Effect of the duration of shelf life on some quality parameters related to bee honey

K. Elencheva-Karaneycheva, I. Zhelyazkova, R. Balkanska

Abstract. The changes in some parameters determining the quality of bee honey are traced after one and two years of storage at room temperature (5 – 8°C in winter months and 25 – 35°C in summer months). On samples of multifloral and honeydew honey (n=27) the following quality parameters have been defined: water content (%), electrical conductivity (μS/cm), specific optical rotation ([ά]20 ), pH, total acidity (meq/kg), diastase activity (units by Gote), D hydroxymethylfurfural (HMF – mg/kg) content. It was found that the duration of storage at ambient conditions has a pronounced impact on the amount of HMF for copper samples analyzed. There were no significant changes in the amount of HMF in honeydew honey and in most of multifloral bee honey samples. Depending on the duration and storage conditions, the values from other quality parameters being within admissible limits stated in Bulgarian (BDS 3050/80, Decree 48/2003) and international regulations.

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Determining the quality characteristics of ready-to-cook minced meat products through hyperspectral images

K. Kolev

Abstract. In the study a model has been developed for obtaining polarized hyperspectral images of ready-to-cook minced meat products. Polarized hyperspectral characteristics have been taken down, which confirmed the adequacy of the model developed for determining the quality characteristics of ready-to-cook minced meat products. An algorithmic structure has been developed of the software platform for objective quality grading of ready-to-cook minced meat products through processing of hyperspectral images. A system of zonal incremental scanning for quality grading of ready-to-cook minced meat products through processing of hyperspectral images has been proposed.

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Monitoring of milk acid coagulation by rotational viscometer

P. Boyanova, P. Panayotov, B. Milenkov, H. Dinkov

Abstract. In the following work possibilities to monitor the acid coagulation dynamics by rotational viscometer are discussed. There is established suitable speed of rotation of the cylinder, in line with the delicate structure of the gel. The time to achieve the isoionic point in the acid coagulation of milk can be determined by changing the viscosity. The obtained results give grounds to assert that the viscometers cannot be used alone for the detailed monitoring of acid coagulation. Viscometers can be used as the reference method for monitoring changes of dynamic viscosity of milk during acid coagulation and determining the point of gelation. To establish the parameters of acid coagulation dynamics titratable acidity (°T), pH and lactic acid accumulation on milk (%) were followed.

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Effects of lycopene on the colour and sensory characteristics of cooked sausages

D. Gradinasrska, K. Danov, K. Valkova-Jorgova

Abstract. Research was conducted in order to determine the effect of tomato lycopene addition and reduction of included nitrites on the chemical composition, residual nitrite quantity, muscle pigment oxidation processes, colour characteristics and overall sensory evaluation of cooked perishable sausages. Experimental samples with three lycopene concentrations and different nitrite quantities, and a reference sample with standard and reduced sodium nitrite content were prepared. It was found that the increase in the included lycopene quantity was accompanied by an increase in the values of the red а* and yellow b* component of the experimental sample colour. The best colour characteristic and colour stability of the cut surface was observed with the samples made using 100 mg.kg -1 and 50 mg.kg-1 of sodium nitrite and 40 mg.kg -1 of lycopene. The sausages made only with the addition of lycopene and 100 mg.kg -1 sodium nitrite and 80 mg.kg -1 lycopene had lower sensory evaluation compared to the samples with standard (100 mg. kg-1) or reduced (50 mg.kg-1) nitrite and lycopene quantity.

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Comparative technical and economic analysis of systems for liquid manure management

V.Dimova, R.Georgiev, Ch.Miteva, N.Nedelcheva

Abstract. The objective of the study is to make a comparative analysis of the most important technical and economic parameters of technological variants for cleaning, storage and treatment of liquid manure, in order to develop and explain from a theoretical and analytical point of view economical design solution of a system for manure management in a pig farm. To achieve the objective the amount of manure and urine produced in a real farm in Bulgaria with a capacity of 3704 pigs has been determined, a detailed technical and technological project of the facility for storage of liquid manure (“lagoon” type) has been developed and the technological processes for existing farm system for manure separation have been examined and detailed. The total built-up areas and volumes for both variants of the system for managing liquid manure and the initial investment costs for constructing and equipping with equipment have been defined, as on this basis a comparative technical and economic analysis has been made and a preferred variant for the practic has been proposed. It has been found out that the variant with a liquid manure separating system is more economical than the variant with a semi-buried scrape lagoon by the volume and planning parameters: by total built-up area – by 7,4% and by total built-up volume – 2,1 times, which brings less pollution to the environment. The variant with a lagoon is more economical than the one with a liquid manure separating system by the following parameters: by total construction cost for building the manure storage facilities – 2,2 times, by total cost of the manure management equipment – 2,6 times, by total investment costs for constructing and equipping with manure management equipment for the manure storage facilities – 2,4 times.

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Application of NIRS as a rapid and alternative method for prediction of heavy metals content in soil

M.Todorova, S. Atanassova , B. Sitaula, D. Apturachim, P. Valkova, D. Dermendgieva

Abstract. Determination of heavy metals content in soil by acid or microwave mineralization and spectrophotometer measurement via AAS or ICP are sufficiently accurate, but they are time consuming and labour intensive. These methods are not flexible enough for environmental research. Application of near infrared spectroscopy (NIRS) as a tool for ecological assessment and monitoring of soil quality have been investigated recently. The reported results for determination of trace elements in soil by NIRS are controversial. The objective of this study was to investigate the application of NIRS as a rapid and nonexpensive method for determination of heavy metals content in soil. A total of 121 soil samples from the 0–20 and 20–40 cm layer were collected from Stara Zagora, Chirpan, Kazanlak and Gurkovo regions. Total Zn, Cu, Pb, Ni and Cd content in the investigated soil samples were determined by AAS using AAnalyst 800 Atomic Absorption Spectrometer, Perkin Elmer. Near-infrared spectra of all soil samples were measured using spectrophotometer NIRQuest 512, within the range from 900 to 1700 nm. PLS regression was used for developinged models related tested parameters to the spectra. According to the statistical parameters of a regression procedure the best accuracy of determination was obtained for total Cu content with correlation coefficient R=0.92 and RPD=3.9 for the calibration set of data and r=0.77 and RPD=2.3 for the test data. Models for determination of Cd, Pb, Zn and Ni content via near-infrared spectroscopy could be classified as with good to low accuracy of determination, according to the obtained ratio SD/SEC and SD/SEP.

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New data for some rare macromycetes in Bulgaria

M. Lacheva

Abstract. New records on twenty-seven rare macromycetous species are reported. Eleven species are of high conservation value included in the Red List of fungi in Bulgaria. The predominant part of macromycetes belongs to the class Agaricomycetes, one species belongs to the class Pezizomycetes. All taxa are presented with brief chorological data and notes on their distribution in the country. Presented are macroscopic pictures of some of the typical species.

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Optimizing of rotary hoe weed control in field bean crop at transition to organic agriculture in Dobrudzha. I. Crop injuries

I. Iliev, G. Milev

Abstract. The weed control is a basic problem in organic agriculture. Most often it leads by multiple mechanical treatments, which except significant weed destruction show certain positive as well as some negative influence on the crop. In this investigation the influence of rotary hoe working rate and number of treatments on field bean crop at transition to organic agriculture in Dobrudzha. The hoeing speed, the working depth and the number of hoeing were factors in the trial. The crop density, the number of injured plants per ha, crop height, pod placement height, 1000 grain weight, moisture content at harvesting and the bean yield were measured. The increase of working speed and hoeing depth, as well as the number of treatment leads to proved decrease of crop density, but did not decrease the yield. At most aggressive treatments the crop height and lowest pod height were lowered. There is no significant influence of rotary hoe working rate and number of treatments on the 1000 grain weight and on the moisture content at harvesting.

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The evolution and current state of agricultural land and livestock exploited in organic farming system in Romania

I. Răducuţă, A.T. Bogdan, I. Van, D. Rebega, C. Fabian, I. Grosulescu

Abstract. Organic agriculture can successfully contribute to a sustainable development of the Romania’s rural areas because in our country there are extremely favorable conditions for practicing of large-scale organic farming, and particularly in the hill and mountain areas. The purpose of this study was to analyze the evolution and current state of organic agriculture in Romania, with special reference to the organic land, the number of organic producers, the use of organic agricultural land and the organic livestock. To achieve these objectives we have studied the official statistical data, we calculated the percentage difference between the reference years and we interpreted data obtained. The results showed that the total area of organic land in Romania in 2010 it was 260,000 ha, from which 70.3% are organic agricultural land and 29.7% are organic non-agricultural land. The area of organic agricultural land in 2010 was 182,706 ha, being with 1.9 times higher as compared with the existing area in 2006, representing 1.37% of the total agricultural land. As regards the use of organic agricultural land, it was found that in 2010 the largest part of them, namely 81.0% were occupied with arable land, 17.3% with pastures and meadows and 1.7% with permanent crops (vineyards and orchards). Also this study shows that in 2010 there were 3,078 organic producers. The production of organic crops and the rearing of organic animals are the main activities in the organic sector at farm level. Livestock farmed organically in 2010 were as follows: 12,761 heads of cattle, 57,678 heads of sheep and goats, 537 heads of pigs and 23,740 heads of birds. The results showed also that cattle and sheep are the most popular species reared using organic production methods.

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Evapotranspiration of sunflower crops depending on irrigation

A. Matev, R. Petrova, H. Kirchev

Abstract. The aim of the study is to analyze the influence of irrigation regime on evapotranspiration (ET) of sunflower, in terms of total and average daily values, its effectiveness in terms of yield, and the peculiarities of its formation. The field experiment was conducted in the region of Plovdiv, with hybrid PR-64-E-83. The variants of the study are: without irrigation, optimal irrigation with initial humidity at 75% of FC for the layer 0–80 cm and irrigation with 50% and 150 % of irrigation rate, respectively. Seasonal evapotranspiration of sunflower varies from 274 to 342 mm. Irrigation with 50% of the optimal irrigation depth causes ET increasing with an average of 33.1% (from 26.1 to 37.4%). The optimally irrigated sunflower uses from 475 to 559 mm. Increase of ET as compared with the rainfed sunflower is an average of 67%. In case of irrigation with 150% of the irrigation depth ET increases with extra 2.5 – 26.7% (an average of 13.5%). ET of sunflower was formed in the following way for the conditions of the experiment: In rain-fed conditions rainfalls share 49 – 82% and water supply – from 18 to 51% of ET. By irrigation with 50% of rate the sharing of rainfalls is 36-64%, for water supply is 17-33% and irrigation depth – 14-31%. By optimum irrigation sharing is respectively 28-56%, 16-23% and 25-49%. The maximum value of daily ET for rainfed sunflower varying from 3.3 to 5.6 mm. Irrigation with norm of 50% increases values of ET to 5.2 – 6.1 mm. The maximal value of this regime of irrigation is most often in the flowering period. In case of optimal irrigation the maximal values of daily ET will remain the same usually to the beginning of phase „seeds fill”, and the values are between 6 and 7 mm.

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