Mycotoxin, fruit concentration

Mycotoxins are toxic secondary metabolites produced by fungi growing within or on foods. They can be a serious threat to human and animal health (Nagler el al., 2001). Table 11.4 details mycotoxins associated with soft drinks and fruit juice manufacture and raw materials. Patulin is the most common mycotoxin associated with fruit juice, particular ly apple juice (Pitt Hocking, 1997). It commonly occurs if juice is produced from stored apples. Mould growth in infected apples increases with time, raising levels of patulin. The use of windfall apples for juice is also a factor. Avoidance of windfall apples, filtration of juice and pressing quickly after harvest are all methods to reduce the incidence of patulin in juice. Patulin can be destroyed by fermentation to cider or by the addition of ascorbic acid (Marth, 1992). Within Europe, the European Union has set a limit of 50 ig/kg for patulin in both apple juice and cider. A recent survey of apple products in Chile found that 28% of samples of juice and concentrate exceeded this limit (Canas Aranda, 1996). 

IV. Mycotoxins in Fruit Products and Impact of Processing on Mycotoxin Concentration... 

IV. MYCOTOXINS IN FRUIT PRODUCTS AND IMPACT OF PROCESSING ON MYCOTOXIN CONCENTRATION... 

Apples and pears are the fruits most frequently contaminated with patulin. As a consequence, most scientific publications on mycotoxin contamination of fruit juices deal with the occurrence of patulin in apple juice. Table V shows the most important surveys on the occurrence of patulin in apple juice for the last five years. The frequency of contamination ranged from 13 to 81%. Apart from one Turkish study with a mean of 140 pg/L (Yurdun et al., 2001), mean patulin concentrations were rather low and usually below 50 pg/ L. The highest patulin concentration was 733 pg/L, but concentrations up to 1150 pg/kg have occasionally been reported for commercially available apple juice (Beretta et al., 2000). 

Certain groups of a population may be at risk for elevated exposure to mycotoxins if certain fruit products significantly contribute or even dominate the daily diet. This has especially been shown for infants and young children for patulin in apple juice and ochratoxin A in dried vine fruits. Furthermore, wine and cider may significantly contribute to ochratoxin A intake of adults. As a consequence, maximum mycotoxin concentrations for certain fruit products have been established in several countries. 

We should also mention that LiChrolut EN was successfully used for SPE pre-concentration of 90 pesticides from water—acetone extracts of fresh frxtits and vegetables with a subsequent pesticide analysis by GC-MS [285]. Only the most polar pesticides (methamidophos, acephate, and omethoate) could not be determined by this technique. Finally, a simple, fast, and sensitive method of determining a mycotoxine potuline (a metabolite of many moulds Penicillium and Aspergillus) in fruits and fruit juices was developed [286]. The method includes SPE pre-concentration of the toxin on Purosep 200 and its quantification by normal-phase FIPLC and provides recoveries over 90%, with LOD five times lower than the allowed tolerance Hmit, 50 Xg/kg. 

Mycotoxins are toxic chemical metabolic products produced by microscopic mold fungi that colonize cereal crops, fruits, and vegetables and some of them exhibit carcinogenic and mutagenic properties. The allowed maximum levels in foodstuffs are very low and exhaustive exU action, preconcentration, and clean-up processes are required to attain the desired sensitivity. The alternative of ED (amperometric detection) combined with HPLC can be useful to simplify the detection of such low concentration levels. However, it has been used rarely for the analysis of these compounds in food because many of these compounds can be elecfrochemically oxidized or reduced at extreme potentials. Visconti et al [144], analyzed... 

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