... pemmican - I'd like to try it. I guess the value of pemmican over jerk is that it has the fat one requires in the diet
Yes, that's right. Some early explorers in the U.S. died because they took large quantities of lean meat with them not knowing the importance of fat. If you increase the amount of protein in the diet, you also need to increase the amount of fat to help with its metabolization or you get depleted in vitamin A, which is very dangerous.
Whites had to learn the proper thing to do from the Indians. Now it seems we have to learn such things all over again with the current stupidity over low-fat diets. U.S. dietary guidelines are effectively based on the economic needs of American agribusiness (which grows and processes acre upon acre of maize ("Indian corn")) and British guidelines are based on U.S. ones, and here we are ...
In point of fact, it's not fat in the diet that's the problem (apart from unnatural synthesized vegetable fats marketed by agribusiness) but sugar. That's what responsible for the obesity epidemic (and a lot of other health problems) as explained here by Pobert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology:
http://www.youtube.com/watch?v=dBnniua6-oM
A must watch for anyone who's got kids, and a searing indictment of the American food industry.
along with vitamins from berries/fruit added in.
I'm not sure that they add much in that way, but they were certainly put in for the flavour, and they may have tended to help preservation:
http://books.google.co.uk/books?id=kFOw3koWpJ0C
Important from the point of view of vitamins would be the fat-soluble ones (particularly A and D), which were in the added fat. Fat is also important for a number of other biological functions. It was found the past that pemmican was the only concentrated food on which men can actually live and work for extended periods.
In general, you can -- sorry conventional "wisdom" -- survive on a totally carnivorous diet, and several peoples did for at least part of the year. However, you do need to know
which parts of the carcass to eat (e.g., marrow, adrenal glands for vitamin C), you have to eat some of it raw, and above all you need to eat plenty of the fat.
Myra Shackley in
Using Environmental Archaeology is very interesting on this.
http://www.amazon.co.uk/dp/0713448504/
We know from ethnographic accounts that North American Indians would preferentially use the carcasses of older male animals, because of the greater quantity of fat on them. Often leaner carcasses would simply be abandoned on site. They would also sometimes remove only the cuts high in fat -- liver, tongue, etc. and abandon the rest of the carcass. Archaeological evidence, such as that from the Garsney Bison Kill site in Canada, shows us the same thing:
http://books.google.com/books?id=Z7XGFSp3drkC&pg=114
This stuff you hear about primitive peoples' using everything on a carcass is a load of bull from ill-informed people who project modern Western obsessions onto them. Hunter-gatherers may have
had a use for all parts of an animal; but they didn't always use them. It's modernized resource-starved societies that worry about "waste" -- hence Samuel Hearne's strictures on the "wastefulness" of the Canadian Indians.
This is highly informative on the general diet of North American Indians:
http://www.trit.us/traditional_diets/native_americans.html
Anyway, to return to pemmican -- it was, and remains,
the perfect concentrated food, but it could go off. The women used to ram it down with sticks in parfleches (and even jump on the parfleches) to try to exclude the air. It was a hit-and-miss affair, but if it worked, it would keep for a long time.