Exploring the Use of Lactulose in Probiotic Dairy Products

SUMMARY

on the work "Studying the possibility of using lactulose syrup as part of probiotic dairy products"

Intestinal dysbacteriosis, characterized by qualitative and/or quantitative changes in the microflora, is currently very common. To one degree or another, it is detected in 75-90 % citizens of Russia. This is due to the current environmental and socio-economic situation, the massive and often uncontrolled use of antibacterial and hormonal drugs, irrational and malnutrition, hypovitaminosis, an abundance of chronic diseases and other factors. As a result, in most people, the balance of the intestinal microflora is disturbed, there is a decrease in bifidobacteria and a shift towards opportunistic bacteria that begin to dominate in the intestine [I].

To restore the body to its previous state of health, a complete, preservative-free food or probiotic products and special therapeutic preparations are needed. In combination, they are able to suppress pathogenic microflora, while creating favorable conditions for the reproduction of beneficial ones: bifido-, lacto-, propiono- and other bacteria.

There are two approaches to the prevention and treatment of dysbacteriosis. The first is based on the introduction of beneficial bifidobacteria and lactobacilli into the intestines with the help of usually taken orally in the form of special preparations, or foodstuffs enriched with these bacteria. However, in recent years, preference in the treatment of dysbacteriosis has been given to the so-called prebiotics - special substances that, reaching the colon, form a nutrient medium for the host's own normal flora and, thereby, activate their growth and vital activity. Such substances are called bifidus factors.

The most studied and widespread bifidus factor is lactulose, a synthetic disaccharide, which is the active principle of the drug "Lactusan" [2].

2. The purpose of the research: Establishment of the optimal concentration of lactulose syrup "Laktusan" in a fermented milk product enriched with bifidobacteria, using lyophilized biomass of Joint-Stock Company "Partner".

3. Materials and methods

The basic object of research was bioyogurt "Bifidok"®, prepared in laboratory conditions according to TU 9222-009-16414608-02. A feature of this product is the fermentation of milk with a starter consisting of thermophilic lactic streptococcus and Bulgarian bacillus, and bifidobacteria (lyophilized biomass produced by CJSC Partner according to TU 9383-002-16414608-95).

Lactulose syrup "Laktusan" manufactured by 000 "Felicata Holding" was used as a source of lactulose. "Lactusan" is a syrup of light yellow color, sweet and sour in taste. The active substance of "Laktu-san" is lactulose - a synthetic disaccharide that does not break down in the human digestive tract.

In ongoing studies, lactulose syrup was added with stirring to milk before pasteurization.

The tested doses of "Lactusan" as part of the bio-yogurt "Bifidok"® were the following values from the volume of fermented milk: 0.1%; 0.3 %; 0.5 %; 1.0 %.

The control in the studies was the bioyogurt "Bifidok"®, developed without the use of lactulose syrup in the composition of the test.

The criteria for assessing the quality of the product in the studies were:

- organoleptic characteristics of the product;

— titratable acidity of the product;

- active acidity of the product;

- the content of bifidobacteria in the freshly processed product and at the end of the shelf life (7 days).

3 Accounting for viable bifidobacteria in products was carried out according to the MUK

4.2.999-00, determination of titratable acidity according to GOST 3624-92, active acidity was determined potentiometrically on a pH 410 pH meter.

The crops were incubated in a thermostat at a temperature of 37-38 C for 3-5 days.

Storage of the finished bioyogurt was carried out at a temperature of +6 C for 7 days.

The specific rate of death of bacterial cells was determined by the formula:

IsN-IsN

^⁼  1m "(h-¹) [3], IgN^xt

where: nh is the number of bifidobacteria in a fresh product, cfu/cm³;

^

nk is the number of bifidobacteria at the end of the storage period, CFU/cm;

t is the duration of storage, h.

4. Results

The results of studies on the effect of the use of "Lactusan" on the organoleptic characteristics of the bioyoghurt "Bifidok"® are shown in Table 1.

One of the main criteria for evaluating the possibility of using lactulose syrup as part of a probiotic fermented milk product was the absence of its negative effect on the organoleptic characteristics of this product. In our case, when applying "Lactusan" in the amount of 1.0 % of the volume of milk (experiment No. 5), the product had a strong foreign taste and smell, not characteristic of traditional yogurt. Therefore, lactulose syrup in the indicated concentration cannot be used as part of fermented milk products.

Lactusan had no effect on the performance of the technological process in the range of tested concentrations: the fermentation time of the product in the control and experimental options was 4-5 hours, the milk clot in the finished product in all studied