Nedyalko Katrandzhiev

Publications (6) View all

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  Available from: Nedyalko Katrandzhiev

  Conference Proceeding: Non-destructive sorting of potatoes

  Katrandzhiev N., G. Krivoshiev, R. Chalucova
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  ABSTRACT: The internal quality of potatoes and other vegetables and fruits is an important quality factor for both consumers and food industry. There are several diseases and defects, which have no effect to the quality of potato skin. Therefore internal defects remain invisible to human and also to ordinary camera. V-camera instrument V at V-camera stands for "virtually peeling". In this method and technology the potato, or other skinned fruit or vegetable, is virtually peeled by measuring the NIR transmission of potatoes and simultaneously measuring the NIR reflection from the potato skin.
  8-th international conference of food physicists physics and physical chemistry of food, Hungary, Budapest; 01/2009
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  Conference Proceeding: Algorithm for correction of primary spectrometric data

  Nedyalko Katrandzhiev
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  ABSTRACT: In practice the collecting of the educational data for a opto-electronic system is a long process. When it is about collecting data for seasonal production, the process itself becomes seasonal. But if the system which scans the production doesn’t function properly, we have two alternatives – to stop the measurement and to correct the system, thus we are missing the season and we are waiting for the next one or we can analyze the problem and decide whether the data could be processed later without any loss of information. This publication examines the exact same problem in Lock-In amplifier of the NIR system.
  ELECTRONICS - ET 2007, Bulgaria, Sozopol; 01/2007
• Thesis: Optoelectronic system for precise sorting of potato tubers by using the method "Seeing Through Layers"

  Nedyalko Katrandzhiev
  01/2005, Degree: Ph.D., Supervisor: R. Chalucova
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  Article: Assessing internal quality of fruit and vegetables

  prof. dr. sci. Georgi Krivoshiev, dr. Raina Chalucova, eng. Nedyalko Katrandzhiev
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  ABSTRACT: The external quality attributes of fruits and vegetables detected by reflection do not bring sufficient information about the presence of internal diseases and defects, chemical composition, degree of maturity etc. That is why the problem how to be seen, observed and known the internal status of those objects without destruction of the layer (i. e. skin or peel) that protects them from damaging effects of the environment has always been a topical one. The Project NIQAT funded by the European Commission was directed to solution of this problem with potatoes, apples and peaches assessment based on the method “ Seeing Through Layers” (STL) created by G. Krivoshiev in 1996. The STL is a method for non-destructive measurement of the internal (i.e. of the fruit flesh) optical density eliminating the disturbing spectrum of the peel by means of diffuse reflectance. As this is equal to a virtual removal of the skin (peeling), the photometric camera implementing the STL method was named V-(virtual) camera. Here is presented a variant of V-camera as a part of the conveyor system for potato tubers sorting – NIQAT. There are also given mathematical models and results of non-destructive determination of the internal optical density and classification of potatoes in real time, as well as some basic technical parameters of NIQAT system.
  New Food. 01/2004;
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  Available from: Nedyalko Katrandzhiev

  Conference Proceeding: New Technology for Potatoes Sorting

  G. Krivoshiev, R. Chalucova, A. Liungov, P. Bojilov, N. Katrandzhiev
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  ABSTRACT: The quality of potatoes for industrial processing is determined solely by the tubers internal flesh quality regardless of that of the skin (peel). In case of defects on the peel due to diseases, pests, mechanical injury and soil pollution the at present known sorting machines most frequently discard such tubers as defective although their interior is flawless. Sorting devices based on diffuse reflectance can not detect defects located 2-3 mm below the surface. Therefore, tubers with flawless peel but having internal defects like cavities, dark coloration, vitreousness etc. are erroneously assessed as fit for processing. The sorting machines based on diffuse transmittance detect both internal and external defects but can not discriminate between them as the tuber spectrum contains the disturbing spectrum of the peel as well. Thus, tubers with flawless flesh having defects on the peel caused by scab, rhizoctonia, physical impacts etc. are assessed and sorted as unfit for processing. The result is the incomplete use of the raw material incurring losses to both producers and processors of potatoes. The NIR system presented in this poster is – to a great extent - free from the above indicated disadvantages because it is based on the method “Seeing Through Layers” (STL). According to STL method the internal transmittance is predicted by measuring the transmittance and reflectance of the objects without their peeling or slicing. This is equivalent to measurement of tubers transmittance after their virtual peeling which is the main advantage of the new NIR technology - that is the internal quality is identified non-destructively and independently of the peel quality status.
  12th International Diffuse Reflectance Conference (IDRC), Wilson College, Chambersburg, Pennsylvania, USA; 01/2004