Hydrolysis of whey proteins by proteases extracted from Cynara cardunculus and immobilized onto highly activated supports

Abstract

Blends of cardosins A and B, enzymes present in aqueous extracts of the flowers of the thistle (Cynara cardunculus L.), have for long been used as rennets by the cheesemaking industry in the Iberian Peninsula. These dimeric proteases are present in the stigmae and stylets of said flowers, and are thought to play a role in sexual reproduction of the plant. In the present research effort, production of cardosin derivatives (starting from a crude extract), encompassing full stabilization of their dimeric structure, has been attempted via covalent, multi-subunit immobilization onto highly activated agarose-glutaraldehyde supports. Boiling such enzyme derivatives in the presence of sodium dodecyl sulfate and beta-mercaptoethanol did not lead to leaching of enzyme, thus proving the effectiveness of the attachment procedure. Furthermore, derivatives prepared under optimal conditions presented ca. half the specific activity of the enzyme in soluble form, and were successfully employed at lab-scale trials to perform (selective) hydrolysis of alpha-lactalbumin, one of the major proteins in bovine whey.

Immobilization of halophilic Bacillus sp. EMB9 protease on functionalized silica nanoparticles and application in whey protein hydrolysis

“…Whey, a byproduct of dairy industry is rich in soluble proteins and contains high levels of essential amino acids, vitamin B, lactose and salts. Whey proteins comprise approximately 20 % of the total milk proteins [34,36], the most important of which are b-lactoglobulin and a-lactalbumin, representing 70-80 % of the total protein content [34,36,37]. Protein hydrolysates obtained upon hydrolysis of whey proteins have been reported to exhibit antimicrobial, antioxidant, antihypertensive and lipid-lowering properties [38].…”

Jacaratia corumbensis O. Kuntze a new vegetable source for milk-clotting enzymes

“…Aqueous extracts of these flowers have been employed for ages in Portugal and bordering regions of Spain for the production of traditional cheeses from raw ewe's milk (Roa et al, 1999) and/or goat's milk (Silva et al, 2003). High levels of proteolytic enzymes in the flowers are responsible for the effective clotting of milk (Lamas et al, 2001). Plant proteases employed for cheese production in various areas of the world include papain, bromelain, ficin, oryzasin, cucumisin, sodom apple protease and lettuce protease, extracted from Carica papaya, Ananas comosus, Ficus glabra, Oriza sativa, Cucumis melo ssp, Calotropis procera and Lactuca sativa, respectively (Uchikaba and Kaneda, 1996;Asakura et al, 1997;Lo Piero et al, 2002).…”

Whey Proteins as Source of Bioactive Peptides Against Hypertension

“…This is the case of aspartic proteinases present in the flowers of Cynara cardunculus -a plant related to the (common) globe artichoke. They can cleave the whey protein backbone next to hydrophobic amino acid residues, especially Phe, Leu, Thr and Tyr [82,175], and act mainly on -La, either in whole whey or following concentration to whey protein concentrate (WPC) [176][177][178]; conversely -Lg appears not to be hydrolyzed thereby to a significant extent [82,175].…”