8589356425

Z.Konarbayeva, A.Saparbekova. L.Mamayeva. SELECTION OF STARTER CULTURES FOR THE MILK-GRAIN PRODUCTION

S. lactis SS-2	6-6.5	75	4.78	3.6
S. cremoris SSp-3	3.5-4	85	5.05	2.5
S. lactis SSa-1	4-5	75	5.20	2.5
S. therrnophilus SPa-1	4-4.5	90	5.85	2.4
L. bulgaricus SPm-2	7-7.5	130	4.20	5.2
S. lactis SPz-1	5-5.5	90	4.20	3.2
L. plantarum SPz-2	20-21	135	3.20	4.5
S. lactis K-1	4.5	100	4.20	3.6
S. cremoris K-3	4.5	75	5.40	2.3
L. plantarum Kz-2	25-28.5	145	3.20	5.3
S. therrnophilus Kz4	5-5.5	110	4.75	3.8
5. lactis TU-5	8-8.5	75	5.40	3.4
S. lactis Tuz-2	4-5	95	3.80	4.1

At development of new lactic acid combined products it needs to reaserch aroma forming, proteolytic and lipolytic activity of obtained lactic acid bacteria, so that according to thesc properties to select strains having a practical meaning.

There is a direct dependence between organoleptic properties of lactic acid products, that is - their taste, aroma and amount of free amino acids in them, products of transformation of these amino acids and also a numbcr of free fatty acids, monoglycerines and diacilglycerines, that are accumulated by proteolytically and lipolytically active lactic acid bacteria [11, 12].

In the presence of only lactic acid the clots of milk are characterized by a fiat flavor. The aroma of the ciot is added due to by-products of lactic acid fermentation (carbondioxide, acetic acid, ethanol, ethyl carbonic acid, diacetyl, and ethyl aldehyde), products of proteolytic protein breakdown (pcptides, amino acids, sulfur-containing compounds - mercaptan, dimethyl disulfite) and lipolysis (fatty acids).

The acid forming capacity of the studied strains was different. The limit of acid accumulation is from 110 °T to 300 °T. The duration of milk coagulation is from 3 to 38 hours.

Cardinal temperaturę points for generation and fermentation process of lactic acid bacteria are different. Even within the limits of one class they can rangę, depending on the conditions of development. It is found that the activity of ripening process depends on how quickly the microorganisms overcome the lag-phase and the compulsory criterion of determining the activity of lactic acid bacteria is the activity of acid formation.

For the carrying out the analyses on the activity of acid formation the following strains were used: S. cremoris SL-12, S. cremoris K-3, S. lactis SSa-1, S. therrnophilus SPa-1 (Fig. 1).

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Duratlołi ofilpeiiinę.lioiirs

Streptococcus cremoris K-3 Streptococcus cremoris SL-12

Streptococcus lactis SSa-1 Streptococcus thermophlus SPa-1

Fig. 1. Determination of activity of acid formation of lactic acid bacteria.

It is determined that the largest ability to acid formation is typical for S. cremoris K-3 and S. lactis SSa-1. The ciot is formed on the 10-12th hour of fermentation process (at introduction of culture of loops per 10'² L. of milk). At this the ciot is characterized by dense uniform consistency and nice sour milk taste and aroma. The number of viable microorganisms is also the highest among the given strains (Fig. 2).

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Journal oflndustrial Technology and Engineering, 2012, 2(3): 29 - 36