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Rehydration of dried Latvian cranberries affected by drying conditions Texte intégral
2012
Ruse, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rakcejeva, T., Latvia Univ. of Agriculture, Jelgava (Latvia) | Berzina, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the current research was to study the effect of drying conditions on the rehydration kinetics of Latvia wild grown and on cultivated cranberries. The research was accomplished on fresh wild cranberries and cultivated cranberry cultivars ‘Ben Lear’ and ‘Pilgrim’ harvested in Kurzeme region of Latvia in the first part of October 2010 and immediately used in the drying experiment. Three methods were used for pre-treatment of berries: perforation, halving and steam-blanching. Before drying in a convective drier the berries were pre-treated using all three methods and berries were dried in a microwave vacuum drier using two pre-treatment methods – steam-blanching and halving. Parts of berries were dried in the microwave vacuum drier without pre-treatment (whole berries). For drying experiments, convective and microwave vacuum drier were used. Cranberry samples were rehydrated in water at +20±1 °C and +40±1 °C. The moisture content of the cranberry samples after rehydration was estimated as oven-dry method. The rehydration properties of cranberries increased with the increase in temperature, up to +40±1 °C, the increase being more significant at the initial stages of the process. Microwave drying possibly produces a sample with increased porosity, which in turn leads to improved rehydration characteristics and a softer product and may reduce processing time. Pre-treatment of berries did not significantly influence the increasing intensity of moisture content during rehydration, but the drying methods within rehydration at the temperature of +40±1 °C significantly influenced the increasing intensity of moisture content.
Afficher plus [+] Moins [-]Preliminary results of 1-methylcyclopropene influence on apple quality during storage Texte intégral
2012
Juhnevica, K., Latvian State Inst. of Fruit-Growing, Dobele (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Skudra, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Skrivele, M., Latvian State Inst. of Fruit-Growing, Dobele (Latvia) | Seglina, D., Latvian State Inst. of Fruit-Growing, Dobele (Latvia) | Skudra, G., Latvia Univ. of Agriculture, Jelgava (Latvia)
Apples are the most popular and common fruits in Latvia. Storage technology is crucial to preserve fruit quality as long as possible. Choosing the appropriate gas content of the storage environment can prolong storage life two to three times for apples. The aim of the research was to compare six different type of apple grown in Latvia, which was stored in diverse conditions. All experiments were performed at Latvia State Institute of Fruit-Growing through 2011 – 2012. For fruits before storage, 1-methylcyclopropene (1-MCP), which blocks the emission of ethylene, was used. Apples were stored in a cooler and in ULO type plastic bags in a modified environment with two different gas contents. The temperature of the environment was +2 ±1 °C with 90% relative humidity. Changes in physicochemical (soluble solids, total acids and flesh density) indexes were examined before and during the storage. The results showed 1-MCP has a positive effect on quality preservation of fruit. Fruits stored in ULO type plastic bags (gas content: 1.5% O2 and 2.5% CO2) had the best results in preservation of physico-chemical indexes. Examination of results revealed that physico-chemical indexes changed the most in samples stored in the cooler.
Afficher plus [+] Moins [-]Influence of genotype and harvest time on the phenolic content of horseradish (Armoracia rusticana L.) roots Texte intégral
2012
Tomsone, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kruma, Z., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lepse, L., Pure Horticultural Research Centre, Tukuma reg. (Latvia)
Horseradish (Armoracia rusticana L.) is a perennial plant, with a particularly pungent flavour and significant antioxidant properties. The aim of current research was to determine the total phenol content and antioxidant properties of horseradish depending on genotype and harvest time. For experiments nine genotypes of horseradish roots collected at different times were investigated. Fresh plant material was extracted with ethanol/water solution (80:20 v/v). Total phenols content (TPC) of plant extracts was determined according to the Folin-Ciocalteu spectrophotometric method and results were expressed as gallic acid equivalents (GAE). Antioxidant activity of the extracts was measured on the basis of DPPH˙ free radical scavenging activity and the final results were expressed as inhibition of 2,2-diphenyl-1- picrylhydraziyl (DPPH˙) in percent (I, %). Total phenols content varied among analysed types of horseradish. The highest TPC was detected in horseradish root genotype 280 harvested in September and it also demonstrated the highest DPPH˙ radical scavenging activity, whereas the lowest TPC was detected in horseradish root genotype 26B also harvested in September. TPC and DPPH˙ scavenging antioxidant activity were also significantly influenced by harvest time. Positive correlation was found between antiradical activity and the total phenols content in horseradish roots harvested in September. In further experiments, use of horseradish as natural antioxidants in different food matrixes should be studied.
Afficher plus [+] Moins [-]Consumers’ attitude towards availability and quality of gluten-free products in the Latvian market Texte intégral
2012
Ozola, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Straumite, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
Celiac disease is an autoimmune enteropathy disease, triggered in genetically susceptible individuals by ingested gluten from wheat (Triticum), rye (Secale cereale), barley (Hordeum vulgare) and other closely related cereal grains. The only way of the effective daily treatment is a strict gluten-free diet. From the investigation of products available in the local market, it was found that Latvian producers do not offer gluten-free products. The aim of this research was to study a celiac patient’s attitude to gluten-free product quality and availability in the Latvian market and purchasing habits. The survey was designed using website www.visidati.lv, and a questionnaire was sent to people suffering from celiac disease. The respondents were asked to fill in the questionnaire from the beginning of December 2010 till the end of July 2011. The questionnaire was performed with 131 celiac patients, respondents were from all Latvian regions and they answered 15 questions. One of the most important questions was aimed to find out consumers’ opinion about quality of gluten-free products, consumption patterns of gluten-free products, and, moreover, their interest in products made in Latvia. Respondents were asked to name gluten-free products they mainly buy and give specific purchase locations, evaluate the quality of products and necessity for products produced in Latvia. The results of questionnaire show that the consumers are satisfied with the quality of gluten-free flour, flour blends and pasta, but are not satisfied with the quality of bread and confectionery available in the Latvian markets.
Afficher plus [+] Moins [-]Physical-chemical characterization of industrial wheat bran from Latvia Texte intégral
2012
Radenkovs, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Klava, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
Cereal and whole grain products are an important source of dietary fiber in the human diet. Since the milling process highly influences the proportions of the different cell types in the bran, it is expected that brans originating from different genetic/agricultural backgrounds and produced by different processes have different chemical composition. Wheat (Triticum aestivum) bran has not been studied in Latvia, therefore the aim of the present study was to analyze physical – chemical characteristics of wheat bran from Latvia’s industrial mills. Four bran samples were collected from two industrial mills: Stock Company ‘Dobeles dzirnavnieks’ and SC ‘Rigas dzirnavnieks’. All experiments were performed at the Food Technology of Latvia University of Agriculture in May 2011-February 2012. The particle size distribution of the bran samples was determined by sieving. The content of titratable acidity (TA) was detected by titration with 0.1 M NaOH till pH 8.5 was stable for 1 minute. Wheat bran colour was analysed by Hunter Lab colour measurement instrument using ColorTec colorimeter PCM/PSM in CIE L * a * b* system. Moisture content was analyzed using standard ICC 110/1 method by sample drying for 2 h at 150 °C. Results showed that there were significant differences between varieties (p0.05) for titratable acidity and for particle size, but no significant differences (p0.05) were found between the varieties in moisture, pH and colour. TA varied from 6.40±0.71 to 12.05±0.21°, moisture content- from 10.01±0.51% to 11.61±0.47%, pH–from 6.31±0.61 to 6.80±0.05, but colour of bran between the samples did not significantly differ.
Afficher plus [+] Moins [-]The influence of different selenium concentrations on the barley grain 'class' sprouting activity and content of total phenols Texte intégral
2012
Antonenko, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kreicbergs, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
Barley (Hordeum vulgare L.) grain is the main raw material in brewing industry, because beer taste and production process depend on barley grain qualitative indices. One of the barley grain’s qualitative indices is grain sprouting activity. There have been numerous researches that showed the effects of selenium (Se) on hull-less barley sprouting activity and positive influence on biologically active substances and high vitamins concentration in grain (Dūma et al., 2002), but hull-less barley is not widely used. The aim of this study was to explore the influence of different selenium concentrations on the barley grains sprouting activity and content of total phenols. Barley with grain viability of 92% have been soaked in diverse solutions (Se concentration 0.5 mg LE-1 – 10 mg LE-1) for 12 hours, then the grain sprouted at the temperature of +18±2 °C for 5 days and dried in the oven for 48 hours at a temperature of +50 °C. After sprouting, the sprouting activity of the grain was determined, but total phenols amount was determined after grain desiccation. The obtained results showed that the increase in selenium concentration in a solution increased barley grain sprouting activity from 16.3% (0.5 mg LE-1) to 27.9% (10 mg LE-1), but the amount of total phenols decreased.
Afficher plus [+] Moins [-]Investigations into the enhancement of cow's milk oxidative stability Texte intégral
2012
Antone, U., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sterna, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Zagorska, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
The quality and nutritional value of milk and dairy products are considerably influenced by the stability of its constituents. The aim of the present study was to evaluate the possibility of enhancing oxidative stability of cow’s milk fat and vitamin B2 using carrots and palm oil feed supplement CAF 100 as sources of natural antioxidants in cow feed. Milk samples were collected after 25-day period of feed supplementation. The intensity of riboflavin losses during its photo oxidative degradation in sunlight was measured by the fluorometric method. A slight and significant (p is less than 0.05) difference in higher vitamin B2 stability was seen in carrot-supplemented group (TG1) milk, where the losses of vitamin B2 were by 3.01% less compared to CG (CG). The oxidative stability of butter oil samples stored in 60 °C temperature was analyzed by peroxide value (PV) method. The oxidative stability of samples initially affected by light from both trial groups was significantly (p is less than 0.05) higher compared to CG showing the good potential of the cow diet enrichment with carotenoid additives. The longest induction period (larger than 14 days) was observed in CAF-100- supplemented (TG2) cow milk fats, which can be explained by carotenoids and tocopherol presence and its possible synergism in fat protection. The induction periods of the TG1 and CG were 12.03 and 10.97 days, respectively.
Afficher plus [+] Moins [-]Fatty acid composition of the meat of elk, deer, roe deer and wild boar hunted in Latvia Texte intégral
2012
Strazdina, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jemeljanovs, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sterna, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
Every autumn and winter period, game animals - elk (Alces alces), deer (Cervus elaphus), roe deer (Capreolus capreolus) and wild boar (Sus scrofa scrofa) - provide an excellent input in the diversification of many consumer meals. In the recent years, consumption and assortment of game meat products has significantly increased. At the moment there are only few biochemical composition investigations of the game meat. The meat of wild animals is more favourable for human health, because it has a lower content of saturated fatty acid, but a higher content of protein. Therefore the aim of our investigation was to compare biochemical composition of the game meats hunted in Latvia. Investigations were carried out in different regions of Latvia. In the studied samples, protein, intramuscular fat, fatty acids and cholesterol were determined. The biochemical analysis of 54 samples was carried out. The results of the analysis showed that protein content in all types of the meat samples was 22.36 - 22.92%, which is not statistically significant. The fat content, on the other hand, was significantly lower: 1.33 ± 0.88% in elk meat samples, and 1.59 ± 0.59% in roe deer meat samples. Content of cholesterol varied from 64.41% to 95.07% in the ruminant meat samples of different species. From the dietetic point of view, the meat samples of roe deer had the best composition of fatty acids.
Afficher plus [+] Moins [-]Children with special needs family education as a partnership comprehension in rural area Texte intégral
2012
Kokle-Narbuta, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Family education as a support to families where children are with special needs is mentioned in family politics statements. Unfortunately, family education problems in rural areas characterise present day situation in Latvia. Professionals with less specific knowledge essential to deal with special needs satisfaction is a reality in rural areas in Latvia. It is vital to advance family autonomy, develop an opportunity to deal with consequences that disabilities cause and, improve environmental conditions for children with special needs. The aim of this article is to fortify necessity of family education as a partnership comprehension development to children with special needs in rural area. The investigation was carried out in National Rehabilitation centre ”Vaivari” in April 2012, by involving families with children with special needs. Analysis of scientific resources has been done; survey and statistical analysis of data were carried out, by using non-parametric method - Mann Whitney U test. During the research, the main family education comprehension aspects to families living in rural or city area and having children with special needs are identified. The advantages in special needs satisfaction context in rural areas and city environment are analysed. Measurements of respondent attitude to innovative family education e-solutions are made. Objectively and subjectively determined social isolation risk of families having children with special needs in rural area show the necessity to use family resources related to consequences that disabilities create. It is necessary to develop ways to use modern technological opportunities, provide appropriate family education and partnership with professionals.
Afficher plus [+] Moins [-]Thermal weed control in Norway spruce (Picea abies (L.) H.Karst.) nursery Texte intégral
2012
Silingiene, G., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Vasinauskiene, R., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Racinskas, J., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Growing of economics and new technologies has caused the environment pollution and more intensive use of natural resources. The principles of stable and balanced forestry became more and more important. Ecologization forests economy directly and indirectly impacts environment, water, air, landscape. It is not allowed to use chemicals in ecological farms. In Lithuania the number of ecological farms is growing that is why the new effective ecological methods are needed to protect seedlings from weeds. Alternative to mechanical control of weed is to use high temperature. In ecological farms weed control after sowing time is pursued in mechanic, and recently in thermal way. In thermal weed control the surface of soil remains mechanically undisturbed, the roots of cultural plants remain undisturbed, too. These features are very important in forest nurseries, where different kinds of tree species are growing. Seedlings are very small at the beginning of growing, so mechanical weed control is difficult. Thermal weed control could be a good alternative. Comparable data of 2009-2011 thermal weed control research in Norway spruce (Picea abies (L.) H. Karst.) nursery is given. The efficiency of destroyed 16 weed sorts using thermal and mechanical ways of weed control is given. Thermal weed control for short age weeds is 20.3% more effective in comparison with mechanical way. Mechanical way is 35.2% more effective for perennial weeds. It was detected that in order to control weeds of different growth stages, it is necessary to use different treatment time of damp water stream.
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