Tsvetko Prokopov

University Of Food Technology - Plovdiv | UFTP · Environmental Engineering

The aim of the present study was to examine the performance of residue from extracted onion processing waste for the ability to remove Cr (VI) ions from aqueous solutions. The characterization of applied biosorbent was conducted by FT-IR analysis. Batch experiments were carried out and the effects of different adsorption process parameters were det...

Onion processing waste (OPW) was dried in a convective hot-air laboratory scale dryer at 50, 60, 70 and 80ºC. The effect of drying temperature on the drying characteristics and on the total phenolic and total flavonoid content of dried samples was determined. Three mostly used models were applied for fitting the experimental drying curves. The resu...

In this paper we propose a model for implementation of value eco-innovations of clean production through ecodesign in the SMEs of the food industry in Bulgaria. The clean production is a preventative approach to managing environmental aspects. The paper presents the essence of clean production through ecodesign, the methods for its achievement and...

The aim of present study is to examine the performance of Cape gooseberry (Physalis peruviana L.) residues consisting of husks (CGH) and stalks (CGS-1 and CGS-2) in respect to removal of Cr (VI) ions from aqueous solutions. The characterization of the applied biosorbents is conducted by FT-IR analysis. Batch experiments are carried out and the effe...

Purpose The ecological footprint of the food industry and the requirements of the bio-based economy result in the need for deepening the concept of corporate sustainability. CSR provokes the implementation of eco-innovation with high value added. A main source of value added and sustainability is the integrated implementation of ecodesign practices...

Agricultural and processing activities generate enormous amounts of tobacco waste, and the stalks left after harvesting of the leaves constitute a significant share. The stalks of common tobacco (N. tabacum L.) were considered a promising source for processing and recycling, but very little is known about the properties of the stalks from other Nic...

Tobacco (Nicotiana tabacum L.) aroma is an important attribute of tobacco quality and is influenced by a variety of minor chemical components, including carotenoid degradation products. The objectives of this work were to determine the content of the most important fragrance-shaping carotenoid degradation products in the essential oils (EOs) of the...

The quantity of tomato wastes combined with beneficial characteristics of components of the wastes justifies the great interest of researchers and manufacturers in extracting of carotenoids from this low cost material. In this study the response surface (RSM) approach and Box-Behnken design (BBD) were used to explore the possibility of modelling an...

Industrial onion waste powder (IOWP) was used as an additive in wheat flour at different levels: 0, 1, 2, 3, 4 and 5%. The effect of onion waste addition on the mixing properties of the dough and quality of bread was investigated. The mixing properties of the dough were determined by farinograph. The bread were characterized and evaluated for crumb...

The development of food products that contain value-added dietary fibre beside different classes of phytochemicals is of great interest nowadays. The present research aimed to evaluate the powder obtained from onion processing waste (OPW) for its potential use as a value-added by-product in food sector. Data on chemical and microbiological characte...

The equilibrium moisture content of onion processing waste powder is studied and the sorption and desorption curves at 20, 40, 60 and 80°C are presented. Values of equilibrium moisture contents for temperatures higher than 20°C have been obtained by the Pass and Slepchenko's method. The adsorption and desorption isotherms were determined by the sta...

The purpose of this paper is to tested Jerusalem artichoke stalks as a cheap biosorbent for its ability to remove Mn (II) ions from aqueous solution. Batch experiments were carried out to evaluate the effects of pH, biosorbent particle size, dosage, initial metal concentration and contact time. The maximum removal efficiency of about 97.0 % was rea...

The aim of this study was to evaluate the adsorption capacity of the Schiff base chitosan-cinnamaldehyde for its application in dairy wastewater pre-treatment. Chemical oxygen demand (COD) reduction was used to evaluate the adsorption efficiency. The maximum COD percentage reduction of 33.5% was obtained at 40.0 C, pH 9.0, adsorbent dose 20 g L-1 ,...

Enzyme-assisted extraction of carotenoids from tomato peels of the Bulgarian cultivar "Stela", one of the most widely used cultivars by the canning industry, was examined in this study. The carotenoid content in raw tomato peels was established by HPLC analysis. A two-step protocol was followed: the tomato peels were fi rst treated with enzymes and...

Ultrasound-assisted extraction (UAE) of carotenoids from tomato peels of two of the most widely used Bulgarian industrial tomato cultivars was investigated in this study. The carotenoid content in raw tomato peels was established by HPLC analysis. The application of UAE was compared to conventional organic solvent extraction, where the carotenoid c...

The possibility of applying cabbage leaves in confectionary is almost unknown and thus is investigated in the current study. A sucrose-sweetened sponge cake was enriched with white cabbage powder. The addition of vegetable biologically active component resulted in energetic value reduction and enrichment of the new product with mineral substances a...

Stalks' powder of Jerusalem artichoke (Helianthus tuberosus L.) was tested as an agricultural waste product for the removal of Cu (II) ions from aqueous solution. Batch experiments were carried out to evaluate the effects of pH, biosorbent dosage, initial metal concentration and contact time. The maximum removal efficiency of about 71 % was reached...

The operations of the relatively new wastewater treatment plant of Hisarya, Bulgaria were evaluated in the present paper. The bacterial diversity of activated sludge from aeration basins of cyclic type (SBR-method) during the seasons was studied. The Cyclic Activated Sludge System is one of the most popular sequencing batch reactor (SBR) processes....

In the present paper the operation of wastewater treatment plant (WWTP) in the town of Hisarya which includes a biological stage with aeration basins of cyclic type (SBR-method) was studied. The values of the standard indicators of input and output water from the wastewater treatment plant were evaluated. Moreover, the reached effects due to the bi...

The main working environment parameters such as noise, microclimatic and lighting were investigated in this research for two Bulgarian medium small and medium dairy processing enterprises. The measured daily noise exposure levels were in the 69,7 ÷ 90,1 dB (A) range. The average illumination of the working surfaces was between 104 and 353 lx. The a...

The effect of ultrafiltration and diafiltration of whey from kashkaval, and of reverse osmosis of the ultrafiltration permeate on several ecological indices, i.e. chemical oxygen demand (COD permanganate oxydability), chemical oxygen demand (COD bichromate oxydability), 5-day biological oxygen demand (BOD 5) and undissolved substances was investiga...

Virtually all foods are derived from living cells from animals and plant origin and in some cases from some microorganisms by biotechnology methods. Thus, foods are for the most part composed of “edible biochemicals”. One of the most important goals of the food scientist is to make foods as safe as possible whether they are used fresh or processed....

For a rapidly rotating gravitating homogeneous drop of a magnetized liquid a system of equations determining configurations of the drop in the third approximation for perturbations caused by magnetic strains is obtained and examined. It is shown that a nonlinear increase of nonaxisymmetric deformations takes place near the bifurcation points and th...