Preservation Of Milk Research Articles

Colchicine can keep the viability of bacteria in mastitic milk by preventing leukocyte phagocytosis in dairy cow and goat.

Despite the occurrence of mastitis, no bacteria were detected in any of the milk samples after culture. This is partially because the neutrophils present in milk phagocytose bacteria during milk preservation. In this study, we investigated whether colchicine inhibited the decrease in viable bacteria in milk by suppressing phagocytosis during preservation. The number of viable bacteria decreased when cow milk was preserved for 5 h. However, the addition of 0.1 and 1% colchicine significantly increased the number of viable bacteria (p < 0.05). The percentage of culture-negative cow's milk increased more than two-fold after 5 h compared to that at 0 h of preservation, however this percentage was significantly reduced by the addition of colchicine (p < 0.05). When goat milk with mastitis was incubated with bacteria (Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus), the percentage of phagocytosed neutrophils decreased significantly with the addition of colchicine (p < 0.05). These results indicate that colchicine suppressed the decrease in the number of viable bacteria by preventing neutrophil phagocytosis during milk preservation. These findings may help in the identification of mastitis-causing bacteria and the selection of antibiotics for the treatment of mastitis.

Cold Plasma Technology: A Sustainable Approach to Milk Preservation by Reducing Pathogens and Enhancing Oxidative Stability

Cold Plasma Technology: A Sustainable Approach to Milk Preservation by Reducing Pathogens and Enhancing Oxidative Stability

Improving the bactericidal activity of carvacrol against Bacillus cereus by the formation of sodium casein-stabilized nanoemulsion and its application in milk preservation

Carvacrol has great antibacterial activity against Bacillus cereus, and its action mechanism was comprehensively studied in this work. It could not only control the growth of B. cereus by affecting the integrality of cellular structure and physiological metabolism, but also inhibit the swarming motility, biofilm formation, and toxins production. To increase the stability of carvacrol during the application, the sodium casein (SC)/hydroxypropyl-β-cyclodextrin (HPCD)/carvacrol nanoemulsion was fabricated. The mean particle size and polydispersity index of the nanoemulsions were 113.8 nm and 0.23, respectively, at SC and HPCD concentrations of 2% and 1%. FTIR analysis demonstrated that carvacrol was successfully encapsulated into the nanoemulsions. The MIC and MBC of nanoemulsions against B. cereus were 0.15 and 0.30 mg/mL, respectively, which were lower than those of free carvacrol (0.19 and 0.38 mg/mL). Carvacrol in nanoemulsions showed a slow and sustained release behavior. Furthermore, the nanoemulsions had good stability (particle size <200 nm) after storage at 4 °C and 25 °C for 15 days. Notably, the nanoemulsions were effective in controlling the growth of B. cereus in whole, low-fat, and skim milk and had better antimicrobial activity than free carvacrol. The results indicated that carvacrol nanoemulsions have potential in the antibacterial application of the food industry.

Lipidomics unveils changes in oxidised lipids in human breast milk by high‐pressure processing

SummaryHuman breast milk is a complex fluid rich in bioactive molecules crucial for infant growth and development. Global health organisations recommend exclusive breastfeeding to optimise infant health. In cases where maternal milk is unavailable, donor breast milk from human milk banks (HMBs) serves as an essential alternative. Currently, human breast milk preservation relies on Holder pasteurisation (HoP), which, while effective at pathogen inactivation, can compromise breast milk's nutritional and biological properties. High‐pressure processing (HPP) is an alternative pasteurisation method that utilises high pressure to kill pathogens without degrading nutrition. This study examined HPP's impact on donor breast milk lipids, sugars and antioxidants. Metabolomics reveals diverse bioactive compounds, including lipids, polyphenols and polyketides, elucidating breast milk's complexity. Some lipid subclasses respond to HPP; ceramides decreased under both treatments, while fatty aldehydes and esters increased under specific HPP conditions. Additionally, we quantified oxidised lipids, notably dietary oxysterols (DOxS), known for pro‐oxidant and pro‐inflammatory properties. These findings enhance understanding of HPP targeted approaches and breast milk's complexity, contributing to innovative milk preservation techniques that could advance specialised infant nutrition and assist donor milk banking systems.

Antibacterial Mechanism of Garviecin LG34 Against S. Aureus and L. Monocytogenes and its Application in Milk Preservation

The objective of this study was to reveal the antibacterial mode of action of garviecin LG34 against S. aureus CICC 21600 and L. monocytogenes CICC 21633 and measure the inhibitions on these two foodborne pathogenic bacteria in milk. Antibacterial mechanism of garviecin LG34 was ascertained by its effect on the efflux of Potassium (K+) ions, extracellular electrical conductivity, UV-absorbing substances, potential across the membrane (ΔΨ), and cell permeability. The inhibition of garviecin LG34 against S. aureus CICC 21600 and L. monocytogenes CICC 21600 in milk was studied by viable counting method. Supplementation with 160 AU/ml of garviecin LG34 had a bactericidal effect on S. aureus CICC 21600 and L. monocytogenes CICC 21633. A total of 80, 160, and 320 AU/ml of garviecin LG34 resulted in the effusion of potassium ion and UV-absorbing substances, the leakage of cellular electrolytes, and the dissipation of electrical potential across the membrane of these two food-borne bacteria and showed a dose-dependent. Moreover, the increase in cell permeability of both strains was observed by flow cytometer after cells treated with 160 AU/ml of garviecin LG34. Garviecin LG34 significantly inhibited the growth of these two food-borne bacteria in milk, especially in skimmed milk. Garviecin LG34 could cause pore formation, intracellular materials release, and permeability increase of S. aureus CICC 21600 and L. monocytogenes CICC 21633, and could be applied to milk as bio-preservative.

Advancements in Camel Milk Drying Technology: A Comprehensive Review of Methods, Chemical Composition, and Nutritional Preservation

With interest in camel milk growing due to its nutrients and biologically active compounds, research into methods of processing and drying it is crucial. In recent decades, extensive studies have explored its chemical composition and health benefits with a focus on drying techniques and their effects on its properties. This review systematically summarizes the available literature on camel milk drying processes and their effects on its chemical composition with a view to shortening the drying time. To achieve this goal, we meticulously reviewed numerous studies published between 2014 and 2024 to identify optimal drying methods that maximize the preservation of camel milk’s nutrient components and bioactive compounds. Our analysis revealed significant findings: freeze drying preserves nutrients better than spray drying, but is less efficient. Spray drying, while faster, tends to compromise some nutritional values. Conclusively, optimizing drying parameters can improve production efficiency and nutrient retention.

Sodium Alginate–Soy Protein Isolate–Chitosan–Capsaicin–Nanosilver Multifunctional Antibacterial Composite Gel

We constructed a sodium alginate/soy protein isolate/chitosan gel system and incorporated silver nanoparticles reduced by capsaicin into the system, forming a sodium alginate–soy protein isolate–chitosan–capsaicin–silver nanoparticle composite gel (SA/SPI/CTS/CAP/Ag). In tests, the SA/SPI/CTS/CAP/Ag gel exhibited excellent antimicrobial properties. Using the agar diffusion method, the inhibition zone diameter for Staphylococcus aureus was determined to be 29.5 mm. Soy protein isolate (SPI), containing a large number of hydrophobic amino acid residues, effectively enhanced the moisture retention capability of the gel and improved its stability to a certain extent at an appropriate addition concentration. In a milk preservation experiment, the SA/SPI/CTS/CAP/Ag gel significantly extended the shelf-life of the milk. In dye adsorption experiments, the adsorption curve of the SA/SPI/CTS/CAP/Ag gel well fitted a pseudo-second-order kinetic model. It showed a degree of adsorption capacity for methylene blue, malachite green, methyl orange, and Congo red, with the most significant adsorption effect for malachite green being 42.48 mg/g. Considering its outstanding antimicrobial performance, preservation ability, and adsorption capacity, the SA/SPI/CTS/CAP/Ag gel holds significant potential in wastewater treatment and as an antimicrobial gel in the exploration of food preservation.

Validation of a Portable Fluorescence Spectroscopy System to Monitor Heat Damage in Industrially Processed Milk.

Heat treatments play a critical role in ensuring the safety and preservation of milk, but it can affect its nutritional and sensory properties. The present paper proposes the use of a portable system based on fluorescence spectroscopy as an alternative method for the quantification of four thermal damage markers at once (hydroxymethylfurfural, sulfhydryl groups, ascorbic acid, and riboflavin). The obtained prediction models using autofluorescent compounds (tryptophan, dityrosine, Maillard compounds, and riboflavin), validated with skimmed milk processed under several industrial conditions, granted the development of a portable and/or online system, allowing for the real-time monitoring of thermal damage and control of the heat treatment process. The results of this study will certainly contribute to the development of new process analytical technologies for the dairy industry, enabling quality control and adjustment of the manufacturing process to ensure safe and high-quality products.

Breast milk preservation: thermal and non-thermal processes and their effect on microorganism inactivation and the content of bioactive and nutritional compounds.

Human Breast Milk (HBM) is widely acknowledged as the best nutritional source for neonates. Data indicates that, in 2019, 83.2% of infants in the United States received breast milk at birth, slightly reducing to 78.6% at 1 month. Despite these encouraging early figures, exclusive breastfeeding rates sharply declined, dropping to 24.9% by 6 months. This decline is particularly pronounced when direct breastfeeding is challenging, such as in Neonatal Intensive Care Units (NICU) and for working mothers. Given this, it is vital to explore alternative breast milk preservation methods. Technologies like Holder Pasteurization (HoP), High-Temperature Short-Time Pasteurization (HTST), High-Pressure Processing (HPP), UV radiation (UV), and Electric Pulses (PEF) have been introduced to conserve HBM. This review aims to enhance the understanding of preservation techniques for HBM, supporting the practice of extended exclusive breastfeeding. It explicitly addresses microbial concerns, focusing on critical pathogens like Staphylococcus aureus, Enterococcus, Escherichia coli, Listeria monocytogenes, and Cytomegalovirus, and explores how various preservation methods can mitigate these risks. Additionally, the review highlights the importance of retaining the functional elements of HBM, particularly its immunological components such as antibodies and enzymes like lysozyme and Bile Salt Stimulated Lipase (BSSL). The goal is to provide a comprehensive overview of the current state of HBM treatment, critically assess existing practices, identify areas needing improvement, and advocate for extended exclusive breastfeeding due to its vital role in ensuring optimal nutrition and overall health in infants.

Effectiveness of video assisted teaching programme on knowledge and attitude regarding techniques of expression, preservation and utilization of breast milk among working lactating mothers

Effectiveness of video assisted teaching programme on knowledge and attitude regarding techniques of expression, preservation and utilization of breast milk among working lactating mothers

Effect of UHT Thermal Treatment on the Secondary Structures of Milk Proteins: Insights From FTIR Analysis and Potential Allergenic Activity.

Although thermal treatments are beneficial for the preservation and safety of milk, they can also alter its immunogenic activity by affecting its protein components. To achieve precise results, it is essential to identify the specific proteins that cause food allergies. Therefore, investigating the possible alterations of cow's milk proteins (CMPs) resulting from thermal treatments is necessary. In this study, the Fourier transform infrared spectroscopy (FTIR) technique was used to analyze the effect of UHT thermal treatment on the secondary structures of milk casein. Using the second derivative, six characteristic peaks were identified in the Amide I region, ranging from 1700 to 1600 cm-1. It was found that thermal treatments produce shifts in absorption peaks, indicating changes in protein conformation and possibly in allergenic activity. These shifts were clearly identified in the first characteristic peak of samples M8 and M9, from 1621 to 1600 cm-1. The results suggest that thermal treatments may promote protein aggregation by increasing β turns and reducing β sheets and α helices, which could enhance the allergenic potential of the proteins and facilitate the formation of complexes between different milk proteins, such as β-lactoglobulin and κ-casein. Further studies are needed to experimentally validate the allergenic activity of proteins modified by thermal treatments, as only an analytical method (FTIR) was used to evaluate the secondary structures of the proteins.

Changes in properties of human milk under different conditions of frozen storage

Human milk is the best source of nutrition for infants. Lower freezing temperatures and faster freezing rates allow for better preservation of human milk. However, research on the freezing conditions of human milk is limited. This study investigated the effectiveness of quick freezing and suitable freezing conditions for home preservation. Human milk was stored under different freezing conditions (−18 °C, −18 °C quick freezing, −30 °C, −40 °C, −60 °C, and − 80 °C) for 30, 60, and 90 days and then evaluated for changes in the microbial counts, bioactive protein, and lipid. The results showed that the total aerobic bacterial and Bifidobacteria counts in human milk after storage at freezing temperatures of − 30 °C and lower were closer to those of fresh human milk compared to − 18 °C. Furthermore, the lysozyme loss, lipid hydrolysis degree, and volatile organic compound production were lower. However, −18 °C quick freezing storage was not markedly different from −18 °C in maintaining human milk quality. Based on the results, for household and environmental reasons, the recommended temperature for storing human milk is suggested as −30 °C.

Combined effect of γ-irradiation and antibacterial formulations based on natural compounds for preservation of mother's milk

The antibacterial potential of citrus extract, EOs (mediterranean formulation, oregano, lemongrass, cinnamon and clove), organic acids and salts (citric acid, lactic acid and sodium carbonate) was evaluated against E. sakazakii, E. coli O157:H7, S. aureus, L. monocytogenes, S. Typhimurium, B. cereus by determining the minimal inhibitory concentration (MIC). Based on the results, MIC value ranges from 312.5 to 5000 ppm against tested bacterial strains, with citrus extract showing the highest antibacterial activity (312.5 ppm). Four antimicrobial formulations based on quaternary combination of compounds were developed based on the fractional inhibitory concentration (FIC) index. Formulation 1 (Oregano/Mediterranean formulation/Citrus extract/Lactic acid), Formulation 2 (Cinnamon/Lemongrass/Citrus extract/Citric acid), Formulation 3 (Oregano/Mediterranean formulation/Citrus extract/Citric acid), Formulation 4 (Cinnamon/Lemongrass/Citrus extract/Lactic acid) showed a synergistic effect against all tested pathogens. Results demonstrated that bacterial radiosensitivity (1.34–3.99) was increased by the combined treatment of γ-irradiation with developed formulations in frozen mother's milk. Formulation 3 and 4 induced greater radiosensitivity in bacterial strains including sporulated B. cereus (1.90 and 1.89 respectively) compared to formulation 1 and 2. Therefore, the combined treatment can be an effective method to reduce the γ-irradiation dose (kGy) required to eliminate the pathogens and assures the safety of frozen mother's milk.

Photon-phonon coupling cold sterilization technology for milk preservation

With the continuous innovation of food processing and preservation technology, cold sterilization technology has become a hot research topic in dairy industry. This study firstly developed a novel photon-phonon coupling (PPC) cold sterilization technology, and its effects on the control of microbes in raw milk, milk sensory, nutritional composition and characteristics of whey proteins were explored, with the simulated low-temperature pasteurization (65 °C for 30 min, SLP) and microwave ultraviolet (MUV) as two comparative technologies. The results suggested that PPC showed bacterial reduction in raw milk by as high as 4.8 log, while indicated slight impacts on the color, taste and smell of raw milk, the main nutrients, as well as lactoferrin and immunoglobulin. Moreover, the impacts of PPC, SLP and MUV on whey proteins were systematically investigated, focusing on the protein structure, surface charge and hydrophobicity. This study provides a reliable and refined research basis for developing cold sterilization technology for food preservation.

Isolation, antibacterial characterization, and alternating tangential flow–based preparation of viable cells of Lacticaseibacillus paracasei XLK 401: Potential application in milk preservation

It is desirable to obtain high levels of viable Lacticaseibacillus paracasei, a widely used food probiotic whose antibacterial activity and potential application in milk remain largely uninvestigated. Here, we isolated and purified the L. paracasei strain XLK 401 from food-grade blueberry ferments and found that it exhibited strong antibacterial activity against both gram-positive and gram-negative foodborne pathogens, including Staphylococcus aureus, Salmonella paratyphi B, Escherichia coli O157, and Shigella flexneri. Then, we applied alternating tangential flow (ATF) technology to produce viable L. paracasei XLK 401 cells and its cell-free supernatant (CFS). Compared with the conventional fed-batch method, 22 h of ATF-based processing markedly increased the number of viable cells of L. paracasei XLK 401 to 12.14 ± 0.13 log cfu/mL. Additionally, the CFS exhibited good thermal stability and pH tolerance, inhibiting biofilm formation in the abovementioned foodborne pathogens. According to liquid chromatography-mass spectrometry analysis, organic acids were the main antibacterial components of XLK 401 CFS, accounting for its inhibition activity. Moreover, the CFS of L. paracasei XLK 401 effectively inhibited the growth of multidrug-resistant gram-positive Staph. aureus and gram-negative E. coli O157 pathogens in milk, and caused a reduction in the pathogenic cell counts by 6 to 7 log cfu/mL compared with untreated control, thus considerably maintaining the safety of milk samples. For the first time to our knowledge, ATF-based technology was employed to obtain viable L. paracasei on a large scale, and its CFS could serve as a broad-spectrum biopreservative for potential application against foodborne pathogens in milk products.

Graphene - Coated Surface Plasmon Resonance(SPR) Sensor for Detection of Preservatives in Milk : A Theoretical Investigation

Milk is an essential dietary staple for human sustenance. However, the presence of various contaminants, notably preservatives, within milk can potentially pose significant health risks and impact overall well-being. Consequently, the meticulous surveillance of pollutants and impurities, particularly preservatives, in natural and everyday food products has emerged as a pivotal endeavor to ensure food safety and enhance its overall quality. In this research study, the Surface Plasmon Resonance (SPR) technique is strategically employed for a theoretical exploration of preservatives, namely hydrogen peroxide, formaldehyde, and sodium carbonate, within milk. The investigation encompasses varying concentrations of these preservatives, ranging from 0% to 14.3%. Concurrently, the refractive indices span from 1.34550 to 1.35093, representing the concentration between the minimum (0%) and maximum (14.286%) concentrations of hydrogen peroxide, formaldehyde, and sodium carbonate. To authenticate the efficacy of the proposed sensor, an extensive assessment of performance parameters is conducted. These parameters encompass Sensitivity, Full Width at Half Maximum (FWHM), Figure of Merit (FOM), and Detection Accuracy (DA), with calculations performed for each specific case.

Intelligent active films of sodium alginate and konjac glucomannan mixed by Lycium ruthenicum anthocyanins and tea polyphenols for milk preservation and freshness monitoring

To achieve real-time monitoring of food freshness, a pH-responsive film based on sodium alginate-konjac glucomannan loaded with Lycium ruthenicum anthocyanins (LRA) was prepared, with the addition of tea polyphenols (TP) to enhance the stability of LRA. The surface structure of the films was observed by AFM. The results of FTIR and molecular docking simulation showed that LRA and TP were bound to polysaccharide by hydrogen bonds. The mechanical properties, barrier properties, and antioxidant/antibacterial properties of the films were significantly improved and the films showed obvious color response to pH. Notably, the AFM images showed TP and LRA could lead to more severe damage to the bacterial structure. The results of molecular docking simulation suggested that TP and LRA could act on different components of the bacterial cell wall, indicating their synergistic mechanism in antimicrobial activity. Moreover, the stability of LRA was improved due to the interactions of TP and polysaccharides with LRA. The aggregates formed by TP and LRA were clearly observed by AFM. Finally, the film showed excellent preservation and freshness monitoring effect in milk. In conclusion, TP-LRA-SA-KGM intelligent film exhibited excellent performance and represented a promising novel food packaging material with potential applications.

Influence of Storage and Preservation of Milk on the Performance of a Voltammetric Electronic Tongue

An alternative approach to analyze complex matrixes such as milks lies on multivariate description of the chemical composition of samples where non-specific fingerprints are analyzed using data mining methods. Portable electronic tongues (ET) are of great interest for the dairy industry [1]. However, still several problems related to the fouling of the electrodes and the preservation conditions limit their usage in milk analysis. For thus, the sensor´s development methods need to be adapted in order to reduce the fouling of electrodes caused by milk components, among which stand out fat and proteins. For that reason, these kind of matrixes need to be pre-treated to eliminate, or at least substantially diminish their presence.The benefits of using ETs in the dairy industry have been explored by different researchers [2]. These works have been used to discriminate and classify milk samples with different characteristics such as freshness, nutritional composition, adulterations, etc. However, due to its extremely complexity, the fouling of the electrodes reduces the repeatability and lifetime of the sensors. Another factor to take into account is the microbiologic process that start immediately after milking, due to it can modify the composition of milk. For that reason, it is necessary to develop techniques that not only decrease the fouling but limit also the growth of organisms without interfering in the electrochemical measurements.The necessity to optimize the measurement protocols in order to guarantee the capabilities of the sensors systems has led us to analyze and to evaluate the effect of practices such as dilution, sonication, freezing or addition of preservatives such as azidiol on the responses of electrochemical sensors. In this work, a portable system formed by an array of serigraphied sensors coupled to a pattern recognition software has been developed and used to analyze raw milk obtained from cows with different characteristics (lactation days, days of pregnancy, number of pregnancies...). In this work, it has been concluded that the performance of the sensory system is drastically improved if milk samples are diluted and sonicated previous to the analysis. In addition, it has been evidenced that the use of preservation methods such as the addition of azidiol or the freezing at -20ºC has also an important influence in the electrochemical responses. Principal Component Analysis of the signals obtained using the optimized conditions has allowed the discrimination of 12 milks with different characteristics.[1] C. Garcia-Cabezon, G.G. Teixeira, L.G. Dias, C. Salvo-Comino, C. García-Hernandez, M.L. Rodriguez-Mendez, F. Martin-Pedrosa, Analysis of phenolic content in grape seeds and skins by means of a bio-electronic tongue, Sensors (Switzerland). 20 (2020) 1–14. doi:10.3390/s20154176.[2] Lluis Pascual, Marisa Gras, Daniel Vidal-Brotóns, Miguel Alcañiz, Ramón Martínez-Máñez, Jose V.Ros-LisA voltammetric e-tongue tool for the emulation of the sensorial analysis and the discrimination of vegetal milks, Sensors and Actuators B: Chemical, Volume 270, 1 October 2018, Pages 231-238 Acknowledgments: We appreciate the financial support of MINECO-FEDER National Plan (PID2021-122365OB-100). Junta de Castilla y Leon- FEDER VA202P20. CLU-2019-04 and «Infrastructure Network of Castilla y León (INFRARED)» UVA01. Tractor Plan In Advanced Materials Focused On The Key Industrial Sectors In Castilla Y León: Agri-food, Transport, Energy And Construction (MA2TEC). We would also like to thank the Calidad Pascual farm (Aranda de Duero) for the loan of samples (ALIVAC-IDI-20211051).

Activation of lactoperoxidase system and its potential for microbial inhibition and preservation of milk in the Great African Rift Valley climate

Activation of lactoperoxidase system and its potential for microbial inhibition and preservation of milk in the Great African Rift Valley climate

E-beam irradiation of defatted liquid camel and cow milk fractions: Antiproliferative, antidiabetic and antioxidant activities

The aim of this work was to assess the suitability of electron beam (e-beam) irradiation (at 5, 10 and 20 kGy) to treat defatted liquid cow and camel milk and their whey and casein fractions. The different milk fractions were investigated for their antiproliferative, antidiabetic and antioxidant activities. Irradiated milk fractions did not indicate any cytotoxic effect on HEK293T cell line, except for sweet whey of cow milk treated at 20 kGy, the acid whey of camel milk treated at 5, 10 and 20 kGy and β casein of cow and camel milk treated at 10 and 20 kGy. The non-irradiated and irradiated whey fractions of camel milk and the irradiated β-casein of cow milk demonstrated anti-proliferative activity against A549 tumor cell line. Irradiated and non-irradiated whey fractions of camel and cow milk exhibited interesting inhibition percentage of α-amylase (varying from 73.24 ± 2.71% to 98.99 ± 0.84% for cow milk and from 64.68 ± 2.49% to 99.39 ± 0.17% for camel milk). Whey fractions seemed to be the most resistant to e-beam irradiation. Ebeam treatment (5–20 kGy) preserved or improved the DPPH radical scavenging activity of the majority of cow and camel milk fractions, ranging from 6.27 ± 0.74% to 59.75 ± 0.84%. Industrial relevanceThe present work highlighted the suitability of e-beam irradiation as safe and friendly treatment for the preservation of cow and camel milk and corresponding whey and casein fractions. E-beam treatment at 10 kGy seems to be effective treatment for whey of camel and cow milk, preserving or enhancing the antiproliferative, antioxidant and antidiabetic activities. Ebeam treatment at 5–10 kGy is suggested to be an emergent food preservation technology with the ability of preservation or promotion of milk bioactivity.