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Protein-based Wood Adhesives Current Trends of Preparation and Application
Published in Zhongqi He, Bio-based Wood Adhesives, 2017
Birendra B. Adhikari, Pooran Appadu, Michael Chae, David C. Bressler
Casein. Bovine milk typically contains about 3.5 percentage protein, out of which 80 percentage is casein and 20 percentage is whey. Hence, casein can be extracted commercially at a yield of 2.5-3.0 kg per 100 kg skim milk. Based on the coagulating agent used during production, there are two basic types of casein available in the market—acid and rennet casein. Acid casein is produced by the action of acid on milk and is of two types: (i) casein obtained as a precipitate by adjusting the pH of skim milk to 4.6 with mineral acids such as hydrochloric or sulphuric acid; and (ii) casein obtained as a precipitate of skim milk by acidification due to lactic acid produced in situ with lactic acid bacteria. In rennet casein, coagulation is obtained by the action of an enzyme called rennet on skim milk. Acid or enzyme treatment for precipitation of casein yields a mixture of casein curd and whey from which whey (the liquid product) is separated, and the casein curd is washed with water and then dried to produce casein (Audic et al., 2003; Southward, 1998). The pH of acid casein ranges from 4.6 to 5.4, and its protein content is nearly 85 percentage. The pH of rennet casein ranges from 7.3 to 7.7, and its protein content is nearly 80 percentage (Southward, 1998).
Physical networks of biopolymers
Published in K. Dušek, S.I. Kuchanov, Polymer Networks '91, 1992
Casein (milk) gels are important technologically because they form the basis of cheese, yoghurt and other similar products. The term casein, itself, describes a number of different proteins (αs1,αs2,B and κ-caseins), which occur in milk as roughly spherical but highly voluminous micelles, typical DP ≈10000, particularly stabilized by colloidal calcium phosphate. Treating whole milk with an enzyme chymosin (rennet) is believed to cleave away the κ-casein which exists on the “outside” of the micelle, producing a coagulate (curd), which is separated from the remaining liquor (whey), a solution of whey proteins. Many detailed studies of casein aggregation have been carried out, although most often using the methods of classical colloid science (Ref.26).
Computerized Automation Controls in Dairy Processing
Published in Gauri S. Mittal, Computerized Control Systems in the Food Industry, 2018
Cheese is the fresh or ripened product obtained after coagulation and whey separation of milk, cream, partly skimmed milk, buttermilk, or a mixture of these products. The cheese varieties available on the market can be broadly classified according to (1) moisture content—hard, semi-hard, and soft cheese; (2) coagulation method—using rennet, acid, or both rennet and acid (cottage cheese); (3) microorganism used for ripening—lactic acid bacteria or others such as molds (for Roquefort, Gorgonzola, and Camembert); and (4) texture—round eyed, granular, and close-textured. Figure 22 shows a schematic of the simplified cheesemaking process.
Effects of skim milk concentrate dry matter and spray drying air temperature on formation of capsules with varying particle size and the survival microbial cultures in a microcapsule matrix
Published in Drying Technology, 2018
Rebecca Würth, Petra Foerst, Ulrich Kulozik
An alternative spray drying encapsulation process was developed by Würth et al.,[7] which consists out of three steps. Reconstituted skim milk concentrate was treated with rennet enzyme at cold temperatures (step I) to prevent aggregation. This matrix solution was transformed into the water-insoluble gel state by increase in temperature, which occurs during spray drying (step II) and warm rehydration (step III) of the powder, also called capsule precursor (CP). The last step is necessary for a complete capsule formation, because the residence time in the spray dryer is too short to complete the rennet-based gel formation. In the previous study, it has been shown that by low TS contents and moderate drying temperatures, the properties of the final capsule formation can be improved toward a better capsule gelation.
Production of highly active fungal milk-clotting enzyme by solid-state fermentation
Published in Preparative Biochemistry & Biotechnology, 2019
Cirium V. Chinmayee, Cheral Vidya, Amsaraj Rani, Sridevi Annapurna Singh
The main characteristic of calf rennet is not just the ability to coagulate casein but its high specificity to cleave kappa casein at Phe105-Met106 obtaining para-kappa casein and glycomacropeptide.[7,8] This specific cleavage results in maximum curd yield, while the currently available vegetable and microbial rennets are nonspecific. Non – specific hydrolysis during cheese making could result in low yields, bitter peptides and off flavors during aging.[6,9]
A systematic review of biodegradable materials in the textile and apparel industry
Published in The Journal of The Textile Institute, 2023
HuiYing Bao, Yan Hong, Tao Yan, Xiufen Xie, Xianyi Zeng
Milk protein fabric has delicate hand feel, soft luster, good warmth, excellent moisture absorption and breathability, good wearing comfort, and unique moisturizing and antibacterial and anti-inflammatory health effects. With excellent properties for apparel application, it can be used in knitted, woven, non-woven, and other ways to develop fabrics for apparel application. It is widely used in high-grade underwear, shirts, home wear, T-shirts, milk cashmere dresses, etc. However, milk protein fiber also causes high pollution in the production process, has poor heat resistance of the fiber, poor color vividness, and high price, which affects its application in the textile and apparel industry. Researchers have conducted several studies for this purpose. Thill et al. (2021) used rennet-induced aggregation to develop a sustainable way to spin micellar casein fibers from milk, reducing the use of harsh chemicals in the fiber spinning process. Bier et al. (2017) investigated the effects of different chemical compositions and temperature treatments on the properties of milk casein fibers, and the results showed that chemical modification as well as temperature treatment significantly increased the water resistance of the fibers. Benli and Bahtiyari (2018) studied the dyeing of casein fibers by natural dye source of onion peel and observed that the coloration of milk casein fibers could be controlled more easily by using onion peel. In addition, to improve the properties of milk protein fibers for apparel applications and effectively reduce the production cost, they can be blended with other fibers to give the fabrics unique properties and qualities. Such as through blending milk protein fiber with cotton blended fabric can maintain the excellent moisture absorption, breathability, and warmth of cotton fiber. It also improves the healthiness, drapability, and luster of the fabric. It is blending milk protein fiber with wool fiber, making the fabric comfortable and light to wear. It has good thermal performance. The blended fabric improves the prickly feeling of pure cashmere fabric when wearing it close to the body. Blending makes it more mildew and moth-resistant, wearable, and washable. With the gradual improvement and maturity of the milk protein fiber production process, these problems will be better solved, milk protein fiber will have a broader development prospects and development space.