Antinutrient Resources

In general, plant secondary metabolites can have positive and negative effects (Weston A. Price). The reason I don't try to categorically avoid them, but treat them with caution, is that these effects are multiplicitious and biological: very hard to predict what they will do, good or bad...

However, unless we know about the problems with antinutrients, we won't know why eating raw flour or dough is dangerous, why green potatoes are toxic, or how many raw red kidney beans it takes to kill a man (not very many).

But on the whole, unless you are allergic, most antinutrients will be digested, and some are actually good for you. For example, this article mentions that inositol hexaphosphate is a break-down product of phytic acid. Most phytic acid is broken down by digestion, and there is evidence that it can have beneficial effects as well as deleterious effects.

This article points out that most sweet potato antinutrients are destroyed by baking, as opposed to boiling. This FAO article on all the major food crops and their antinutrients specifies that " Heating to 90°C for several minutes inactivates trypsin inhibitors", which explains why baked sweet potatoes are nontoxic. (But the article also points out that diseased or moldy sweet potatoes may have toxins that are not completely deactivated by cooking ....moldy vegetables should not be consumed. Apparently, toxins in normal potatoes are also not destroyed by normal cooking methods. Furthermore, sweet potatoes do not have lectins, but normal potatoes do. These compounds can have some antidigestive effects, but most should be destroyed by cooking.

Antinutrients are important, but I think methionine and nutrient density / glycemic index considerations are more important overall. A few potatoes or slices of bread shouldn't hurt most people, but if you have the luxury of chooses less toxic plant products, sweet potatoes and especially squash and pumpkins are some of the best sources of nutrients, with the least amount of antinutrients.

Presentations about Presentations

SlideShare.net contains a huge number of awesome presentations. If TED.com is the best place to learn what makes a great talk, slideshare.net is the best place to focus on the slides behind the speaker. Its funny, but there are whole schools devoted to the technique of writing, but the ability to craft compelling slides is so often overlooked.

The site is also a great place to store presentations in the cloud.

The Magical North Central Texas that Used To Be

North Central Texas is composed of three major ecosystems, the Cross Timbers, Black Prairie, and Fort Worth Prarie. Less than 150 years ago, sparkling streams were abundant with trout, perch, and catfish...and alligators! Indeed, Kendall (1845) found alligators along the San Gabriel in the southern Blackland Prairie as "too plentiful for any useful purposes." Black bear were also common, along with mountain lion. Brooke (1848) reports gray wolves as far east as McLennan County, ocelot in bottoms of Brazos River near Waco in McLennan County. The last jaguar record was a large male killed in Mills County (Lampasas Cut Plain) in 1903.

Other vanished creaturs out of this Noah's Ark world include river otter, ringtail (a cat-like creature), badger, javalina (collared peccary), bison, pronghorn antelope, turkeys, and prarie chickens. Many of these animals still persist in zoos or mountains out west, but some cannot be found anywhere on the planet. For example, both the ivorybilled woodpecker and the carolina parakeet, once found near modern day Dallas/Ft. Worth, are extinct.

Estimates of the destruction of the Blackland Prairie ecosystem range from 98% (Hatch et al 1990) to 99% (Riskind and Collins 1975) to more than 99.9% (Burleson 1993). Some of the last remnants can still be seen at the Nature Conservancy's Clymer Meadow Preserve. Slightly more Fort Worth Prarie and Cross Timbers survive. Dyksterhuis (1946) studied relics of the Fort Worth Prairie, and, surprisingly, Cross Timbers are still one of the largest relatively unaltered forest vegetation types in the eastern United States (Stahle &Hehr 1984), but there are more in Oklahoma, for example, Pontotoc Ridge Preserve. Examples of old-growth Cross Timbers forests in North Texas are found in Comanche County (Leon River), Tarrant County (Fort Worth Nature Center), and Throckmorton County (Nichols Ranch).

Prairie remnants are threatened by eastern red cedar (Juniperus virginiana) and cedar elm (Ulmus crassifolia) because of a lack of natural fire. Results include reduction in broad-leaved plants and increased abundance of grasses. (Diamond & Meins 1993). Over much of the slope-lands, as muich as three feet of soil have been eroded, exposing barren rock where once was prairie soil (Hayward &Yelderman 1991). So, although remnants remain, they are often degraded by various human activities such as heavy grazing or selective cutting and their authenticity is rarely noticed or protected.....I wonder how many people realize what used to be?

Much of this text, and the image, are from Shinner's and Mahler's Illustrated Flora of North Central Texas, published by Botanical Research Institute of Texas.

More great info about Texas Native Plants, from the Plant Resources Center at UT - Austin.