The objective of the research was the shelf life extension of a salad with meat in mayonnaise. The microbial stability of the salad with meat in mayonnaise packaged under vacuum, in modified atmosphere, and using 'Sous vide' technology was examined and compared with conventionally packaged (in ambient air) salad. The salads were packaged in polyamide/polyethylene pouches with barrier properties as well as in pouches made from biodegradable plasticized poly-β-hydroxybutyrate or polylactic acid film. Control samples without preservatives were packed in traditional polypropylene containers covered with non-hermetic lids. PURASA L Powder Opti Form (sodium lactate) in the amount 5 g kgE-1, 10 g kgE-1, and 15 g kgE-1, and ethyl alcohol in the amount of 2 ml were used as single preservatives for separate samples. The studies of the samples were carried out after 1, 3, 7, 10, 15, 18, 25, 29, 42, and 52 storage days at the temperature of +4+-0.5 deg C. Experimentally the quality of the salad with meat in mayonnaise was characterized by measuring the total plate count of microorganisms. The obtained results indicate that different packaging technologies and addition of preservatives show significantly different influence on the microbial growth in different samples. 'Sous vide' packaging technology was effective for the shelf life extending and guarantee of safety of the salads with meat in mayonnaise.

The objective of the present study was to investigate the microbiological content of cows’ milk in Latvia’s organic farms with a purpose to detect potential microbiological threats in milk. Samples were collected in December 2011 at 12 biological dairy farms of Latvia. Raw milk samples (N=155) obtained from cow composite milk were studied. The total mesophilic aerobic and facultative anaerobic microorganisms (MAFAM), the presence of coliforms and coagulase-positive staphylococci, count of yeasts and moulds were analysed using standard methods. Of the sampled cows 50% had a low somatic cell count (SCC) (LESS THAN 200,000 cells mLE-1), 23% - high, but 27% had a very high SCC (greater than 500,000 cells mLE-1). The mean value of MAFAM in the samples with low, high and very high SCC was 4.7, 5.0 and 5.0 log10 colony forming units (cfu) mLE-1, respectively. The yeasts were present in 57% of milk samples with the mean concentration of 3.1 log10 cfu mLE-1. Moulds were found in 27% of all milk samples; their mean concentration was 4.4 log10 cfu mLE-1. Identified mould strains belonged to genera Absidia, Aspergillus, Geotrichum, Mucor and Penicillium. In cases of subclinical mastitis and latent mammary infection the most distributed mastitis pathogens were Staphylococcus aureus, Micrococcus kristinae, Bacillus cereus and coagulase negative staphylococci.

Enteral feeding also known as enteral nutrition is nutrient delivery into the stomach. Products for enteral nutrition are a specific group of products designed to provide nutrients to the human body in case of various diseases and after surgery, when the daily intake of the product is affected. Today market offers special dietetic products, which are supplemented with synthetic vitamins and minerals, which bioavailability in the body is lower than that of natural organic complexes. Therefore it is important to develop special dietetic products from natural raw materials. The aim of this study was to evaluate the effect of vacuum cooking on the content of bioactive compounds, soluble solids, pH and shelf life of enteral food made from fresh and semi-finished (heated) fruit and vegetable juices. For this research enteral food was made using fresh or semi-finished fruit and vegetable juices. Products were vacuum cooked in 0.02 MPa pressure, with boiling point 67 °C, and 0.06 MPa pressure at 79 °C, withstander for 15 min. All samples were stored at room temperature and tested for their content of vitamin C, total carotenoids, anthocyanins, total phenols and antioxidant activity and microbiological safety, as control untreated enteral food samples were used. The obtained data showed that samples made from semi-finished juices have higher contents of vitamin C and total carotenoids and anthocyanins than samples prepared from fresh juices, but this wasn’t observed with content of total phenols and antiradical scavenging activity (DPPH), where the type of ingredients used for sample preparation had no significant effect.

Fresh meat is a highly perishable product due to its biological composition as it serves as an ideal environment for the growth and propagation of microorganisms and common food-borne pathogens. High pressure processing (HPP) is a cold pasteurization treatment to extend shelf-life while preserving the sensory and nutritional characteristics of the product. The aim of this research was to evaluate the effects of HPP on the fresh porcine Musculus longissimus lumborum microbial load and related physical properties (pH, water activity aw, and moisture content). Vacuum packed meat samples were treated at 50, 100, 200, 300, 400, and 500 MPa for 1, 5, and 15 min in a high-pressure processor ISO-Lab S-FL-100-250-09-W (Stansted Fluid Power Ltd., UK). Pressure treatment above 300 MPa resulted in a significant (p is less than 0.05) decrease of total plate count. However, the studied pressurizing time had no significant effect on microbial lethality at the same pressure applied. Other important parameters such as water activity, moisture, and pH were determined as they directly affect microorganism growth and resistance to pressure. A slight increase in pork pH was observed with increased pressure. No significant changes in water activity and moisture content were observed as a result of high pressure treatment. For future researches it would be important to evaluate the dynamics of microbial growth during storing as part of cells after pressure treatment are injured and not eliminated immediately; therefore, microbial count may further decrease during cold storage.

The effect of some ingredients on stability of butter during its storage time has been investigated in order to better evaluate the functionality of confectionery. The research established that butter does not contain enough free fatty acids, derived as a result of hydrolysis, to decrease the number of mould and group of Enterobacteriaceae, but they hinder the growth of yeast and aerobic mesophilic and facultative anaerobic microorganisms. The quality of the products can be provided and propagation of microorganisms can be hindered by the comounds that are not traditional preservatives, such as vanilin and glucose syrop. A 10% glucose syrup additive worked as the facilitator of the development of microorganisms because it increased growth of aerobic mesophilic and facultative anaerobic microorganisms, 50% of glucose syrup additive worked as the procrastinator of the development of microorganisms.

There is an increasing demand in the development of new and better types of organic plant fertilizers. The aim of the present study was to evaluate if the beneficial effect of vermicompost on plant growth and development could be further promoted by adding different amounts of bat guano using two model species under controlled conditions, as well as to assess the microbiological characteristics of bat guano and soil after its application. The study was performed at the Faculty of Biology, University of Latvia, during 2013 and 2014. The amount of bacteria was significantly lower in guano in comparison to vermicompost samples. No actinobacteria were present, but yeasts were found in the guano sample. Soil fungal populations after the application of organic fertilizer from vermicompost and bat guano were dominated by potentially plant growth promoting fungi Trichoderma and Mortierella. However, at increased guano concentration (300 g kg˗1) the proportion of potentially plant pathogenic fungi significantly increased. Addition of bat guano to vermicompost fertilizer significantly enhanced the positive effect of the fertilizer on growth and development of winter rye (Secale cereale L.) and potato (Solanum tuberosum L.) plants.

This article presents the results of a comparative evaluation of preventive treatment of udder with probiotic agents: ‘Dipal’ (manufacturer DeLaval - Sweden), ‘Zorka’ (manufacturer «NPP Farmaks» - Russia). We have received data on the effects of probiotic preparation on quality of milk and number of somatic cells in milk. Research has been conducted in two dairy farms of Almaty region of the Republic of Kazakhstan. Lactobacillus acidophilus 05ch - isolated from shubat (South Kazakhstan region, Turkestan). Lactococcus lactis 010k - isolated from three-day kumys (Zhambyl region, Merke). These probiotics are used as a means for sanitary treatment of the udder of cows. Thus, the procedure of determining the antagonistic activity revealed their high activity against both gram-negative and gram-positive microorganisms, notably Staphylococcus aureus (10-13 mm), Escherichia coli (12 mm), Proteus vulgaris (10-14 mm), Salmonella abortus ovis (11-13 mm). Significant changes in the milk indices can be found in the experimental group: 9.1% rise of lactose, and 7.2% reduction of protein. The level of protein increased by 4.1% , whereas the amount of lactose, on the contrary, went down 1.6%, which may be indicative of the increase in the content of serum protein when the udder is inflamed. The examination of the milk obtained from the cows of the control and experimental groups showed a nearly double reduction in the number of somatic cells from 488.00 down to 178.000 thousand, which was caused by the daily treatment of cows by probiotic cultures during 2 weeks.