Post by gilbert on Dec 27, 2017 15:44:42 GMT -5
I'm interested in breeding new varieties, possibly new species even, of staple crops. I'm also interested in trialling unusual or wild species. Most crop families contain at least some toxins or anti-nutritive factors. For many of these things, taste is not a sure indicator, and the dose is everything. A tuber might taste fine, and be edible in small amounts, without making it a good staple crop due to some toxin or anti-nutrient that would have cumulatively detrimental effects. Or possibly acute ones for that matter! Weather, variety, preparation and storage conditions can cause chemical concentrations to vary widely.
Is there any way to perform some sort of analysis on a potential new crop to determine what might be lurking within?
This post is partially triggered by the following quotes from Bill at Cultivariable:
As someone who was interested in growing this species, such warnings are appreciated. There is no end to the amount of misinformation floating around the web. Further, I've often had to tell others that strongly bitter garden produce is not necessarily "healthy;" in fact, in some species, it can indicate potential toxins. However, there are species of bitter vegetables that ARE safe to consume; a bitter flavor is not a sure indicator either way, and the "bitter=healthy" idea was probably started by such bitter greens as dandelion and chicory.
Is there any way to perform some sort of analysis on a potential new crop to determine what might be lurking within?
This post is partially triggered by the following quotes from Bill at Cultivariable:
Most modern potato varieties contain less TGA than 10mg/100g, but there are many heirloom varieties that exceed the 20mg/100g safety limit. A study of Norwegian varieties found that some contained high TGA levels, reaching 34.5mg/100g in the variety Prestkvern (Berug 1962); a study of German varieties found a maximum level of 35mg/100g (Maga 2009); and a study of Swedish varieties found that about 9% of early crop varieties exceeded 20mg/kg. A survey of modern American varieties found levels ranging from 1.8 to 13mg/100g (Wolf 1946), but there are many heirloom varieties available in the United States that have never been tested.
While TGA levels are generally pretty low in domesticated potatoes, they can be extremely high in wild potato species. There is almost no risk of confusing domesticated and wild potatoes, since most people have no access to wild potatoes. One possible exception in the United States is the “Four Corners Potato,” Solanum jamesii. I have read a number of articles about this potato recently that imply that it is edible or at least provide no warning about its glycoalkaloid content. Johns (1990) found TGA levels as high as 128mg/100g for this species, a level more than six times the 20mg/100g safety limit. The primary glycoalkaloid is tomatine, which, as mentioned above, we cannot as easily detect by flavor. If you ate these potatoes despite the bitterness, it would only take about three ounces to put a 70kg person into the danger zone. The native Americans who consumed this potato did so by eating it with clay to adsorb the glycoalkaloids.