2005 * XVI * 1

A. Elias, P. Elias, A. Kiis.    
  The content of nitrates, nitrites and important groups of microorganisms in Edam-type cheeses 9
The content of nitrates, nitrites and important groups of microorganisms in Edam-type cheeses. The objective of the research work was to determine the content of nitrates, nitrites and important groups of microorganisms in Eesti and Pühajärve cheeses, and to study their changes and interaction during the process of ripening.

The content of nitrates and nitrites of cheeses was determined according to the Nordic Standard NMKL No. 165, 2000 by using liquid chromatograph. For microbiological analyses the respective IDF and EV standard methods were applied. After pressing, the fresh Eesti cheese contained 55 mg NaNO3 /kg on the average. During ripening for 3–4 weeks, the content of nitrates decreased by 10 mg/kg, maintaining the average level of 45 mg NaNO3 /kg in fully ripened cheeses.

After pressing, the average nitrate content of fresh Pühajärve cheeses was 69.8 mg NaNO3/kg. During the average ripening period of 14 days, similarly to that of Eesti cheese the content of nitrates decreased by 10 mg/kg. Thus, the average level of nitrates 59.8 mg NaNO3 /kg (range 37–88 mg/kg) in ripe Pühajärve cheeses exceeded the EU limits (50mg/kg) by 9.8 mg/kg.

The content of nitrites in all the studied cheese batches of both Eesti and Pühajärve cheeses was <5 mg NaNO2 / kg, i.e. in compliance with the norms set by the EU.

The average total bacterial count of Eesti cheese after pressing was 480 million cfu/g, count of lactococci, lactobacilli and that of spores of anaerobic bacteria 360 million cfu/g, 3800 cfu/g and 31.4 cfu/g, respectively. In the course of ripening, both the total bacterial count and content of lactococci dropped, retaining the level of 7.8 million cfu/g and 3.1 million cfu/g, respectively. The count of lactobacilli and spores of anaerobic bacteria increased, reaching in ripened cheeses the average of 4.7 million cfu/g and 229 cfu/g, respectively.

The average total bacterial count of Pühajärve cheese after pressing was 98 million cfu/g, the count of lactococci, lactobacilli, and spores of anaerobic bacteria was 75 million cfu/, 14 thousand cfu/g and 170 cfu/g, respectively. During ripening the total bacterial count and count of lactococci decreased, ranging between 9.9 million cfu and 8.2 million cfu per gram, on the average, whereas the count of lactobacilli and spores of anaerobic bacteria increased up to 12 million and 201 cfu per gram, respectively.

Statistical analysis of the obtained data (Spearman correlation) revealed that higher activity and content of starter lactococci inhibited the development of anaerobic bacteria at the ripening stage (P<0.01). The nitrate content of cheeses also suppressed the development of anaerobic bacteria and lactobacilli, whereas it did not affect the reproduction of lactococci of starter cultures (P<0.05).

Keywords: nitrates, nitrites, total count of bacteria, lactococci, lactobacilli, spores of anaerobic bacteria, Edamtype cheese.

E. Haak.  
  Efficiency of phosphorous and potassium fertilizers in sea buckthorn cultivating 20
Efficiency of phosphorous and potassium fertilizers in sea buckthorn cultivating. At the Polli Horticultural Institute in South-Estonia an experiment was established in 2000 on light-texture loam soil, pH 5.7, with 95 mg phosphorous, 139 mg potassium, 933 mg calcium and 69 mg magnesium per kg/soil. Control variant was left without fertilizing. P and K were used pre-planting (ploughing depth) fertilizers for stockpile (P2O5 and K2O, both 500 kg/ha). In the following four variants the fertilizers were given in early spring, after one year on the grass surface: P2O5 and K2O, both 200 kg/ha, P2O5 and K2O, both 100 kg/ha, P2O5 – 200 kg/ha, and K2O – 200 kg/ha. This is the first experiment in sea buckthorn fertilizing in Estonia. The growth of trees was not affected when the trees were fertilized with PK. However, the yield of fruits (botanically small juicy stone fruits, like berries) was 30% smaller when PK was used as stock-fertilizer or given in every second year P2O5 and K2O both 200 kg/ha. The conclusion is that PK fertilizing is not needed in fertile soils. Sea buckthorn can be cultivated in moved grass land.

Keywords: Hippophäe rhamnoides, PK-fertilizers, growth, yield.

J. Lehtsaar, P. Zeiger.  
  Effect of investments and various subsidies and application of value added tax schemes on crop cultivation enteprise's cash flow 30
Effect of investments and various subsidies and application of value added tax schemes on crop cultivation enterprise’s cash flow. Due to cyclical nature of grain crop cultivation and receipt of various subsidies in autumn and winter, agricultural holdings need additional funding on account of external capital to balance their cash flows, generated from business. Payment of capital support to rural entrepreneurs was started in Estonia in 1997 to facilitate investments. Simultaneously, schemes for the payment of various direct aid were launched. In 2001, European Union pre-accession investment support programme (SAPARD) was launched. Investment support revived the purchase of new machinery and equipment while also contributing to building and reconstruction of production premises in the countryside. At the same time, support funds were mostly distributed among relatively limited number of rural entrepreneurs, therefore contributing to unheterogeneous development of rural areas. According to Article 25 of the Sixth Directive of the Council of European Communities, Member States may impose flat rate value added tax scheme on agricultural holdings. If flat rate tax scheme is applied, agricultural holding is not required to register as value added tax liable. Therefore, agricultural holding must not deduct value added tax, paid on production inputs, from value added tax payable upon the sales of agricultural production. To compensate for such a restriction, the agricultural holding is expected to add value added tax, by applicable rate, to the taxed value of agricultural produce sold and therefore compensate for the funds spent on value added tax upon purchase of inputs.

Keywords: investment, support, cash flow, flat rate value added tax scheme.

P. Lulla, R. Gross, T. Paaver.  
  Genetic diversity and differentiation of imported into Estonia rainbow trout (Oncorhynchus mykiss) strains based on microsatellite DNA variation 37
Genetic diversity and differentiation of imported into Estonia rainbow trout (Oncorhynchus mykiss) strains based on microsatellite dna variation. The variation of 10 microsatellite loci was analyzed in eight rainbow trout strains (the North American Donaldson strain, two Finnish strains, four Danish strains and a Norwegian strain). The most variable locus was Ssa85 (total of 24 alleles), whereas the least variable was Ssa197 (total of 2 alleles). The strains of Finnish origin were on an average more variable than the strains of Danish origin (allelic richness 5.9 and 4.9, respectively; expected heterozygosity 0.73 and 0.65, respectively), while the variability of Donaldson and Norwegian strains was similar to the Finnish strains. The average level of differentiation (FST) among the strains was 0.10 and ranged from 0.03 (between the Norwegian and Finnish Arvo-Kala strain) to 0.18 (between the Danish Cofradex and Ollerupgård strains). Based on genetic distances, the strains grouped into three clusters but the clustering was not always consistent with the country of origin, e.g. the Finnish Joutsa strain clustered together with the Danish Cofradex strain and the Finnish Arvo-Kala strain clustered together with the Donaldson strain, while only three Danish strains (Hansen, Ollerupgård and Sangild) formed a single cluster. Based on the likelihood of multilocus genotypes, 86.8% of individuals could be correctly classified into their strain of origin, which demonstrates a good potential of microsatellite loci for genetic tagging of rainbow trout strains.

Keywords: rainbow trout, microsatellites, genetic diversity.

T. Saue, J. Kadaja.  
  Growth stages of winter rye and accumulated temperatures 44
Growth stages of winter rye and accumulated temperatures. A calculating scheme to determine temperature constants (mean accumulated temperatures between plants growth stages) was elaborated. It was applied on the example of rye. Accumulated active and effective temperatures above different threshold temperatures were calculated. The optimum threshold temperatures and summarizing methods were selected on the basis of minimum errors discovered in using these constants in the forecast of next stages. Data of phenological observations from 11 stations of Estonian agrometeorological network from 1965 to 2001 were utilized. In describing of plant development the most appropriate ones were positive accumulated temperatures and accumulated active temperatures above 5 °C. Widely used accumulated effective temperatures above 5 °C and active temeratures over 10 °C did not give acceptable results for winter rye. Conveniently chosen accumulated temperatures described the development ever better than calendar time, excepted for the period between new vegetation and spearing. Some differences occurred between varieties. Less heat is needed for 'Jõgeva 112', more for 'Kustro', which requirement grows especially at the time of ripening. No essential trends were observed for the temperature constants.

Keywords: winter rye, growth stages, accumulated temperatures. 

P. Zeiger, J. Lehtsaar, Ü. Kerner.  
  The effect of income tax changes on income of households 61
The effect of income tax changes on income of households. This research aims to analyse the effect of income tax reform in progress on income of households. For the purpose of analyses, households have been distributed between income groups, based on their income. Effect on income of households was analysed by household groups. Different development alternatives were applied to assess the estimated effect of minimum basic exemption and income tax rate. The first development scenario or the changes arising of amendments to the Income Tax Act would help the households with the largest income to save most compared to the reference alternative. Implementation of the other alternative or linking basic exemption to gross minimum wages while not changing the income tax rate (26%) would have more positive effect on households with lower income, meaning approximately 50% of the households in Estonia’s case. The second development scenario allows to decrease progressive wealth-based stratification, while improving the financial coping of population with lower wages and expectedly diminishing the demand for social benefits.

Keywords: income tax, income of households, saving.