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Comparison of Ethanol Stability and Chemical Composition of Camel Milk from Five Samples. Animals (Basel) 2022; 12:ani12050615. [PMID: 35268184 PMCID: PMC8909706 DOI: 10.3390/ani12050615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 01/01/2023] Open
Abstract
This research was carried out to study the variation in ethanol stability and chemical composition of five camel milk samples, including two pasteurized samples (Alwatania and Darir alabaker) and three raw samples (Majaheim, Wadah, and Hamra). Ethanol stability was analyzed by dispersing camel milk samples with 0 to 100% ethanol (v/v). The findings indicate that camel milk samples precipitated after adding an equal volume of ethanol at concentrations between 50% and 64% ethanol, depending on the milk sample. The addition of sodium chloride at different concentrations (1−10%) to camel milk resulted in a significant increase in ethanol stability, and samples from Majaheim and Alwatania exhibited the highest ethanol stability values (88%). In contrast, the addition of EDTA to camel milk for pH ranging between 5.9 and 7.1 has increased ethanol stability with a sigmoidal shape in camel milk. The largest ethanol stability differences were observed in a camel milk sample from Alwatania. Thus, the level of Ca2+ in camel milk may contribute to ethanol stability by shifting the entire profile to higher ethanol stability values. The chemical composition of different camel samples was also determined. The lactose content of camel milk varied significantly (p < 0.05) across samples, ranging from 4.37% in Majaheim camel milk to 4.87% in Alwatania camel milk. The total solids of camel milk varied significantly between raw and pasteurized samples, ranging between 10.17% and 12.10%. Furthermore, protein concentration in camel milk obtained from different camel samples varied, from 2.43% to 3.23% for Hamra and Alwatania, respectively. In conclusion, ethanol stability in camel milk was dependent on the camel breed, pH level, ionic strength, and EDTA addition.
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da Costa CHF, de Paula IL, da Silva PHF, Perrone ÍT, Stephani R, Cappa de Oliveira LF. Colloidal stability of milk: reinterpretation of alcohol test results by digital microscopy. J DAIRY RES 2022; 89:1-4. [PMID: 35225179 DOI: 10.1017/s0022029922000176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this research communication we propose a new approach by portable digital microscopy with a 200× objective to improve the visualization of microparticles of pasteurized milk submitted to the alcohol test. Not only did the method reduce the subjectivity of the readings, but also generated high resolution images of the microparticles, which allows the creation of a specific image pattern for each type of final product. In comparison to a control pasteurized milk treatment, the results confirmed the effect and the specificity of added salts (sodium citrate, disodium phosphate or their combination) on the stability of the milk to the alcohol test. Finally, the mixture of stabilizing salts of citrate/phosphate provided the highest degree of stability to pasteurized milk among the treatments studied.
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Affiliation(s)
| | - Igor Lima de Paula
- Department of Chemistry, Núcleo de Espectroscopia e Estrutura Molecular, Federal University of Juiz de Fora,Juiz de Fora, MG, 36036-330, Brazil
| | | | - Ítalo Tuler Perrone
- Department of Pharmaceutical Sciences, Federal University of Juiz de Fora, Juiz de Fora, MG, 36036-330, Brazil
| | - Rodrigo Stephani
- Department of Chemistry, Núcleo de Espectroscopia e Estrutura Molecular, Federal University of Juiz de Fora,Juiz de Fora, MG, 36036-330, Brazil
| | - Luiz Fernando Cappa de Oliveira
- Department of Chemistry, Núcleo de Espectroscopia e Estrutura Molecular, Federal University of Juiz de Fora,Juiz de Fora, MG, 36036-330, Brazil
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3
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Erxleben SW, Pelan E, Wolf B. Effect of ethanol on the stability of sodium caseinate stabilised emulsions. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2021.107058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Li S, Ye A, Singh H. Seasonal variations in composition, properties, and heat-induced changes in bovine milk in a seasonal calving system. J Dairy Sci 2019; 102:7747-7759. [PMID: 31326173 DOI: 10.3168/jds.2019-16685] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/23/2019] [Indexed: 11/19/2022]
Abstract
We determined seasonal variations in the composition and characteristics of bovine milk, as well as heat-induced changes in the physicochemical properties of the milk, in a typical seasonal-calving New Zealand herd over 2 full milking seasons. Fat, protein, and lactose contents varied consistently during the year in patterns similar to those of the lactation cycle. Seasonality also had significant effects on milk calcium, ionic calcium, fat globule size, buffering capacity, and ethanol stability, but not on casein micelle size. The ratio of casein to total protein did not vary significantly over the season, but late-season milk had the highest content of glycosylated κ-casein (G-κ-CN) and the lowest content of α-lactalbumin in both years. We observed significant between-year effects on protein, total calcium, ionic calcium, pH, and casein:total protein ratio, which might have resulted from different somatic cell counts in the 2 years. Compared with heating at 90°C for 6 min, UHT treatment (140°C for 5 s) induced greater dissociation of κ-casein, a similar extent of whey protein denaturation, a lower extent of whey protein-casein micelle association, and a larger increase in casein micelle size. Indeed, UHT treatment might have triggered significant dissociation of G-κ-CN, resulting in aggregation among the casein micelles and increased apparent mean casein micelle diameter. Seasonality had significant effects on the partitioning of G-κ-CN between the micelle and the serum phase, the extent of whey protein-casein micelle association under both heating conditions, and the casein micelle size of the UHT milk.
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Affiliation(s)
- Siqi Li
- Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
| | - Aiqian Ye
- Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
| | - Harjinder Singh
- Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
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Singh J, Prakash S, Bhandari B, Bansal N. Comparison of ultra high temperature (UHT) stability of high protein milk dispersions prepared from milk protein concentrate (MPC) and conventional low heat skimmed milk powder (SMP). J FOOD ENG 2019. [DOI: 10.1016/j.jfoodeng.2018.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lin Y, Kelly AL, O'Mahony JA, Guinee TP. Effects of milk heat treatment and solvent composition on physicochemical and selected functional characteristics of milk protein concentrate. J Dairy Sci 2018; 101:6799-6813. [PMID: 29803416 DOI: 10.3168/jds.2017-14300] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/13/2018] [Indexed: 11/19/2022]
Abstract
Milk protein concentrate (MPC) powders (∼81% protein) were made from skim milk that was heat treated at 72°C for 15 s (LHMPC) or 85°C for 30 s (MHMPC). The MPC powder was manufactured by ultrafiltration and diafiltration of skim milk at 50°C followed by spray drying. The MPC dispersions (4.02% true protein) were prepared by reconstituting the LHMPC and MHMPC powders in distilled water (LHMPCw and MHMPCw, respectively) or milk permeate (LHMPCp and MHMPCp, respectively). Increasing milk heat treatment increased the level of whey protein denaturation (from ∼5 to 47% of total whey protein) and reduced the concentrations of serum protein, serum calcium, and ionic calcium. These changes were paralleled by impaired rennet-induced coagulability of the MHMPCw and MHMPCp dispersions and a reduction in the pH of maximum heat stability of MHMPCp from pH 6.9 to 6.8. For both the LHMPC and MHMPC dispersions, the use of permeate instead of water enhanced ethanol stability at pH 6.6 to 7.0, impaired rennet gelation, and changed the heat coagulation time and pH profile from type A to type B. Increasing the severity of milk heat treatment during MPC manufacture and the use of permeate instead of water led to significant reductions in the viscosity of stirred yogurt prepared by starter-induced acidification of the MPC dispersions. The current study clearly highlights how the functionality of protein dispersions prepared by reconstitution of high-protein MPC powders may be modulated by the heat treatment of the skim milk during manufacture of the MPC and the composition of the solvent used for reconstitution.
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Affiliation(s)
- Yingchen Lin
- Teagasc Food Research Centre Moorepark, Fermoy, Co. Cork, Ireland, P61 C996
| | - Alan L Kelly
- School of Food and Nutritional Sciences, University College Cork, Cork, Ireland, T12 Y337
| | - James A O'Mahony
- School of Food and Nutritional Sciences, University College Cork, Cork, Ireland, T12 Y337
| | - Timothy P Guinee
- Teagasc Food Research Centre Moorepark, Fermoy, Co. Cork, Ireland, P61 C996.
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McGrath BA, Fox PF, McSweeney PLH, Kelly AL. Composition and properties of bovine colostrum: a review. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13594-015-0258-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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8
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Fagnani R, Beloti V, Battaglini APP. Acid-base balance of dairy cows and its relationship with alcoholic stability and mineral composition of milk. PESQUISA VETERINARIA BRASILEIRA 2014. [DOI: 10.1590/s0100-736x2014000500002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study aimed to associate the occurrence of acid-base disorders with the alcoholic stability of milk from animals in the field, and to evaluate differences between the mineral composition of milk that was both stable and unstable in alcohol. The sample comprised 96 dairy cows, where the milk and blood of each corresponding animal was collected. The mineral composition of stable and unstable milk in alcohol was different and may be related to acid-base disturbances. The average amount of phosphate was lower in the milk that was unstable in alcohol, while potassium was greater. Frequency of the alcoholically unstable milk cases was higher in the cows with acid-base disturbances. Respiratory alkalosis was the disorder that was most observed.
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Miwa N, Nio N, Sonomoto K. Effect of enzymatic deamidation by protein-glutaminase on the textural and microstructural properties of set yoghurt. Int Dairy J 2014. [DOI: 10.1016/j.idairyj.2013.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Ye R, Harte F. Casein maps: effect of ethanol, pH, temperature, and CaCl2 on the particle size of reconstituted casein micelles. J Dairy Sci 2013; 96:799-805. [PMID: 23200467 PMCID: PMC4559271 DOI: 10.3168/jds.2012-5838] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 10/21/2012] [Indexed: 12/31/2022]
Abstract
Although conditions favoring casein micelle aggregation are well known, factors promoting the dissociation of the casein micelle are not fully understood. It was our objective to investigate the ethanol-induced dissociation of micellar casein as affected by temperature and a wide range of pH, along with the concentrations of calcium and casein. Two different concentrations of casein micelles were dispersed in imidazole buffer with 0 to 80% ethanol (vol/vol) and 2 and 10mM calcium. Apparent micelle size was determined by dynamic light scattering at 5, 30, and 60°C. In the absence of ethanol, casein precipitation occurred at pH 4.6 in imidazole buffer. Ten to forty percent ethanol promoted casein aggregation (>1,000 nm) and higher temperature (30 and 60°C) enhanced this effect. Higher ethanol concentrations at 50 to 80% induced the dissociation (<40 nm) of the casein micelle upon acidification (pH <5) and alkalization (pH>8) in imidazole buffer. In addition, higher concentrations of casein (0.25mg/mL) and calcium (20mM) caused the formation of larger aggregates (>1,000 nm) in the presence of ethanol when comparing with the initial lower concentrations of casein (0.1mg/mL) and calcium (2mM). Casein micelle dissociation can be achieved near the isoelectric pH by modifying the solvent composition and temperature.
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Affiliation(s)
- Ran Ye
- Department of Food Science and Technology, University of Tennessee, 2605 River Road, Knoxville 37996-4539
| | - Federico Harte
- Department of Food Science and Technology, University of Tennessee, 2605 River Road, Knoxville 37996-4539
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Abstract
SUMMARYCaprine skim-milk exhibits markedly lower ethanol (EtOH) stability than bovine skim-milk but can still be characterized by a sigmoidal pH profile. As with bovine milk, the position of this profile along the pH-axis was found to be sensitive to available Ca levels. Manipulation of salt levels, either by serum interchange, addition or diminution did not result in any significant increase in the EtOH stability high pH asymptote, Smax, and reduction of the colloidal calcium phosphate of caprine milk also had no significant effect. EtOH stability/pH profiles similar to those of bovine milk were achieved only by chemical modification of the caprine milk protein by reaction with aldehydes and anhydrides. It is concluded that the low EtOH stability of caprine milk as compared with bovine milk is due to the different proportions of the individual caseins present, in particular the lack of an αsl-casein homologue in caprine milk.
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Abstract
SUMMARYMilk samples from three groups of cows were taken at frequent intervals throughout lactation following autumn-, winter- or spring-calving. The ethanol (EtOH) stability/pH profile was determined for each sample and its characteristic parameters calculated. The lactational trends in these parameters were examined. Asymptotic maximum EtOH stability (Smax) was low in early lactation but rose rapidly to a value which showed no further lactational trends. Asymptotic minimum stability (Smin) for samples from autumn- and winter-calving cows showed a decrease which could be associated with the transition to summer grazing but no obvious lactational effects. The slope parameter increased slowly during lactation. The profile pK value decreased in early lactation, but thereafter increased throughout lactation giving the most obvious effect observed in direct measurement, namely an alkaline shift in the profile as lactation progressed. The EtOH stability calculated at a fixed pH of 6·6 passed through a maximum, characteristic for each cow, in the first weeks of lactation but declined steadily thereafter. This behaviour mirrors the lactational behaviour of the soluble salt balance ratio calculated from the original data of White & Davies (1958).
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Abstract
SummaryWe have investigated the role of pH in the destabilization of milk and sodium caseinate solutions by ethanol. Ethanol shifted the pH of minimum stability of both caseinate and milk to higher values. A linear relation between this pH and the reciprocal dielectric constant of the mixture was observed. The addition of calcium to these alcoholic mixtures also increased the pH of minimum stability. The results are discussed in terms of the alcohol-induced shifts in the pK values of important constituent amino acids and of the effect of alcohol on soluble Ca levels.
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Factors affecting the ethanol stability of bovine milk: V. Effects of chemical modification of milk protein. J DAIRY RES 2009. [DOI: 10.1017/s0022029900022585] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SUMMARYThe effect of chemical modification of milk protein on the ethanol (EtOH) stability of skim-milk has been investigated. Modification of lysine residues by reaction with anhydrides increased the EtOH stability whereas amidation of carboxyl groups destabilized the milk. Lysine modification also counteracted destabilization induced by Ca2+addition. By using multiple linear regression techniques these latter effects can be accounted for in terms of the changes they bring about in micellar charge. These results provide a further verification and an extension of the previously proposed mechanism for EtOH-induced coagulation of skim-milk.
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Abstract
SummaryA convenient and sensitive method for determining γ-casein content of skim milk is described. It is based on quantitative separation in which the soluble fraction obtained from skim milk (1·5 ml) in a solvent system consisting of 50% (v/v) ethanol, 0·4 M-Na thiocyanate and 0·15 M-CaCl2 was applied to a small column of DEAE-cellulose and eluted with 0·02 M-Tris-HCl buffer (pH 8·0) containing 0·03 M-NaCl and 6 M-urea. Protein in this fraction (5 ml) was measured from its absorbance at 280 nm. The method is applicable also to heated skim milk. Its availability for investigating proteolysis in milk is expected from the fact that incubation of skim milk with porcine plasmin at 37 °C for 3 h increased γ-casein content, an increase that was lowered by addition of soyabean trypsin inhibitor. Incubation of raw skim milk with 0·02% (w/v) NaN3 resulted in increase in γ-casein with time and with increasing temperature. This was accompanied by a time lag, the length of which increased with decreasing temperature. The degree of proteolysis in skim milk, expressed as the amount of increase in γ-casein after 20 h of incubation at 37 °C, showed two pH optima, one at pH 8·0 and the other at pH 7·2–7·5. These results suggested that the present method.of γ-casein determination can be used for more precise studies of the milk plasmin system in which important factors, such as plasminogen activator and inhibitors, are involved.
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Abstract
SUMMARYSeveral ionic components of ultrafiltrate were measured in bulk and individual cow milks and an assessment was made of their relationship with the parameters of the corresponding ethanol (EtOH) stability/pH profiles. From linear regression analysis the strongest relationships (P < 0·001) were between soluble salt balance [expressed as (Ca+Mg) minus (Pi+Cit) or as the ratio to (Pi+Cit)] and pK (correlation coefficient, γ ∼ 0·82) or Smax, the maximum stability at high pH (γ ∼–0·72), and between Pi and pK(γ = –0·84)or Smax (γ = –0·61). These relationships agree with the view that the parameters of the EtOH stability/pH profile are determined by pH-induced changes in concentration of divalent cations. Natural variations in these parameters may be attributed to variations in relative concentrations of divalent cations and their chelators. EtOH stabilities at the natural pH of bulk milks from winter/spring- and autumn-calving animals were lowest in early and late lactation. The most important contributory factors appeared to be a high salt balance ratio in late lactation and a low natural milk pH in early lactation. The main component responsible for variable salt balance ratio was usually soluble Pi. Decrease in EtOH stability at the natural pH of late lactation milks reflected a more general change in the characteristics of the EtOH stability/pH profile, seen as an increase in pK and, in extreme cases, a decrease in Smax and profile gradient.
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Abstract
SummaryThe ethanol (EtOH) stability of skim milk and the stability towards aggregation of casein micelles diluted into ethanolic buffer solutions were compared using data obtained from previously published experiments. Differences in absolute stability and in relative response were observed when Ca2+ level and pH were adjusted, the buffer system results lying below those from skim milk in both cases. Increasing the ionic strength of skim milk adjusted to pH 7·0 lowered its EtOH stability whereas increasing the ionic strength of the diluting buffer increased the stability of the casein micelles. The hypothesis is put forward that the differences are due to the simultaneous precipitation of Ca phosphate when EtOH is added to skim milk. This draws calcium from the caseinate sites of the micelle, counteracting the destabilizing effects of the EtOH towards the micelle. Such removal and the consequent restructuring are kinetically controlled and micellar precipitation in skim milk finally occurs when the micellar coagulation time falls within the time scale of the restructuring reactions.
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Abstract
SUMMARYThe ethanol (EtOH) stability characteristics of skim-milk concentrates were found to be governed by their chloride ion content. This effect appeared to be largely one of ionic strength. At pH values around 7·0 and above, EtOH stability showed a linear decrease with increasing chloride content but at pH values < 7 the relationship was non-linear. This empirical observation allows the EtOH stability of a skim-milk concentrate to be predicted from simple measurements on the original milk sample. Moreover, predicted increases in the EtOH stability of concentrated milks were obtained when the levels of monovalent ions in the system were reduced either by dialysis before or after concentration or by ultrafiltration.
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Mezdour S, Boyaval P, Korolczuk J. Solubility of αS1-, β- and κ-casein in water-ethanol solutions. ACTA ACUST UNITED AC 2008. [DOI: 10.1051/dst:2008001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Tsioulpas A, Grandison A, Lewis M. Changes in Physical Properties of Bovine Milk from the Colostrum Period to Early Lactation. J Dairy Sci 2007; 90:5012-7. [DOI: 10.3168/jds.2007-0192] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Mezdour S, Brulé G, Korolczuk J. Physicochemical analysis of casein solubility in water-ethanol solutions. ACTA ACUST UNITED AC 2007. [DOI: 10.1051/lait:2006022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Radford SJ, Dickinson E, Golding M. Stability and rheology of emulsions containing sodium caseinate: combined effects of ionic calcium and alcohol. J Colloid Interface Sci 2004; 274:673-86. [PMID: 15144844 DOI: 10.1016/j.jcis.2003.12.045] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Accepted: 12/19/2003] [Indexed: 12/22/2022]
Abstract
We have investigated the combined effect of ionic calcium and ethanol on the visual creaming behavior and rheology of sodium caseinate-stabilized emulsions (4 wt% protein, 30 vol% oil, pH 6.8, mean droplet diameter 0.4 microm). A range of ionic calcium concentrations, expressed as a calcium/caseinate molar ratio R, was adjusted prior to homogenization and varying concentrations of ethanol were added shortly after homogenization. A stability map was produced on the basis of visual creaming behavior over a minimum period of 8 h for different calcium/caseinate/ethanol emulsion compositions. A single narrow stable (noncreaming) region was identified, indicating limited cooperation between calcium ions and ethanol. The shear-thinning behavior of the caseinate-stabilized emulsions is typical of systems undergoing depletion flocculation. Addition of calcium ions and/or ethanol was found to lead to a pronounced reduction in viscosity and the onset of Newtonian flow. The state of aggregation was correlated with emulsion microstructure from confocal laser scanning microscopy. Time-dependent rheology (18 h) with a density-matched oil phase (1-bromohexadecane) revealed that the visually stable emulsions were time-independent low-viscosity fluids. Surface coverage data showed that increasing amounts of caseinate were associated with the oil-water interface with increasing R and ethanol content. A decrease in free calcium ions in the aqueous phase with moderate increases in R and ethanol content was observed, which is consistent with greater calcium-caseinate binding (aggregation). Ostwald ripening occurred at the high-ethanol emulsion compositions that were stable to depletion flocculation. While the coarsening rate was low, this can account for the cream plug formation observed during gravity creaming experiments. The caseinate emulsion with no ionic calcium or ethanol exhibits depletion flocculation from excess nonadsorbed caseinate submicelles. Addition of calcium ions reduces the submicelle number density via specific calcium-binding in the aqueous phase (fewer, larger calcium-caseinate aggregates) and at the droplet surface (increased surface coverage). Nonspecific ethanol-induced (calcium-dependent) caseinate submicelle aggregation in the bulk phase and on the droplet surface (increased surface coverage) culminates in a reduction in the number density of caseinate submicelles. A narrow window of inhibition of depletion flocculation occurs in systems containing both calcium ions and ethanol, both species combining to aggregate the protein and so reduce the density of free submicelles.
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Affiliation(s)
- Stewart J Radford
- Procter Department of Food Science, University of Leeds, Leeds LS2 9JT, UK
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Effect of extracts of oak (Quercus petraea) bark, oak leaves, aloe vera (Curacao aloe), coconut shell and wine on the colloidal stability of milk and concentrated milk. Food Chem 1999. [DOI: 10.1016/s0308-8146(98)00248-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Shilton NC, Johnson A, Lewis MJ. An investigation of a possible relationship between the ethanol stability of milk and the fouling of milk in an ultra high temperature process. INT J DAIRY TECHNOL 1992. [DOI: 10.1111/j.1471-0307.1992.tb01716.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Affiliation(s)
- C Holt
- Hannah Research Institute, Ayr, Scotland
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The effect of environmental conditions on the steric stabilization of casein micelles. Colloid Polym Sci 1986. [DOI: 10.1007/bf01469535] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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33
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MOHAMMAD KS, FOX PF. Influence of some polyvalent organic acids and salts on the colloidal stability of milk. INT J DAIRY TECHNOL 1983. [DOI: 10.1111/j.1471-0307.1983.tb02229.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Horne DS, Parker TG. Factors affecting the ethanol stability of bovine casein micelles: 3. Substitution of ethanol by other organic solvents. Int J Biol Macromol 1981. [DOI: 10.1016/0141-8130(81)90099-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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