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Benefits of casein additives in historic mortar mixes
Published in Jan Kubica, Arkadiusz Kwiecień, Łukasz Bednarz, Brick and Block Masonry - From Historical to Sustainable Masonry, 2020
K. Falkjar, J. Erochko, M. Santana, D. Lacroix
Casein is a protein naturally occurring in bovine milk; it is divided into three protein subgroups: α-casein, β-casein and κ-casein. Further subgroups of α-casein exist (Atamer, et al., 2017). Bovine casein typically contains 48% α-casein, 34% β-casein and 15% κ-casein (Atamer, et al., 2017). The chemical structure, comprising of a series of amino acids, is the same except for the number of phosphate groups present (Bian & Plank, 2013). Casein is typically extracted from milk by means of acid precipitation: casein precipitates at a pH less than 4.6 (Bian & Plank, 2013), is partially insoluble near a neutral pH—κ-casein is soluble while the other types of casein are insoluble (Zittle & Custer, 1963)—and dissolves completely at a pH greater than 10.0 (Post, Arnold, Weiss, & Hinrichs, 2012). Lime mortar, for which the main constituent is calcium hydroxide, has a pH of 12.6, equivalent to that of a saturated calcium hydroxide solution, therefore, casein dissolves in the mortar and has been shown to increase the workability of the mortar and to improve adhesive properties (Asselin-Boulanger, 2018). In particular, the anionic phosphate component causes the protein to absorb calcium existent in masonry mortar, and thus behave as a superplasticiser additive (Zittle & Custer, 1963). It has been used to increase the workability of mortars since medieval times in many parts of Europe (Ince, 2012) (ASTM International, 2018). It was also used in glues and adhesives in the 19th century (ASTM International, 2013), and is still used to the present day as an additive in certain paints.
Dairy By-Products as Source of High Added Value Compounds
Published in Francisco J. Barba, Elena Roselló-Soto, Mladen Brnčić, Jose M. Lorenzo, Green Extraction and Valorization of By-Products from Food Processing, 2019
Noemí Echegaray, Juan A. Centeno, Javier Carballo
Glycomacropeptide is a C-terminal peptide (f 106–169) of the κ-casein released by the coagulant enzyme (chymosin) in the first stage of the enzymatic coagulation of milk during the cheese manufacture; the peptide is glycosylated in the Thr131, 133, 135, 142 and Ser141 positions of the backbone (Eigel et al. 1984). Being released from the casein micelles, it passes to the serum and is eliminated with it during the whey drainage. Glycomacropeptide accounts for 0–15% of the whey proteins, being its content maximum in sweet whey from an enzymatic coagulation of the milk. It is a very interesting molecule showing functional properties, such as emulsification, foaming and gel formation ability, and also biological properties including reduction of gastric secretion, growth factor for Bifidobacterium, anti-carcinogenic effect, inhibition of cholera toxin, prevention of intestinal infection, hemagglutinin inhibition, modulation of immune response, stimulation of cholecystokinin release, and nutritional management of phenylketonuria (Neelima et al. 2013). Being its sole origin the hydrolysis of the κ-casein by chymosin, its presence has been used for detection of cheese whey adulteration in milk (Neelima et al. 2013).
Application of Nanotechnology in the Safe Delivery of Bioactive Compounds
Published in V Ravishankar Rai, Jamuna A. Bai, Nanotechnology Applications in the Food Industry, 2018
Behrouz Ghorani, Sara Naji-Tabasi, Aram Bostan, Bahareh Emadzadeh
Bovine milk contains four different caseins, namely, αs1-, αs2-, β- and κ-caseins, from which β-casein forms nanosized micelles while the other caseins form micelles of larger and uncontrolled sizes. β-Casein has therefore been used as nanocarrier for several bioactive ingredients. Some structural and physicochemical properties of caseins such as binding of ions and small molecules, excellent emulsification, self-assembly properties, pH-responsive gel swelling behavior, the ability to interact with other macromolecules to form complexes or conjugates, and control of the bioaccessibility of the bioactives have made them good candidates for being applied in delivery and controlled release systems (Ron et al. 2010; Semo et al. 2007). Some recent studies focused on the encapsulation of bioactive compounds using milk proteins are shown in Table 12.2.
Spontaneous interaction of lactoferrin with casein micelles or individual caseins
Published in Journal of the Royal Society of New Zealand, 2018
Although κ-casein is a relatively minor component of the casein proteins, it is located primarily at the casein micelle surface with the N-terminal region associated with the micelle core and the C-terminal region protruding from the micelle surface as a flexible hair. This arrangement of hairs at the surface provides steric stability and this is the primary force in the stability of the casein micelles (Walstra 1990; Holt & Horne 1996; de Kruif et al. 2012; Anema 2014). The casein micelles in milk serum are remarkably stable, withstanding the various processing steps involved in modern commercial production of dairy products such as high temperatures and pressures, high shear and variations in concentration. Even the processes involved in producing milk powders, and their subsequent reconstitution to re-form liquid milk products, does not significantly alter the casein micelles as the reconstituted milk has many properties that are similar to those of the original fresh milk (Singh & Newstead 1992; Kelly et al. 2003; Nieuwenhuijse & van Boekel 2003).
Potential utility of callus proteases as a milk clotting alternative to naturally propagated Wrightia tinctoria proteases
Published in Preparative Biochemistry & Biotechnology, 2022
Anusha Rajagopalan, Vasuki Aluru, Malini Soundarajan, Bindhu O. Sukumaran
Enhanced MCI alone does not warrant cheese with desirable characteristics. Cheese characteristics depend largely on the extent of hydrolysis of different caseins. Each casein is reported to be associated with distinct cheese properties like texture (α1 and α2 casein), flavor (β-casein), and clotting efficiency (κ-casein).[33] Caseinolytic pattern differs with manufacturing process, protocols followed for ripening, and are unique for each cheese variety. Evaluation of casein degradation pattern that impacts yield and sensory characteristics of cheese is thus vital while assessing the suitability of protease to be a rennet substitute.[34] Industrial cheese production demands minimum nonspecific proteolysis and precise ratio between protein and peptides.[35] Hydrolysis of casein in the order of κ-casein followed by α and β caseins is one of the requirements for quality cheese.[36] This study reconfirms the pattern of casein hydrolysis by rennin and Enzeco® reported earlier.[31,37] Presence of prominent high intense lower molecular weight band with rennin could have resulted from κ-casein hydrolysis. Intense lower molecular weight bands that appeared in Enzeco® hydrolyzed casein hydrolysate could probably be the reason for characteristic flavor for the cheese made using them. This study comprehends the influence of age of callus on the degree of casein hydrolysis with κ-casein being their first target followed by α and β caseins. This observation validates the results of high MCI associated with CCEs. Prominent intense band similar to that with rennin was absent in 14th day CCE casein hydrolysis. This probably denotes non-specific hydrolysis of κ-casein by 14th day CCE, a characteristic property of vegetable coagulant. From the accessible literature, studies focusing on callus as a milk coagulant source and delineation of molecular interactions between these coagulants with casein are scarce. Positive controls used in this study are currently in use in cheesemaking across the globe. Enzeco®, a commercial plant-based coagulant, is obtained from Cynara and rennin is from bovine source allowing the authors to compare and justify the callus proteases as milk coagulant. Results from our earlier studies on casein hydrolysis by C. gigantea callus and crude proteases from plant’s stem and leaf revealed its closer resemblance to Enzeco®.[31] However, stem proteases did not completely hydrolyze κ-casein unlike the results from this study. Results from this study suggest CCE from callus of W. tinctoria stem could be used in cheese making nevertheless with distinctive cheese characteristics. Overall, results reveal 28M1 (28th day CCE containing 0.5 mg/L NAA), with high MCA and comparatively low CA, may possibly serve as a vegetable coagulant for cheese making.