Benders'dictionary of nutrition and food technology

39615–20 °C, but they will grow in cold stores at or below 0 °C; thetemperature must be reduced to about −10 °C before growthstops, but the organisms are not killed and will regrow when thetemperature rises.Bacteria of the genera Achromobacter, Flavobacterium,Pseudomonas and Micrococcus; Torulopsis yeasts; and moulds ofthe genera Penicillium, Cladosporium, Mucor and Thamnidiumare psychrophiles.psyllium Also known as plantago or flea seed, Plantago psyllium.Small, dark reddish-brown seeds which form a mucilaginousmass with water; used as a bulk-forming laxative.pteroylglutamic acid (pteroylglutamate), pteroylpolyglutamic acid(pteroylpolyglutamate) See folic acid.PTFE Polytetrafluoroethylene, a polymer resistant to heat andmany chemicals, and with low coefficient of friction, used tomake non-stick coatings for cooking utensils.ptomaines Obsolete name for amines formed by decarboxylationof amino acids during putrefaction of proteins; putrescine fromarginine, cadaverine from lysine, muscarine in mushrooms (alsoneurine formed by dehydration of choline). They have anunpleasant smell and were formerly thought to cause food poisoning,but are in fact harmless, albeit sometimes the products ofpathogenic bacteria.ptyalin Obsolete name for salivary amylase.ptyalism Or sialorrhoea, excessive flow of saliva.puberty, delayed The normal onset of puberty in boys is betweenthe ages of 12 and 15; a number of factors may delay this, especiallydeficiency of zinc. Severely zinc-deficient boys of 20 arestill prepubertal.PUFA Polyunsaturated fatty acids.puffballs Edible wild fungi; mosaic puffball Calvatia (Lycoperdon)caelata, giant puffball C. gigantea (may grow to 30 cm indiameter), normally eaten while still relatively small and fleshy,much prized for their delicate flavour. See mushrooms.puffer fish See tetrodontin poisoning.puffing gun For manufacture of puffed cereals by explosionpuffing.A chamber (the gun) is charged with the grain material,subjected to high-pressure steam, then the pressure is releasedvery rapidly. The shot of grain is propelled into an expansionvessel, when it expands to 3–10 times its original volume.pullulanase See debranching enzymes.pulque Sourish beer produced in central and south America bythe rapid natural fermentation of aquamiel, the sweet mucilaginoussap of the agave (American aloe or century plant, Agaveamericana). Contains 6% alcohol by volume.