scholarly journals Methods of Assessing Milk Proteins Coagulation as a Part of the Forecasting System of Technological Properties

Author(s):  
Elena Illarionova ◽  
Alexandr Kruchinin ◽  
Svetlana Turovskaya ◽  
Alana Bigaeva

Introduction. An integrated monitoring of raw milk’s contents, quality, and security is a key factor that guarantees the high-quality dairy production. As a result, new research methods of rennet clotting are a topical and urgent area of study. The research objective was to systemize and analyze the basic criteria and assessment methods of rennet-induced protein gels in milk systems. Study objects and methods. The authors reviewed the official Russian criteria and methods of raw milk assessment by its rennet coagulation properties. The research also featured the most widespread instrumental approaches used in best practices from around the world. Results and discussion. In Russian and foreign cheese production, milk is always tested for its physicochemical and microbiological indicators, with a mandatory check of its coagulation characteristics. Russian cheese-makers use different modifications of rennet and rennet-fermenting tests based on subjective sensory evaluation, while international scientific trends in this area aim at developing and improving instrumental methods by using a complex indicator MCP. This indicator characterizes the parameters of rennet coagulation with the help of such devices as Formagraph, Lattodinamografo, Optigraph, etc. Formagraph is a simple instrument for measuring rheological properties of milk clotting. It was popular in the late XX century. The resent years saw the development of other methods of instrumental control, including those based on optical measurements. For instance, Ortigraph is one such instrument that receives unified data on coagulation properties of raw milk by using near-infrared waves. Sensory and instrumental methods have their advantages and disadvantages. However, the most significant criteria for a quick test of cheeseability, yield, and quality are the speed of analysis and the comparability and reproducibility of results. Conclusion. To improve cheeseability testing, Russian cheese-makers need to use the international experience, which offers standardized evaluation criteria in combination with various instrumental approaches. However, the integration of foreign regulations and methods into Russian studies is not the only option. The improvement and development of national instrumental methods of evaluating milk protein coagulation is also crucial.

Author(s):  
Monika Kozelková ◽  
Miroslav Jůzl ◽  
Táňa Lužová ◽  
Květoslava Šustová ◽  
Aneta Bubeníčková

This work deals about evaluation of qualitative parameters of rennets. During the six months storing of rennets were determined following qualitative parameters: pH, rennet coagulation time, activity (strange) of rennet and dose of rennet, and finally were used instrumental methods: Near infrared spectroscopy (NIR) for recognizing age of rennets and spectrophotometric methods of determining the color of rennets. The theory found in the references suggests, that the activity of rennet should decrease by an average of 1–2 % per month, but the results are showing, that are changing quality of rennets namely mostly activity (strange) of rennet, which was decreased by 33% per half year. In analysis of color of rennets weren’t observed major changes by the whole group. Some statistical differences were detected in the partial values L*a*b*, most advantageous were evaluation by rennet total color change during storage, which were higher than noticeable change in four samples. The least color changes (P > 0.05) were observed in microbial rennets, with no values observed (ΔEab < 2) that can be recognized even by the human eye when subjected to parallel comparison. It was found that the NIR analysis can be used to recognizing of rennets, which are different ages.


Author(s):  
Alina NASALEAN ◽  
Laurentiu OGNEAN ◽  
Sergiu MUNTEAN ◽  
Stefana BALICI ◽  
Horea MATEI

The milk’s proteins provide nutritional and biologically active values, essential in human and animal nutrition. In the case of goat milk, the proteins’ concentration and quality represent basic indices for the evaluation of the nutritional and biologically active values. The proposal is to comparatively analyse the protein profile of milk. The milk was collected from two different breeds: French Alpine and Romanian Carpathian. During March and April 2016 there were collected samples of raw milk in hygienic and sanitation conditions. There were two lots: first lot has 10 Carpathian goats and the second lot has 10 Alpine goats. The protein composition of goat milk was established with SDS-PAGE, after the evaluation of the total proteins’ concentration with the Bradford method. The quantitative and percentage data obtained with electrophoresis revealed few differences between those 8 identified protein fractions. Between those two lots, regarding the levels of β-CN, k-CN and β-lactoglobulines there were significant differences. The other protein fractions have values almost identical. Statistical analysis of obtained data shaped the differences in the protein profile at those two breeds. Based on those differences it is to note the superior potential of the Alpine breed regarding the content in biologically active milk proteins. Regarding the obtained data, this study brings new contributions for the evaluation and analysis of protein profile as a nutritive and biologically active component of goat milk, confirming its character as a functional aliment.


1958 ◽  
Vol 25 (1) ◽  
pp. 32-51 ◽  
Author(s):  
Peggy B. Taylor ◽  
L. F. L. Clegg

The determination of apparent lactic acid has been used as a basis for a rejection test for raw milk. The method consists of precipitation of milk proteins with barium chloride, sodium hydroxide and zinc sulphate, and the addition of ferric chloride to the filtrate to produce the yellow colour of ferric lactate. Lactic acid is not solely responsible for the production of the yellow colour, which, nevertheless, gives a good relationship with keeping quality of milk (measured as hours to the C.O.B. end-point at 22° C.) and the values have been expressed as ‘apparent lactic acid’.The relationship of winter and summer milks to keeping quality has been studied, and a value of 0·03% apparent lactic acid in milk is equivalent to an average keeping quality of 5¾ and 8½ hr. for winter and summer milks, respectively. A value of 0·03% is recommended as the earliest value of apparent lactic acid at which milk could be rejected.The apparent lactic acid in colostrum and late-lactation milk and in milk from cows suffering from mastitis has been determined, and only in late-lactation milk were the values found to be significantly higher than usual in fresh raw milk, and an inverse relationship between yield and apparent lactic acid is suggested.Permanent glass matching disks have been prepared for use in a Lovibond comparator. This permits the intensity of the yellow colour produced with 1% ferric chloride to be determined and the apparent lactic acid in milk estimated.Grateful acknowledgement is made to the management and staff of the Dairy Department of the Reading Co-operative Society and the Farmer's Clean Milk Dairy, Reading, and local milk producers for supplying samples for experiments; to the N.M.T.S. staff in Reading for help in finding suitable farmers, and to the Dairy Husbandry Department of the N.I.R.D. for information about and samples of abnormal and late-lactation milk. Our particular thanks are due Miss Marie Gruber for technical assistance, to Dr N. J. Berridge for the suggestion and help on the work on pH change as an indication of keeping quality (given in the appendix), and to Dr A. T. R. Mattick for the advice given in this work.


Author(s):  
I. N. Skidan ◽  
C. Prosser ◽  
I. N. Zakharova

The physicochemical properties of infant adapted milk formulae that affect their tolerability and effectiveness depend on the composition and quality of the raw ingredients, the production process, the storage conditions and the quality control of the finished products. The technology of manufacturing a powdered infant formula includes a variety of methodsfor processing componentsthat make up its composition, including raw milk. This processing is accompanied by a noticeable change in a number of physical, chemical and biological properties of the individual components of milk, their loss, the formation of fundamentally new chemical compounds. The most frequent reactions observed during the heat treatment of milk include the formation of bonds between reactive carbonyl groups of the sugar and the amino groups of amino acids, followed by the appearance of a large number of low- and high-molecular compounds, the so-called Maillard Reaction Products(MRP). The study of MRP in recent years hasincreasingly attracted the attention of medical practitioners because of the discovery of these compounds in infant formula and their potential danger to children’s health. This review provides evidence that powdered infant adapted formulae produced with an original technology based on whole goat milk with a native ratio of the main groups of milk proteins(whey – 20% and casein – 80%) have a minimum potential for unwanted effects associated with MRP.


2020 ◽  
Vol 4 (4) ◽  
pp. 151 ◽  
Author(s):  
Alena Smirnova ◽  
Georgii Konoplev ◽  
Nikolay Mukhin ◽  
Oksana Stepanova ◽  
Ulrike Steinmann

Milk is a product that requires quality control at all stages of production: from the dairy farm, processing at the dairy plant to finished products. Milk is a complex multiphase polydisperse system, whose components not only determine the quality and price of raw milk, but also reflect the physiological state of the herd. Today’s production volumes and rates require simple, fast, cost-effective, and accurate analytical methods, and most manufacturers want to move away from methods that use reagents that increase analysis time and move to rapid analysis methods. The review presents methods for the rapid determination of the main components of milk, examines their advantages and disadvantages. Optical spectroscopy is a fast, non-destructive, precise, and reliable tool for determination of the main constituents and common adulterants in milk. While mid-infrared spectroscopy is a well-established off-line laboratory technique for the routine quality control of milk, near-infrared technologies provide relatively low-cost and robust solutions suitable for on-site and in-line applications on milking farms and dairy production facilities. Other techniques, discussed in this review, including Raman spectroscopy, atomic spectroscopy, molecular fluorescence spectroscopy, are also used for milk analysis but much less extensively. Acoustic methods are also suitable for non-destructive on-line analysis of milk. Acoustic characterization can provide information on fat content, particle size distribution of fat and proteins, changes in the biophysical properties of milk over time, the content of specific proteins and pollutants. The basic principles of ultrasonic techniques, including transmission, pulse-echo, interferometer, and microbalance approaches, are briefly described and milk parameters measured with their help, including frequency ranges and measurement accuracy, are given.


2002 ◽  
Vol 56 (5) ◽  
pp. 599-604 ◽  
Author(s):  
Young-Ah Woo ◽  
Yoko Terazawa ◽  
Jie Yu Chen ◽  
Chie Iyo ◽  
Fuminori Terada ◽  
...  

A new measurement unit, the MilkSpec-1, has been developed to determine rapidly and nondestructively the content of fat, lactose, and protein in raw milk using near-infrared transmittance spectroscopy. The spectral range over 700 to 1100 nm was used. This unit was designed for general glass test tubes, 12 mm in diameter and 10 mL in volume. Al2O3 with a thickness of 2.5 mm was found to be optimum as a reference for acquiring the milk spectrum for this measurement. The NIR transmittance spectra of milk were acquired from raw milk samples without homogenization. The calibration model was developed and predicted by using a partial least-squares (PLS) algorithm. In order to reduce the scattering effect due to fat globules and casein micelles in NIR transmittance spectra, multiplicative scatter correction (MSC) and/or second derivative treatment were performed. MSC treatment proved to be useful for the development of calibration models for fat and protein. This study resulted in low standard errors of prediction (SEP), with 0.06, 0.10, and 0.10% for fat, lactose, and protein, respectively. It is shown that accurate, rapid, and nondestructive determination of milk composition could be successfully performed by using the MilkSpec-1, presenting the potential use of this method for real-time on-line monitoring in a milking process.


1983 ◽  
Vol 46 (2) ◽  
pp. 90-94 ◽  
Author(s):  
THAKOR R. PATEL ◽  
FRANCIS M. BARTLETT ◽  
JAWED HAMID

Several bacterial isolates from raw milk produced proteases. Most of such 28 isolates were gram-negative rods which were oxidase- and catalase-positive. All the isolates grew at temperatures in the range of 0–35°C, but failed to grow at 37°C. Nineteen of these isolates were tentatively assigned to genus Pseudomonas, and were used in the present investigation. Extracellular proteases from these psychrotrophic pseudomonads were heat-resistant, being able to retain partial activity even after heat-treatment at 120°C for 10 min. Milk proteins were preferred substrates by these proteases although some also hydrolysed bovine serum albumin, hemoglobin and ovalbumin. The optimum pH for the maximum activity was between pH 7.2 and 7.4. Divalent metal ions like Cu2+, Co2+, Hg2+, and Zn2+ were inhibitory to protease activity while Ca2+, Mg2+, and Mn2+ had little or no inhibitory effect on the proteases. Induced levels of protease production were observed when cultures were grown in minimal media containing either casein or nonfat dried milk powder. Glucose, citrate and lactose repressed enzyme synthesis in a minmal salts medium containing either casein or nonfat dried milk powder. Protease activity was also detected in cultures grown in minimal medium containing glutamine. Proteases from different isolates varied in their molecular weights.


Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2407-2414 ◽  
Author(s):  
Yuan Liu ◽  
Gongxun Bai ◽  
Li Jiang ◽  
Youjie Hua ◽  
Liang Chen ◽  
...  

AbstractUltrathin two-dimensional (2D) materials have drawn great attention in recent years due to their promising applications in biomedicine and atomically optoelectronic devices. In this work, we have fabricated a 2D In2Se3 nanosheet doped with Nd3+ ions via the two-step method of solid phase synthesis and liquid exfoliation. Owing to the special inner 4f-4f energy level transitions, lanthanide ions can emit photons with almost the same energy in different environments. Here, a stable near-infrared luminescence from Nd3+-doped 2D In2Se3 nanosheets has been realized, which includes emission bands around 910, 1057, and 1324 nm. The doping of Nd3+ ions extends the emission region of In2Se3 nanosheets. Moreover, the photoluminescence mechanism of Nd3+ ions was investigated through a series of optical measurements. This work not only provides a reliable method to fabricate lanthanide ion-doped 2D materials but also possesses a great significance for luminescence study of lanthanide ions in the 2D matrix.


2018 ◽  
Vol 10 (2) ◽  
pp. 1 ◽  
Author(s):  
Revathy B. Menon ◽  
Lakshmi V. S. ◽  
Aiswarya M. U. ◽  
Keerthana Raju ◽  
Sreeja C. Nair

A novel drug delivery system is the one that ensures optimum dose at the right time, at the right location. Porphysomes are among those drug delivery systems. Porphysomes are a means of vesicular drug delivery systems. They are liposome-like structures composed completely of porphyrin lipid. The porphysomes encapsulates the active medicament in vesicular structure. They are having an aqueous core which can be loaded with the medicament. They have the capacity to destroy the disease tissues. They absorb the heat in the near infrared region and release this heat to destroy the diseased tissues. Porphysomes are having immense applications in the field of positron-electron therapy (PET), photoacoustic imaging, photothermal therapy etc. This review article discusses regarding the Porphysome-the drug delivery system, its advantages and disadvantages, composition, method of preparation, applications and various aspects related to the porphysomal drug delivery.


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