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Casein and Caseinate: Methods of Manufacture
Abstract
Casein is the principal protein found in milk. It is responsible for the white, opaque appearance of milk. It is combined with calcium and phosphorus in clusters termed micelles. Until the 1960s, casein was primarily used in technical, nonfood applications, such as adhesives for wood, paper coating, leather finishing, synthetic fibers, and plastics. But in the last 30–35 years, casein has been principally employed in food applications as an ingredient for enhancing the food’s physical properties, including whipping and foaming, water binding and thickening, emulsification and texture. Casein also improves a food’s nutritive value.
... The first step in the preparation of casein was separating the casein from skimmed milk. Rennet was added to warm milk (40-50℃) to bring pH value to about 4.6, at this value, maximum precipitation of curd occurs, while the other part is known as whey [31,32]. ...
... Finally, dried casein is milled and packed to create granules of a size of 0.1-0.5 mm. The produced casein is white to slightly yellow [31][32][33]. Figure 2 presents the procedure of casein preparation from spoiled milk in this study. ...
... Therefore, an appropriate alkaline solution was prepared to homogeneously dissolve the casein. 1 Molarity of sodium hydroxide (NaOH) solution was prepared to confirm a suitable soil-casein mixture. For improving casein dissolvability, the (NaOH) solvent was heated up to 70°C [31]. Casein powder was added to the NaOH solution and continuously stirred via a magnetic stirrer till the powder was completely dissolved and formed a homogeneous casein solution. ...
Gypseous soil is a metastable soil that causes problems in the constructions built on it under wetting conditions. Due to the harmful effects of traditional soil binders such as lime or cement on the environment, alternative environmental-friendly materials have been used to decrease this impact. Casein biopolymer is introduced in this study as a new binder for gypseous soil improvement and milk waste minimizing purposes. The study focused on three primary soil features: compaction properties, shear strength, and collapse potential. These three soil properties are important in the ground improvement techniques. In this study, different casein concentrations were added to the soil with varying gypsum contents. According to the compaction results casein reduces the maximum dry density while increasing the optimum moisture content. Soil treated with casein had a collapse potential of 65–80% lower than untreated soil. The shear strength of casein-treated soil increased significantly in both dry and moist conditions. The current study results suggest the recycled casein as an eco-friendly additive for gypseous soil treatment rather than traditional chemical materials.
... However, the binding and especially the binding kinetics between Ca 2+ and the caseins have been less investigated and are far less understood. Sodium caseinate (NaCas), a commercial milk product from skim milk used for infant formulas and as ingredient in other food products, is a perfect model for investigating the binding and binding kinetics of calcium at different temperatures and pH since calcium has been removed completely from the milk caseins during the NaCas production process (da Silva et al., 2018;Sarode et al., 2016). ...
... Calcium association to the caseins and calcium release from the caseins are considered important for the bioavailability of calcium from milk and dairy products and for the structural changes during milk processing and storage (Ferraretto et al., 2001;Liu et al., 2018;Sarode et al., 2016). In this work, we have established new methods to follow binding kinetics between Ca 2+ and caseins, that will elucidate calcium induced structural changes and aggregation important for calcium biovailability and texture of dairy products. ...
... The effect of calcium addition to the casein UV-visible spectra is different for the different caseins. MCI is hardly affected by calcium ions probably because in this ingredient casein, micellar structure is kept intact by colloidal calcium phosphate (da Silva et al., 2018;Sarode et al., 2016). The process induced by calcium ions in the second reaction step for the caseins seems to have similar effects on the protein structure of the micelles. ...
The kinetics of binding of calcium ions in molar excess to individual caseins and casein ingredients was studied in pH 6.4 aqueous solutions using stopped-flow absorption spectroscopy. An initial second-order reaction, faster for β-casein than for αs-casein due to lower energy of activation (ΔEa1,β = 8.2 kJ∙mol⁻¹; ΔEa1,α = 18.1 kJ∙mol⁻¹, respectively), is followed by a slower first-order reaction with similar energies of activation (ΔEa2,β = 25.3 kJ∙mol⁻¹ and ΔEa2,α = 20.7 kJ∙mol⁻¹) as determined from temperature dependence of rate between 25°C and 50°C. Sodium caseinate reacts faster with calcium than both αs-casein and β-casein in the first reaction of the two consecutive reactions, while the rate of the second falls between αs-casein and β-casein. Global spectral analysis showed the UV-visible spectra of the reaction intermediates of the caseins to be more similar to the final products than to the initial casein reactants. Dynamic and static light scattering indicated decreasing particle sizes and increasing particle surface upon calcium-binding most significantly at low temperatures. The calcium binding to casein was found endothermic by isothermal titration calorimetry. Calcium binding seems to be controlled by enthalpy/entropy compensation corresponding to an isoequilibrium temperature of 38 ℃ in agreement with binding of calcium to o-phosphoserine rather than to aspartate or glutamate side chains of the caseins. Binding capacity and affinity for calcium to αs-casein and sodium caseinate both increased with increasing temperature in agreement with the endothermic nature of the binding. Decreasing enthalpy of binding for each calcium indicating a decrease in heat capacity of the caseins upon calcium-binding. The small difference between binding enthalpy and energy of activation for association of calcium to αs-casein lead to the conclusion that calcium dissociation goes through an early transition state. The rate of calcium dissociation hardly depends on temperature also explaining why calcium binding to caseins is important for calcium bioaccessibility.
... Casein is one of the most important protein found exclusively in milk. It amounts for approximately 80% of the total milk protein (Sarode et al. 2016). It is present in the form of micelles (20-300 nm in diameter) of which 93% is casein and rest are the salts of casein (caseinates) with calcium, sodium, magnesium, potassium, phosphate and other minerals (Sarode et al. 2016;Badem and Uçar 2017). ...
... It amounts for approximately 80% of the total milk protein (Sarode et al. 2016). It is present in the form of micelles (20-300 nm in diameter) of which 93% is casein and rest are the salts of casein (caseinates) with calcium, sodium, magnesium, potassium, phosphate and other minerals (Sarode et al. 2016;Badem and Uçar 2017). Casein gets precipitated at pH 4.6 by acidification as it is the isoelectric point. ...
... Casein gets precipitated at pH 4.6 by acidification as it is the isoelectric point. Casein is constituted of four monomers, namely α S1 (~38%), α S2 (~10%), β (~34%) and κ-caseins (~15%), which are held together by non-covalent interactions such as hydrogen bonding, hydrophobic and electrostatic interactions (Atamer et al. 2017;Sarode et al. 2016). Except cysteine, casein is a rich source of essential amino acids. ...
Dairy industry produces a lot of by-products which when not utilised suitably, get added to the waste. The largest component produced during the coagulation process of casein is the blue-greenish liquid containing an important milk protein ‘whey proteins’. Similarly, ‘casein proteins’ are produced as a by-product during commercial production of dairy whey. However, the casein so obtained needs to be converted into edible form before using in food applications. Research on edible coatings has been in the focus for its ability to reduce moisture losses, impart good barrier properties (gases), moderate elongation, good tensile strength, high flexibility and having no effect on taste or flavour most often. Whey and casein proteins can be effectively used in the development of edible coatings with improved physicochemical and textural properties. Plasticisation is required during the production of whey and casein protein-based coatings and films as they often lack flexibility. Conjugates and additives are added to modify the binding characteristics of the coatings. Milk proteins are a field of interest for developing edible coatings as these have good tensile strength, good oxygen barrier properties, moderate elongation, reduce moisture loss and, hence, preserve the original flavour and sensory profile. These also do not impart their own taste or flavour. Applications of whey protein isolates/concentrates and edible casein/caseinates in the formation of edible coatings have yielded good results. Various developments are constantly being made to prepare value-added products using whey and edible casein with enhanced nutritional value and better shelf life.
... in various foods such as cheese, ice cream, edible film, and health supplements (Badem and Ucar, 2017;Sarode et al., 2016). ...
... Further, incredible stage in casein processing is dehydration (Djaeni et al., 2015;Haque and Roos, 2006), which is a final step for producing potassium caseinate. In this case, drying is applied to induce mass transfer process, including removal of water present in the product (Sarode et al., 2016). In addition, drying in the processing of potassium caseinate is further addessed to extend storability of the product, resulting in dry matter, which easily modifies its chemical components. ...
... Statistical data exhibit a more satisfied content of crude protein in casein treated with oven-drying in comparison to freeze-drying, while the use of CH 3 COOH + oven-drying is also more satisfied than CH 3 COOH + freeze-drying regarding content of crude protein. Felix da Silva et al. (2018) and Sarode et al. (2016) reported that rate of denaturation and agglomeration of milk protein was noticeably controlled by heating and chemical conditions, that is, temperature and pH. These conditions must be emphasized in order to regulate rate of protein denaturation. ...
The aims of the present study were to characterize physicochemical characteristics and chemical structures by Fourier Transform Infrared (FTIR), and mark dissolved protein content, microstructure, and moisture content of potassium caseinate prepared by drying methods and acid strength. The experiment was arranged according to a factorial complete randomized design with triplicates, while data from FTIR and microstructure analysis was presented descriptively. The results demonstrated that acids and drying methods for preparing potassium caseinate could increase antioxidant activity, with a* score (reddish) and b* score (yellowish). Specifically, the freeze-drying method coupled with acid treatments accounted for reducing moisture content but improved viscosity and microstructural properties. Briefly, we could argue that drying techniques and acids established noticeable effects on the quality of potassium caseinate.
... It can be precipitated by the addition of acid, membrane separation, or enzymatic coagulation. [76] The major commercial products of casein are calcium caseinate and sodium caseinate. Whey protein (18-19% of total milk proteins) is a byproduct recovered from cheese whey. ...
... Casein is used in the preparation of whipped toppings, ice-creams and cake mixes. [76] Whey protein inhibits lipid oxidation in an oil-in-water emulsion. They are used in the preparation of whey drinks, bakery products, confectionery products, pastries, reduced-fat ice-creams, yogurts and infant formulas. ...
... [58] Casein serves as a matrix former in cheese-type products. [76] The addition of native or enzyme-treated whey protein decrease the melting rate, overrun and hardness of the reduced-fat ice-cream. [148] MC reduces the ice crystal formation in ice-creams. ...
Stabilizers are used to enhance the textural properties and shelf-life of the foods without altering their nutritional properties. The availability of a wide array of stabilizers makes the selection of suitable stabilizers a tedious job. The purpose of this review is to provide a comprehensive picture of the extraction/production, chemistry, techno-functional properties, stability, safety and food and therapeutic applications of natural, microbial and modified stabilizers. The cost and safety aspects have also been discussed. This review also appraises and provides insights on the potential suitability of different stabilizers in diverse food sectors viz., bakery, dairy, meat and fruit and vegetables.
... The largest casein producers are New Zealand (150,000 tons), Netherlands (85,000-10,000 tons) and Germany (25,000-40,000 tons). The global market for casein or caseinates used in the food industry ranges from 200,000 to 2,500,000 tons [118]. ...
... The development of food technologies and their applications has increased the production of casein and the demand for it. Its production differs from that of non-food casein (also called industrial casein) because food casein is produced under sanitary conditions [118]. In addition, food-grade chemicals are used for its production that undergoes sufficient heat treatment to ensure that casein is safe for human consumption [118]. ...
... Its production differs from that of non-food casein (also called industrial casein) because food casein is produced under sanitary conditions [118]. In addition, food-grade chemicals are used for its production that undergoes sufficient heat treatment to ensure that casein is safe for human consumption [118]. Intensive research on production technologies over the years and their implementation into factories has significantly improved the approaches for food-grade casein production. ...
Natural biopolymers are an interesting resource for edible films production, as they are environmentally friendly packaging materials. The possibilities of the application of main animal proteins and natural polysaccharides are considered in the review, including the sources, structure, and limitations of usage. The main ways for overcoming the limitations caused by the physico-chemical properties of biopolymers are also discussed, including composites approaches, plasticizers, and the addition of crosslinking agents. Approaches for the production of biopolymer-based films and coatings are classified according to wet and dried processes and considered depending on biopolymer types. The methods for mechanical, physico-chemical, hydration, and uniformity estimation of edible films are reviewed.
... Bahan yang digunakan adalah susu rendah lemak yang berumur 3 (tiga) hari mendekati apkir. Susu tersebut kemudian diisolasi kaseinnya mengikuti metode Sarode et al. (2016) dengan menambahkan HCl encer (10%) pada suhu 35 °C, pH 4,1 sampai 4,6 agar terjadi koagulasi. Presipitat kasein yang muncul dalam bentuk gumpalan kemudian disaring untuk dipisahkan dari cairan whey. ...
... Selanjutnya, kasein digiling dalam keadaan dingin untuk mencegah kerusakan protein dan diayak untuk mendapatkan ukuran yang seragam. Kasein yang diperoleh disimpan dalam wadah tertutup (Sarode et al., 2016). ...
... This protein is combined with calcium and phosphorus as clusters of casein molecules, called micelles / calcium phospho-caseinate. Casein protein consists of different proteins, α-casein, β-casein and κ-casein [5] , [17]. ...
... For producing 60 mesh and 80 mesh casein, a pin mill is better than a hammer mill. After the grinding operation, it is sieved into different mesh sizes and then bagged [17]. ...
Processing milk into dairy products leaves a large portion of milk protein, which can be used in many ways. Milk protein is composed of casein and whey protein. Casein is predominate bovine milk protein, which forms large colloidal particles and present in the form of casein micelles. Whey is liquid by products in chess manufacturing or liquid obtained from remove fat and casein from milk. Generally, protein, especially milk protein, has multiple functions in food, such as emulsification, foam formation and stability. Condensed milk protein is a high quality protein that is found naturally in the milk. These milk powders provide powerful and nutritious multifunctional nutrients for the global food and beverage industry due to their high protein content. Milk Protein also consider high quality protein and provide various nutritional benefits, which should be included into the diets. The objective of this review is to overview of milk protein and milk protein concentrates in terms of production and various application in food.
... Casein proteins comprise 80% of the total protein content in milk which precipitated from skim milk by acidifying the milk to produce acid casein to its isoelectric point of approximately 4.6 or the milk is treated with rennet to produce rennet casein. The casein is then being separated, washed, and dried [11,28]. Casein is mainly comprised of three principal components, α, β, and κ, that formed colloidal micelles in milk which contains numerous amounts of casein molecules that are being stabilized by a calcium-phosphate bridge [11]. ...
... Casein is mainly comprised of three principal components, α, β, and κ, that formed colloidal micelles in milk which contains numerous amounts of casein molecules that are being stabilized by a calcium-phosphate bridge [11]. Due to excellent functional properties and natural abundant sources, caseins are used in numerous manufactured products such as in bakery applications, beverages, milk product, snack foods, edible films, etc. Casein or caseinates in the world market used in the food industry were reported in the range between 200,000 and 2,500,000 tons [28]. Caseins and caseinates can be prompted into edible films from aqueous solutions. ...
... The casein micelles remain stable during the majority of commonly used milk processes-heating, compacting, and homogenization. It is possible to preserve micellar integrity through extensive electrostatic and hydrogen bonding, as well as hydrophobic interactions (Sawale 2016). ...
... Whey proteins represent a type of protein which remains in milk serum upon pH/rennet coagulation of casein during the manufacture of cheese or casein (Sawale 2016). Whey protein, which represents approximately 20% of total milk proteins, is a mixture of proteins with diverse functional properties. ...
Biodegradable polymers have become an import focus of interest in recent years. They include polymers manufactured from feedstocks originating either from non-renewable petroleum resources or from renewable biological resources. This review presents a general overview of biodegradable polymers, with a special emphasis on the polymers based on proteins and carbohydrates. Most biodegradable polymers (e.g., starch, chitin, cellulose, collagen and other polypeptides) have been synthesised or are formed in the natural environment during the growth cycles of organisms. These complex forms of carbohydrate consisting of glycosidic bonds are usually one of the major constituents of animal and vegetable exoskeletons (cellulose, carrageenan, chitin). Scientists have already identified certain microorganisms and enzymes that can degrade such polymers. Certain polymers draw attention to their biodegradability property. Bacteria, plants and animals produce this type of polymer, which presents the possibility for very momentous renewable resources. Some of the main plant proteins that can be used as potential sources are soy protein, corn protein (zein) and wheat proteins (gluten). Casein, collagen protein or gelatin, and keratin are important animal proteins. Environmental effects and chemical structure are the main factors upon which biodegradability depends. Another feature that depends on these factors is mechanical behaviour. Some other factors that impact mechanical behaviour are: processing parameters, storage, etc.
... Compared with other protein-based lms, these lms have exceptional exibility, clarity, and homogeneity. 31 According to Sarode et al., 32 whey proteins are a form of protein that can be extracted from milk serum by adjusting the pH when processing casein and are also present in cheese whey. Whey proteins could help to improve the quality of edible lm packaging. ...
There is significant interest in creating biobased polymers and innovative industrial techniques that can minimize fossil fuel use and migration to an eco-friendly and sustainable way of life.
... The second candidate is casein, found in milk, which shows similar molecular characteristics to BSA (isoelectric point of 4.6 [26] and the molecular weight of 20-25 kDa [27]). The third candidate is L-lysine, which is neither protein nor polymer. ...
Perfluorinated-alkyl substances (PFAS) pose an unmet threat to the public because they are not strictly monitored and regulated. Perfluorinated-carbon alkyl chains (PFOA), a type of PFAS, at 70 fg/μL is the current health and safety recommendation. Current testing methods for PFOA and PFAS chemicals include HPLC-MS/MS and molecularly imprinted polymers, which are expensive, time-consuming, and require training. In this work, PFOA and PFOS detection was performed on a paper microfluidic chip using competitive interactions between PFOA/PFOS, cellulose fibers, and various reagents (L-lysine, casein, and albumin). Such interactions altered the surface tension at the wetting front and, subsequently, the capillary flow rate. A smartphone captured the videos of this capillary action. The samples flowed through the channel in less than 2 min. Albumin worked the best in detecting PFOA, followed by casein. The detection limit was 10 ag/μL in DI water and 1 fg/μL in effluent (processed) wastewater. Specificity to other non-fluorocarbon surfactants was also tested, using anionic sodium dodecyl sulfate (SDS), non-ionic Tween 20, and cationic cetrimonium bromide (CTAB). A combination of the reagents successfully distinguished PFOA from all three surfactants at 100% accuracy. This low-cost, handheld assay can be an accessible alternative for rapid in situ estimation of PFOA concentration.
... Therefore, 0.3% of sodium hydroxide (40%) was used to standardize the pH of acid curd-9 treatment to elevate the pH to 4.6. The composition of acid curd made from MCC in our study was in the range of typical acid curd made from skim milk on a dry basis (Blanchette et al., 1996;Klei et al., 1998;Sarode et al., 2016;Hammam et al., 2021). The composition of acid curd depends on the composition of starting material, final pH, and process conditions, such as cooking temperature, washing curds, and pressing (Wong et al., 1976). ...
Process cheese products (PCP) are dairy foods prepared by blending dairy ingredients (such as natural cheese, protein concentrates, butter, nonfat dry milk, whey powder, and permeate) with nondairy ingredients [such as sodium chloride, water, emulsifying salts (ES), color, and flavors] and then heating the mixture to obtain a homogeneous product with an extended shelf life. The ES, such as sodium citrate and disodium phosphate , are critical for the unique microstructure and functional properties of PCP because they improve the emulsification characteristics of casein by displacing the calcium phosphate complexes that are present in the insoluble calcium-paracaseinate-phosphate network in natural cheese. The objectives of this study were to determine the optimum protein content (3, 6, and 9% protein) in micellar casein concentrate (MCC) to produce acid curd and to manufacture PCP using a combination of acid curd cheese and MCC that would provide the desired improvement in the emulsification capacity of caseins without the use of ES. To produce acid curd, MCC was acidified using lactic acid to get a pH of 4.6. In the experimental formulation, the acid curd was blended with MCC to have a 2:1 ratio of protein from acid curd relative to MCC. The PCP was manufactured by blending all ingredients in a Kitch-enAid blender (Professional 5 Plus, KitchenAid) to produce a homogeneous paste. A 25-g sample of the paste was cooked in the rapid visco analyzer (RVA) for 3 min at 95°C at 1,000 rpm stirring speed during the first 2 min and 160 rpm for the last min. The cooked PCP was then transferred into molds and refrigerated until further analysis. This trial was repeated 3 times using different batches of acid curd. MCC with 9% protein resulted in acid curd with more adjusted yield. The end apparent viscosity (402.0-483.0 cP), hardness (354.0-384.0 g), melting temperature (48.0-51.0°C), and melting diameter (30.0-31.4 mm) of PCP made from different acid curds were slightly different from the characteristics of typical PCP produced with conventional ingredients and ES (576.6 cP end apparent viscosity, 119.0 g hardness, 59.8°C melting temperature, and 41.2 mm melting diameter) due to the differences in pH of final PCP (5.8 in ES PCP compared with 5.4 in no ES PCP). We concluded that acid curd can be produced from MCC with different protein content. Also, we found that PCP can be made with no ES when the formulation uses a 2:1 ratio of acid curd relative to MCC (on a protein basis).
... Gram-positive bacteria (Staphylococcus aureus) would be slightly more sensitive to CEO than gram-negative ones (Escherichia coli) as they allow diffusion of hydrophobic compounds through its lipopolysaccharide membrane 156 Please do not adjust margins Please do not adjust margins abundance of casein allow its extensive use in manufactured products in the food industry such as in bakery applications, beverages, milk product, and many studies reported its use for chemical, biological and nutritional applications [278][279] . For instance, the world market of casein or caseinates used in food industry are reported to reach 2,500,000 tons per year 280 . Due to its strong cohesive interactions reflecting high intermolecular hydrogen, electrostatic and hydrophobic bonds, the formation of films in aqueous media without additional processing is highly probable. ...
To fight nosocomial infections, the excessive use of antibiotics has led to the emergence of multidrug-resistant microorganisms, which are now considered a relevant public health threat by the World Health Organization. To date, most antibacterial systems are based on the use of petro-sourced polymers, but the global supplies of these resources are depleting. Besides, silver NPs are widely accepted as the most active biocide against a wide range of bacterial strains but their toxicity is an issue. The growing interest in natural products has gained increasing interest in the last decade. Therefore, the design of functional antibacterial materials derived from biomass remains a significant challenge for the scientific community. Consequently, attention has shifted to naturally occurring substances such as essential oils (EOs), which are classified as Generally Recognized as Safe (GRAS). EOs can offer an alternative to the common antimicrobial agents as an inner solution or biocide agent to inhibit the resistance mechanism. Herein, this review not only aims at providing developments in the antibacterial modes of action of EOs against various bacterial strains and the recent advances in genomic and proteomic techniques for the elucidation of these mechanisms but also presents examples of biobased polymer resource-based EO materials and their antibacterial activities. Especially, we describe the antibacterial properties of biobased polymers, e.g. cellulose, starch, chitosan, PLA PHAs and proteins, associated with EOs (cinnamon (CEO), clove (CLEO), bergamot (BEO), ginger (GEO), lemongrass (LEO), caraway (CAEO), rosemary (REO), Eucalyptus globulus (EGEO), tea tree (TTEO), orange peel (OPEO) and apricot (Prunus armeniaca) kernel (AKEO) essential oils). Finally, we discuss the influence of EOs on the mechanical strength of bio-based materials.
... In the last few decades, casein has found numerous applications in the food industry such as enhancing the physical properties of food products (whipping, foaming, water-binding, thickening), improving their emulsifying capacity and texture. Casein also increases the nutritional value of foods (Sarode et al., 2016). Spreadbury (1978) fed casein to New Zealand White rabbits in a study investigating their protein and amino acid requirements. ...
Rabbits are classified as obligate herbivores. However, under natural conditions, some members of the family Leporidae incorporate animal products into their diets. Therefore, it seems biologically justified to supplement the diets of farmed rabbits with feeds of animal origin as sources of protein, fat and minerals. The aim of this review was to describe, from a historical perspective, the use of various feeds of animal origin in rabbit nutrition. The applicability of by-products from mammal, poultry, fish and invertebrate processing for rabbit feeding was evaluated, including the future prospects for their use. A review of the available literature revealed that various animal-based feeds can be valuable protein sources in rabbit diets, but their inclusion levels should not exceed 5-10%. Studies investigating their efficacy have been conducted since the 1970s. In some regions of the world, the use of animal-derived protein in livestock feeds was prohibited due to the risk of spreading bovine spongiform encephalopathy (BSE). However, the interest in animal by-products as protein sources in livestock diets is likely to increase since the above ban has been lifted.
... High heat stability and the ability to melt are properties of caseinates. In addition, when in solution, caseinates presents excellent surfactant property due to its hydrophilic and hydrophobic segments (Sarode et al., 2016) However, the emulsifying properties of sodium caseinate decrease at acid pH. In such pH values, the net attractive forces between the casein molecules increase, resulting in a self-association of the adsorbed and non-adsorbed protein components (Allen et al., 2006), which could lead to emulsion destabilization (Perrechil et al., 2014). ...
Surfactant-polyelectrolyte complexes (SPECs) based on lecithin and sodium caseinate were produced and the effects of such binding on the physical, chemical and emulsifying properties were evaluated and compared with the two ingredients in isolation. Negative, neutral, and positive charged SPECs were obtained. Zeta potential values and size distributions of the SPECs were dependent on the mass ratio between compounds. Electrostatic association decreased the polydispersity index in comparison with pure compounds solutions. Analysis of interfacial properties showed that solutions containing SPECs promoted a greater reduction of surface tension and interfacial tension with sunflower oil when compared with pure compounds solutions. Emulsions produced with SPECs in 10:1 lecithin:sodium caseinate ratio proved to be more stable than emulsions prepared with pure compounds. Thus, the complexation improved the emulsifying properties of lecithin and sodium caseinate establishing SPECs as potential natural emulsifiers.
... Casein is a dominant protein (80% of total protein) of milk from bovine and rich source of essential amino acids except for cysteine. It is commonly available as sodium caseinate as a commercial ingredient and is a potent source of protein for a variety of processed food products, and it also imparts physicochemical, functional and nutritional characteristics (Sarode et al., 2016) to the food. The matrix of grains and milk includes products that are ready to consume such as beverages, yogurt and weaning foods in which the conventional grains such as wheat and rice are incorporated. ...
The present study was performed to study the simulated fermented matrix of quinoa, chia, and teff with caseinate. Fermentation was carried out at a pH of 4.6 and complexes obtained upon 0, 2, 5, and 9 hours along with the final complex (pH 4.6) were analyzed for total phenolic and flavonoid contents and antioxidant activities. The highest values were obtained for chia‐caseinate complex (TPC – 21 mg GAE/g, TFC – 37 mg QE/g, DPPH – 27 mM TE/g, ABTS – 13 mM TE/g, FRAP – 25 mM TE/g, reducing power – 13 mg AAE/g). Structural characterization via FTIR analysis revealed the formation of a stable complex held mainly by hydrogen bonding and hydrophobic interactions. Moreover, it also suggested destabilization of β‐sheet structures and enhanced gelation property. The appearance of the unsaturated lipid peak (1744 cm‐1; 2924 – 2926 cm‐1) in the chia‐caseinate complex implied superior nutritional functionality. The thermal analysis confirmed the denaturation of proteins and degradation of starch crystallites in matrices and also suggested the formation of bioactive peptides. Thus, it was concluded that these simulated fermented matrices may be used as a base for designing functional foods to achieve techno‐biofunctionality.
... Herein, IgG (pI 6.5-8.3) was separated from bulk milk proteins (initial pH 6.1) by removing the maximum of casein as well as other milk proteins that may interfere with IgG detection. Ideally, all the casein in milk sample would be precipitated simply by adding enough acid to bring the pH value to 4.6 [44]. Therefore, 1.4 mL of 2 M HCl solution was added to 1 mL of milk to bring the pH of milk to 4.6. ...
In contrast to reported enzyme-based immunoassays, an enzyme-free immunoassay (optical and electrochemical) is presented here for the first time that can be used as point-of-need detection bioplatforms of bovine IgG as goat milk adulterant. In the first format, Prussian blue nanoparticles (PBNPs) were used as antibody catalytic labels in a competitive colorimetric microplate immunoassay. Absorbance measurement was performed photometrically at 450 nm. After in-depth optimization, excellent sensitivity was achieved (0.01% cow/goat volume ratio), which is 100 times lower than the limit allowed by the European legislation (EL) (1% v/v), thanks to the high catalytic activity of PBNPs compared with natural peroxidase. Moreover, the antibody-PBNPs bioconjugates showed excellent stability over 4 weeks (> 94% of the initial response) confirming the successful anchoring of the antibodies to the surface of the PBNPs. On the other hand, a label-free voltammetric immunoassay for the detection of bovine IgG was developed. The sensing principle was based on the hindrance of charge transfer between ferri-ferrocyanide redox couple and the screen-printed gold electrodes modified with bovine IgG antibody. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the step-by-step modification of the electrode surface. Under optimal conditions, this single-step electrochemical analysis achieved a high sensitivity of 0.1% (cow/goat) when monitoring the ferrocyanide oxidation at + 0.092 V (vs. Ag/AgCl) using differential pulse voltammetry (DPV). The selectivity of the developed immunoassays was evaluated for different species of milk of similar composition, and both immunoassays exhibited a selective response only to bovine IgG. Unlike conventional immunoassays, the developed enzyme-free immunoassays have many attractive features for the detection of milk adulteration, whether they are used in quality control laboratories for routine milk analysis (optical immunoassay) or at on-site checkpoints (electrochemical immunoassay) using wireless electrochemical detectors. The sensors provide high sensitivity (≤ 0.1%), excellent precision (RSD < 6%), low cost (no enzyme is required) and ease of operation, including handling of milk samples.
Graphical abstract
... Due to these many attributes, casein and its derived ingredients are used as food additives in various food and non-food products. Sodium caseinate is the most commonly used casein-based ingredient [5]. This ingredient is a soluble form of casein obtained via the neutralization of acid casein by NaOH. ...
Electrodialysis with a bipolar membrane coupled to an ultrafiltration module (EDBM-UF) is a hybrid technology recently developed as an ecofriendly alternative to chemical acidification to produce casein and caseinate from skim milk. In this study, the composition and functional properties of casein and caseinate obtained by chemical acidification/basification and by the EDBM-UF method from winter and summer milks were analyzed and compared. Results show that the emulsifying properties, solubility, water holding, and gelling capacities are equivalent between casein and caseinate from both methods. However, the foaming properties of EDBM-UF ingredients were improved, and casein was less hygroscopic. Additionally, the season of milk influenced certain functional properties, such as water-holding capacity and hygroscopicity. Therefore, these results allow concluding that EDBM-UF ingredients have equivalent or higher functionality than chemically produced ingredients, and that the EDBM-UF process would be a more eco-efficient alternative to the chemical one.
... Furthermore, changes in the environmental parameters, such as ionic composition, osmotic stress, shear, pH, or heating temperature, have been reported to cause rearrangements of their structure. Due to the behaviour of hydrophilic bonds, this framework provides a high colloidal particle dispersion of hydrophobic fractions (Sawale, 2016). ...
Due to its high nutritional value and increasing consumption trends, plant-based proteins were used in a variety of dietary products, either in their entirety or as partial substitutions. There is indeed a growing need to produce plant-based proteins as alternatives to dairy-based proteins that have good functional properties, high nutritional values, and high protein digestibility. Among the plant-based proteins, both lentil and quinoa proteins received a lot of attention in recent years as dairy-based protein alternatives. To ensure plant-based proteins a success in food applications, food industries and researchers need to have a comprehensive scientific understanding of these proteins. The demand for proteins is highly dependent on several factors, mainly functional properties, nutritional values, and protein digestibility. Fermentation and protein complexation are recognised to be suitable techniques in enhancing the functional properties, nutritional values, and protein digestibility of these plant-based proteins, making them potential alternatives for dairy-based proteins.
... Aptamer discovery procedure was achieved by incubating inactivated cells with SELEX library and separation of bound library members by centrifugation in the presence of casein which is the most important component in milk at high amount (about 24-29 g/L) [27]. Otherwise, it was a traditional cell-SELEX procedure [28,29]. ...
A Surface Plasmon Resonance (SPR) aptasensor was developed for the detection of Brucella melitensis (B. melitensis) in milk samples. Brucellosis is a bacterial zoonotic disease with global distribution caused mostly by contaminated milk or their products. Aptamers recognizing B. melitensis were selected following a whole bacteria-SELEX procedure. Two aptamers were chosen for high affinity and high specificity. The high affinity aptamer (B70 aptamer) was immobilized on the surface of magnetic silica core-shell nanoparticles for initial purification of the target bacteria cells from milk matrix. Another aptamer, highly specific for B. melitensis cells (B46 aptamer), was used to prepare SPR sensor chips for sensitive determination of Brucella in eluted samples from magnetic purification since direct injection of milk samples to SPR sensor chips is known for a high background unspecific signal. Thus, we integrated a quick and efficient magnetic isolation step for subsequent instant detection of B. melitensis contamination in one ml of milk sample by SPR with a LOD value as low as 27 ± 11 cells.
... β-glucan (β-1-3,1-6 glucan from Shengqing Biotechnology Co., Ltd) and casein (CAS No.9000-71-9) were used to represent polysaccharide polymers and protein polymers respectively. Casein is negatively charged, with an isoelectric point of about 4.6 and a pH of 6.6 (Sarode et al., 2016). ...
A new type of binder was developed by grafting casein and β-glucan to investigate its effect on tailings erosion and plant growth. 6% casein and 2% β-glucan were recommended as the best ratio of the new biopolymer binder, which had the best effect on the soil utilization of iron tailings. The infrared analysis of the new binder demonstrated that casein and β-glucan reacted adequately as raw materials. The results of physichemical properties and loss prevention of iron tailings showed that the binder-treated soils demonstrated lower erod-ibility compared with untreated iron tailings. The particle size of the tailings was increased after the addition of the binder. In treated soil, the content of soil organic matter increased significantly, which provided sufficient nutrients for the plants growing. Compared with natural tailings without binder, plant height, fresh weight, chlorophyll content, and enzyme activity (POD and SOD) were also significantly increased. This study overcame the current defects of biopolymer in soil improvement and provided an environmentally friendly method to prevent the loss of iron tailings and promote its soil utilization efficiency.
... The general process in the production of caseinate powders is shown in Figure 1.2. Caseinate powders are produced from either freshly precipitated acid casein curds (obtained by mixing pasteurized skim milk with food-grade acids until the isoelectric point of caseins is reached) or from dry acid caseins via a reaction with an alkali solution (Sarode et al., 2016). Depending on the type of alkali solution used to neutralize refined acid casein curds, which are initially washed several times in water to remove any residual whey, various types of caseinate powders with different functionalities (such as sodium caseinate, calcium caseinate, potassium caseinate and ammonium caseinate powders) are produced. ...
... Casein is a stable protein present in milk that is also commonly used in food industry. Whey proteins are another protein present in the milk serum extracted by adjusting the pH during the processing of casein (Sarode et al., 2016). Whey proteins can be used in the development of edible film packaging have many environmental benefits because of their ability to regulate oxygen, moisture, lipid, carbon dioxide, taste, aroma transfer and biodegradability (Gounga et al., 2007;Ozdemir and Floros, 2008). ...
Maintaining the safety and quality of food are major concerns while developing biomaterial based food packaging. It offers a longer shelf-life as well as protection and quality control to the food based on international standards. Nano-biotechnology contributes to a far extent to make advanced packaging by developing multifunctional biomaterials for potential applications providing smarter materials to consumers. Applications of nano- biocomposites may thus help to deliver enhanced barrier, mechanical strength, antimicrobial and antioxidant properties to novel food packaging materials. Starch derived bioplastics, polylactic acid and polyhydroxybutyrate are examples of active bioplastics currently in the food packaging sector. This review discusses the various types of biomaterials that could be used to improve future smarter food packaging, as well as biomaterials' potential applications as food stabilizers, pathogen control agents, sensors, and edible packaging materials. The regulatory concerns related to the use of biomaterials in food packaging and commercially available biomaterials in different fields are also discussed. Development of novel biomaterials for different food packaging applications can therefore guarantee active food packaging in future.
... Acid casein is precipitated from skim milk by acidification; on the other hand rennet casein is obtained when the milk is treated with rennet. Casein world production, together with caseinates, is estimated between 430.000 and 460.000 tonnes, being New Zealand, the Netherlands, and Germany its main producers.53 Casein can be further classified as edible or industrial. ...
The pursuit of sustainable and environmentally friendly materials has been powered by environmental concerns and the decline in oil reserves. Among the different routes toward this end, the replacement of oil-based materials by renewable materials stands out. In this way, protein based materials have gained interest. This review article summarizes the progress achieved in the synthesis of hybrid protein/synthetic polymer nanoparticles which have the potential to be used in industrial applications. Although technical achievements and efficacy proofs concerning the increased compatibility of polymer/protein are already available, practical implementation in industry still represents an additional challenge and should be the focus of interest in future research. The available literature supports the potential of hybrid protein/polymer nanoparticles in the production of ecofriendly alternatives for large scale applications as coatings, paints, adhesives and films.
... The general process in the production of caseinate powders is shown in Figure 1.2. Caseinate powders are produced from either freshly precipitated acid casein curds (obtained by mixing pasteurized skim milk with food-grade acids until the isoelectric point of caseins is reached) or from dry acid caseins via a reaction with an alkali solution (Sarode et al., 2016). Depending on the type of alkali solution used to neutralize refined acid casein curds, which are initially washed several times in water to remove any residual whey, various types of caseinate powders with different functionalities (such as sodium caseinate, calcium caseinate, potassium caseinate and ammonium caseinate powders) are produced. ...
Spray-dried dairy products are an important group of tradable dairy commodities due to the diversity in their compositions, nutritional values and functionalities. With recent advances in spray-drying technology, the list of spray-dried dairy products is endlessly expanded. It is not limited to the conventional products such as skim milk and whole milk powders, but is also expanded to high-fat, high-protein and high-lactose milk powders (e.g. caseinate, milk protein concentrates, whey protein powders, cream powder and butter powder), infant formulas and even encapsulated dairy powders. In this chapter, the basic fundamentals of the spray-drying operation unit and its applications in the production of such dried dairy products are presented with a focus on their compositions and key processing steps.
... Imagen tomada y editada de http://www.food-info.net/es/protein/milk.htm Bibliografía: [80][81][82][83][84][85][86][87][88][89] ...
This book is intended for anyone passionate about nutrition and
sports supplementation. It aims to introduce readers to what
regards the subject, combining areas such as nutrition, biological chemistry, the physiology of the exercise, food science and pharmacology. It is by no means intended to replace a good
book on each of these areas, just try to give a general snapshot of each of the substances that are currently being used in the world of supplementation sports, its functions, applications, benefits and doses that are usually used.
Heber E. Andrada
October 5, 2020
... During the process known as curdling, the casein is precipitated, washed, and dried, resulting in the separation from whey proteins. When the water soluble derivatives of acid caseins react with alkali solutions, the resulting product is known as caseinate [166]. Sodium caseinate (SC) is the most common form of casein used as a coating material due to their physicochemical features that confer excellent surface active properties similar to caseins, as well as an increased resistance to heat denaturation. ...
The consumption of probiotics has been associated with a wide range of health benefits for consumers. Products containing probiotics need to have effective delivery of the microorganisms for their consumption to translate into benefits to the consumer. In the last few years, the microencapsulation of probiotic microorganisms has gained interest as a method to improve the delivery of probiotics in the host as well as extending the shelf life of probiotic-containing products. The microencapsulation of probiotics presents several aspects to be considered, such as the type of probiotic microorganisms, the methods of encapsulation, and the coating materials. The aim of this review is to present an updated overview of the most recent and common coating materials used for the microencapsulation of probiotics, as well as the involved techniques and the results of research studies, providing a useful knowledge basis to identify challenges, opportunities, and future trends around coating materials involved in the probiotic microencapsulation.
... It is vastly used in paper coating, wood adhesives, as well as food packaging due to their film-forming properties and barrier resistance to nonpolar substances such as oxygen, carbon dioxide and aromas. One of the biggest limitations of casein is its weak water resistance and stability due to the mass of polar groups, and hence it requires further modification to improve its performance for an effective application in aerogel and other composites [29,30]. ...
The survival of probiotics after spray drying is largely related to drying kinetics experienced by cells in atomized droplets. In this study, the effect of drying kinetics on the viability, integrity of cellular membrane, and digestive stability of Lactobacillus rhamnosus GG and Lactococcus lactis subsp. cremoris was quantitatively examined, using the single droplet drying technique with reconstituted skimmed milk as protectant. Distinct inactivation histories of the strains were observed at 70 °C, with droplet sizes of 1 and 2 μL and air flow velocities of 0.45 and 1 m/s. The two strains showed similar inactivation profiles under the same condition. The order of inactivation rate and the degree of damages on the cellular membrane of dehydrated cells followed the order of drying rate, which was the highest for 1 µL at 1 m/s, followed by 1 µL at 0.45 m/s and 2 µL at 1 m/s, while 2 µL at 0.45 m/s showed the slowest inactivation. For individual drying process, the percentage of live cells with intact membrane was constantly higher than cell survival ratio. Dehydrated cells showed increased viability after 30 min of in situ gastric digestion, which could be due to the resistance of milk proteins to simulated gastric fluid and the rich nutrients of the protectant. Bacterial viability declined again after subsequent in situ intestinal digestion. The findings demonstrated the sensitivity of lactic acid bacteria toward minor changes in drying kinetics. Optimizing drying kinetics may effectively increase the survival and lower the cellular injury of spray-dried probiotics.
In this study, [email protected]2O4 was fabricated through a green synthesis methodology and applied to immobilize laccase. The constructed [email protected]2O4 exhibited porous structures with distinct cavities and suitable magnetic properties. The abundance of aromatic functional groups on the surface renneted casein and possible π-type interaction between laccase and para-κ-casein resulted in a successful immobilization. The biocatalyst retained 50% of its initial activity after 24 reusability cycles, indicating stable immobilization of laccase onto the casein microstructures. The stability of laccase after immobilization was improved by 300% in comparison with the free enzyme, especially in basic pH values. The constructed [email protected]@CoFe2O4 was then incorporated to remove crystal violet (CV) as an environmentally harmful synthetic tri-phenylmethane dye. The prepared heterogeneous biocatalyst effectively diminished the antimicrobial activity of CV up to 81.3% in 40 min against some bacterial strains, resulting from the formation of more minor toxic metabolites identified by liquid chromatography coupled with mass spectroscopy after degradation procedure. The proposed green and feasible method for the preparation of magnetic casein aggregates has not been previously reported. The incorporation of casein, which acted as a molecular chaperon, resulted in a significant improvement in the enzymatic stability and exhibited appropriate reusability for the constructed biocatalytic system.
Foliar feeding of plants can effectively supplement soil fertilization. The effects of foliar application of different levels of casein (CSN: 0, 50, 100 and 150 mg. L⁻¹) and salicylic acid (SA: 0, 75, 150, and 300 µM) were investigated on some vegetative and reproductive growth as well as pigments, phenolic compounds and total antioxidants content indices of garden cress (Lepidium sativum L.) at greenhouse condition. It was observed that CSN applied to at 50 mg. L⁻¹ resulted in the highest stem and root fresh weights, stem dry weight, and diameter of the main stem. Also, the highest chlorophyll b content was obtained in plants treated with 50 and 100 mg. L⁻¹ CSN. In addition, the application of 100 mg. L⁻¹ CSN resulted in the highest leaf nitrogen and phosphorous content, while the lowest values were recorded in the control. The results show that SA application exerted a significant effect on the plant height, leaf fresh and dry weights, stem fresh and dry weights, and the number of florets. The highest plant height and leaf fresh weight were obtained in plants treated with 150 and 300 µM SA. Furthermore, levels of 75, 150, and 300 µM SA application significantly increased leaf dry weight, and chlorophyll b. As well, applications of 150 µM SA led to higher stem fresh and dry weights than the control. Moreover, the number of florets in the levels of 0 and 150 µM SA were higher than in other treatments. Overall, the results suggested that spays of CSN and SA, which showed better growth characters, could be more appropriate for application in garden cress spraying programs.
Milk protein comprising casein and whey proteins is a prized source of dairy protein having nutritional and functional traits. With advent of advanced technologies, it is now feasible to segregate and refine the specific type of dairy proteins to such concentration that can serve to suffice technological considerations required in food systems. Some of the traditionally produced high-protein dairy powders include acid casein, rennet casein, caseinates, and coprecipitates. Subsequently, whey protein concentrate and whey protein isolates became prevalent. Lately, there has been introduction of milk protein concentrate, micellar casein concentrate (MCC) powder, and colostrum powder. The membrane technology and ion-exchange processing has paved the way for production of such highly specialized high-protein ingredients. The majority of these protein foods confers functionality to food, viz., solubility, viscosifying, gelling, emulsifying, and foaming, where they are used as specialized ingredients. These protein powders have varied applications, be it beverages, meat system, baked goods, fermented dairy foods (yogurt, cheese), ice creams, nondairy whiteners, coffee creamers, and so on. Rennet casein or caseinates are highly suited for cheese analog formulations, while MCC powder has special applications in cheese industry. The area that needs to be tackled is producing powder having bland flavor with appropriate solubility for their end-use application.
This paper deals with the development of an empirical model to describe the dynamics of milk acidification process for the production of acid casein. The model is based on the dynamics of the pH profiles during the acidification process since pH is a good indicator of the status of the precipitation. Data from laboratory experiments has been used to identify the parameters in the proposed model. Calibration and validation results, with an independent data set, show that the model is able to predict accurately the pH at different temperatures and acid addition rates. Furthermore, the model has been used in a simulation study as an advisory tool to suggest acid addition, proving the parsimony of the model.
Acidification is an important process in the production of several dairy products and has an impact in taste, viscosity, and shelf life of the products. This paper deals with the development of an empirical mathematical model to describe milk acidification in terms of pH dynamics. The model is built upon experiments of pasteurized skimmed milk acidification for acid-induced casein precipitation and extended to predict the partitioning of calcium and phosphates in the whey and the dynamics of pH during fermentation of yoghurt manufacture. Furthermore, the model can be used directly or in optimization problems to provide recommendations about product design.
Powdered dairy ingredients are added in various food products to impart desired technofunctional properties, improve nutritional values, and sensory characteristics. These ingredients undergo various changes during storage, the extent of these changes is a function of powder composition, processing parameters, and storage conditions. Most of the changes in powder characteristics are associated with the change in free moisture content that occurs due to change in headspace relative humidity and temperature. Uptake of moisture results into various undesirable changes including decrease in Tg, crystallization of lactose, alteration in color (Maillard browning), oxidation of lipids, modifications of protein conformation, changes in surface composition, and particle morphology. These changes adversely affect the physicochemical characteristics, functional properties, and sensory attributes of these ingredients. Crystallization of lactose alters the microstructure and surface chemical composition of powders, induces caking and compromises flowability and solubility. Maillard reactions increase protein-sugar and protein-protein interactions which compromises color and solubility. The composition of powdered dairy ingredients and products, if they are rich in lipids and lactose, are particularly sensitive to changes in headspace RH and temperature. Longer Storage times consolidate the underlying mechanisms driving the undesirable changes mentioned above. This review shows that to preserve the quality of these ingredients during storage, it is essential to design storage parameters (relative humidity, temperature, vapor, and gas barrier of primary packaging) of powdered dairy ingredients and products such a way that crystallization of lactose, lactose-protein interaction, and melting of lipid and migration of lipid to the surface is minimized.
This study aimed to evaluate different fibers (acacia, bamboo, citrus or potato) on texture, rheological properties, color, density, and water activity of processed cheese sauces (PCS) based on acid casein, WPC80 and anhydrous milk fat or organic coconut oil. The interaction between the type of oil/fat, the fiber type and the fiber content was significant regarding almost all parameters studied. The computer vision system (CVS) showed that color changes of sauces could be noticeable by consumers. The main factor influencing the change in all products’ hardness was not fat/oil, but added fibers and their concentrations. The highest increase in hardness, adhesiveness and viscosity was observed in products with potato fiber. The value of storage modulus (G′) was higher than the loss modulus (G″) and tan (δ) < 1 for all samples. Different fibers and their amounts did not influence the water activity of cheese sauces obtained with organic coconut oil (OCO) or anhydrous milk fat (AMF).
Food packaging provides foods for safe transport, storage, or sale. Packaging protects altering resistance and exceptional biological, physical, or chemical needs. Chemical contaminants, microorganisms, light, oxygen, humidity, etc., are the most important factors affecting food quality. Therefore, it is vital to maintain the safety and quality of the foodstuffs during the transport and packing conditions.
Caseins, caseinates and micellar caseins are widely used as ingredients in many food and non-food applications. Separation of caseins from the remaining milk constituents (mainly whey proteins, lactose, minerals) can be achieved by selective precipitation using acid or rennet, or by applying membrane filtration techniques. With membrane filtration, the original structure of the casein micelles can be maintained to a large extent. In recent years, the fractionation of the major casein types (i.e., αs-, β- and κ-casein), as well as the targeted modulation of the techno-functional and digestive properties of casein ingredients, have been the targets of increasing interest.
Fruits and vegetables are particularly perishable commodities as they contain 80–90% of water by weight. Several methods have been employed to protect and increase the shelf life of fresh goods during packaging, transport and storage. Edible coatings are thin films made applied to the exterior surface of a substance, which offers protection against external moisture, oxygen and pathogens. The various components commonly used in the manufacture of edible coatings includes polysaccharides, proteins, lipids, composites and resins. The packaging of fresh fruits and vegetables is an essential step to protect against further contamination, damage and excess moisture loss. Bags, trays, sleeve packs, boxes, cartons and palletized containers are the generally used packaging materials for convenient handling and transportation of fresh products. Various types of films made of polyethylene, polyester, polyvinyl, cellulose and aluminum are currently used in packaging as moisture-resistant materials. Preservatives are compounds added to food substances to prevent the deterioration of quality and spoilage induced by the growth of micro-organisms or unwanted chemical changes from decomposing. The same is also incorporated in fruits-vegetables through physical and chemical modes which prolong the shelf-life of the product even further. The present work discusses the use of different edible coatings, preservatives and packing methods as carriers of functional ingredients on fresh fruits and vegetables to maximize their quality and shelf life. Furthermore, recent developments in the application of antimicrobials during packaging to increase the functionality of foods have been elaborated.
Vegetal and animal proteins have been considered promising alternatives to develop new sustainable food packaging derived from bio-resources. Edible, easy to process, renewable and environmental friendly are just a few characteristics that turn proteins into excellent raw materials to develop edible or biodegradable films. Furthermore, the valorization of industrial wastes or by-products to develop more sustainable films could add value to these products. In this context, food processing industries generate wastes that cause economic and environmental problems; therefore, the valorization of these wastes to obtain proteins could facilitate the waste management as well as the development of value-added products. Despite these environmental benefits, vegetal and animal proteins have some drawbacks and different strategies are explored to overcome those limitations for their use as food packaging. Taking this into account, the aim of this chapter is to provide an overview of the currently developed films and coatings based on animal and vegetal proteins, including active packaging.
Casein-based powders are gaining industrial interest due to their nutritional and functional properties, but they are also known to have poor rehydration abilities. The fundamental physical and chemical mechanisms involved in the rehydration of these powders are essential for determining the critical steps in the manufacturing processes and for developing casein powders with improved rehydration properties. A number of analytical methods have been developed to measure the rehydration ability of powders, but criteria for the selection of methods for casein-based powders have not been provided. This review article provides an overview of the characteristics and methods for the production of casein-based powders, methodologies to measure their rehydration properties, and it summarizes the current state of understanding regarding rehydration. Advancements have been made in the field; however, a fundamental understanding enabling improvement of the rehydration properties of these powders is still lacking.
Background
Casein is the main proteinaceous component of milk and has made us interest due to its wide applications in the food, drug, and cosmetic industries as well as to its importance as an investigation material for elucidating essential questions regarding the protein chemistry. Enzymatic hydrolysis is an important method commonly used in the modification of protein structure in order to enhance the functional properties of proteins. The relationship between enzymatic hydrolysis and structure change of casein need to make more study.
Results
During hydrolysis, degree of hydrolysis in the casein hydrolysates increased rapidly in the initial 20 minutes, reached a plateau after 45 minutes, and then kept relative constant for the rest of the hydrolysis. The relative percentage of the released peptides with molecular weight of over 50 kD significantly decreased with hydrolyzation, while those with MW of 30–50 kD and below 20 kD increased significantly. The contents of a-helix and β-turn in the hydrolysates increased compared to the original casein. Moreover, the molecular flexibilities of the casein hydrolysates, estimated by the ratio of α-helix to β-structure, were lower than that of original casein protein.
Conclusions
The significant changes in molecular weight distribution and structure characteristics of casein hydrolysates were found compared to the control sample. This change should be the basis of enhancement of functional properties.
Dietary intervention as a tool for maintaining and improving physical health and wellbeing is a widely researched and discussed topic. Speculation that diet may similarly affect mental health and wellbeing particularly in cases of psychiatric and behavioral symptomatology opens up various avenues for potentially improving quality of life. We examine evidence suggestive that a gluten-free (GF), casein-free (CF), or gluten- and casein-free diet (GFCF) can ameliorate core and peripheral symptoms and improve developmental outcome in some cases of autism spectrum conditions. Although not wholly affirmative, the majority of published studies indicate statistically significant positive changes to symptom presentation following dietary intervention. In particular, changes to areas of communication, attention, and hyperactivity are detailed, despite the presence of various methodological shortcomings. Specific characteristics of best- and non-responders to intervention have not been fully elucidated; neither has the precise mode of action for any universal effect outside of known individual cases of food-related co-morbidity. With the publication of controlled medium- and long-term group studies of a gluten- and casein-free diet alongside more consolidated biological findings potentially linked to intervention, the appearance of a possible diet-related autism phenotype seems to be emerging supportive of a positive dietary effect in some cases. Further debate on whether such dietary intervention should form part of best practice guidelines for autism spectrum conditions (ASCs) and onward representative of an autism dietary-sensitive enteropathy is warranted.
Casein, the principal protein in cow’s milk, has been extracted commercially for most of the twentieth century. The casein content of whole milk varies according to the breed of cow, stage of lactation and time of milking, but is generally in the range 24–29 gl-1 (Jenness and Patton, 1959a; Fox, 1989). The skim-milk produced from the separation of whole milk to a 40 per cent fat cream (the first stage in the manufacture of casein) consequently contains 25–31 gl-1 casein (Jenness and Patton, 1959b; McDowall, 1971), which accounts for 75-80 per cent of the nitrogen in skim-milk (Dolby et al., 1969; Gordon and Kalan, 1974; Fox, 1989). With a content of 0.7-0.9 per cent phosphorus, covalently bound to the casein by a serine ester linkage, casein as a phosphoprotein is a member of a relatively rare class of proteins (Gordon and Kalan, 1974). The amino-acid content of casein has been well established and includes high proportions of all amino-acids essential to man (Gordon and Kalan, 1974) with the possible exception of cysteine.
Milk protein is consumed widely as a human food, particularly in developed countries. The long history of its inclusion in the human diet and the relative ease with which the major proteins can be purified from raw milk have contributed to its early and extensive characterization by biochemists. Consequently, milk proteins are probably the best characterized of all food proteins; for example, the primary structures of all bovine milk proteins are known and even the three-dimensional structures of the major whey proteins are known. Nevertheless, the molecular characteristics, particularly the tertiary structure, of the caseins remain as a challenge since these proteins are not typical and apparently cannot be crystallized. In the past, the caseins have, at times, been inaccurately classified as denatured or random coil proteins. Although the caseins are apparently more flexible and less stable than typical globular or rod-shaped proteins, they appear to have some secondary structure and a definite unordered tertiary structure.
We previously reported results based on the examination of a gluten- and casein-free diet as an intervention for children diagnosed with an autism spectrum disorder as part of the ScanBrit collaboration. Analysis based on grouped results indicated several significant differences between dietary and non-dietary participants across various core and peripheral areas of functioning. Results also indicated some disparity in individual responses to dietary modification potentially indicative of responder and non-responder differences. Further examination of the behavioural and psychometric data garnered from participants was undertaken, with a view to determining potential factors pertinent to response to dietary intervention. Participants with clinically significant scores indicative of inattention and hyperactivity behaviours and who had a significant positive changes to said scores were defined as responders to the dietary intervention. Analyses indicated several factors to be potentially pertinent to a positive response to dietary intervention in terms of symptom presentation. Chronological age was found to be the strongest predictor of response, where those participants aged between 7 and 9 years seemed to derive most benefit from dietary intervention. Further analysis based on the criteria for original study inclusion on the presence of the urine compound, trans-indolyl-3-acryloylglycine may also merit further investigation. These preliminary observations on potential best responder characteristics to a gluten- and casein-free diet for children with autism require independent replication.
In the present paper the thermal behavior of casein is studied for the first time by the TG-FTIR technique. The casein is the main protein in milk being of a great interest due to its many uses in the cosmetic, food and pharmaceutical industries. Through the thermal stability study, the TG, DTG and DTA methods allowed the specification of the temperature range in which casein is thermally stable (0–176C). Casein is totally degraded at 770.6C in air without residue, and at 610C in nitrogen atmosphere the resulted residue being 20% of the initial weight. Thermal degradation in air of casein shows two domains: an endothermic one (30–248C) also present in nitrogen degradation, and an exothermic one (248–770.6C). In nitrogen atmosphere all the degradation stages are endothermic. The TG-FTIR analysis shows that in 30–248
C temperature range, both in air and in nitrogen, the same gaseous species are eliminated and in the same order. In 248–770.6C temperature range of the gaseous species evolved by the casein degradation
in air is slightly different from that of the gaseous species resulted under nitrogen atmosphere. From the results of the TG-FTIR study we advanced the most probable overall mechanism of the casein thermal
degradation both in air and in nitrogen atmosphere.
In the analysis of biological matrices, the application of o-phthaldialdehyde in the presence of a thiol component (OPA-method) for the quantitative determination of free - and -amino groups in amino acids, peptides and proteins as well as their hydrolytic or proteolytic products, respectively, is well known. The most frequently used thiol compound is mercaptoethanol. The use of this substance has the disadvantage that the initially generated isoindole often undergoes intramolecular rearrangement which often leads to a decrease in extinction at the monitoring wavelength of 340 nm. The present paper describes a modified method in which mercaptoethanol was replaced by N,N-dimethyl-2-mercaptoethylammonium chloride. The use of the new thiol component in the OPA reaction results in long-term stability of the extinction values (plateauing > 1 h). The modified method is further characterized by high accuracy and precision.