Benders'dictionary of nutrition and food technology

417Rothera’s test For ketones in urine; reaction with ammoniumhydroxide, ammonium sulphate and sodium nitroprusside to givea purple colour in the presence of ketones.roti See chappati.rôtisserie Method of cooking which developed from the traditionalrotating spit above an open fire; the food is rotated whileroasting, so bastes itself.roughage See fibre, dietary; non-starch polysaccharides.round worm See nematode.roux The foundation of most sauces; prepared by cookingtogether equal amounts of fat and plain flour, for a short timefor white sauces, and longer for blond or brown sauces.The sauceis then prepared by stirring in milk or stock.Rovimix TM Stabilised preparations of vitamins, as beadlets coatedwith a gelatine–starch mixture, used to enrich foods.royal jelly The food on which bee larvae are fed and which causesthem to develop into queen bees. Although it is a rich source ofpantothenic acid and other vitamins, in the amounts consumedit would make a negligible contribution to human nutrition. 2%of its dry weight is hydroxydecenoic acid, which is believed to bethe active queen substance. Claimed, without foundation, to haverejuvenating properties for human beings.RPV Relative protein value, a measure of protein quality.RQ See respiratory quotient.RTE Ready to eat.rubble reel Machine for cleaning materials such as wheat. Thematerial is fed into a long inclined reel made of perforated metalthat rotates inside a frame. The perforations become largernearer the bottom, so that there is a graded sieving of the materialas it passes down the reel.Rubner factors See energy conversion factors.rum Spirit distilled from fermented sugar cane juice or molasses;may be colourless and light tasting or dark and with a strongflavour. Traditionally rum is darker and more strongly flavouredthe further south in the Caribbean it is made. There are threemain categories: Cuban, Jamaican and Dutch East Indies; andseveral types: aguardiente (Spain, Portugal and S America),Bacardi (trade name, originally from Cuba), cachaca (Brazil),cane spirit (S Africa), Demerara rum (Guyana), 35–60% alcoholby volume, 1.0–1.8 MJ (250–420 kcal) per 100 mL.rumen See ruminants.ruminants Animals such as the cow, sheep and goat, whichpossess four stomachs, as distinct from monogastric animals, suchas human, pig, dog and rat. The four are: the rumen, or firststomach, where bacterial fermentation produces volatile fatty