Separation methods for milk proteins on polyacrylamide gel electrophoresis: Critical analysis and options for better resolution

Sharma, Nisha; Sharma, Rajan; Rajput, Y. S.; Mann, Bimlesh; Singh, Raghuraj; Gandhi, Kamal

doi:10.1016/j.idairyj.2020.104920

Cited by 41 publications

(32 citation statements)

References 82 publications

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“…Actually, SDS-PAGE is widely used as it does not require expensive equipment. However, large protein aggregates fail to migrate into the gel and the analysis only provides a semi-quantitative estimation [ 28 , 29 ]. Recent applications reported by literature support the reliability of CZE under reducing conditions in the separation of both native and denatured whey proteins [ 25 , 30 , 31 ], although the incomplete solubilization of large aggregates may also represent a limitation with this technique, as discussed below.…”

Section: Resultsmentioning

confidence: 99%

Focus on the Protein Fraction of Sports Nutrition Supplements

et al. 2022

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Increasing awareness of balanced diet benefits is boosting the demand for high-protein food and beverages. Sports supplements are often preferred over traditional protein sources to meet the appropriate dietary intake since they are widely available on the market as stable ready-to-eat products. However, the protein components may vary depending on both sources and processing conditions. The protein fraction of five commercial sports supplements was characterized and compared with that of typical industrial ingredients, i.e., whey protein concentrates and isolates and whey powder. The capillary electrophoresis profiles and the amino acid patterns indicated that, in some cases, the protein was extensively glycosylated and the supplemented amino acids did not correspond to those declared on the label by manufacturers. The evaluation by confocal laser scanning microscopy evidenced the presence of large aggregates mainly enforced by covalent crosslinks. The obtained findings suggest that, beside composition figures, provisions regarding sports supplements should also consider quality aspects, and mandatory batch testing of these products would provide more reliable information to sport dieticians.

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Section: Resultsmentioning

confidence: 99%

Focus on the Protein Fraction of Sports Nutrition Supplements

et al. 2022

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“…Among electrophoresis methods, the most utilised techniques for extracting milk or its product proteins are native gel electrophoresis, urea-PAGE, and SDS--PAGE, with its advantages and disadvantages. In native gel electrophoresis, proteins do not denature and remain inactive (Sharma et al 2021). It has been observed that this technique is not suited for separating the casein protein.…”

Section: Discussionmentioning

confidence: 99%

Comparison of extraction methods and nutritional benefits of proteins of milk and dairy products: A review

Javed¹,

Arshad²,

Arif³

et al. 2022

Czech J. Food Sci.

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Proteins are the second most essential macromolecules after nucleic acids. This article aimed at the comparative analysis of extraction methods and nutritional benefits of milk and dairy products. Proteins form the body mass and perform several crucial tasks that include acting as a catalyst and carrying out different metabolic reactions in the body. Furthermore, protein acts as a transporter, transmits nerve impulses, provides mechanical support or immune protection, and controls growth. Several sources of proteins are present, but milk holds an important place due to its biological activities. The considerable health benefits of milk and its products are due to proteins. Yoghurt and cheese have significant importance among milk products. Proteins of milk and its products can be extracted by pH adjustment through homogenisation, centrifugation, and deproteinisation. There are several techniques for identifying and quantifying milk and product proteins. The Kjeldahl and spectrophotometric methods are the most widely used methods for quantifying proteins in milk and its products. Furthermore, these techniques include electrophoresis and chromatographic methods, including native gel electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), urea-PAGE, capillary electrophoresis, and isoelectric focusing. A few are chromatographic methods like reverse-phase high-performance liquid chromatography (RP-HPLC), size exclusion chromatography, and ion-exchange chromatography. Each technique has its advantages as well as disadvantages. The selection of the process depends upon the type of protein. The extracted proteins from milk and its products have many health or therapeutic effects that exhibit antimicrobial, antiproliferative, antioxidant, antihypertensive, anticancer, antiviral, and immunomodulatory effects. Yoghurt has prime importance among milk products because of its therapeutic effects and more protein.

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“…The ideal formula to fulfill infant needs should contain α-CN, β-CN and β-Lg in lower amounts to those detected in the investigated IFs, as the most common type of food allergen for infants and young children, β-casein A1, has been associated with a range of allergic diseases, including type 1 diabetes [49,[60][61][62]. When β-casein A1, commonly found in CM in Europe, the United States, Australia, and New Zealand [63], is digested, it releases the β-casomorphin-7 peptide, which presents opioid and inflammatory properties and is considered an allergen. However, although β-casein A1 comprises the main allergen agent, other factors should also be considered.…”

Section: Discussionmentioning

confidence: 99%

Protein Quality in Infant Formulas Marketed in Brazil: Assessments on Biodigestibility, Essential Amino Acid Content and Proteins of Biological Importance

et al. 2021

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Infant formulas, designed to provide similar nutritional composition and performance to human milk, are recommended when breastfeeding is not enough to provide for the nutritional needs of children under 12 months of age. In this context, the present study aimed to assess the protein quality and essential amino acid content of both starting (phase 1) and follow-up (phase 2) formulas from different manufacturers. The chemical amino acid score and protein digestibility corrected by the amino acid score were calculated. The determined protein contents in most formulas were above the maximum limit recommended by FAO and WHO guidelines and at odds with the protein contents declared in the label. All infant formulas contained lactoferrin (0.06 to 0.44 g·100 g−1) and α-lactalbumin (0.02 to 1.34 g·100 g−1) below recommended concentrations, whereas ĸ-casein (8.28 to 12.91 g·100 g−1), α-casein (0.70 to 2.28 g·100 g−1) and β-lactoglobulin (1.32 to 4.19 g·100 g−1) were detected above recommended concentrations. Essential amino acid quantification indicated that threonine, leucine and phenylalanine were the most abundant amino acids found in the investigated infant formulas. In conclusion, infant formulas are still unconforming to nutritional breast milk quality and must be improved in order to follow current global health authority guidelines.

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Separation methods for milk proteins on polyacrylamide gel electrophoresis: Critical analysis and options for better resolution

Cited by 41 publications

References 82 publications

Focus on the Protein Fraction of Sports Nutrition Supplements

Focus on the Protein Fraction of Sports Nutrition Supplements

Comparison of extraction methods and nutritional benefits of proteins of milk and dairy products: A review

Protein Quality in Infant Formulas Marketed in Brazil: Assessments on Biodigestibility, Essential Amino Acid Content and Proteins of Biological Importance

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