Ultrasonic processing: effects on the physicochemical and microbiological aspects of dairy products.

Dairy products that are contaminated by pathogenic microorganisms through unhygienic farm practices, improper transportation, and inadequate quality control can cause foodborne illness. Furthermore, inadequate storage conditions can increase the microflora of natural spoilage, leading to rapid deterioration. Ultrasound processing is a popular technology used to improve the quality of milk products using high-frequency sound waves. It can improve food safety and shelf life by modifying milk protein and fats without negatively affecting nutritional profile and sensory properties, such as taste, texture, and flavor. Ultrasound processing is effective in eliminating pathogenic microorganisms, such as Salmonella, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes. However, the efficiency of processing is determined by the type of microorganism, pH, and temperature of the milk product, the frequency and intensity of the applied waves, as well as the sonication time. Ultrasound processing has been established to be a safe and environmentally friendly alternative to conventional heat-based processing technologies that lead to the degradation of milk quality. There are some disadvantages to using ultrasound processing, such as the initial high cost of setting it up, the production of free radicals, the deterioration of sensory properties, and the development of off-flavors with lengthened processing times. The aim of this review is to summarize current research in the field of ultrasound processing and discuss future directions.

Listeria monocytogenes an Emerging Pathogen: a Comprehensive Overview on Listeriosis, Virulence Determinants, Detection, and Anti-Listerial Interventions.

Listeria monocytogenes, the third most deleterious zoonotic pathogen, is a major causative agent of animal and human listeriosis, an infection related to the consumption of contaminated food products. Even though, this pathogen has been responsible for the outbreaks of foodborne infections in the early 1980s, the major outbreaks have been reported during the past two decades. Listeriosis infection in the host is a rare but life-threatening disease with major public health and economic implications. Extensive reports on listeriosis outbreaks are associated with milk and milk products, meat and meat products, and fresh produce. This bacterium can adapt to any environmental and stress conditions, making it a prime causative agent for major foodborne diseases. The pathogen could survive an antibiotic treatment and persist in the host cell, thereby escaping the standard diagnostic practices. The current review strives to provide concise information on the epidemiology, serotypes, and pathogenesis of the L. monocytogenes to decipher the knowledge on the endurance of the pathogen inside the host and food products as a vehicle for Listeria contaminations. In addition, various detection methods for Listeria species from food samples and frontline regimens of L. monocytogenes treatment have also been discussed.

An indirect competitive biotin-streptavidin enzyme-linked immunosorbent assay for the determination of dimethyl phthalate (DMP) in milk and milk products.

After the "plasticizer event" in Taiwan, phthalic acid esters (PAEs) have been listed in "Inedible materials possibly added into food illegally" and "Commonly abused food additives." As one of the PAEs family, DMP has long been a problem of great concern due to its potential impacts on human health. In order to detect DMP with high sensitivity and specificity, a sensitive indirect competitive biotin-streptavidin enzyme-linked immunosorbent assay (BA-ELISA) has been established in this study. A high-titer rabbit polyclonal antibody (pAb-DMP) targeting DMP was obtained, and the procedures of BA-ELISA were optimized for the determination of DMP in milk and milk products. Under optimal conditions, good linearity was achieved within a range of 0.024 to 6.027 µg L(-1), with low cross-reactivity values for DMP structural analogues (lower than 10%). The median inhibitory concentration (IC50) was 0.356 µg L(-1) and the limit of detection (LOD) was 0.0082 µg L(-1). Finally, the concentrations of DMP in milk and milk products ranged from 1.03 µg kg(-1) to 7.23 µg kg(-1) by BA-ELISA. Satisfactory recoveries (90.26-112.38%) and coefficient of variation (CV) values (5.08-8.46%) were obtained. These results were consistent with those using gas chromatography-mass spectrometry (GC-MS), which further confirmed that the proposed BA-ELISA was accurate, specific, reliable and rapid for routine monitoring trace DMP residues in foodstuff, especially milk and milk products.

Mass spectrometry-based techniques for identification of compounds in milk and meat matrix.

Food including milk and meat is often viewed as the mixture of different components such as fat, protein, carbohydrates, moisture and ash, which are estimated using well-established protocols and techniques. However, with the advent of metabolomics, low-molecular weight substances, also known as metabolites, have been recognized as one of the major factors influencing the production, quality and processing. Therefore, different separation and detection techniques have been developed for the rapid, robust and reproducible separation and identification of compounds for efficient control in milk and meat production and supply chain. Mass-spectrometry based techniques such as GC-MS and LC-MS and nuclear magnetic resonance spectroscopy techniques have been proven successful in the detailed food component analysis owing to their associated benefits. Different metabolites extraction protocols, derivatization, spectra generated, data processing followed by data interpretation are the major sequential steps for these analytical techniques. This chapter deals with not only the detailed discussion of these analytical techniques but also sheds light on various applications of these analytical techniques in milk and meat products.

Milk ladder as a therapeutic option for cow's milk allergy: Proposal for a step-by-step plan for cow's milk introduction in cow's milk allergy.

In regard to cow's milk allergy, the current option of avoiding can be expanded by (re-)introducing milk using a milk ladder. So-called "food ladders" are internationally well known and utilized for both non-IgE-mediated and IgE-mediated cow's milk allergy. Stepping up the stairs from highly processed baked goods with milk via cooked milk products to pasteurized fresh milk reflects the status of acquired tolerance of each level. The allergenicity of milk depends on processing and amount. By implementing the milk ladder, it can enhance the clinical process of tolerance development, lead to meeting nutrient requirements quickly, and involve parents actively in the therapeutical process. The milk ladder, for the first time being published and adapted for Germany, describes a structured framework that might be adapted individually regarding the time period on a certain level or other variations such as preparation/amount of milk products. From a safety perspective, healthcare professionals should pay great attention to patient selection and education prior to implementing the milk ladder. Detailed advice as well as recipes and a graphical presentation can be found in the supplemental material.

Rapid and label-free detection of Brucella melitensis in milk and milk products using an aptasensor.

In this work, a novel quartz crystal microbalance (QCM) aptasensor is designed for the diagnosis of Brucella melitensis bacteria, which affects the Mediterranean fever (brucellosis) from the zoonotic diseases that are very common in the Middle East Countries. The method is based on the selection of B. melitensis bacterium from solutions using B. melitensis specific binding aptamer (Apt) attached magnetic nanoparticles. The surface of the magnetic nanoparticles (i.e.,Fe3O4) was modified by 3-aminopropyltriethoxysilane (APTES) and then grafted with a hydrophilic macromonomer poly(ethyleneglycol)-methacrylate (PEG-MA) as a first block polymer and glycidylmethacrylate (GMA) as a second block functional polymer via atom transfer radical polymerization (ATRP) method [Fe3O4 @SiO2 @p(PEG-MA-GMA)], then, the specific binding aptamer was immobilized. The aptamer immobilized magnetic nanoparticles were used for the pre-concentration of the target bacterium, and the same aptamer sequence was also immobilized on the QCM chip and used for the quantitative detection of B. melitensis using QCM aptasensor. The detection limits of the QCM aptasensor were in the range 1.02-1.07 CFU mL-1, with recoveries up to 79%. The synthesized [Fe3O4 @SiO2 @p(PEGMA-GMA)] nanoparticles showed a good permanence and high isolation recoveries for the pull down of the target bacterium from food samples, after recycling eight times. The method was successfully applied to target bacterium determinations in milk and milk product samples.

Screening of antibiotics and chemical analysis of penicillin residue in fresh milk and traditional dairy products in Oyo state, Nigeria.

BACKGROUND AND AIM: There are global public health and economic concerns on chemical residues in food of animal origin. The use of antibiotics in dairy cattle for the treatment of diseases such as mastitis has contributed to the presence of residues in dairy products. Penicillin residues as low as 1 ppb can lead to allergic reactions and shift of resistance patterns in microbial population as well as interfere with the processing of several dairy products. Antibiotic monitoring is an essential quality control measure in safe milk production. This study was aimed at determining antibiotic residue contamination and the level of penicillin in dairy products from Fulani cattle herds in Oyo State. MATERIALS AND METHODS: The presence of antibiotic residues in 328 samples of fresh milk, 180 local cheese (wara), and 90 fermented milk (nono) from Southwest, Nigeria were determined using Premi® test kit (R-Biopharm AG, Germany) followed by high-performance liquid chromatography analysis of penicillin-G residue. RESULTS: Antibiotic residues were obtained in 40.8%, 24.4% and 62.3% fresh milk, wara and nono, respectively. Penicillin-G residue was also detected in 41.1% fresh milk, 40.2% nono and 24.4% wara at mean concentrations of 15.22±0.61, 8.24±0.50 and 7.6±0.60 µg/L with 39.3%, 36.7% and 21.1%, respectively, containing penicillin residue above recommended Codex maximum residue limit (MRL) of 5 µg/L in dairy. There was no significant difference between the mean penicillin residues in all the dairy products in this study. CONCLUSION: The results are of food safety concern since the bulk of the samples and substantial quantities of dairy products in Oyo state contained violative levels of antibiotic residues including penicillin residues in concentrations above the MRL. This could be due to indiscriminate and unregulated administration of antibiotics to dairy cattle. Regulatory control of antibiotic use, rapid screening of milk and dairy farmers' extension education on alternatives to antibiotic prophylaxis, veterinary prescriptions and withdrawal periods are recommended to prevent residues.

Analysis of phthalates in milk and milk products by liquid chromatography coupled to quadrupole Orbitrap high-resolution mass spectrometry.

A new analytical method was developed and validated for simultaneous analysis of 27 phthalates in milk and milk products. Response surface methodology was employed to optimize a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation method. Ultrahigh-performance liquid chromatography and electrospray ionization quadrupole Orbitrap high-resolution mass spectrometry (UHPLC/ESI Q-Orbitrap) was used for the separation and detection of all the analytes. The method was validated by taking into consideration the guidelines specified in Commission Decision 2002/657/EC and 2007/19/EC. The extraction recoveries were in a range of 90.7% to 104.6%, with coefficient of variation <5.6%. The 27 compounds behave dynamic range in the 0.1-1000µgkg(-1) concentration, with correlation coefficient >0.99. The limits of detection for the analytes are in the range 0.32-2.6µgkg(-1). This method has been successfully applied on screening of phthalates in 96 commercial milk and milk product samples.

Effect of milk and milk products consumption on physical growth and bone mineral density in Korean adolescents.

This study was conducted to investigate the relationship among the current status of calcium intake from milk and milk products, physical growth and bone mineral density in 664 male and female middle school and high school students aged 15-17 years. In the study, the current status of calcium intake from milk and milk products was analyzed, and the height, body composition, and bone mineral density of the right heel bone (calcaneus) were measured. The daily calcium intake of milk and milk products was calculated as the 'dairy equivalent of calcium', which is the calcium content in 200 mL of white milk. The cutoffs of tertiles of the dairy equivalent of calcium were calculated and then the subjects were categorized into 3 groups according to the tertiles, Q1 group (lower intake group), Q2 group (middle intake group) and Q3 group (upper intake group). The daily calcium intake of milk and milk products in Q1, Q2 and Q3 groups was 16.2 mg, 99.7 mg, and 284.0 mg, respectively, and the ratio of milk and milk product consumption to the daily total calcium intake was 5.4%, 27.4%, and 49.7%, respectively. The ratio of total calcium intake to the daily recommended intake in study subjects was 30.5% in Q1, 42.3% in Q2, and 60.7% in Q3, with significant differences (P < 0.05). Height, body weight, BMI, and % of body fat in three tertile groups (Q1, Q2 and Q3) were not significantly different. However, the T scores for bone mineral density in female students in three tertile groups (Q1, Q2 and Q3) was significantly different (P < 0.05). The study showed that the intake of milk and milk products in adolescents, particularly in girls, can improve the bone mineral density without increasing body weight, and thus confirmed that milk intake is important in adolescence.