A. A. Nesterenko

Kuban State Agrarian University, Krasnodar, Russia

Electromagnetic field as the activator of starting cultures

With the development of market relations more and more attention is paid to increasing volume of production of high-quality specialty meat products. Thus, production volume of cold smoked sausage increased from 1.8% (in 1990) to 5% (in 2005) and it’s expected that the volume should increase up to 7.5% by 2013 (approximately 225 thousand tons) of the total production volume of sausage products [1].

Conventionally, cold smoked sausage technology suggested using cold meat products of high quality for its production. Due to livestock reduction and cold beef shortage in the 90’s many meat-processing factories producing cold smoked sausage replaced cold meet with defrost meat products including the products that don’t meet the requirements of quality. Consequently it led to unstable quality of production and production loss due to technological deficiency [2].

One of the ways of eliminating deficiency, making the quality of cold smoked sausage stable and increasing of production is to use advanced technologies.

The aim of this paper is to create optimal conditions for starter cultures activation with electromagnetic treatment for their quick development and reduction of fermented sausages maturation time.

Starter cultures in fermented sausages production allow speed up production process and make it more cost effective. The main advantages of starter cultures are the following:

• Wild-type microorganisms growth inhibition;

• pH level reduction;

• creating optimal conditions for color producing

reactions;

• taste and flavor characteristics accomplishments;

• increasing lipid level consistency.

A certain flora of preferred microorganisms should dominate in cold smoked sausages but not unpredictable microorganisms of a wild-type. One of the significant characteristics of starter cultures is their ability to produce lactic acid from carbohydrates and thus enable the reduction of pH level. Bacteria producing the acid can be divided into two groups: «homofermentative» and «heterofermentative».

Materials and methods.

As an experimental sample for bacteriological research we used STARMIX starter cultures «Start-Start» which provide quick production of mild lactic acid, give tender flavor, hard texture and distinct and consistent salting color.

In order to define the influence of electromagnetic emission on starter cultures microbiological analysis has been conducted which revealed growth index of microorganisms on meat-and-peptone agar.

Medium used for the primary micro flora cultivation doesn’t affect organoleptic and physicochemical characteristics of a finished product. Thus we can apply it together with treated culture on the first stages of forcemeat composing.

For preliminary activation we placed starter cultures in a culture medium for 72 hours, afterwards they were treated with electromagnetic field. The results of the treatment are given in Table 1.

Table 1. Results of starter culture cultivation after electromagnetic treatment.

№	Time min	Frequency, Hz	Voltage, V	Amount of microorganisms, CFU g^-1
1	control			8,2*10^6
2	30	25	50	3,3*10^7
3	60	25	50	4,3*10^8
4	30	35	75	7,7*10^8
5	60	35	75	2,9*10^8
6	30	45	92	7,7*10^7
7	60	45	92	3,9*10^9
8	30	100	150	2,0*10^8
9	60	100	150	1,7*10^7
10	30	150	50	3,1*10^8

As it’s shown in Table 1, after electromagnetic treatment of starter cultures with frequency of 45 Hz for 60 minutes we get intensive growth of microorganisms.

Magnetic fi eld infl uence on microorganisms

According to data about changes of speed and balance in many chemical reactions in magnetic field it’s determined that magnetic field interaction with paramagnetic and diamagnetic molecules, which constitute the most part of the cell, is characterized by the energy of magnetic interference. This energy is much less than the energy of heat motion. Thus it can be considered that magnetic field doesn’t change and, consequently, doesn’t disturb the nature of chemical bonds in substances in general and in biological systems, in particular [3].

Magnetic field influences some physical and chemical properties of water in the cells: surface tension, viscosity, conductivity, inductivity, light absorption. Water properties changes lead to the changes in integrated water system with protein molecules, nucleic acids, polysaccharides, lipids. It’s determined that magnetic field, changing the energy of the weak interactions, influences supramolecular structural organization of living things. It results in quantitative changes in chemical reactions certain of which proceed with enzymes. There are several types of magnetic fields, thus some of them activate biological objects. Their basis is rotating electromagnetic field.

It should be noted that electromagnetic field and local electromagnetic fields formed around ferromagnetic particles, are rotational and contrary to constant fields their influence can be different [4].

Thus, electromagnetic treatment of starter cultures is one of the most effective ways influencing their activity. This physical method allows speed up the process of growth and maturation of fermented sausage 1.5–2.0 times.

Conclusions.

Introduction of activated starter cultures during the first stages of chopping allows decreasing pH level down to 5.1–5.3 in a shorter period of time. Quicker pH reduction is important not only for growth inhibition of putrefactive microflora the growth optimum of which is in pH range 7.0–7.4, but it also significantly influences the speed of air drying. PH level in the range close to isoelectric point of meat proteins (5.1–5.5) creates better conditions for lowering water-binding capacity and, consequently, is optimal for producing nitric oxide pigment responsible for fresh sausage color.

Antagonistic relations between different microorganisms significantly influence composition of microflora during sausage maturation. Many lactic acid bacteria strains have distinct antagonism associated with wild-type microflora of forcemeat.

Microbe-antagonists have salt fastness that allows them actively proliferate in the process of gradual dehydration of the product. In the result of the fast proliferation lactic bacteria and micrococcus push out gram-negative bacteria, aerobic putrefactive bacilli, and staphylococci. It influences the time period of fermentation of sausage and their shelf life.

Literature:

1. Timoshenko, N.V. Significance of electromagnetic treatment in production technology of cold smoked sausage / N. V. Timoshenko, А. A. Nesterenko, A.I. Reshetnyak // European Online Journal of Natural and Social Sciences 2013. – vo2, No.2, С 248-252.

2. Nesterenko, А. А Activation of starter cultures induced by electromagnetic treatment [Text] / A. A. Nesterenko, A. I. Reshetnyak // European Online Journal of Natural and Social Sciences. – 2012. – Vol.1, № 3. – Р. 45-48.

3. Нестеренко, А. А. Влияние активированных электромагнитным полем низких частот стартовых культур на мясное сырье / Нестеренко А. А., Горина Е. Г. // Политематический сетевой электронный научный журнал Кубанского государственного аграрного университета (Научный журнал КубГАУ) [Электронный ресурс]. – Краснодар: КубГАУ, 2014. – №05(099).– С. 786-802. – IDA [article ID]: 0991405053. – Режим доступа: http://ej.kubagro.ru/2014/05/pdf/53.pdf, 1,063 у.п.л.

4. Нестеренко, А. А. Применение стартовых культур в технологии производства ветчины / А. А. Нестеренко, Ю. А. Зайцева // Вестник Казанского государственного аграрного университета. – 2014. – № 1(31) – С. 65-68.