Category: N
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Non-esterified fatty acids (NEFA)
Free fatty acids in the blood, as opposed to triacylglycerols.
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Non-digestible oligosaccharide
An oligosaccharide that is not digested (or minimally digested) in the upper gastrointestinal tract.
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No effect level (NEL)
With respect to food additives, the maximum dose of an additive that has no detectable adverse effects.
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No adverse effect level (NOAE)
With respect to food additives, equivalent to No Effect Level.
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N-nitroso compounds
Are a group of chemicals that occur ubiquitously. They are formed in the environment and can be absorbed from food, water, air and industrial and consumer products, formed within the body from precursors in food, water and air, inhaled from tobacco smoke, and naturally occurring.
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Nitrogen conversion factor
Factor by which nitrogen content of a foodstuff is multiplied to determine the protein content; it depends on the amino acid composition of the protein. For wheat and most cereals it is 5.8; rice, 5.95; soya, 5.7; most legumes and nuts, 5.3; milk, 6.38; other foods, 6.25. In mixtures of proteins, as in dishes and…
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Ninhydrin test
For the amino group of amino acids. Pink, purple or blue colour is developed on heating an amino acid or peptide with ninhydrin. A neurological test of sensation following peripheral nerve injury; used to detect a sympathetic response as indicated by sweat.
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Night blindness
Nyctalopia. Inability to see in dim light as a result of vitamin A deficiency. First symptom of vitamin A deficiency. The individual is unable to adapt to changes in light intensity. It is reversible if the vitamin is provided. Abnormal reduction in vision in darkness, due to deficiency of vitamin A or to retinal disorder;…
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Nicotinic acid
One of the vitamers of niacin. A B vitamin. Nicotinic acid is a derivative of pyridine and is interchangeable with its amide, nicotinamide. Both forms of the vitamin are equally active. Nicotinamide is a component of the coenzymes NAD (nicotinamide adenine dinucleotide) and NADP, its phosphate. Nicotinic acid is required in the diet but can…
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Nicotinamide
One of the vitamers of niacin. Nicotinamide, the amide of nicotinic acid, is usually used instead of the latter in the treatment of vitamin B deficiency. A basic amide that is a member of the vitamin B complex, used in the prophylaxis and treatment of pellagra.