Potatoes - analysis of nutrients

During 2009/2010 the Swedish National Food Administration anaylsed nutrional content in new potatoes, old potatoes, and catering potatoes. The nutrient content in potatoes may vary between different varietites and may change during storage and cooking, which was accounted for while sampling and analysing. The analysis showed that poatoes can be classified as source of vitamin C, vitamin B6 and potassium according to EU defintitions. For potatoes boiled with peel, salt content was low even after boiling with added salt. Boiling reduced vitamin C and thiamin contents by about 20 percent in potatoes cooked with and without shell. Between potato varieties concentration of different nutrients varied with up to 20 percent. Storage for 5 months reduced vitaimn C by 60 percent, while content of vitamin B6 increased by about 20 percent, possibly due to germination. The content of monosaccharides increased as a result of degradation of disaccharides and starch. Nutrient content in catering poatoes did not significantly differ from that of potato varieties commonly consumed. One serving of boiled potatoe (175 g) contained more than 20 percent of recommended daily intake of vitamin C, niacin, Vitamin B6 and potassium. The potato analysis were part of the annual analysis projects carried out by the Swedish National Food Administration to update the food database with nutritional values of commonly consumed foodstuffs

Is there a substantial change in nutrient content of plant foods available on the marekt over time

The aim of this report was to examine if there has been any substantial changes in nutrient content of plant foods available on the market over time. The background is a debate in Swedish media concerning changes in nutrient content as a consequence of e.g. depletion of the soil. The work has concentrated on identifying both factors that influence the actual nutrient content of plant foods and on factors that only influence the published nutrient data. The influence of development and changes in analytical procedures over time is discussed. Further there are examples on how calculations, definitions and other procedures in data compilation might influence published nutrient data. It is concluded that it is impossible to state if there has been any substantial changes in nutrient content over time. Because of lacking documentation of samples, sample handling and analytical procedures it is not possible to exclude other factors behind observed changes in nutrient content