The objective of this study was to examine the range of variation and correlation relationships of some grain physical traits of different barley types. Field experiments were carried out at the State Stende Cereal Breeding Institute from 2004 to 2006. Grain samples of 52 spring barley (Hordeum vulgare L.) genotypes were analysed for 1000 grain weight, test weight, relative hardness index and hull content. The mean value of 1000 grain weight and test weight for two-row barley was significantly higher than for six-row barley. Test weight for hull-less barley was significantly higher than for covered ones (mean values - 774.6 g lE-1 and 669.8 g lE-1 respectively). The hull content was higher for six-row barley type (10.4%) than for two-row (8.6%) barley. There was no significant difference in relative hardness index between different types of barley. The coefficient of variation for grain hardness ranged from 13.7% for six-row barley to 18.7% for hull-less barley. Among varieties bred in Latvia relative hardness index ranged from 47.1 for two-row variety ‘Sencis’ to 80.4 for only six-row variety ‘Druvis’. Significant (p is less than 0.05) positive correlation was detected between grain hardness index and β-glucans for covered two-row head types of barley (r2-row, covered =0.418 is greater than r25; 0.05=0.396).

Jerusalem artichoke powder (JAP) from Jerusalem artichoke (Helianthus tuberous L.) roots is a nutritive valuable product that can be used for a healthy product development. The influence of JAP on the quality and degree of liking of cakes was investigated. Sensory evaluation of cakes was realized in two stages: the first - to define the quality attributes of the cakes with JAP from the point of view of the experts, the second – to find out the consumers' views on the cakes, whose quality has been improved in accordance with the recommendations of the experts. As a control sample, the classic home cake was evaluated. Control sample was compared with the cakes, where the amount of wheat flour prescribed by recipe was partly substituted with JAP at different concentrations. Experts evaluated cakes and defined the highest acceptable concentrations of JAP in cakes. For the consumers it was offered to assess the cakes with JAP at concentration 30% and with different taste and aroma enhancers. Cakes with 30% of JAP additive were the most favoured by the sensory properties: aroma, texture, softness elasticity, porosity and softness, surface crust, appearance, colour, shape, and size. Results of analysis of variance showed that there no significant differences in the degree of liking between the cakes with JAP and the cakes with taste and aroma enhancer additives (p is greater than 0.05). There had been performed hardness analysis and colour measurement for cakes with JAP. The observed results declare high influence of aroma and taste enhancer on cakes structure and colour.

A study was done at the Latvia State Institute of Fruit-Growing, evaluating new domestic plum (Primus domestica L.) selections, for which in 2008 -2010 some fruit quality characteristics were studied. In result of evaluation four new cultivars were selected from the breeding material and in 2010 handed in for cultivar registration in Latvia. Cultivar 'Ance' is early ripening one month before 'Victoria'. Cultivar 'Adele' is medium ripening one week before 'Victoria'. Fruits keep well in cool storage. Cultivar 'Sonora' is medium ripening one week after 'Victoria' and self-fertile. Fruits of this cultivar keep well in cool storage, too. Cultivar 'Lotte' is medium-late ripening two weeks later than 'Victoria', and is partially self-fertile. Average of three years, the highest soluble solids content was found for cultivar 'Adele' (13.28 Brix%), but cultivar 'Sonora' had the total content of acids (1.28 g 100 gE-1). Significant changes in flesh firmness were observed at different storage times for cultivars 'Ance' and 'Lotte'. Significant variations in the total content of acids were determined for 'Ance'. Whereas cultivar 'Sonora' demonstrated substantial fluctuations in soluble solids content. Correlations between firmness and soluble solids content were observed for cultivars 'Ance' (r=-0.731), 'Adele' (i=-0.436) and 'Sonora' (r=0.526). Cultivar 'Lotte' produced correlations between firmness and total content of acids (i=-0.536). Significance of interaction was determined within cultivars, years, and years x cultivars.

The rowanberries (Sorbus aucuparia L.) are small orange-red fruits of a rowan tree and belong to the family Rosaceae. These berries have been described as an important source of flavonoids, and their antioxidant activity affects reactive oxygen species and lipid peroxidation; therefore they are suitable for production of health-food products. The ripe wild rowanberries have traditionally been used for jellies and jams, but their use as a food ingredient has been less popular because of their bitter taste. Sweeter and less astringent than wild rowanberries are different cultivars of sweet rowanberries and hybrids with other species. The aim of the current research was to determine physical and chemical parameters and sensory properties of rowanberry marmalades. The experiments were carried out in the Faculty of Food Technology of Latvia University of Agriculture. The purees of wild rowanberry and six different rowanberry cultivars were chosen for the production of marmalades. Chemical, physical and sensory indices of the product – moisture, total carotenoids, tannins, colour, hardness and intensity of sensory properties (flavour, colour, bitterness) – were determined as quality indicators. The results showed large variability in the physical and chemical parameters between the marmalades of different rowanberry cultivars and hybrids. The sensory evaluation of marmalades from rowanberry cultivars ‘Moravica’, ‘Mitchurinskaya krasnaya’, ‘Sorbinka’ and hybrid of rowanberry × hawthorn ‘Granatnaya’ showed that the degree of liking was from “neither like nor dislike” to “like moderately”, and marmalades from wild rowanberry, S. aucuparia var. sibirica and hybrid of rowanberry × pear ‘Alaya Krupnaya’ – from “dislike moderately” to “dislike slightly”.

One of the causes of cardiovascular diseases and overweight problem is a high consumption of sweets. Sugar is traditional food sweet matter. A change of sugar may therefore both change the perception of texture of products. The aim of the research was to evaluate properties of agar-agar jellies prepared with Jerusalem artichoke (Helianthus tuberosus L.) syrup (JAS). Soluble dry matter of experimental samples was determined by Mettler Toledo Refracto, separated sugars - by liquid chromatography, and acidity of jellies - by titration with 0.1 M NaOH. The measurements of pH were made by pH-meter Jenway 3510. Determination of vitamins B1 and B2 was made by the AOAC Official Method 986.27 and 970.65. Texture of samples was determined by using a Texture Analyser (Model TA.XT Plus; Stable Micro Systems), by cylindrical probe (P/25). Colour of jellies was evaluated by using Colour Tec-PCM. The results showed that soluble dry matter decreased from 64.5˚ Brix to 57.5˚ Brix, sucrose decreased by 6%, the acidity increased from 7.2 to 17.8˚, and pH values ranged between 3.8 and 4.5. The hardness of the samples decreased from 50.66N to 40.05N by increasing of added JAS concentration. Adding JAS in jelly, the content of vitamins B1 and B2 increased. Lightness “L” fluctuated between 24.26 and 14.60 with increase JAS concentration. The research suggests that different percents of Jerusalem artichoke syrup could be used as sugar substitute. The product becomes healthier, but the gels obtain a darker colour. Therefore it is recommended to look for other version to improve the colour of experimental jellies.

There is growing interest in products without added sugar; thus, sugar consumption is directly related to diabetes and other illnesses such as obesity. A change in the type of sugar and content may therefore both change the perception of sweetness and texture of products. The aim of the research work was to evaluate properties of agar-agar jellies prepared with inulin syrup, galactose syrup and malt extract to replace sugar. Agar gels were prepared to substitute sugar with inulin syrup, galactose syrup and malt extract. Texture of experimental samples was determined by using a Texture Analyser (Model TA.XT Plus; Stable Micro Systems). Colour of jellies was evaluated by using Colour Tec-PCM and Jenway 3510 was used for pH measurements. Obtained results showed that different kinds of sugar containing syrups could be used as sugar substitute for production of a new type jellies. Hardness of the experimental samples is influenced by the sugar type containing syrup. The hardness is determined in the experimental samples by replacement of sugar by increasing concentration of inulin syrup. Decreasing hardness values are observed by increase of added malt extract (maltose) and galactose syrup concentration in samples. The pH values of experimental samples ranged between 3.11 and 4.45. Higher L* value of experimental samples are with galactose syrup. Lightness “L” changed between 20.92 and 18.11 increasing inulin syrup concentration. The same situation can be observed using malt extract as sugar substitute.

Raw milk cheeses are known to have more intense and strong flavour and different texture due to natural microbiota and enzymes. Nevertheless, there are concerns about safety of these products. For microbial inactivation heat treatment of milk is used, but it can adversely affect the flavour, taste and texture of the product. Therefore, applying non-thermal technology such as high pressure processing is attracting alternative. The aim of this study was to examine the effects of high pressure treatment of cow`s milk at a wide range of pressures (400–600 MPa) on milk rennet coagulation time, curd firmness and curd yield. Processed milk samples were subjected to enzymatic coagulation using commercial rennet to determine rennet coagulation time, yield of coagulum and curd firmness. High pressure processing insignificantly influences coagulation properties of whole milk. However, the magnitude of changes depended on applied pressure. Rennet coagulation time and curd yield were significantly different (p is less than 0.05) among the pressure treated milk samples. The higher firmness of the curd form pressurized milk than that of raw or pasteurized milk, evaluated positively. The main effects of high pressure treatment in milk appeared to involve dissociation of casein micelles from the colloidal to the soluble phase. This study suggests that high pressure treatments of milk at 500 MPa or 550 MPa for 15 min may be beneficial for improving the coagulation properties of milk. These positive effects indicated that high pressure processing may have potential for new cheese varieties development.

No simple method has yet been found for satisfactory wood bio-resistance improvement regarding material performance in its end-use. An attempt to obtain material with proper strength and bio-durability by combined wood thermal modification and impregnation with a biocide is being researched. To select the most appropriate treatment conditions for the combined process, changes in wood physical and mechanical properties depending on the treatment temperature were investigated in the present study. For the investigation, in Latvia the most widespread wood – softwood pine (Pinus sylvestris L.) and hardwood birch (Betula spp.) was used. Changes of wood mechanical and physical properties due to thermal modification were investigated and effect of treatment temperature and relative humidity on wood characteristics evaluated. It was found that, due to different degree of changes, no identical treatment conditions suit for birch and pine wood. Birch wood is considerably more sensitive to temperature and acceptable strength was maintained only for birch wood treated at 150 °C and for pine wood treated at 160 °C. Nevertheless at higher environmental humidity equilibrium moisture content and consequently radial and tangential swelling increased for all studied wood types, substantially smaller changes due to elevated humidity were detected for modified wood.

Sea buckthorn berries are one of the most important sources of vitamins, minerals, organic acids, polyphenols and other biologically active substances in human nutrition. The shelf life of fresh chilled berries does not exceed one week. The venues of research were Fruit and Berry Processing Centre of the Dobele Horticultural Plant Breeding Experimental Station and Packaging Material Testing Laboratory of the Faculty of Food Technology, Latvia University of Agriculture, from August until October 2005. Two most popular sea buckthorn cultivars in Latvia - 'Avgustinka' and 'Prozrachnaja' - were used for the study. Sea buckthorn samples were packed in ready-made PET/adhesive/PP containers supplied by 'Huhtamaki'. Gas mixture with initial composition of 10% of O2, 10% of CO2, 80% of N2 and ambient air as control were used. Containers were sealed on the packaging equipment 'TECNOVAC Pratica'. Packed sea buckthorn samples were stored at +4+-1 deg C temperature for 50 days. The aim of this study was to clarify the effect of the initial concentration of gas mixture in the package made from plastic of high barrier properties on the quality of fresh sea buckthorn berries during storage time. The results showed that shelf life of fresh sea buckthorn berries without any significant quality changes can be extended till 30 days by packaging in containers with high barrier properties and air ambiance.

From legume seeds it is possible to make new products with different physical properties such as size and hardness by using extrusion-cooking. Peas are products that normally need a rather long cooking time, but extrusion-cooking can make them more usable in daily human diet. As protein based food products in markets are less represented than those based on carbohydrates, but for balanced diet protein intake is essential, our aim was to ensure availability of such products, so experiments were carried out in order to establish optimal moisture content for grey pea (Pisum sativum L.) flour extrusion. Three grey pea (Pisum sativum L.) based products were obtained with different water amount added before extrusion, and their size, volume mass and colour was analyzed in order to ascertain what amount of water is best for such products. Results show significant differences for size, volume mass and colour changes, establishing that the best of the products was the one with 9.00±0.01 g∙100gE-1 added water. This product had better characteristics than others, where 11.00±0.01 g∙100 gE-1 and 7.00±0.01 g∙100 gE-1 water was added. The products with 9.00±0.01 g∙100 gE-1 added water were by more than 100 g∙LE-1 lighter than other products, also colour changes compared to non extruded pea flour were fewer than for other samples and their size was the biggest of all obtained products, averagely 11±1mm.