The experiment was conducted to analyse the effect of fermented acid whey permeate on milk yield and composition in the lactating cows. Propionic acid bacteria and their metabolites have been used in the lactating cows feeding over decades, primarily to improve growth performance, feed conversation and milk production efficiency. Two groups of the lactating cows were arranged in the study: control group (n=50) and experimental group (n=50). Experimental group’s animals received 0.5 L of fermented whey permeate daily. Acid whey permeate was inoculated with the freeze-dried PS-4 (Propionibacterium freudenreichii subsp. shermanii, Chr.Hansen, Denmark) starter and fermented anaerobically for 48 hours at 20±2 ºC. Fat, protein, lactose and total solids concentration in acid whey permeate and fermented acid whey permeate was analysed by the standard methods, but propionic acid was detected by HPLC. Milk composition and quality indices were determined at the beginning of the study and each month during 6 months period. At the end of the study the feeding of fermented acid whey permeate was stopped, but milk composition and quality data were monitored additionally after one month. Milk fat, protein, lactose, total solids, urea concentration and somatic cell count were analysed by a near infrared spectroscopy. The variability in milk composition and quality data across trial was greater in the experiment group than in the control. Milk fat and somatic cell count were significantly different (p is less than 0.05) than other studied parameters in the experimental group cows’ milk. Milk yield and lactose concentration were tended to increase during feeding of fermented acid whey permeate in the lactating cows without significant differences between control and experimental groups. Fermented acid whey permeate as feed supplement improves energy metabolism for dairy cows which results in the higher milk yield and fat concentration.

Fermentation is one of the ancient technological processes used in food production which influences the shelf-life of meat and meat products, also significantly affects the sensory properties like aroma and flavour. The objective of the present study was to evaluate the elaborated technology for a new fermented sausage production on the product quality and sensory properties. Sausages were produced by the standard technology using glucono-delta-lactone or starter culture. The drying of samples differs from 3 to 4 weeks at the same conditions; samples were dried for 4 weeks which produced with the starter culture, and 3 weeks which produced with glucono-delta-lactone. The sausages were tested at the end of the production, analysing pH, water activity, moisture and salt content, as well as the presence of Listeria monocytogenes, colony forming units of Listeria monocytogenes and Enterobacteriaceae in the sausage samples were analysed. The sensory evaluation was organised after getting Listeria monocytogenes testing results. The moisture content, water activity and salt content significantly differed (p is less than 0.05) among samples, no differences were established in pH, taste and flavour liking. The presence of Listeria monocytogenes was not established in samples which indicates that the producer properly applies a hurdle technology in fermented sausage production. Sensory evaluation results showed higher scores for texture and appearance in fermented sausages with glucono-delta-lactone. The study results confirmed that fermented sausages with glucono-delta-lactone during 3 weeks of drying can achieve corresponding safety criteria and sensory properties which are set for semidry fermented sausages.

Nitrogen management strategy in plant growth period based on chlorophyll content evaluation in plant can improve nitrogen usage efficiency and reduce environmental contamination. This study is aimed to determine the impact of different nitrogen and sulphur fertilizers rates on dynamics of chlorophyll content in winter wheat during vegetative growth and to determine the relationship between nitrogen and chlorophyll content and grain yield of winter wheat. Field trial involving a winter wheat (Triticum aestivum L.) variety ‘Kranich’ was conducted at the LUA Research and Study Farm Vecauce during a three-year period (2012-2015). The treatments were 0, 85, 153, 175+S21, 175 (in 2015), 187 N kg haE−1 and different nitrogen norms according to chlorophyll meter Yara N-tester (Konica Minolta Ltd.) data: 180, 150, 205 N kg haE−1 depending on the year. The results of the trial show that the maximum chlorophyll content in different plant parts was observed at the end of flowering stage. The chlorophyll content depended on the level of mineral fertilisation. The highest chlorophyll content in leaves, stems and ears was obtained by using additional sulphur in two trial years. Usage of chlorophyll meter Yara N-tester obtained the highest chlorophyll content in all analysed plant parts in one trial year. Chlorophyll content was significantly dependant on plant growth stage in stems in all trial years, in leaves in two trial years, and in ears in one year. Nitrogen fertilization significantly affected chlorophyll content in leaves and stems in one trial year. Close positive correlation was observed between grain yield and wheat plant chlorophyll content and average nitrogen concentration at the end of flowering stage in all three trial years.

Faba beans (Vicia faba L.) are an excellent protein source and should be more present in human diet, but due to their long cooking time, they are rarely used. So, in order to increase the accessibility of faba beans (Vicia faba L.), experiments were carried out to obtain new food products. Extrusion-cooking was chosen as the potential thermal cooking process and two different products were obtained. One was made exclusively from faba bean (Vicia faba L.) flour, while the second one was produced with a 50% addition of wheat flour to bean flour. Protein content, size, volume mass, pH and starch content for obtained products were analysed in order to characterise the products, as well as to see the differences from non-extruded faba beans (Vicia faba L.) and obtained samples. The experiments were carried out using faba beans (Vicia faba L.) obtained at Ltd. “Pure Horticultural Research Centre”. They were milled at Ltd. “Grauda spēks” and extruded with a twin screw extruder at Ltd. “Milzu”. The experiments showed that the extrusion process had decreased the protein content by 9%, but the starch content had risen by 13% with the addition of wheat flour. But, for sample, without added wheat flour differences were not significant. No significant size differences were observed in the obtained samples and pH values had no significant differences between extruded samples.

The objective of this study is to investigate the stability of total phenolic content (TPC) and antioxidant activity after high temperature and short time (HTST) extrusion cooking of a wheat and rice-based crispbreads with addition of apple, carrot and pumpkin by-products obtained after juice extraction and dried. Raw materials for crispbread production were wheat flour, rice flour, wheat bran (72%, 24% and 4% respectively) with addition of microwave–vacuum dried by-product powder in different amount (5%, 10%, 15%, 20%). Extrusion process was performed by using a laboratory singlescrew extruder GÖTTFERT 1 screw Extrusiometer L series (Germany). Total phenolic content (TPC) was determined using the Folin Ciocalteu method. Antioxidant activity was evaluated by free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant scavenging activity using a modified colorimetric method. Comparing different raw formulations, it was observed that the TPC of the apple by-product flour was significantly higher (p is less than 0.05) than in carrot and pumpkin flour. TPC in cereal-based crispbread was 36.06±1.15 before extrusion and 13.90±1.01 mg GAEgE-1 DW (milligram Gallic acid equivalent per 100 g of dry weight (mg GAE 100 gE−1 DW) after extrusion. Addition of apple BPF increased TPC in crispbreads to 106.25±2.08, carrot BPF 84.73±3.45 and pumpkin BPF to 108.82±1.04 mg GAEgE−1 DW. Antioxidant activity of control sample was 1.07±0.01mg TE (Trolox equivalents) gE−1 DW but in samples with addition of 20% apple by-products, it reached 3.77±0.02 TE gE−1 DW for samples with 20% carrot by-products reached 2.52±0.03TE gE−1 DW and for samples with 20% pumpkin by-products reached 3.77±0.02 TE gE−1 DW.

Legume seed inoculation prior to sowing is a well-known practice in agriculture. Nitrogen fixation, due to the symbiotic relationship between legumes and rhizobia, improves the productivity of legumes. Rhizobia strain specificity can be observed very often, leading to differences in the total protein content. In this study two faba bean cultivars (‘Karmazyn’ and ‘Bartek’) and five pea cultivars (‘Retrija’, ‘Zaiga’, ‘Lāsma’, ‘Vitra’ and ‘Bartek’) were tested using various rhizobia strains. In addition, strain effectivity was observed in four different soil types. Overall, the protein content increase was observed after seed inoculation with Rhizobium sp. Rhizobia strain and plant cultivar interaction specification was observed. Plant cultivar appeared to have a decisive role in the formation of protein content when inoculated with Rhizobium sp. From these pilot experiments, it can be concluded that, when choosing Rhizobium sp. strains for legume inoculation, soil type also should be considered. Rhizobia has the potential to be used as a commercial preparation intended for increasing legume protein content, alongside with increased legume yield; however, different rhizobia strains should be mixed together to achieve the optimal result.