[Investigation of the iron-binding capacity of the bovine lactoferrin].

In this work, studies were carried out to obtain and determine the iron-binding ability of lactoferrin isolated from milk of Holstein-Friesian (black-and-white) breed of cows, which is the main stock of the Russian cattle herd (CH). Aim of the study was to obtain lactoferrin and determine its iron-binding capacity for substantiating the raw material resources of its industrial production as an easily digestible source of ferrous iron for the production of dietary supplements and/or specialized foods. MATERIAL AND METHODS: To optimize the production of lactoferrin in the conditions of dairy enterprises, we used a method of lactoferrin isolation from cow's milk in its own modification, which consisted in the degreasing of whole milk by centrifugation and double cation-exchange chromatography with successive application of the following sorbents: CM-cellulose (CM-52) and Macro-Prep High Q Support. RESULTS AND DISCUSSION: The developed modification of the method of chromatographic production of lactoferrin has shown its effectiveness and availability for production at domestic dairy enterprises. The purity of lactoferrin is about 95%, and the content is about 74 µg/cm3. Iron-binding capacity was determined in apo- and holoforms of lactoferrin. The ability of saturation of apolactoferrin with iron has been shown. CONCLUSION: The new obtained factual material allows us to express the prerequisites for further research to justify the possibility of using the iron-saturated form of hololactoferrin of cow milk of the Holstein-Frisian breed as a domestic raw material for dietary supplements and specialized foods.

[The study of starter cultures compositions influence on the cholesterol level in fermented meat products].

The article considers the possibility of using starter cultures compositions to reduce cholesterol in meat fermented products. An analysis of own researches and other scientific data allowed to conclude that the ability to reduce cholesterol by starting cultures in vitro is the strain-specific property. In view of the technological properties and the ability to reduce cholesterol in vitro, six compositions of starter cultures from the MGUPP collection were suggested. The compositions consisted of microorganisms belonging to the three genuses: Lactobacillus, Pediococcus and Staphylococcus. The absence of antagonism between the strains within each composition was determined by perpendicular strokes. Strains of each composition were co-cultured in a medium containing cholesterol. The residual cholesterol amount in the medium was determined after 24 hours by the Zlatkis- Zakmethod. This method is based on the cholesterol reaction with FeCl3 in the presence of concentrated sulfuric acid and glacial acetic acid to form a yellow colored complex. It was found that the compositions showed stronger activity for cholesterol reduction than each strain separately. Synergistic effect of cholesterol reduction was detected in starter cultures strains included into compositions. Reduction of cholesterol observed at 25.0-45.7%of its initial concentration in the medium. In those compositions, which included strains with a high capacity to reduce cholesterol, total cholesterol degradation ability was also higher. It was found that starter cultures reduced cholesterol not only in vitro, but also in the process of meat raw material fermentation in production of dry-smoked sausage. Composition a (Lactobacillus sakei 105, Pediococcus pentosaceus 31, Staphylococcus xylosus 45 at a ratio of 1:1:1) was chosen for the manufacture of drysmoked sausage. Bacterial composition was introduced into the meat raw materials on the mince preparation step in an amount of 109 CFU/g mince. Cholesterol maintenance in minced meat and ready-made dry-smoked sausages was determined by HPLC. In minced meat it was 840±10 mg/kg. In the ready sausages the greatest amount of cholesterol was detected in the control sample and was 971±15 mg/kg. Increasing cholesterol levels apparently due to loss of product weight by drying. Cholesterol level decreased by 21.4% in the test sample with the addition of bacterial composition (763±12 mg/kg).