Benders'dictionary of nutrition and food technology

388PRI Population reference intake of nutrients; see referenceintakes.prickly ash Bark and berries of Zanthoxylum americanum andZ. cIava-herculis, used as a food flavour, reputed to be a circulatorystimulant, and antirheumatic. Also known as toothachebark.prickly pear Fruit of the cactus Opuntia spp., also called Indianfig, barberry fig, tuna or sabra fruit, an important part of the dietin certain areas of Mexico. The stems or pads are nopales.Composition/100 g: (edible portion 75%) water 88 g, 172 kJ(41 kcal), protein 0.7 g, fat 0.5 g, carbohydrate 9.6 g, fibre 3.6 g, ash1.6 g, Ca 56 mg, Fe 0.3 mg, Mg 85 mg, P 24 mg, K 220 mg, Na 5 mg,Zn 0.1mg, Cu 0.1mg, Se 0.6µg, vitamin A 2µg RE (28µgcarotenoids), B 1 0.01 mg, B 2 0.06 mg, niacin 0.5 mg, B 6 0.06 mg,folate 6 µg, C 14 mg. A 100 g serving (1 fruit) is a good source ofMg, vitamin C.primigravida Woman experiencing her first pregnancy.primipara Woman who has given birth to one infant capable ofsurvival.See also parity.principal component analysis Mathematical technique for condensinga metabolomic spectrum to a single point on a graph,permitting rapid comparison between different species, experimentaland control groups, etc.prions Small, glycosylated proteins (M r 27 000–30 000) in thebrain cell membranes; to a considerable extent they are speciesspecific.A modified prion, designated PrPsc, resistant to digestion,heat and chemical agents, is the cause of spongiformencephalopathies.Pritikin programme Low-fat, low-cholesterol diet combined withexercise, to prevent heart disease, developed by Nathan Pritikin,1979.probiotics Preparations of microbial culture added to food oranimal feed, claimed to be beneficial to health by restoringbalance to the intestinal flora. Organisms commonly involvedinclude Bifidobacterium spp., Enterococcus faecium, Lactobacillusspp., Saccharomyces bulardii.See also bacteriocins; milk, acidophilus; prebiotics.probucol Drug used in treatment of primary hypercholesterolaemia;acts by inhibiting synthesis of cholesterol and increasingcatabolism of low-density lipoprotein (see lipoproteins,plasma).procarcinogen A compound that is not itself carcinogenic, butundergoes metabolic activation in the body to yield a carcinogen,commonly as a result of phase i metabolism.