I have planted so many different nut trees in Putt Myra forest garden partly because I'm on the hunt for crops that can replace the usual staple crops in the form of cereals and potatoes, but also oilseeds and protein-rich legumes.
An important parameter to keep track of, then, of course, the nutritional content of the nuts. Firstly, the nuts can be divided into starchy and fatty nuts. For the starchy nuts hear chestnuts, Acorn, Monkey puzzle tree nuts and ginkgo while walnuts, hazelnuts, pine nuts, hickory and pecan nuts are among the fat- and protein-rich nuts.
Unfortunately, there is only little information about the nutritional content of the unusual nuts. In the table below I have compiled the information I have been able to find in the literature regarding the content of makronäringsämen (protein, fat, carbohydrates) of a number of different nuts. The variation in nutrient content learns, however, be large and depends very much on local growing conditions and this appears only rough averages. Nuts from healthy walnut trees have such. shown to have higher protein content and better fat composition than nuts from stressed trees [1]. For the sake of comparison, I have also included data for some of our usual staple crops, ie. self, corn, rice and potatoes are all carbohydrate crops, and oilseed rape, which may compete with the fat-rich nuts. All values in the table are converted to 10% moisture so that the figures should be compared better.
| Crop | Protein (%) | Grease (%) | Fiber (%) | Carbohydrates (%) | Source | |
|---|---|---|---|---|---|---|
| Skogsek (OAK) | 8.5 | 4.9 | 3.9 | 72.7 | [3] | |
| SWEET CHESTNUT (Castanea sativa) | 8.9 | 3.6 | 6.4 | 71.1 | [5] | |
| Self, Organic | 12.2 | 3.1 | 74.7 | [7] | ||
| Majskorn, fresh | 10.2 | 2.1 | 6.4 | 71.3 | [7] | |
| Okokt basmatiris | 9.5 | 1 | 0.5 | 79 | [7] | |
| Potato (cooked) | 7.5 | 0.4 | 8.8 | 73.3 | [7] | |
| Hassel (Corylus avellana) | 12 | 59.6 | 2.4 | 16 | [4] | |
| Genuine walnut (Juglans regia) | 15.2 | 56.1 | - | 13.7 | [4] | |
| Black walnut (Juglans cinerea) | 25 | 64 | - | 8.7 | [4] | |
| Black walnut (Juglans nigra) | 20.5 | 59.3 | - | 14.8 | [4] | |
| Rapeseed (dried) | 26.9 | 52.6 | 5.8 | 4.7 | [8] |
As we see, the nutritional values of the nuts of the same magnitude as that of annual crops. As for fats can extract edible oil from the fat-rich nuts by pressing them, just as it does in the production of rapeseed oil. The highest quality nötoljan can be made of hazelnuts. Unlike many other vegetable oils exhibits a better balance between omega 3 omega 6 and its composition is almost identical with olive oil, which otherwise is considered the healthiest oil from the plant kingdom [2]. Hazelnut oil can be found more often in our Swedish grocery stores and it tastes really good.
The nutritional content is of course not everything if you want to find perennial staple crops from nut trees, Therefore, it is important to also examine the different species yields. More on that in the next part of the series on nötodling.
Sources
[1] Westergaard, L., 2013 [personal communication].
[2] Hultén, K., 2014 [personal communication].
[3] Crawford, M., The oaks. Agroforestry News, 20(1): p. 1-40, 2011.
[4] Crawford, M., Nut Crops – Appendices, 2012.
[5] Crawford, M., History of Sweet Chestnut. Agroforestry News, 18(4): p. 32-39, 2009.
[6] Saltå mill. Self, quite. Accessed 2014-01-27; Available from: http://www.saltakvarn.se/produkter/vete-helt/, 2014.
[7] NFA. Livsmedelsdatabasen. Accessed 2014-01-31; Available from: http://www.slv.se/sv/grupp1/mat-och-naring/vad-innehaller-maten/livsmedelsdatabasen-/, 2014.
[8] Knutsson, H., Introduction to Small-scale production and use of rapeseed cake, 2007.