About the table values

Missing and unknown values If the table value is zero, iteither means that the nutrient is not present in the food (reference 50) or that the amount is so small that the nutrient is not detected by the analytical method (reference 60a).

When the content is unknown (missing value), a hyphen (–) appears. In the spreadsheet file missing values appear as M. .

All table values represent levels

Table values in the Food Composition Table must not be understood as exact amounts, but rather as representative levels of the nutrient content. In vegetable foods, the content of nutrients will vary greatly according to type, growing conditions and degree of ripeness when harvested and used. The nutrient content in foods of animal origin vary with the breed of the bird or animal and feed. Conditions during storage, transport, industrial processing and/or preparation in the household are also of importance for the nutrient content in foods, products and dishes. There always also will be some variation in the analytical results from a laboratory.

From an analytical sample to the table value

Analysing the content of nutrients in foods is expensive. Thus in many cases, composite samples of foods produced in different parts of the country or from the largest food companies are analysed. Selection of food samples is based on statistics for production and/or turnover of the 3-5 varieties that together comprise about 80 % of the market for the particular food group. For each manufacturer or product type, the composite sample consists of 3-5 subsamples with different production dates.

Edible part

All foods in the food composition table have a value for edible part.

In meat products described as without skin, the skin is not included in the product, which means the product only includes meat, bone and connective tissue.

Energy

The internationally accepted standard unit for energy in the SI system is the joule (J). Because many people still use calories, the food content of energy is given both in kilojoules (kJ) and as kilocalories (kcal).

In the energy values energy from dietary fibre are also included.

Calculation factors used in the Food Composition Table:

The calculation factor for dietary fibre is lower than for carbohydrates because not all types of dietary fibre can be converted to energy in the human body.

Energy-yielding nutrients

Fats, fatty acids, cholesterol

The Norwegian Food Composition Table presents values for total fat, the sum of respectively saturated fatty acids, trans-unsaturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids, cholesterol and fifteen fatty acids. Trans-unsaturated fatty acids are formed in the rumen of ruminants and by industrial hydrogenation of long-chain fatty acids in oils. The table values for trans-unsaturated fatty acids are partly based on Norwegian analyses performed after 2000, and partly calculated on the basis of results from Transfair, a European collaborative project carried out during 1995-97 (1). However, information from Norwegian food companies shows that the content of trans-fatty acids from industrially processed fat probably is lower today than a few years ago for a number of products (2,3). Partially hardened fat often is replaced with fat types that are more saturated (palm oil, coconut oil). The type of added fat should be declared in the list of ingredients on the packaging of industrially produced foods.

Fatty acids make up 90-95 % of the fat content as a rule, but in some foods this proportion can be much lower. The rest of the fat is mainly glycerol, but some cholesterol, plant sterols and phospholipids may also be present.

When using the table values for fatty acids, it is important to be aware of that the food composition table has published values for some fatty acids only. The table does not have a complete fatty acid profile. The sum of the individual fatty acids will always be the same as or below the sum of saturated, monounsaturated and polyunsaturated fatty acids. The sum of the individual fatty acids is not necessarily in accordance with the sum of saturated, monounsaturated and polyunsaturated fatty acids, because all existing fatty acids are not present in the food composition table.

Omega-3 and omega-6 classified fatty acids consist of several fatty acids. The most common are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) for omega-3, and linoeic acid (LA) and arachidonic acid (ARA) for omega-6 fatty acids. Often only the mentioned fatty acids are analysed, thus sometimes the sum of omega-3 and omega-6 can be a bit lower than the actual content.

Carbohydrates

Table values are calculated as the sum of starch and sugars; available carbohydrates. A few of the carbohydrates values borrowed from other food composition tables might be calculated by difference. By calculating by difference, the carbohydrate is defined as what is left after subtracting the sum of water, protein, fat, alcohol, dietary fibre and ash in 100 g food. Carbohydrate values that are based on difference can be somewhat larger than analysed values since other, undefined substances may also be included.

The total mono+disaccharides comprise the naturally occurring glucose, fructose (fruit sugar), lactose (milk sugar) and maltose (malt sugar), as well as sugar (sucrose) or other sugars that are added during preparation and production. In Norwegian nutrient labelling total mono- and disaccharides is called Sukkerarter.

Added sugars comprise refined or industrially processed sugar in the form of glucose, fructose, lactose, maltose, sucrose, glycosid syrup and other hydrolysed starch products as glucose syrup and high fructose syrupthat is added during industrial production or home preparation. Naturally occurring sugars in fruit, vegetables and il kare not considered as added sugars.

Dietary fibre

Dietary fibre is not included in the carbohydrates. From 2015, the Norwegian analytical values for dietary fibre are based on the AOAC 2009.01 method. Analytica values from 2014 and earlier are analysed by using the method AOAC 985,29 (from 1985) and AOAC 991,43 (from 1991).

Protein

The protein content is calculated from the analysed nitrogen content. The calculation factor from nitrogen to protein varies somewhat with the amino acid composition of the food (4):

* The dairy industry use the protein factor 6,25, which is in accordance with the current regulations on food labelling. In the literature, a protein factor of 6,38 often is used for this food group, but it is decided to use the same protein factor (6,25) as the food industry.

Alcohol

In labelling of alcohol containing drinks , the alcohol content is presentes as volume percentage. The alcohol concentration is converted to weight percentage, i.e. grams of pure alcohol per 100 g drink. For beer, wine and other alcoholic beverages that have about the same specific weight as water, i.e. 1, the weight percentage is calculated as 0.8 times the volume percentage. Liqueur and sweet vermouth have a higher specific weight because of the sugar content, 1,1 and 1,05 respectively. Pure alcohol has a specific weight of 0,95 (5). 

Vitamins

The food composition table includes values for twelve substances with vitamin activity:

Vitamin A

Retinol is only found in animal foods and beta-carotene only in colour-rich vegetables and some fruits. Total vitamin A activity is calculated as the sum of retinol + 1/12 beta-carotene and termed retinol activity equivalents (RAE).

In some contexts, the concentration of vitamin A is given in international units (i.u.): 1 i.u. vitamin A = 0.3 µg retinol equivalent.

Vitamin B group

This group comprises the vitamins B1 (thiamin), B2 (riboflavin), Niacin, B6 (pyridoxine, pyridoxal, pyridoxamine), Folate and B12 (cobalamins). Vitamin B1 (thiamin) is presented as hydrochlorides, while some other food composition tables do not include the salt part of the molecule in their values.

The conversion factor of thiamin chloride to thiamin is 0.892.
From pyridoxine the conversion factor is 0.823.

Folate is a generic term for a number of more or less unstable forms of folic acid (pteroylglutamic acid). Pure folic acid is only found in food supplements. Norwegian analytical values for folate are determined by means of a microbiological method, while other, not quite comparable, methods of analysis can have been used in other countries.

Vitamin C

Vitamin C is found in food in two forms, ascorbic acid and dehydroascorbic acid. The Norwegian analytical values represent the sum of those two forms. Not all foreign food tables include the dehydroascorbic acid.

Vitamin D

Few foods contain vitamin D naturally. Industrially produced vitamin D (ergocalciferol or vitamin D2) has the same vitamin D activity as in the natural form (D3).

In some contexts, vitamin D is still given in international units (i.u.): 1 i.u. vitamin D = 0.025 µg vitamin D.

Vitamin E

Vitamin E has previously been used as a common name for several variants of tocopherol and tocotrienol. Today, only alpha-tocopherol is considered to have vitamin E activity, but the designation alpha-TE is still used (1). In some foreign tables, other tocopherols and trienoles are also converted to alpha-tocopherol equivalents (6).

In some contexts, vitamin E is still given in international units (i.u.): 1 i.u. vitamin E = 0.67 mg alpha-tocopherol equivalents.

Minerals and trace elements

The food composition table has values for ten minerals and trace elements:

M = mineral, T = trace element.

Iron

Iron (Fe) occurs both as haeme iron and nonhaeme iron in foods. Haeme iron is found only in animal foods, while nonhaeme iron is found in both animal and vegetable foods. In the Food Composition Table, no difference is made between the two forms.

Sodium/salt

The content of sodium (Na) is low in both animal and vegetable raw foods. The amount of salt added under industrial production and in household preparation can vary considerably. The sodium values for composite products, prepared raw foods and dishes are therefore especially uncertain. 1 g salt contains about 0.4 g sodium (i.e. 0.393 g).

Iodine

From 2018, most of the food items have iodine values. The University of Oslo, department of nutrition, has conducted a project in 2017-2018 in order to compile iodine values for the Norwegian Food Composition Table.

References

1. Hulshof KF, van Erp-Baart M-A, Anttolainen M et al. (1999) Intake of fatty acids in Western Europe with emphasis on trans fatty acids: The TRANSFAIR study. Eur J Clin Nutr 53(2):143-57.
2. Johansson L, Borgejordet Å, Pedersen JI. (2006) Trans fatty acids in the Norwegian diet. Tidsskr Nor Lægeforen 126:760-3. (English summary)
3. Mattilsynet og Sosial- og helsedirektoratet (2005). Bruk av delvis herdet fett og innhold av transfettsyrer i matvarer på det norske markedet i 2003. Resultater fra spørreundersøkelse blant norske produsenter og importører. Oslo.
4. Jones, D.B. (1941) Factors for Converting Percentages of Nitrogen in Foods and Feeds into Percentages of Protein. United States Department of Agriculture, Circular No. 183. Slightly revised edition.
5. Food Standards Agency (2002). McCane and Widdowson's The Composition of Foods, Sixth summary edition. Cambridge: Royal Society of Chemsitry.
6. Greenfield H, Southgate DAT (2003). Food composition data. Production, management and use. Second edition. FAO, Rome.