Preparation of lactose‐free milk by using salt‐fractionated almond (Amygdalus communis) β‐galactosidase

Abstract

β-galactosidase was isolated from almond (Amygdalus communis) extract by ammonium sulfate precipitation. Almond proteins precipitated by using ammonium sulfate and then dialysed exhibited 5.3-fold purification of β-galactosidase, and the yield of enzyme preparation was 96.5%. The partially purified β-galactosidase exhibited pH and temperature optima at pH 5.5 and 50• C, respectively. The enzyme was significantly stable against heat, pH, calcium and magnesium ions and D-galactose. The almond β-galactosidase preparation exhibited over 89% activity even after 2 months storage at 4• C. Hydrolysis of lactose in milk and whey was performed in a stirred batch process by using this enzyme preparation. These observations indicated that the hydrolysis of lactose increased continuously with time. The enzyme could hydrolyse 94% of lactose in buffer solution and whey whereas 90% of lactose hydrolysis was achieved in milk. The main aim of the present study was to prepare lactose-free milk, which must be free from contamination, and the process should be inexpensive.

Immobilization of β-galactosidase from Lactobacillus plantarum HF571129 on ZnO nanoparticles: characterization and lactose hydrolysis

“…The soluble enzyme retained 90.92 % Bioprocess Biosyst Eng residual activity after treating with 120 U of amylase, because the cross-linked enzyme retained 97.18 % activity under identical amylase treatment. Similar behavior has been reported for b-galactosidase from A. oryazae adsorbed on the surface of beads and cross-linked with glutaraldehyde [45]. To remove the lactose present in the small intestine immobilized b-galactosidase may be given orally, which contains amylase.…”

Characterization of β-galactosidase in the Crude Plant Extract of <i>Artemisia judaica</i> L. in Presence and Absence of Some Heavy Metals

“…The loss of activity of the enzyme at higher temperatures could be attributed to its unfolding and subsequent loss of active site due to denaturated proteins [50]. The same optimum temperature obtained (50°C) for nasturtium, peach and Hymenaea courbaril [51,46,47].…”

Extraction, Purification and Characterization of Apricot Seed β-Galactosidase for Producing Free Lactose Cheese

“…On the other side, the enzyme retained more than 60% of its activity at temperatures ranged from 40-65°C. The loss of activity of the enzyme at higher temperatures could be attributed to its unfolding and subsequent loss of active site [17]. The optimum temperature of β-galactosidase was in the range 40-60°C [27,28,30].…”

“…Additionally, Lactosehydrolysed milk used for the preparation of yoghurt and cheese manufactory accelerate the acidification process that reduces the set time of yoghurt and develop the structure and flavor in cheese [14]. β-Galactosidases are found in microorganisms (bacteria, fungi, yeasts), plants especially in almonds, peaches, apricots, apples and animal organs [15][16][17]. The β-galactosidases extraction and purification from many microorganisms for the preparation of de-lactosed milk shown inhibition to Ca +2 , an essential milk component occurring at the concentration of 30 mM, indicating that lactose hydrolysis with these preparations are not effective [18].…”