Assessing digestibility of Hadza tubers using a dynamic in‐vitro model

Abstract

Roasting may provide other benefits such as ease of peeling and chewing to extract edible parenchymatous tissue. A powerful factor in glucose acquisition is tuber quality, placing emphasis on the skill of the forager. Other nutrient assays yielded unexpectedly high values for protein, iron, and iodine, making tubers potentially valuable resources beyond caloric content.

Current views on hunter‐gatherer nutrition and the evolution of the human diet

“…However, in an attempt to replicate results on mice, Cornélio, de Bittencourt‐Navarrete, de Bittencourt Brum, Queiroz, and Costa () found that weight fluctuations were similar regardless of cooked or raw feed. Further work modeling cost of chewing (Zink & Lieberman, ) and digestive bioaccessibility (Schnorr et al, ) also do not support the conclusion that cooked foods offer a marked improvement in energy availability. These equivocal conclusions warrant further study into the impact of cooking on human nutritional acquisition.…”

“…This is achieved by exposing enzyme binding sites and increasing particle surface area relative to volume. Efficient mixing and exposure to acids in the stomach is also aided by particle size reduction, and peristaltic movement of the ingesta through the small intestine proceeds at a constant and controlled rate in the absence of clumping (Schnorr, Crittenden, Venema, Marlowe, & Henry, ). Therefore, even a high quality plant‐heavy diet (which may have characterized most hominin diets in subtropical ecologies) must have posed insurmountable barriers to adequate nutritional provisioning prior to external mechanical food processing techniques (Dominy et al, ; Zink, Lieberman, & Lucas, ), or more advanced technology such as cooking (Carmody & Wrangham, ).…”

“…Since gelatinized starch has exposed amylose, this makes it much more susceptible to digestion by amylase enzymes from human saliva or pancreatic fluid (Butterworth, Warren, & Ellis, ). Due to the importance of food processing to human metabolism and health, many investigators have advocated for more research on contextually informed models of processing technologies, particularly cooking, to empirically evaluate their benefit to human consumers (Messner & Schindler, ; Schnorr et al, ; Schnorr, Crittenden, & Henry, ; Wollstonecroft, Ellis, Hillman, & Fuller, ; Zink et al, ).…”

Neandertals' large lower thorax may represent adaptation to high protein diet

“…It is noteworthy that most underground storage organs, which have been proposed as a likely major human plant food (eg. Wrangham et al, ), are quite fibrous (Conklin‐Brittain et al, ), and their digestibility is low, even when they are cooked by present day hunter gatherers (Schnorr et al, ), so if they were consumed by Homo species in significant quantities, a larger colon and hence a large lower trunk in these species would have likely been preserved to allow energy extraction from the fibrous content. At the other extreme it is also conceivable, though not common in anthropological thinking at present, that other Homo species beside Neandertal also consumed a diet high in meat, and therefore faced similar challenges to their fitness and similar adaptive solutions as the ones described here. In this case, H. sapiens' narrow torso may point to an ability to acquire sufficient amounts of fat or high proportion of plant sourced foods or both, in the framework of an acceptable energy budget, which provide a release from the need to possess the described adaptations to cope with a high protein diet.…”

Reflections on nutrition in biological anthropology

“…Interestingly, the extent to which cooking affects starch gelatinization and hence improves digestibility is dependent on the amount of water used in cooking (Wang & Copeland, ), and it is likely that early Homo used dry roasting techniques. In another contribution to the question of cooking, Schnorr et al () demonstrated that modern day Hadza hunter‐gatherers use a brief roasting technique that does not consistently improve in vitro enzymatic digestibility. This unexpected result complicates the story and indicates research is needed on a wide range of potential cooking techniques, and a wide range of potential foods.…”