Benders'dictionary of nutrition and food technology

4achylia Absence of a secretion; e.g. achylia gastrica is absence ofgastric secretion.acid–base balance Body fluids are maintained just on the alkalineside of neutrality, pH 7.35–7.45, by buffers in the blood andtissues. Buffers include proteins, phosphates and carbondioxide/bicarbonate, and are termed the alkaline reserve.Acidic products of metabolism are excreted in the urine combinedwith bases such as sodium and potassium which are thuslost to the body. The acid–base balance is maintained by replacingthem from the diet.acid dip Immersion of some fruits in an acid dip (commonlyascorbic and malic acids) prior to drying to improve the colourof the dried product by retarding enzymic browning.acid drops Boiled sweets with sharp flavour from tartaric acid(originally acidulated drops); known as sourballs in USA.acid foods, basic foods These terms refer to the residue of themetabolism of foods. The minerals sodium, potassium, magnesiumand calcium are base-forming, while phosphorus, sulphurand chlorine are acid-forming. Which of these predominates infoods determines whether the residue is acidic or basic (alkaline);meat, cheese, eggs and cereals leave an acidic residue, whilemilk, vegetables and some fruits leave a basic residue. Fats andsugars have no mineral content and so leave a neutral residue.Although fruits have an acid taste caused by organic acids andtheir salts, the acids are completely oxidised and the sodium andpotassium salts yield an alkaline residue.acidity regulators See buffers.acid number, acid value Of a fat, a measure of rancidity due tohydrolysis (see hydrolyse), releasing free fatty acids from thetriacylglycerol of the fat; serves as an index of the efficiencyof refining since the fatty acids are removed during refining andincrease with deterioration during storage. Defined as milligramsof potassium hydroxide required to neutralise the free fatty acidsin 1 g of fat.acidosis An increase in the acidity of blood plasma to below thenormal range of pH 7.35–7.45, resulting from a loss of the bufferingcapacity of the plasma, alteration in the excretion of carbondioxide, excessive loss of base from the body or metabolic overproductionof acids.See also acid–base balance.acids, fruit Organic acids such as citric, malic, and tartaric, whichgive the sharp or sour flavour to fruits; often added to processedfoods for taste.acidulants Various organic acids used in food manufacture asflavouring agents, preservatives, chelating agents, buffers, gelling