with extraneous impurities. They are a source of additional semination with pathogenic microflora that requires their preliminary treatment, in particular thermal or radiation sterilization.

However till now there are no methods of sterilization which allow preserving thermolabile aromatic substances of spices.
Today specialists of different companies develop promising methods of achieving guaranteed stable aroma of meat and other foodstuff. One of the promising methods is use of target chemical substances extracts responsible for aromatic properties.

However their successful application depends on identification of aroma-forming components, and a strict dosage provides for completeness and stability of products aroma.

Experimental researches on identification of chemical components of dry spices and CO2-extracts of the same name, as well as estimation of aromatic properties of meat products made using them, are carried out at the Chair of Technology of Meat and Meat Products together with scientists of the Chair of Analytical Chemistry of the Voronezh State Technological Academy with the participation of the Chair of Technology of Meat and Fish Products of The Krasnodar State Technological University. Dry spices (fragrant pepper (pimento), coriander and nutmeg, and CO2-extracts of spices of the same name, as well as half-smoked Aromatic sausage produced using dry spices and CO2-extracts were studied.

A specific aroma of dry spices and their CO2-extracts is connected with the content of chemical substances of various natures. The basic aroma-forming substance of fragrant pepper is pimento oil contained as follows: eugenol (terpene spirit), cineole (C10 H18 O - simple ether of cis-terpine), phellandrene (C10 H16) and caryophyllen (C14 H24). The basic aroma-forming component of coriander seeds is limonene. Aroma-forming components of nutmeg are: geraniol of a and ß forms (C10 H18 O), eugenol, linalool, camphene (3.3-dimerhyl-2-methylene-bicyclo-(1,2,2] heptane), a-pinen - are part of ether oil. CO2-extracts are received by extraction of fragrant active substances from spicy aromatic, ether-olive, vitamin, and medicinal vegetable raw materials. They preserve a natural aroma, transmit taste of an initial spice, are enriched with fat-soluble biologically active substances (vitamins and provitamins E, D, K, F, carotin). They also contain, flavour, bactericidal, antiallergic, anti-inflammatory, refreshing, hormonal and other useful components in dependence on the character of initial raw materials. CO2-extracts are well stored, compact, because they represent concentrates, are easily dosed for lack of solvents, are economic in use.

At the same time, there is a problem of using natural spices and CO2-extracts of them when manufacturing sausage products, for lack of objective methods of estimating their qualitative and quantitative composition, as well as methods of spicy aromatic raw materials identification, irrespective of a person's value judgment.
One of the up-to-date instrumental analysis methods is piezo-quartz microweighing, which allows identifying and determining the amount of aromatic substances, and according to these results one can estimate the quality of a product.
The target of the authors studies was to identify aromatic substances of CO2-extracts and to estimate organoleptic properties of meat products using some half-smoked sausages produced with dry spices and their CO2-extracts.

The experimental studies were carried out using an installation consisting of a detecting cell, piezo-resonance gauges, a frequency meter and a compressor.

The piezo-resonance gauge is a measuring converter in which a piezo-quartz resonator with resonant electromechanical properties was used as a sensitive element (transducer). As the transducers, plates of quartz were used in resonators. The piezo-resonator represents an oscillatory system. It comprises a vibrator, (a quartz plate of 5-16 mm diameter of round, square or rectangular form, on which both sides excitation electrodes of Ag are deposited at the centre, a fastening element of the vibrator and some medium.

In the course of the experiments, piezo-quartz resonators of AT section with the rated fluctuation frequency of 8 - 10 MHz were used. This choice is caused by the chemical nature of the analysed substance and connected with the necessity to maintain the thickness of the resonators modifier layer being close to monomolecular. Such a condition is important to retain the linearity of the correlation between changes of the determined substance mass and fluctuation frequency of the crystal.

If the weighing errors connected with the losses of energy in the modifier prevail, use of the resonators with rather low intrinsic fluctuation frequencies is inexpedient.
At high fluctuation frequencies the modifier shows properties of a solid body, and the measurement error decreases.

After the sorption process was carried out and the results were recorded, it was assumed that when exciting by alternating current, the intrinsic resonant frequency of the crystal (8 - 10 MHz) is determined by its mass.
In conformity with the dependence set by Zauerbrei, the frequency changes of the mass increment were described in accordance with the equation:


F is frequency shift, Hz;
F is resonant frequency of the piezo-crystal, MHz;
м is increment of the crystal mass due to the adsorption of odorous substances (OS), g;
А is crystal active area, cm2.

A number of various nature sorbents were selected for the experiments. Their selection was based on the chemical affinity sorbate - sorbent. During the experiments the mass of the sorbent deposited films was changed in the interval of 2 - 7 mkl the scope of the analysed material samples - in the interval of 5 - 15 mkl. According to the series of the carried out experiments, isotherms of the sorption presented a dot diagram of the ?F=f( ? ) dependence were plotted.
By the maximum signals received within the sorption of dry spices and CO2-extracts of the same name using the sorbents of various natures, "visual prints" looking like leaf-type diagrams are plotted.

A comparative estimation of flavour substances of natural spices and CO2-extracts by the prints has shown that CO2-extracts (using pimento, nutmeg and coriander) at the same mass fraction of the material under analysis contain much more ether oils being the main flavour component and represent a concentrate of target flavour substances.

The analysis of "Aromatic" sausage by aroma has quantitatively shown that a product based on CO2-extract has a larger area of prints when sorpting that proves the completeness and quality of displaying aromatic properties of the product.

Thus, the estimation of product aromatic properties using the modified piezosensors, is based on a quantitative and qualitative analysis of specific substances and consequently is objective. Such a method allows estimating completeness and quality of the aromatic properties with a high degree of objectivity, it allows identifying a falsification and guarantying a high quality of products.



1. Diagram of the detecting cell: input of samples, air for regeneration, front
projection, top view.


2. Diagram of the piezoquartz resonator: piezoelectric element (vibrator); excitation electrodes with a film covering or without it; fastening elements of the vibrator; waves propagating in the medium (including the film covering).


3.
4. Examples of the leaf-type diagrams of some dry and CO2-extracts of spices, a "visual print" of CO2-extracts of coriander, pimento and nutmeg.
5. "Visual prints" of the Aromatic half-smoked sausage on the sorbents of various nature

A) Using natural spices
B) Using CO2-extracts
1) Sorben fulleren t with the 2 mkg mass of the film; 2)Sorbent Crown with film mass 7 mkg;
3) Sorbent Triton X-305 with film mass 5 mkg; 4) Sorbent Apiezon with film mass 7 mkg; 5) Sorbent proxanole with film mass 5 mkg; 6) Sorbent polyvinylpyrrolidone with film mass 7 mkg; 7) Sorbent polyphenilmethylsilicon with film mass 5 mkg;





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