Occurrence of 6-methoxymellein in fresh and processed carrots and relevant effect of storage and processing.
The occurrence of 6-methoxymellein (6-MM) in fresh and conventionally processed carrot products (for a total of 176 samples) marketed in European locations and the effect of Alternaria spp. infection and storage conditions on 6-MM accumulation were investigated. 6-MM was found in 78% of tested samples with levels ranging from 0.02 to 76.00 microg/g, with only 1 of 79 fresh carrots exceeding the "just noticeable difference" level for 6-MM. Storage of carrots at 1 degree C was suitable to maintain low levels of 6-MM for a period of at least 17 weeks. No effect of Alternaria spp. infection was observed on 6-MM occurrence. The fate of 6-MM during carrot juice processing was also investigated by using different enzyme formulations for maceration and blanching procedures. Levels of 6-MM in blanched carrots obtained by boiling water or steam treatment were reduced by 69 or 33%, respectively, as compared to fresh carrots. No decrease in 6-MM levels was observed after maceration with pectinolytic enzyme preparations (Rapidase Carrot Juice and Ultrazym AFP-L). A reduction of 6-MM by 85 or 94% was obtained after the entire cycle of carrot juice processing, depending on the blanching procedure used.
De Girolamo
Annalisa
A
Institute of Sciences of Food Production, Via Amendola 122/o, 70126 Bari, Italy. annalisa.degirolamo@ispa.cnr.it
Solfrizzo
Michele
M
Vitti
Carolina
C
Visconti
Angelo
A
D000528:Alternaria; D001628:Beverages / Q000032:analysis; D003374:Coumarins / Q000032:analysis*; D018552:Daucus carota / Q000737:chemistry* / Q000382:microbiology; D005506:Food Contamination; D005511:Food Handling / Q000379:methods*; D049934:Isocoumarins; D000094162:Phytoalexins
D003374:Coumarins; D049934:Isocoumarins; C080190:6-methoxy-8-hydroxy-3-methyl-3,4-dihydroisocoumarin; D000094162:Phytoalexins