FOOD ADDITIVES AND CONTAMINANTS PART A-CHEMISTRY ANALYSIS CONTROL EXPOSURE & RISK ASSESSMENT

Sun drying of seedless grapes (Vitis vinifera cv. Sultanina) is widely practised in the western Aegean Region providing Turkey with a significant share in the world trade of sultanas. Research was initiated in 1998 to determine the incidence of ochratoxin A (OTA), to identify the major factors resulting in contamination and to develop techniques to reduce or prevent contamination. This paper assesses OTA formation in five experimental vineyards located in Manisa province of Turkey between 1998 and 2003. The cultural practices recorded were tillage (type and timing), fertilisation, plant protection, irrigation, trellising, pruning, GA(3) application, harvest maturity and date, and drying practices (type of drying yard, dipping into alkaline solution, length of drying period). In the experimental vineyards, no OTA was found at veraison. OTA levels in grapes harvested at fresh maturity ranged between <LOD and 8 ng g(-1), whereas in dried sultanas they were between <LOD and 35 ng g(-1). The frequency of OTA-positive samples increased in dried grapes compared with fresh. The number and timing of tillage, number of damaged berries, and removal of damaged/infected berries prior to sun drying were identified as the major good practices that may contribute to the reduction of OTA in sultanas

Ochratoxin A in sultanas from Turkey I: Survey of unprocessed sultanas from vineyards and packing-houses

WOS: 000233851900010PubMed ID: 16332638A method for the determination of ochratoxin A ( OTA) in sultanas from Turkey using extraction with a sodium bicarbonate solution ( 2% NaHCO3) followed by immunoaffinity clean-up and liquid chromatography with fluorescence detection was used to assess the frequency of occurrence and level of OTA. In-house validation was carried out with spiked samples at levels of 0.15, 1.5, 5.0 and 10 mu g kg(-1) and average recoveries were 91, 93, 87 and 89%, respectively. The limits of detection and limit of quantification in Turkish sultanas were 0.026 and 0.09 mu g kg(-1), respectively. A survey for the presence of OTA was carried out on 264 unprocessed sultana samples during the production seasons between 1998 and 2000 collected annually from vineyards and from packing-houses. The analyses of unprocessed sultanas showed that 32.2% of the total number of samples contained no detectable OTA, whereas 9.8% of sultana samples had OTA concentrations above 10 mu g kg(-1), and the remaining 58% had levels within the range 0.026-10 mu g kg(-1). There were big differences in median concentrations between years. Considering the year of production, it appears that sultanas produced in 1998 and 2000 showed the lowest incidence of OTA contamination ( median < 0.02 mu g kg(-1)), whereas 2002 showed the highest incidence ( median 4.3 mu g kg(-1)1). The overall mean OTA concentration was calculated as 3.4 mu g kg(-1), and the overall median as 0.9 mu g kg(-1). Among the samples analysed, the highest detected level of OTA was 54 mu g kg(-1)

Project to phase-out methyl bromide in the dried fig sector in Turkey

26th International Horticultural Congress -- AUG 11-17, 2002 -- TORONTO, CANADAWOS: 000189407100007Turkey is one of the major dried fruit and nut producing countries. Methyl bromide (MeBr) is the common fumigant to control storage pests that infest during drying and storage. Compared with other dried fruits and nuts, storage pest infestation threatens dried fig production the most. MBr is regarded as a major anthropogenic compound that depletes the ozone layer. Furthermore, MeBr is a toxic gas and can pose risk to human health if over-exposure or accidents occur. The Montreal Protocol and the phase-out of methyl bromide have increased the urgency to search for new technologies. This project will lead to the phase-out of MBr as a stored product treatment in the Turkish dried fig sector by evaluating the economic and technical feasibility of two alternative technologies: 1) CO2 at elevated temperatures and/or CO2 in combination with pressure, and 2) magnesium phosphide in combination with heat in gas tight chambers. In addition, the project will include activities for ensuring a proper technology transfer, through a training programme and dissemination of information directed at actual MeBr users in the Turkish dried fig industry. Until today, field surveys are carried out to evaluate the importance of target species. Dried fig fruits are treated with magnesium phosphide and CO2 at various concentrations and at different temperatures. Quality parameters such as total soluble solids (%), titratable acidity (%), pH, dry matter (%), water activity (WA), colour (L, a and b values by Minolta chromometer) and sugaring (%) are assessed in treated and non-treated samples.Canadian Soc Hort Sci, Int Soc Hort Sci, Univ Guelp