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Pinheiro JS, Rocha LG, de Andrade DR, Rotta PP, Rezende JP, Pires ACS, Marcondes MI. Unveiling unstable non-acid incidence in Holstein cows fed with corn silage or sugarcane. J Dairy Sci 2022; 105:9226-9239. [PMID: 36175236 DOI: 10.3168/jds.2022-21821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 06/27/2022] [Indexed: 11/19/2022]
Abstract
We aimed to evaluate the incidence of unstable non-acid milk (UNAM) in cows fed either sugarcane or corn silage. Second, we aimed to evaluate the effect of daily variation (d 1 to 4) and alcohol grades (72, 78, and 80%) on UNAM incidence. The experiment was conducted as a split-plot crossover design, with 2 periods and 2 roughage types (sugarcane or corn silage). Thirteen multiparous Holstein cows with an average of 281 ± 29 d in milk were randomly distributed into 2 diets. Individual blood (analysis of total proteins, albumin, urea, calcium, phosphorus, magnesium, iron, chloride, glucose, and lactate) and milk samples (analysis of protein, fat, lactose and total solids, somatic cell count, and characterization of the protein profile) were collected during the last 4 d of each period. For UNAM identification, the alcohol test was conducted in milk samples at 4°C; specifically, if the sample presented the formation of clots, this would be noted as positive for UNAM. In addition, the Dornic acidity analysis was performed in the same samples to evaluate the true milk acidity. The use of sugarcane and higher degrees of alcohol were associated with increased UNAM. We observed no daily variation in UNAM. Nevertheless, we found no roughage type effect on the variables most commonly associated with UNAM, such as changes in salts in the casein micelle and, consequently, the zeta potential and the κ-casein (CN) fraction. The Pearson correlation analysis showed that the zeta potential and the concentrations of αS2-CN, blood ionic calcium, lactate, and glucose increased as the incidence of UNAM increased, showing a positive correlation among these variables. In contrast, the concentrations of lactose, phosphorus, and potassium decreased as UNAM increased, presenting a negative correlation. This study brought important discoveries to unveil why cows manifest UNAM. For instance, higher alcohol grades and cows fed with sugarcane had increased the incidence of UNAM. Additionally, animals with a higher incidence of UNAM (sugarcane-fed cows) were related to increased ionic calcium and glucose and changes in milk protein profile, with lower levels of BSA, β-CN, and α-lactalbumin and greater αS1-CN content, all of which were correlated with UNAM. Nonetheless, this trial also provides evidence for the need for further studies to better understand the physiological mechanisms that directly affect the stability of milk protein.
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Affiliation(s)
- Jardeson S Pinheiro
- Department of Animal Science, Federal University of Viçosa, Av P.H.Rolfs, sn, Viçosa, MG 36570-900, Brazil
| | - Lethiane G Rocha
- Department of Animal Science, Federal University of Viçosa, Av P.H.Rolfs, sn, Viçosa, MG 36570-900, Brazil
| | - Dhones R de Andrade
- Department of Animal Science, Federal University of Viçosa, Av P.H.Rolfs, sn, Viçosa, MG 36570-900, Brazil
| | - Polyana P Rotta
- Department of Animal Science, Federal University of Viçosa, Av P.H.Rolfs, sn, Viçosa, MG 36570-900, Brazil
| | - Jaqueline P Rezende
- Department of Food Science, Federal University of Lavras, Lavras, MG 37200-000, Brazil
| | - Ana C S Pires
- Applied Molecular Thermodynamics Group, Department of Food Technology, Federal University of Viçosa, Viçosa, MG 36570-900, Brazil
| | - Marcos I Marcondes
- Department of Animal Sciences, Washington State University, Pullman 99164.
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Tribst AAL, Falcade LTP, Leite Júnior BRDC, Oliveira MM. Why are most physicochemical parameters not useful in predicting the quality of sheep milk? INT J DAIRY TECHNOL 2019. [DOI: 10.1111/1471-0307.12657] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alline Artigiani Lima Tribst
- Center for Food Studies (NEPA) University of Campinas (UNICAMP) Albert Einstein, 291 13083‐852 Campinas SPBrazil
| | - Luiza Toledo Piza Falcade
- Center for Food Studies (NEPA) University of Campinas (UNICAMP) Albert Einstein, 291 13083‐852 Campinas SPBrazil
| | | | - Miguel Meirelles Oliveira
- Center for Technological Education Celso Suckow da Fonseca (CEFET‐RJ) Voluntários da Pátria, 30 27600‐000 Valença RJ Brazil
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Abstract
SUMMARYMilk composition varies greatly throughout the year, due largely to the effects of the diet of the cow and the stage of lactation. Whilst such variations go unremarked with bottled and cartoned milk, they are of major importance to manufacturers who use milk as a raw material. The most obvious example is when the yield of a dairy product is affected, e.g. in Scotland, the volume of milk required to produce 1 kg butter varies between 21.1 and 23.3 1 at different times of the year.In addition, however, some of the more subtle changes in milk composition either affect product quality, e.g. the ease with which butter may be spread, or cause processing difficulties, e.g. instability during heating processes. This paper reviews some of our current knowledge on the relationship between milk composition and the properties of some dairy products — butter, whipping cream, Cheddar cheese, ultra-heat treated milk and full-cream evaporated milk. The aim is to identify those milk components that affect each product or process and then enquire how milk composition may be altered to effect improvements — whether at the farm by dietary manipulation or at the creamery by technological adjustment.It is believed that all the evidence indicates that, despite difficulties due to restrictive legislation, the answer must lie at the creamery. The farmer should concentrate on producing desirable milk solids at the lowest possible cost and leave the technologist to do the fine tuning that leads to improved products.
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Martins C, Arcari M, Welter K, Netto A, Oliveira C, Santos M. Effect of dietary cation-anion difference on performance of lactating dairy cows and stability of milk proteins. J Dairy Sci 2015; 98:2650-61. [DOI: 10.3168/jds.2014-8926] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/06/2014] [Indexed: 11/19/2022]
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Heat stability of milk: pH-dependent dissociation of micellar κ-casein on heating milk at ultra high temperatures. J DAIRY RES 2009. [DOI: 10.1017/s0022029900024481] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYPreheating milk at 140 °C for 1 min at pH 6·6, 6·8, 7·0 or 7·2 shifted the heat coagulation time (HCT)/pH profile to acidic values without significantly affecting the maximum stability. Whey proteins (both β-lactoglobulin and α-lactalbumin) co-sedimented with the casein micelles after heating milk at pH < 6·9 and the whey protein-coated micelles, dispersed in milk ultrafiltrate, showed characteristic maxima–minima in their HCT/pH profile. Heating milk at higher pH values (> 6·9) resulted in the dissociation of whey proteins and κ-casein-rich protein from the micelles and the residual micelles were unstable, without a maximum–minimum in the HCT/pH profile. Preformed whey protein–casein micelle complexes formed by preheating (140 °C for 1 min) milk at pH 6·7 dissociated from the micelles on reheating (140 °C for 1 min) at pH > 6·9. The dissociation of micellar-κ-casein, perhaps complexed with whey proteins, may reduce the micellar zeta potential at pH ≃ 6·9 sufficiently to cause a minimum in the HCT/pH profile of milk.
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Abstract
SUMMARYUrea stabilizes milk to heat only in the presence of a carbonyl compound, such as a reducing sugar. Low molecular weight carbonyl compounds can increase stability in the absence of urea whereas larger molecules, e.g. hexoses and reducing disaccharides, cannot. However, the efficacy of all carbonyl compounds is increased considerably in the presence of urea. Aldehydes and ketones of similar molecular weights appear to be equally effective stabilizers. The optimum concentration of lactose in milk for stability was approximately 1% irrespective of urea concentration within the range 5–20 mM. However, modifying the lactose content of concentrated milks (approximately 8.5% protein) had little effect on heat stability.
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Abstract
SUMMARYThe proteins of bovine milk are the best-characterized food-protein system. Lactoproteins, which have high biological value, contribute ∼25% of dietary protein in North West Europe, North America and Oceania. However, in protein-rich western diets, milk proteins are frequently more highly valued for their functional properties than for their nutritional qualities. The remarkably high heat stability of the caseinate system permits the manufacture of a range of sterilized, concentrated and dehydrated products while its gelation on very limited proteolysis is the basis of cheese manufacture. Skim-milk powders, caseinates and whey protein concentrates are the most flexible and widely used functional proteins in food processing.This communication reviews recent studies on milk proteins with respect to molecular and colloidal properties; coagulation by Ca2+, heat and ethanol; and functional properties and their chemical and enzymic modification.
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Studies on the heat stability of milk: II. Association and dissociation of particles and the effect of added urea. J DAIRY RES 2009. [DOI: 10.1017/s0022029900025188] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SummaryThe sizes of the casein particles in milk heated at 130°C were measured as functions of heating time and of initial pH. The effect of adding 10 mM-urea to the milks was also studied. Turbidities of the milks before and after dispersing the caseinate particles in 8 m-urea/EDTA/β-mercaptoethanol were measured, the latter measurement giving an indication of the extent of covalent cross-linking. Urea was found to modify the behaviour of the milk: diameters of the caseinate particles were considerably altered, and the extent of covalent cross-linking was diminished. These results agree with the observation that more protein is solubilized from the casein micelles when urea is present, indicating that a competitive reaction scheme involving cross-linking in opposition to micellar dissociation may be responsible for the ultimate precipitation of milk by heat.
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Shalabi SI, Fox PF. Heat stability of milk: influence of modification of lysine and arginine on the heat stability-pH profile. J DAIRY RES 1982; 49:607-17. [PMID: 6816842 DOI: 10.1017/s0022029900022755] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Several dicarbonyl compounds (glyoxal, substituted glyoxals, diacetyl and 1, 2-cyclohexanedione) had a marked stabilizing effect on the heat stability of milk, especially in the presence of urea. These reagents are believed to modify arginine more or less specifically suggesting an important role for arginine residues in heat stability. In contrast, modification of lysine residues with dansyl chloride, acetic anhydride or cyanoborohydride had little effect on maximum heat stability although it did alter the HCT-pH profile. Since diacetyl is a natural constituent of fermented milks and cheese, it may be acceptable as an additive to increase the heat stability of milk.
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