Late Blight Food Safety Statement
From Meg McGrath, Assoc. Professor in Plant Pathology
Are the unaffected parts of blighted tomatoes and potatoes safe to eat?
Yes the unaffected parts probably are safe to eat. Parts with symptoms likely do not pose a health risk when consumed either, but they do not look appetizing and will have an off flavor. However, no published scientific study on this specific issue was found to confirm this conclusion, therefore consumers need to make their own decision on food safety. The conclusion that unaffected tissue is safe to consume is based on several points. This pathogen does not produce a toxin that can make people sick, as a few plant pathogens can do. Plant pathogens cannot infect people. No food safety issues have been found with other diseases that affect tomato fruit or potato tubers. Late blight appears to be like other more common diseases, e.g. anthracnose on tomato fruit and pink rot of potato (which incidentally is caused by/ Phytophthora erythroseptica/, a pathogen related to that causing late blight), in that these do not appear to affect plant tissue beyond the area of infection. Many home gardeners likely often cut off diseased tissue rather than throw out the entire fruit or tuber having found the healthy appearing part of these to taste fine. This has not been associated with any human health issues. Diseases like late blight and anthracnose are not considered a health concern for commercial tomato processing. Fruit are sorted to remove affected ones, but this is because of the impact on fruit quality. For home canning, only disease-free, preferably vine-ripened, firm tomatoes are recommended in the USDA Complete Guide to Home Canning because fungal pathogens may raise tissue pH and thereby allow growth of potentially harmful microorganisms.
CCE’s Food Preservation Expert Judy Price echos the caution to only can food that is of the highest quality. The possibility of a dangerous product is great when inferior and questionable food is placed in an anaerobic environment. It is also recommended that only high quality food be frozen, although the same dangers do not exist. Rather, the quality issues of an off flavor and unappetizing product should be considered in freezing tomatoes affected by blight.
1 comment Lori Bushway | Campus News
thank you for this information. we live in southeastern ontario and have lost our tomatoes with a late blight. i did not know if eating the unaffected tomatoe was a health hazard or not. to-day i picked approx 1 and a half bussel of diseased tomatoes and gave them to our cattle to eat, i was very depressed about this. our garden area is very small what should i do next year plant tomatoes or not? any ideas? thank you again.