470 INDEX Lactic acid, (cont tertiary structure, 193 Lactase. 4 e also B-Galactosidase blood, 23 actosyl trans erase, 23 acid,50,120,445,451 Leloir pathway, 23 of ph on redox potential, 44 also Lactococcus: Non-starter lactic UDP-galactose, 23 cid bacteria: Cheese starters and concentration in milk, 21 Lactitol, 48.51 crystallization, 28 Lactobacillus spp, 397, 432 crystal shape, 27 Lactococcus, 211, 412, 41 derivatives of lactose. 42 action of enzymes on casein-derived determination of concentration 62 peptides, 412 aminopeptidase, 412 chloramine-T. 63 cell wall-associated proteinase, 412 hromatographic methods, 6 peptidase, 412 intracellular endopeptidase, 412 colorimetry, 62 proline-specific peptidases, 412 enzymatic methods, 62, 65 Lactococcus lactis ssp. lactis biovar oxidation-reduction titration. 62 citrate metabolism by, 430 0,183,187,188,42 effect of temperature on solubility, 27 mino acid composition, 188 food applications, 41 genetic variants, 188 ffect on heat stability of milk. 369 heat stability of, 36 hydrophobic interaction, 190 lactose glass, 3/, 58, 59 mutarotation, 25 ccurrence and microheterogeneity, 188 utritional aspects, 56-62 physiological function, 191 physical properties, 31 primary structure, 189 production, 39, uaternary structure, 190 relati effect of pH on quaternary structure. relative sweetness, 41, 42 A),190 nsaturated metastable, labile zones condary structure, 189 specific rotation, 25 er, see Hydrometer Lactoperoxidase,131,199,318,319,331-3, 336,341,363 Lactosyl urea, 50 index of fiash and super-HTST Lactotransferrin, 187, 229, 363 3,46-8,353 significance of lactoperoxidase, 332 as bifidus factor. 45 x-lactose. 23. 24 rofora, 48 sandiness, 30 actel duction during sterilization, 45470 INDEX Lactic acid, (cont.) tertiary structure, 193 Lactase, 42 see also P-Galactosidase Lactenins, 332 Lactic acid, 50, 120, 445, 451 Lactic acid bacteria, 428 effect of pH on redox potential, 441 see also Lactococcus; Non-starter lactic acid bacteria: Cheese starters and acidification Lactitol, 48, 51 Lactobacillus spp., 397, 432 Lactobionic acid, 48 Lactococcus, 211, 412, 419 peptides, 412 action of enzymes on casein-derived aminopeptidase, 412 cell wall-associated proteinase, 412 dipeptidase, 412 intracellular endopeptidase, 412 proline-specific peptidases, 412 tripeptidase, 412 Lactococcus lactis ssp. lactis biovar diacetylactis, 397 citrate metabolism by, 430 amino acid composition, 188 denaturation, 192 genetic variants, 188 effect on heat stability of milk, 369 heat stability of, 364 hydrophobic interaction, 190 methods for isolation, 226 occurrence and microheterogeneity, 188 physiological function, 191 primary structure, 189 quaternary structure, 190 /?-Lactoglobulin, 132, 150, 183, 187, 188,442 effect of pH on quaternary structure, 191 191 relationship to retinol (vitamin A), 190, secondary structure. 189 tertiary structure, 189 Lactometer, see Hydrometer Lactonase, 340 Lactoperoxidase, 131, 199, 318, 319, 331-3, 336, 341, 363 index of flash and super-HTST pasteurisation, 331 index of mastitic infection, 332 non-enzymic oxidation, 332 significance of lactoperoxidase, 332 1-lactose, 23, 24 Lactose, 11, 14, 17, 21-66 anhydrous, 30 monohydrate, 29 sandiness, 30 fi-lactose, 23, 24 biosynthesis, 23 anhydride, 30 blood, 23 galactosyl transferase, 23 Leloir pathway, 23 osmotic pressure, 23 role of a-lactalbumin, 23 UDP-galactose, 23 chemical modifications, 43 concentration in milk, 21 crystallization, 28 nucleation, 28 crystal shape, 27 derivatives of lactose, 42 anthrone, 64, 65 chloramine-T, 63 chromatographic methods, 65 chromatography, 62 colorimetry, 62 enzymatic methods, 62, 65 Fehling’s solution, 63, 64 oxidation-reduction titration, 62 phenol, 64 polarimetry, 62 effect of temperature on solubility, 27 fermentation products, 50 food applications, 41 heat-induced changes in, 352 hygroscopicity, 27, 31, 32, 33 intolerance, 23, 56, 58, 59 lactose glass, 31 mutarotation, 25 nutritional aspects, 56-62 physical properties, 31 production, 39, relative humectancy, 42 relative sweetness, 41, 42 solubility, 27 determination of concentration, 62 supersaturation, 29, 38 unsaturated, metastable, labile zones, 28 specific rotation, 25 structural formulae, 24 structure, 23 thermoplasticity, 35 Lactosyl urea, 50 Lactotransferrin, 187, 229, 363 bacteriocidal peptides from lactotransferrin, 234 Lactulose, 43, 46-8, 353 as bifidus factor, 45 cariogenicity, 45 effect on intestinal microflora, 48 formation, 354 production during sterilization, 45 Lactyl palmitate, 51