In lieu of an abstract, here is a brief excerpt of the content:

Approaches to and outcomes of Plant Processing / 73 nixon 1998; Paull et al. 1999). These crystals appear much like microscopic pointed needles and form from oxalic acid bonding with calcium present in plant tissue (Bown 1988).The pointed ends of the calcium oxalate serve two purposes.First,they pierce the oral mucosa,lips,and tongue of the herbivore and, second, they inject the chemical irritant into the bloodstream. in spite of this, people around the world rely upon these plants for a large percentage of their subsistence needs (Wang 1983).Cooking (boiling or baking ) breaks down the protease attached to the raphides, rendering this plant material edible (Bradbury and nixon 1998). ethnohistoric accounts in the middle Atlantic describe the use of earthen ovens used to cook P . virginica. For instance, John smith wrote, “These rootes are much of the greatnes and taste of Potatoes. They use to cover a great many of them with oke leaves and ferne,and then cover all with earth in the manner of a colepit;over it,on each side, they continue a great fire 24 houres before they dare eat it. raw it is no better then poison, and being roasted, except it be tender and the heat abated, or sliced and dried in the sun, mixed with worrell and meale or such like, it will prickle and torment the throat extreamely, and yet in sommer they use this ordinarily for bread” (smith 1986 [1608]:153–154). Peter Kalm (1937) also described a similar activity whereby native people used earthen ovens to render P.virginica edible.interestingly, ethnohistoric accounts depict a similar process for rendering Arisaema triphyllum ( jack-in-the-pulpit) edible. This acridic aroid was reportedly baked for several days prior to consumption (hamel and Chiltoskey 1975; smith 1933). While these cooking activities eliminate the acrid principle in these plants, they do not break down the calcium oxalate crystals (messner and schindler 2010). in fact, researchers have isolated taro raphides from archaeological contexts in the south Pacific (Torrence and Barton 2006). The effect of roasting on the preservation of starch has recently been studied using several different ethnohistoric and ethnographic approaches to rendering Peltandra virginica edible (messner and schindler 2010). Two different types of earthen ovens were used to conduct this research. The first involved pit-roasting rhizomes wrapped in green oak leaves using hot rocks. once loaded the oven was then backfilled to retain the heat. During the three-hour cooking period temperatures in this oven reached approximately 200° centigrade. starch grains from these cooked rhizomes were all completely gelatinized during this process. individual grains burst and fused together into ca. 150-µm clusters. Birefringence was no longer apparent. The second oven type resulted in a substantially different outcome.in this experiment the rhizomes were again packed in green vegetation (oak leaves) and 74 / Chapter 4 the pit was backfilled. A fire built directly on top of this pit was allowed to burn for approximately 12 hours.Temperatures in this fire reached approximately 300° centigrade during this period. starch in these rhizomes reacted differently than in the first experiment. here, a large number of grains were either unaltered or slightly damaged by the cooking process. Also in the assemblage were burst and gelatinized grains; however, even the burst grains maintained mild birefringence. in both cases raphides remained present in the assemblage. researchers concluded that cooking substantially destroys the toxicity of several additional economic wetland species common in the middle Atlantic. Calla palustris (wild calla),Menyanthes trifoliata (bog bean),Nymphaea sp.(waterlily ), and Nuphar lutea (yellow pond-lily) each occur in the ethnohistoric and/or archaeobotanical record throughout north America (Carlson and Jones 1940; Dent 2002; rogers 1980; smith 1929). researchers interested in the use of these plants in northern europe conducted a study geared toward understanding the effect of prolonged ingestion of large quantities of these substances during times of famine (Airaksinen et al. 1986).Their studies determined that a diet consisting of 25–50 percent raw tissue resulted in fatalities in mice.in fact,only a diet composed of 25 percent boiled and/or roasted (180° C/1 hour) root did not adversely affect the mice.Their findings highlight the utility of cooking procedures in rendering these plants edible. Additionally , Airaksinen and colleagues’ study demonstrated that the amount of toxins present in foodstuffs combined with the amount consumed influences whether or not, and the severity with which, a reaction to the toxin may occur. each of the studies above demonstrates the...

Share