Comparison of Orange G Dye, Formol Titration, and Kjeldahl Methods for Milk Protein Determinations

Castillo, L. S.; Trimberger, G. W.; Henderson, Charles; Herrington, B.L.; Turk, K.L.

doi:10.3168/jds.s0022-0302(62)89562-9

Cited by 12 publications

(7 citation statements)

References 8 publications

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“…This method is relatively simple and has been applied primarily to dairy matrices including bovine fluid milk, human milk, ice milk and ice cream, and bovine skim milk powder. Results are comparable to those from Kjeldahl analysis (Pyne 1932; Castillo and others 1962; Hill and Stone 1964; Bakalor 1965; Roeper 1974; Abou Dawood and others 1977; Kumar and Seth 2004). For increased throughput it has been adapted for automated analysis by means of an autotitrator (Bakalor 1965).…”

Section: Review Of Currently Available Methods For Total Protein Quansupporting

confidence: 75%

Total Protein Methods and Their Potential Utility to Reduce the Risk of Food Protein Adulteration

Moore¹,

DeVries²,

Lipp³

et al. 2010

Comp Rev Food Sci Food Safe

175

130

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Kjeldahl and combustion (Dumas) methods are widely accepted for total protein determination but lack analytical selectivity for protein because they measure protein on the basis of sample nitrogen content. Adulteration incidents exploiting this analytical vulnerability (for example, melamine) demonstrate that these methods are no longer sufficient to protect the public health. This article explores the challenges and opportunities to move beyond total nitrogen based methods for total protein measurement. First, it explores the early history of protein measurement science, complexities of current global protein measurement activities, and ideal analytical performance characteristics for new methods. Second, it comprehensively reviews the pros and cons of current and emerging approaches for protein measurement, including their selectivity for protein, ability to detect adulteration, and practicality for routine use throughout the supply chain. It concludes that some existing highly selective methods for food protein measurement have potential for routine quality control. It also concludes that their successful implementation will require matrix-specific validation and the use of supporting reference materials. These methods may be suitable only for food ingredients that have a low degree of compositional variability and are not complex finished food products.

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Section: Review Of Currently Available Methods For Total Protein Quansupporting

confidence: 75%

Total Protein Methods and Their Potential Utility to Reduce the Risk of Food Protein Adulteration

Moore¹,

DeVries²,

Lipp³

et al. 2010

Comp Rev Food Sci Food Safe

175

130

View full text Add to dashboard Cite

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“…Следует отметить, что постоянный коэффициент пересчета результатов формольного титрования в массовую долю белка изначально был рекомендован отечественными исследователями, а зарубежными исследователями иной подход вообще не рассматривался. Так, Л. Карунина и М. Шилович 3 предложили при объеме пробы коровьего молока 10 см 3 использовать коэффициент пересчета 1,94 (для объема пробы 20 см 3 -это 0,97), А. Дуденков -коэффициент 0,959 3 . Американские исследователи [3] по результатам измерений 650 образцов молока от 142 коров установили среднее значение коэффициента пересчета 1,77 для проб молока объемом 10 см 3 , для проб молока объемом 20 см 3 -0,885, отметив, что на величину коэффициента пересчета на общий белок оказывали влияние стадия лактации и сезон года.…”

Section: молочная промышленность №2 2024unclassified

Protein Determination in Milk: Urgent Issues

Lepilkina,

Grigorieva,

Guseva

2024

Dairy Industry

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Formol titration is a familiar method for determining the mass fraction of protein in milk. However, it needs to be adapted to new instruments and modern metrology. The current methodology presented in State Standard GOST 25179-2014 requires a complex procedure to establish the alteration, which is often neglected by commercial laboratories and milk producers. This research clarified the formula for converting formol titration data into protein mass fraction without having to perform a variable correction. By processing 413 measurement results, the authors came up with two formulas: Y = 0.5X and Y 0.48X + 0.10, where Y is the mass fraction of protein (%) and X is the volume of sodium hydroxide spent on titration after adding formaldehyde to milk (cm3). Both formulas provided results close to those obtained by the Kjeldahl method, the correlation coefficient being ≥ 0.99. The conversion formulas made it possible to adapt the formol titration method to modern automatic potentiometric analyzers, thus optimizing the procedure and increasing its accuracy.

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“…Protein content of yoghurt was assessed utilizing the modified method of Castillo et al, [27] by formaldehyde titrations (using oxalate): 10 g of yoghurt samples was mixed with 0.4 g of potassium oxalate, apply 1 ml of phenolphthalein to the blend. The mixture was then titrated with 0.1 N NaOH, until pink coloration was observed.…”

Section: Determination Of Proteinmentioning

confidence: 99%

Extended Storage of Yoghurt by Using Water Extract of Coriander Seeds

Jameel¹,

Mohammed²

2020

JFNR

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The objective of this study was to evaluate the effects of coriander seed extract on the chemical and sensory properties of yoghurt during storage. Coriander seed extract was incorporated in yoghurt at different concentrations, 18 mg/ml (T1C1), 36 mg/ml (T2C2), and 54 mg/ml (T3C3), while a sample without extract (T0C0) was used as a control. Samples were stored at 4°C and were assessed every seven days. The values of lactose, fat, pH, protein, tyrosine, acid degree value, acid value, free fatty acid, and sensory properties for all samples containing extract give higher scores than those of yoghurt without extract. Chemical and sensory evaluations of the yoghurt without plant extract revealed a significant degradation beyond days 28 of storage due to high acidity, and an unpleasant flavour. By contrast, the concentrations of 18, 36 and 54 mg/ml, were shown to have remarkable preservation activity in yoghurt at 42 days. The formulation T3C3, fortified with coriander seed extract at 54 mg/ml, had the highest value in preserving the chemical properties of yoghurt after 42 days, compared with formulas T1C1 and T2C2, which contained 18 mg/ml and 36 mg/ml respectively. Results suggest that coriander extract can be added to dairy products as a natural food preservative, to improve stability during storage.

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Comparison of Orange G Dye, Formol Titration, and Kjeldahl Methods for Milk Protein Determinations

Cited by 12 publications

References 8 publications

Total Protein Methods and Their Potential Utility to Reduce the Risk of Food Protein Adulteration

Total Protein Methods and Their Potential Utility to Reduce the Risk of Food Protein Adulteration

Protein Determination in Milk: Urgent Issues

Extended Storage of Yoghurt by Using Water Extract of Coriander Seeds

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