Production of low-lactose milk by means of nonisothermal bioreactors.
The effect of the immobilization time on the activity of immobilized beta-galactosidase from K. lactis was investigated. Six biocatalytic membranes, different only for the time of the enzyme immobilization, were obtained by using nylon membranes grafted with glycidyl methacrylate (GMA) and activated by hexamethylenediamine (HMDA) and glutaraldehyde (Glu), used as spacer and coupling agent, respectively. Comparison between the isothermal and nonisothermal yield of these biocatalytic membranes was carried out in the process of lactose hydrolysis in milk. All of the results, reported as a function of the immobilization time, have evidenced the influence of our variable parameter on the activity of the catalytic membranes. The membrane giving highest yield under isothermal and nonisothermal conditions was that obtained with 2 h of immobilization time. The industrial application of these membranes has been discussed in terms of percentage reduction of the production times.
Institute of Genetics and Biophysics Buzzati Traverso of CNR, Via G. Marconi 10, 80125 Naples, Italy.
Valentina
V
Grano
Nadia
N
Diano
Sergio
S
Rossi
Marianna
M
Portaccio
Angelina
A
Attanasio
Michele
M
Cermola
Rossella
R
Spiezie
Cristiana
C
Citton
Damiano Gustavo
DG
Mita
D000818:Animals; D019149:Bioreactors; D002384:Catalysis; D002417:Cattle; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005511:Food Handling / Q000295:instrumentation* / Q000379:methods; D006868:Hydrolysis; D007785:Lactose / Q000737:chemistry* / Q000302:isolation & purification*; D008567:Membranes, Artificial; D008892:Milk / Q000737:chemistry*; D013696:Temperature; D014462:Ultrafiltration / Q000295:instrumentation* / Q000379:methods; D001616:beta-Galactosidase / Q000737:chemistry*
D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D001616:beta-Galactosidase; D007785:Lactose