Benders'dictionary of nutrition and food technology

245hydrogen peroxide Antimicrobial agent, H 2 O 2 . Readily losesactive oxygen, the effective sterilising agent, forming water. Canbe used at 0.1% to preserve milk (Buddeised milk, not permittedin the UK), but destroys vitamin C, methionine andtryptophan.hydrogen swells See swells.hydrolyse To split a complex compound into its constituent partsby the action of water, either enzymically or catalysed by theaddition of acid or alkali. Hence hydrolysis.hydropathy Of proteins, their relative preferences for aqueousversus non-polar environments; the extent to which they arehydrophilic or hydrophobic.hydrophile–lipophile balance (HLB value) The ratio ofhydrophilic to hydrophobic groups on the molecules of anemulsifier.hydrophilic A solute that will dissolve in water and other polarsolvents.hydrophobic A solute that will dissolve in non-polar solvents, butnot in water.hydroponics The practice of growing plants without soil in a solutionof inorganic salts.hydrostatic steriliser Continuous steriliser in which the process iscarried out under sufficient depth of water to maintain therequired pressure. Used for continuous sterilisation of cannedfoods on a large scale.hydrotalcite Aluminium magnesium carbonate/hydroxidehydrate; used as an antacid.hydroxocobalamin See vitamin b 12 .hydroxyapatite Calcium orthophosphate hydroxide, the mainmineral of bones, Ca 10 (PO 4 ) 6 (OH) 2 .hydroxybenzoic acid esters See parabens.hydroxycholecalciferol See vitamin d.hydroxylysine Amino acid found only in connective tissue proteins(collagen and elastin); incorporated into the protein aslysine and then hydroxylated in a vitamin C-dependent reaction;abbr Hyl, M r 162.2, pK a 2.13, 8.62, 9.67.hydroxyproline Amino acid found mainly in connective tissueproteins (collagen and elastin); incorporated into the proteinas proline and then hydroxylated in a vitamin C-dependentreaction; abbr Hyp, M r 131.1, pK a 1.82, 9.66. Peptides ofhydroxyproline are excreted in the urine and the output isincreased when collagen turnover is high, as in rapid growth orresorption of tissue. Excretion is significantly lower than normalin children whose growth is impaired by protein–energy malnutrition.Measurement of hydroxyproline in meat products