Cow's milk proteins/allergens

Screening of specific binding peptide for β-lactoglobulin using phage display technology

β-lactoglobulin (β-Lg) is a major food allergen, there is an urgent need to develop a rapid method for detecting β-Lg in order to avoid contact or ingestion by allergic patients. Peptide aptamers have high affinity, specificity, and stability, and have broad prospects in the field of rapid detection. Using β-Lg as the target, this study screened 11 peptides (P1-11) from a phage display library. Using molecular docking technology to predict binding energy and binding mode of proteins and peptides. Select the peptides with the best binding ability to β-Lg (P5, P7, P8) through ELISA. Combining them with whey protein, casein, and bovine serum protein, it was found that P7 has the best specificity for β-Lg, with an inhibition rate of 87.99%. Verified by molecular dynamics that P7 binds well with β-Lg. Therefore, this peptide can be used for the recognition of β-Lg, becoming a new recognition element for detecting β-Lg.

Allergen-specific B cell responses in oral immunotherapy-induced desensitization, remission, and natural outgrowth in cow's milk allergy

BACKGROUND

Antigen-specific memory B cells play a key role in the induction of desensitization and remission to food allergens in oral immunotherapy and in the development of natural tolerance (NT). Here, we characterized milk allergen Bos d 9-specific B cells in oral allergen-specific immunotherapy (OIT) and in children spontaneously outgrowing cow's milk allergy (CMA) due to NT.

METHODS

Samples from children with CMA who received oral OIT (before, during, and after), children who naturally outgrew CMA (NT), and healthy individuals were received from Stanford biobank. Bos d 9-specific B cells were isolated by flow cytometry and RNA-sequencing was performed. Protein profile of Bos d 9-specific B cells was analyzed by proximity extension assay.

RESULTS

Increased frequencies of circulating milk allergen Bos d 9-specific B cells were observed after OIT and NT. Milk-desensitized subjects showed the partial acquisition of phenotypic features of remission, suggesting that desensitization is an earlier stage of remission. Within these most significantly expressed genes, IL10RA and TGFB3 were highly expressed in desensitized OIT patients. In both the remission and desensitized groups, B cell activation-, Breg cells-, BCR-signaling-, and differentiation-related genes were upregulated. In NT, pathways associated with innate immunity characteristics, development of marginal zone B cells, and a more established suppressor function of B cells prevail that may play a role in long-term tolerance. The analyses of immunoglobulin heavy chain genes in specific B cells demonstrated that IgG2 in desensitization, IgG1, IgA1, IgA2, IgG4, and IgD in remission, and IgD in NT were predominating. Secreted proteins from allergen-specific B cells revealed higher levels of regulatory cytokines, IL-10, and TGF-β after OIT and NT.

CONCLUSION

Allergen-specific B cells are essential elements in regulating food allergy towards remission in OIT-received and naturally resolved individuals.

A rapid immunomagnetic beads-based sELISA method for the detection of bovine αs1-casein based on specific epitopes

Although αs1-casein poses significant health risks to individuals with milk allergies, the availability of quantification methods for this allergen remains limited. In this study, we developed an immunomagnetic beads-based immunoassay (IMBs-ELISA) for the precise quantitative detection of bovine αs1-CN, specifically targeting epitope AA173-194. No cross-reactivity was observed with the other 7 food allergens including milk allergen. The linear detection range of the established IMBs-ELISA method was 0.125 μg/mL-2.000 μg/mL, with a limit of detection of 0.099 μg/mL. The accuracy of this method was 1.048 %, and the intra-plate and inter-plate precision achieved 4.100 % and 6.777 %, respectively. Notably, the entire IMBs-ELISA process could be completed within 75 min, representing a substantial time-saving advantage over traditional ELISA methods. These results proved the reliability and rapidity of the IMBs-ELISA method for detecting αs1-CN in real food.

Emerging Parameters Justifying a Revised Quality Concept for Cow Milk

Milk has become a staple food product globally. Traditionally, milk quality assessment has been primarily focused on hygiene and composition to ensure its safety for consumption and processing. However, in recent years, the concept of milk quality has expanded to encompass a broader range of factors. Consumers now also consider animal welfare, environmental impact, and the presence of additional beneficial components in milk when assessing its quality. This shifting consumer demand has led to increased attention on the overall production and sourcing practices of milk. Reflecting on this trend, this review critically explores such novel quality parameters, offering insights into how such practices meet the modern consumer's holistic expectations. The multifaceted aspects of milk quality are examined, revealing the intertwined relationship between milk safety, compositional integrity, and the additional health benefits provided by milk's bioactive properties. By embracing sustainable farming practices, dairy farmers and processors are encouraged not only to fulfill but to anticipate consumer standards for premium milk quality. This comprehensive approach to milk quality underscores the necessity of adapting dairy production to address the evolving nutritional landscape and consumption patterns.

Metabolic Syndrome and Biotherapeutic Activity of Dairy (Cow and Buffalo) Milk Proteins and Peptides: Fast Food-Induced Obesity Perspective-A Narrative Review

Metabolic syndrome (MS) is defined by the outcome of interconnected metabolic factors that directly increase the prevalence of obesity and other metabolic diseases. Currently, obesity is considered one of the most relevant topics of discussion because an epidemic heave of the incidence of obesity in both developing and underdeveloped countries has been reached. According to the World Obesity Atlas 2023 report, 38% of the world population are presently either obese or overweight. One of the causes of obesity is an imbalance of energy intake and energy expenditure, where nutritional imbalance due to consumption of high-calorie fast foods play a pivotal role. The dynamic interactions among different risk factors of obesity are highly complex; however, the underpinnings of hyperglycemia and dyslipidemia for obesity incidence are recognized. Fast foods, primarily composed of soluble carbohydrates, non-nutritive artificial sweeteners, saturated fats, and complexes of macronutrients (protein-carbohydrate, starch-lipid, starch-lipid-protein) provide high metabolic calories. Several experimental studies have pointed out that dairy proteins and peptides may modulate the activities of risk factors of obesity. To justify the results precisely, peptides from dairy milk proteins were synthesized under in vitro conditions and their contributions to biomarkers of obesity were assessed. Comprehensive information about the impact of proteins and peptides from dairy milks on fast food-induced obesity is presented in this narrative review article.

Assessing and Comparing Potential Allergenicity of Two Partially Hydrolyzed Whey-Based Formulas for Infants: A Population-Based Study in China

SCOPE

In cases where breast milk is unavailable or inadequate, hydrolyzed infant formula is recommended as the primary alternative. The aim of this study is to assess and compare the allergenicity of two partially hydrolyzed whey-based formulas (PHF-Ws) using serum samples from patients with cow's milk allergy (CMA).

METHODS AND RESULTS

LC-MS/MS technology is used to investigate the peptide distribution in both samples. The immunoreactivity of two PHF-Ws in 27 serum samples from 50 Chinese infants (02 years) with CMA is analyzed. The results demonstrate that even with a similar a degree of hydrolysis (DH), primary protein sources, peptides with molecular weights <5 kDa, and differences in the number of residual allergenic epitopes in the hydrolyzed peptide segments can lead to varying immune responses.

CONCLUSION

The two PHF-Ws have notably high intolerance rates, exceeding 10% among infants with CMA. Therefore, suggesting that PHF-Ws may not be suitable for infants and children with CMA in China.

Effect of lactic acid bacteria fermentation on cow milk allergenicity and antigenicity: A review

Cow milk is a major allergenic food. The potential prevention and treatment effects of lactic acid bacteria (LAB)-fermented dairy products on allergic symptoms have garnered considerable attention. Cow milk allergy (CMA) is mainly attributed to extracellular and/or cell envelope proteolytic enzymes with hydrolysis specificity. Numerous studies have demonstrated that LAB prevents the risk of allergies by modulating the development and regulation of the host immune system. Specifically, LAB and its effectors can enhance intestinal barrier function and affect immune cells by interfering with humoral and cellular immunity. Fermentation hydrolysis of allergenic epitopes is considered the main mechanism of reducing CMA. This article reviews the linear epitopes of allergens in cow milk and the effect of LAB on these allergens and provides insight into the means of predicting allergenic epitopes by conventional laboratory analysis methods combined with molecular simulation. Although LAB can reduce CMA in several ways, the mechanism of action remains partially clarified. Therefore, this review additionally attempts to summarize the main mechanism of LAB fermentation to provide guidance for establishing an effective preventive and treatment method for CMA and serve as a reference for the screening, research, and application of LAB-based intervention.

A comprehensive review on glycation and its potential application to reduce food allergenicity

Food allergens are a major concern for individuals who are susceptible to food allergies and may experience various health issues due to allergens in their food. Most allergenic foods are subjected to heat treatment before being consumed. However, thermal processing and prolonged storage can cause glycation reactions to occur in food. The glycation reaction is a common processing method requiring no special chemicals or equipment. It may affect the allergenicity of proteins by altering the structure of the epitope, revealing hidden epitopes, concealing linear epitopes, or creating new ones. Changes in food allergenicity following glycation processing depend on several factors, including the allergen's characteristics, processing parameters, and matrix, and are therefore hard to predict. This review examines how glycation reactions affect the allergenicity of different allergen groups in allergenic foods.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

Review: Genetic and protein variants of milk caseins in goats

The milk casein genes in goats, are highly polymorphic genes with numerous synonymous and non-synonymous mutations. So far, 20 protein variants have been reported in goats for alpha-S1-casein, eight for beta-casein, 14 for alpha-S2-casein, and 24 for kappa-casein. This review provides a comprehensive overview on identified milk casein protein variants in goat and non-coding DNA sequence variants with some affecting the expression of the casein genes. The high frequency of some casein protein variants in different goat breeds and geographical regions might reflect specific breeding goals with respect to milk processing characteristics, properties for human nutrition and health, or adaptation to the environment. Because protein names, alongside the discovery of protein variants, go through a historical process, we linked old protein names with new ones that reveal more genetic variability. The haplotypes across the cluster of the four genetically linked casein genes are recommended as a valuable genetic tool for discrimination between breeds, managing genetic diversity within and between goat populations, and breeding strategies. The enormous variation in the casein proteins and genes is crucial for producing milk and dairy products with different properties for human health and nutrition, and for genetic improvement depending on local breeding goals.

Nutritional Profile, Processing and Potential Products: A Comparative Review of Goat Milk

Goat milk contains an abundance of different macro and micro-nutrients. Compared with other milk, goat milk is a viable option due to its low allergy levels and is preferred for infants with cow milk allergies. A wide variety of goat milk-based products, including yoghurt, ice cream, fermented milk, and cheese, are available on the market. They are produced using effective processing technology and are known to exhibit numerous health benefits after consumption. However, goat milk consumption is limited in many nations (compared with cow, buffalo, camel, and sheep milk) due to a lack of awareness of its nutritional composition and the significance of its different byproducts. This review provides a detailed explanation of the various macronutrients that may be present, with special attention paid to each component, its purpose, and the health benefits it offers. It also compares goat milk with milk from other species in terms of its superiority and nutritional content, as well as the types, production methods, health advantages, and other beneficial properties of the various goat milk products that are currently available on the market.

Probiotication of Nutritious Fruit and Vegetable Juices: An Alternative to Dairy-Based Probiotic Functional Products

Fruits and vegetables are widely known to be rich in nutrients, antioxidants, vitamins, dietary fiber, minerals, and a bioactive molecule, making them an essential component of a balanced diet with multiple documented positive effects on human health. The probiotication of plant-based juices for the production of functional and nutraceutical food serves as a healthy alternative to dairy probiotics. They are cholesterol free, lack several dairy allergens, and also encourage ingestion for people with lactose intolerance. This review highlights valuable claims regarding the efficacy of different probiotic strains on various diseases. A comprehensive nutrition comparison and the preference of plant-based over dairy probiotic drinks is also discussed, supported with updated market trends of probiotic drinks (dairy and non-dairy based). An extensive compilation of current plant-based probiotic drinks that are available in markets around the world is listed as a reference. The fermentability of carbon sources by probiotic microorganisms is crucial in addressing the development of plant-based drinks. Therefore, the pathway involved in metabolism of sucrose, glucose, fructose, and galactose in fruit and vegetable juice was also underlined. Finally, the key factors in monitoring the quality of probiotic products such as total soluble solids, sugar consumption, titratable acidity, pH, and stability at low storage temperatures were outlined.

Food allergen ladders: A need for standardization

INTRODUCTION

The process of gradually reintroducing food allergens into an individual's diet is referred to as food allergen "ladders". There remain many questions regarding the foods chosen, structure and composition of the ladder, and medical and safety considerations. The COVID-19 pandemic has propelled us into an era where medicine is increasingly practiced via online platforms, highlighting the need for standardized food allergen ladder approaches for successful and safe introduction of food allergens.

METHODS

We performed a search of currently published food allergen ladders and obtained published information and clinical expertise to summarize current knowledge and suggest future standardized approaches for using food allergen ladders.

RESULTS

There are currently a limited number of published milk, egg, wheat, and soy ladders. We suggest the following points should be considered when developing food ladders: (1) Food allergen: dose, time, and temperature of heating of the food allergen, simplicity of the ladder and recipes, the possible role of the wheat matrix, and testing for allergenic protein levels to standardize doses; (2) Nutritional factors: health and nutritional value of the foods in the ladder, taste, texture, and cultural appropriateness of foods should be considered; and (3) Medical aspects: consideration of which patients are safe to undergo ladders outside of the clinical setting, other safety aspects and risk factors for severe reactions, number of days suggested per steps, and availability and provision of rescue medication. Written instructions and recipes should be provided to families who wish to use food allergen ladders.

DISCUSSION

Food allergen ladders used for gradual reintroduction of food allergens into a food allergic individual's diet are increasingly being used internationally. Standardization regarding the foods included in the ladder and medical considerations are required to practice patient-centered care, best assist patients and families, and ensure safety.

Selecting processing robust markers using high resolution mass spectrometry for the detection of milk in food products

BACKGROUND

Cow's milk allergy is one of the most reported food allergies in Europe. To help patients suffering from food allergies it is important to be able to detect milk in different foods. An analytical method that is gaining interest in the field of allergen detection is Ultra-High Performance Liquid Chromatography-tandem Mass Spectrometry, where the analyte is a target peptide. When these peptide biomarkers are selected the effect of food processing should be taken into account to allow a robust detection method.

OBJECTIVE

This works aims at identifying such processing stable peptide markers for milk for the Ultra-High Performance Liquid Chromatography-tandem Mass Spectrometry based detection of food allergens in different food products.

METHODS

Milk-incurred food materials that underwent several processing techniques were produced. This was followed by establishing tryptic peptide profiles from each matrix using Ultra-High Performance Liquid Chromatography-High Resolution Mass Spectrometry .

RESULT

A careful comparison of peptide profiles/intensities and the use of specific exclusion criteria resulted in the selection of 8 peptide biomarkers suitable for application in Ultra-High Performance Liquid Chromatography-tandem Mass Spectrometry based milk detection methods. One of these markers is a α-lactalbumin specific peptide, which has been determined to be stable in different incurred materials for the first time.

CONCLUSION

To our knowledge, this is the first systematic and experimentally based approach for the selection of suitable milk peptide biomarkers robust towards multiple, often applied food processing techniques for milk. Ensuring the exact knowledge of the food processing circumstances by starting from well-defined raw material and using fully controlled settings to produce incurred test material allowed the construction of a peptide database with robust markers. These robust markers can be used for the development of a robust detection method for milk in different food matrices.

Effects of Cow's Milk Components, Goat's Milk and Sheep's Milk Sensitivities on Clinical Findings, and Tolerance Development in Cow's Milk Allergy

Objective:

Cow’s milk (CM) contains some proteins capable of causing an allergic reaction in a sensitized individual and one of the most common causes of food allergy in childhood. Most of the patients will develop tolerance by the age of 3. In this study, we aimed to evaluate sensitivity to CM allergen components as well as goat’s milk (GM) and sheep’s milk cross reactions in cow’s milk allergic (CMA) patients and to figure out the risk factors for tolerance non-development.

Methods:

This is a retrospective cross-sectional study including 66 patients for IgE-mediated CMA with mean age of 38 months. We evaluated the patients in two groups: Group 1 (n=50): Patients who have no tolerance in oral food challenge test; Group 2 (n= 16): Patients who were found tolerant to CM after elimination diet. Cow’s milk-spesific IgE(sIgE), α-lactalbumin(ALA)-sIgE, β-Lactoglobulin(BLG)-sIgE, casein-sIgE, goat’s milk-sIgE, sheep’s milk-sIgE, skin prick tests(SPTs) with CM and GM, eosinophils in peripheral blood were all compared between two groups.

Results:

In the whole group, goat’s milk-sIgE and sheep’s milk-sIgE were positive in 84.8% and ALA-sIgE, BLG-sIgE, casein-sIgE were positive in 69.7%, 62.7%, 77.3% of the patients, respectively. Two groups were similar in terms of age at onset and diagnosis, gender, median elimination period, total IgE levels, cow’s milk-sIgE and eosinophilia (p>0.05). Mean wheal diameters of CM and GM in SPT (p<0.001), goat’s milk-sIgE (p=0.03), sheep’s milk-sIgE (p=0.01) were significantly higher in Group 1. Cow’s milk-sIgE showed a positive correlation with total IgE (p=0.001), eosinophilia percentage (p=0.04), CM wheal diameter in SPT (p=0.001), casein-sIgE (p<0.001), goat’s milk-sIgE (p<0.001), sheep’s milk-sIgE (p<0.001) in Group 1. Patients with respiratory symptoms and history of anaphylaxis had higher cow’s milk-SPT, cow’s milk-sIgE, casein-sIgE, goat’s milk-sIgE, sheep’s milk-sIgE levels(p<0.05). Gastrointestinal and skin symptoms showed no relation with laboratory findings. Any patient with a history of anaphylaxis did not develop tolerance.

Conclusions:

As with cow’s milk-sIgE levels and high induration diameters in SPT; high casein-sIgE, sheep’s milk-sIgE and goat’s milk-sIgE levels are also risk factors for persistence of CMA. Anaphylaxis, as a first reaction, may also be a risk factor. High cow’s milk-sIgE, casein-sIgE, sheep’s milk-sIgE, goat’s milk-sIgE levels are associated with respiratory symptoms.

A Response Surface Methodology (RSM) Approach for Optimizing the Attenuation of Human IgE-Reactivity to β-Lactoglobulin (β-Lg) by Hydrostatic High Pressure Processing

The response surface methodology (RSM) and central composite design (CCD) technique were used to optimize the three key process parameters (i.e., pressure, temperature and holding time) of the high-hydrostatic-pressure (HHP) processing either standalone or combined with moderate thermal processing to modulate molecular structures of β-lactoglobulin (β-Lg) and α-lactalbumin (α-La) with reduced human IgE-reactivity. The RSM model derived for HHP-induced molecular changes of β-Lg determined immunochemically showed that temperature (temp), pressure (p²) and the interaction between temperature and time (t) had statistically significant effects (p < 0.05). The optimal condition defined as minimum (β-Lg specific) IgG-binding derived from the model was 505 MPa at 56 °C with a holding time of 102 min (R² of 0.81 and p-value of 0.01). The validation carried at the optimal condition and its surrounding region showed that the model to be underestimating the β-Lg structure modification. The molecular change of β-Lg was directly correlated with HHP-induced dimerization in this study, which followed a quadratic equation. The β-Lg dimers also resulted in the undetectable human IgE-binding.

Whey allergens: Influence of nonthermal processing treatments and their detection methods

Whey and its components are recognized as value-added ingredients in infant formulas, beverages, sports nutritious foods, and other food products. Whey offers opportunities for the food industrial sector to develop functional foods with potential health benefits due to its unique physiological and functional attributes. Despite all the above importance, the consumption of whey protein (WP) can trigger hypersensitive reactions and is a constant threat for sensitive individuals. Although avoiding such food products is the most successful approach, there is still a chance of incorrect labeling and cross-contamination during food processing. As whey allergens in food products are cross-reactive, the phenomenon of homologous milk proteins of various species may escalate to a more serious problem. In this review, nonthermal processing technologies used to prevent and eliminate WP allergies are presented and discussed in detail. These processing technologies can either enhance or mitigate the impact of potential allergenicity. Therefore, the development of highly precise analytical technologies to detect and quantify the existence of whey allergens is of considerable importance. The present review is an attempt to cover all the updated approaches used for the detection of whey allergens in processed food products. Immunological and DNA-based assays are generally used for detecting allergenic proteins in processed food products. In addition, mass spectrometry is also employed as a preliminary technique for detection. We also highlighted the latest improvements in allergen detection toward biosensing strategies particularly immunosensors and aptasensors.

Investigation of the effects of some processing conditions on the fate of oxytetracycline and tylosin antibiotics in the making of commonly consumed cheeses from the East Mediterranean

Background and Aim:

Transfer of antibiotics from raw milk to derived products is directly related to the processes involved in the manufacturing of dairy products, including East Mediterranean cheeses, since these have particular flow diagrams of production. The aim of this study was to assess the effects of skimming, pasteurization, curding, pressing, salting, cheese boiling, and whey acidification/heating on two widely used antibiotics in Lebanon, oxytetracycline (OTC) and tylosin (TYL), in the manufacture of commonly consumed cheeses in the East Mediterranean.

Materials and Methods:

Four hundred and fifty kilograms of full-fat bovine milk were spiked with OTC and TYL, then skimmed and pasteurized using holder and high-temperature short-time (HTST) methods. Milk was then processed to make cheeses (23 kg Baladi, 20 kg Akkawi, 20 kg Halloum, and 18 kg Double Cream). Liquid chromatography–mass-spectrometry was used to measure antibiotics. Analysis was performed using Statistical Package for the Social Sciences v25.

Results:

Skimming significantly (p=0.015) decreased TYL concentration by 68.6%. OTC degradation during holder (41-54%) proved to be significant (p=0.015). HTST had a significant (p=0.012) effect on TYL with 32% degradation. Curding step in making Baladi had a significant (p=0.028) effect on OTC only with the concentration increasing by 1.5-fold. Acidification and heating of whey to produce Double Cream decreased significantly (p=0.037) OTC concentration (14.7-46.3%), while TYL concentration increased significantly (p=0.000) by 300%. Pressing and salting in making Akkawi did not have any significant effect, while cheese boiling in making Halloum significantly decreased both antibiotics.

Conclusion:

OTC is transferred to Baladi and Akkawi (curd based) mainly, while double cream (whey based) has a high level of TYL transfer. Hence, people who consume these cheeses excessively could be exposed to high amounts of both antibiotics and thus be prone to their detrimental effect on health.

The conformational structural change of β-lactoglobulin via acrolein treatment reduced the allergenicity

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Acrolein induced structural changes through the cross-linking of BLG.

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The IgE binding capacity of BLG was reduced upon acrolein treatment.

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Stimulation with acrolein-treated BLG decreased RBL-2H3 cells degranulation rates.

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BLG-specific IgE/IgG1, histamine and mMCP-1 levels were reduced in mice model.

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Structural changes resulted in reduction of BLG allergenicity by lipid peroxidation.

β-lactoglobulin (BLG) is a major allergen of milk. Since lipid peroxidation such as acrolein commonly exists during milk processing, it is necessary to evaluate its influence on BLG structure and potential allergenicity. The structure of acrolein-treated BLG was detected using SDS-PAGE, fluorescence, ultraviolet spectrum (UV), circular dichroism (CD) and LC-MS-MS, and the potential allergenicity was assessed by in vitro and in vivo assays. Results showed that acrolein could cause structural changes by BLG aggregation, which decreased the IgE binding capacity. Further, the release of mediators and cytokines decreased with acrolein treatment in RBL-2H3 cells. Mice showed lower allergenicity by the levels of BLG-specific antibody and the release of histamine and mMCP-1. These results explained that acrolein-induced BLG aggregation could damage the allergic epitopes and decrease the allergenicity of BLG in milk. The study will provide a new aspect to explore the natural phenomenon of allergen changes during food processing.

Cow's Milk Processing-Friend or Foe in Food Allergy?

Cow’s milk (CM) is an integral part of our daily diet starting in infancy and continuing throughout our lifetime. Its composition is rich in proteins with a high nutritional value, bioactive components, milk minerals including calcium, and a range of immunoactive substances. However, cow’s milk can also induce a range of immune-mediated diseases including non-IgE-mediated food allergies and IgE-mediated food allergies. Cow’s milk allergens have been identified and characterized and the most relevant ones can be assigned to both, the whey and casein fraction. For preservation a range of processing methods are applied to make cow’s milk and dairy products safe for consumers. However, these methods affect milk components and thus alter the overall immunogenic activity of cow’s milk. This review summarizes the current knowledge on cow’s milk allergens and immunoactive substances and the impact of the different processes up- or downregulating the immunogenicity of the respective proteins. It highlights the gaps of knowledge of the related disease mechanisms and the still unidentified beneficial immunomodulating compounds of cow’s milk.

Variation in Infant Formula Macronutrient Ingredients Is Associated with Infant Anthropometrics

Background: There is wide variation in the macronutrient ingredient base of infant formula. How variation in macronutrient ingredients may impact infant growth remains largely unknown. Methods: The 2015–2016 National Health and Nutrition Examination Survey (NHANES) dataset was utilized, including infant anthropometrics and dietary intake. The protein, fat, and carbohydrate sources of formulas consumed were assembled and considered as potential predictors in multivariable models of infant Z-scores among infants < 6 months, 6–12 months and all infants combined (0–12 months). Results: The following relationships represent ingredient covariates within the final multivariable models of infant Z-scores. Consuming formula with palm oil was associated with higher weight-for-length Z-scores among infants < 6 months, but lower weight-for-age and weight-for-length Z-scores among infants 6–12 months. Consuming soy-protein formulas was associated with lower weight-for-length, head circumference-for-age and abdominal circumference-for-age Z-scores among infants < 6 months. Consuming sucrose-containing formula was associated with higher weight-for-length and abdominal circumference-for-age Z-score among infants 0–12 months. Conclusions: These data provide proof-of-concept that all formulas are not the same. Variation in macronutrient ingredients within the standard formula category is associated with differences in infant anthropometric outcomes. Long-term and mechanistic studies are warranted to pursue these findings; especially for palm oil, soy protein, and sucrose.

Influence of whey protein hydrolysis in combination with dextran glycation on immunoglobulin E binding capacity with blood sera obtained from patients with a cow milk protein allergy

Food protein allergies are a major global concern. Hydrolysis of food proteins reduces their allergenicity, but another novel approach is the covalent attachment of polysaccharides to proteins via the Maillard reaction (i.e., glycation), which blocks some IgE binding epitopes on the protein allergen. We wanted to examine whether enzymatic hydrolysis, combined with glycation, could further reduce IgE binding for people with a cow milk protein allergy. Whey protein isolate (WPI) was hydrolyzed by immobilized trypsin and chymotrypsin to degree of hydrolysis (DH) values of 17 to 27%. Immobilized enzymes were used to avoid heat-treating the hydrolysate (to inactivate the enzymes, because heating could also affect the IgE binding ability of the protein). The resultant whey protein isolate hydrolysates (WPIH) were then glycated with 10-kDa dextran (DX) in aqueous solutions held at 62°C for 24 h. We analyzed the molar mass (M_W) of WPIH samples and their corresponding glycates (WPIH-DX) using size-exclusion chromatography with multi-angle laser light scattering. We obtained blood sera from 8 patients who had been diagnosed with a cow milk protein allergy, and we used a composite serum for IgE binding analysis. The average M_W values of samples WPIH-1 to WPIH-3 decreased from 11.15, 9.46, and 7.57 kDa with increasing DH values of 18.7, 22.5, and 27.1%. Glycation significantly reduced the high bitterness of the WPIH samples, as assessed by a trained sensory panel. The WPIH-DX glycates had significantly reduced WPI-specific IgE binding capacity compared to WPI or unglycated WPIH; we found an almost 99% reduction in IgE binding for the WPIH-DX glycate made from WPIH with a DH value of 27.1%. Hydrolysis of WPI followed by glycation with DX via the Maillard reaction significantly decreased the allergenicity of whey proteins.

Surface plasmon resonance (SPR) biosensors for food allergen detection in food matrices

Food allergies are recognized as a growing public health concern, with an estimated 3% of adults and 6-8% of children affected by food allergy disorders. Hence, food allergen detection, labeling, and management have become significant priorities within the food industry, and there is an urgent requirement for reliable, sensitive, and user-friendly technologies to trace food allergens in food products. In this critical review, we provide a comprehensive overview of the principles and applications of surface plasmon resonance (SPR) biosensors in the identification and quantification of food allergens (milk, egg, peanut, and seafood), including fiber-optic surface plasmon resonance (FOSPR), surface plasmon resonance imaging (SPRI), localized surface plasmon resonance (LSPR), and transmission surface plasmon resonance (TSPR). Moreover, the characteristics and fitness-for-purpose of each reviewed SPR biosensor is discussed, and the potential of newly developed SPR biosensors for multi-allergen real-time detection in a complex food system is highlighted. Such SPR biosensors are also required to facilitate the reliable, high-throughput, and real-time detection of food allergens by the food control industry and food safety control officials to easily monitor cross-contamination during food processing.

Component resolved diagnostic study of cow's milk allergy in infants and young children in northern China

BACKGROUND

Increasing dairy consumption in China has been accompanied by rising incidence of milk allergy. Here we analyzed profiles of specific immunoglobulin E (sIgE) against cow's milk proteins, and assessed their value for milk allergy diagnosis among infants and young children from northern China.

METHODS

Sera collected from 48 patients with milk allergy and 27 negative control subjects was analyzed by enzyme-linked immunosorbent assay to measure sIgE to α-lactalbumin (Bos d 4), β-lactoglobulin (Bos d 5), α-casein (Bos d 9), β-casein (Bos d 11), and κ-casein (Bos d 12).

RESULTS

Among milk-allergic individuals, most were sensitized to at least one milk protein; about half were sensitized to Bos d 5, Bos d 9, Bos d 11 and Bos d 12, respectively, while few had positive serum sIgE against Bos d 4. Bos d 12 sIgE had the largest area under curve (AUC) (0.878; 95% CI, 0.800-0.957) and thus showed the best diagnostic performance in discriminating between milk-allergic and non-milk allergic patients, with a sensitivity of 92.6% and specificity of 72.9% using a statistically optimal cut-off value (OD_450nm, 0.191). The combinations of Bos d 5 + Bos d 12 showed an AUC of 0.926, which was larger than for any individual components.

CONCLUSIONS

Our results revealed inter-individual variation in the sensitization to different milk allergen component. Bos d 12 sIgE showed best performance in diagnosing milk allergy. Milk allergy diagnostic accuracy was further improved using combinations of milk allergen components by application of ROC curves based on logistic regression.

Glycation of whey protein with dextrans of different molar mass: Effect on immunoglobulin E-binding capacity with blood sera obtained from patients with cow milk protein allergy

A growing concern around the world is the number of people who are suffering from food protein allergies. One potential approach to decrease protein allergenicity is to block IgE-binding epitopes of the protein allergen by attachment of polysaccharides via the Maillard reaction (i.e., glycation). Protein glycation has been extensively studied to modify various functional properties. We wanted to examine whether glycates could reduce IgE binding in patients with cow milk protein allergy and to explore how the size (molar mass; M_W) of the polysaccharide affects this IgE-binding capacity. Glycation was performed using the initial step of the Maillard reaction performed in aqueous solutions. The specific goal of this study was to reduce the IgE-binding capacity of whey protein isolate (WPI) through glycation with dextran (DX). Blood sera were obtained from 8 patients who had been diagnosed with cow milk protein allergy, and a composite sera sample was used for IgE-binding analysis by the ImmunoCap (Phadia, Uppsala, Sweden) method. The WPI was glycated with DX of M_W ranging from 1 to 2,000 kDa, and the M_W of purified glycates was determined using size-exclusion chromatography coupled with multiangle laser light scattering. The WPI to DX molar ratios in the glycates made from DX that had M_W values of 1, 3.5, 10 (G10), 150, 500, and 2,000 kDa were 1:4, 1:3, 1:2, 1:1.5, 1:1, and 1:1, respectively. With the increase in the M_W of DX, there was an increase in the M_W values of the corresponding glycates but a decrease in the number of bound DX. The WPI-DX glycates had lower whey protein IgE-binding capacity than native WPI, with the lowest IgE-binding capacity obtained in the G10 glycate. The DX binding ratios and morphology results from atomic force microscopy images suggested that glycation of WPI with small-M_W DX resulted in extensive protein surface coverage, probably due to the attachment of up to 4 DX molecules per whey protein. The lower IgE binding of the G10 glycate was likely due to greater steric hindrance (or a physical barrier) at the surface of the protein. In summary, our results demonstrate that glycating WPI with DX via Maillard reaction can potentially be used to decrease the allergenicity of whey protein.

Modification of IgE binding to αS1-casein by proteolytic activity of Enterococcus faecium isolated from Iranian camel milk samples

Milk is a perfect source of nutrients for neonates. When breast feeding cannot be done, an infant's alimentation is usually initiated to cow's milk, among the primary foods. It has been reported that about 2.5% of juveniles under the age of 3 years manifest allergic reactions to cow's milk proteins. Among the cow's milk proteins, casein fractions are considered as the strongest allergenic proteins. The proteolytic enzymes of lactic acid bacteria (LAB), during fermentation of dairy products, can break down milk proteins especially caseins and subsequently reduce the immune reactivity of allergenic proteins. In this research, raw bovine and camel milk samples were screened for cocci LAB strains and after isolation, their proteolytic activity against bovine milk caseins were evaluated by SDS-PAGE and RP-HPLC. The potential of cocci LAB strains on α_S1-casein degradation and their potential to break down the principle allergenic epitopes of this protein was detected using indirect competitive ELISA. Molecular identification of the best proteolytic strain was fulfilled by 16S rDNA fragment sequencing with universal primers. The obtained results demonstrated that Enterococcus faecium isolated from raw camel milk samples was the most efficient isolate in hydrolyzing Na-caseinate and α_S1-casein. Hydrolysated α_S1-casein by Enterococcus faecium was also less recognized by IgE of bovine milk allergic patients' sera in comparison with native α_S1-casein. It has been proposed that Enterococcus faecium could be an efficient strain in allergenicity reduction of cow's milk proteins. So it could be an excellent candidate to be potentially used in dairy industries.

Polymorphism at donkey β-lactoglobulin II locus: identification and characterization of a new genetic variant with a very low expression

In the last years, donkey milk had evidenced a renewed interest as a potential functional food and a breast milk substitute. In this light, the study of the protein composition assumes an important role. In particular, β-lactoglobulin (β-LG), which is considered as one of the main allergenic milk protein, in donkey species consists of two molecular forms, namely β-LG I and β-LG II. In the present research, a genetic analysis coupled with a proteomic approach showed the presence of a new allele, here named F, which is apparently associated with a null or a severely reduced expression of β-LG II protein. The new β-LG II F genetic variant shows a theoretical average mass (M_av) of 18,310.64 Da, a value practically corresponding with that of the variant D (∆_mass < 0.07 Da), but differs from β-LG II D for two amino acid substitutions: Thr¹⁰⁰ (variant F) → Ala¹⁰⁰ (variant D) and Thr¹¹⁸ (variant F) → Met¹¹⁸ (variant D). Proteomic investigation of the whey protein fraction of an individual milk sample, homozygous FF at β-LG II locus, allowed to identify, as very minor component, the new β-LG II F genetic variant. By MS/MS analysis of enzymatic digests, the sequence of the β-LG II F was characterized, and the predicted genomic data confirmed.

Analysis of Protein-Phenolic Compound Modifications Using Electrochemistry Coupled to Mass Spectrometry

In the last decade, electrochemical oxidation coupled with mass spectrometry has been successfully used for the analysis of metabolic studies. The application focused in this study was to investigate the redox potential of different phenolic compounds such as the very prominent chlorogenic acid. Further, EC/ESI-MS was used as preparation technique for analyzing adduct formation between electrochemically oxidized phenolic compounds and food proteins, e.g., alpha-lactalbumin or peptides derived from a tryptic digestion. In the first step of this approach, two reactant solutions are combined and mixed: one contains the solution of the digested protein, and the other contains the phenolic compound of interest, which was, prior to the mixing process, electrochemically transformed to several oxidation products using a boron-doped diamond working electrode. As a result, a Michael-type addition led to covalent binding of the activated phenolic compounds to reactive protein/peptide side chains. In a follow-up approach, the reaction mix was further separated chromatographically and finally detected using ESI-HRMS. Compound-specific, electrochemical oxidation of phenolic acids was performed successfully, and various oxidation and reaction products with proteins/peptides were observed. Further optimization of the reaction (conditions) is required, as well as structural elucidation concerning the final adducts, which can be phenolic compound oligomers, but even more interestingly, quite complex mixtures of proteins and oxidation products.

Protein Digestion of Baby Foods: Study Approaches and Implications for Infant Health

Protein digestion is critical for infants. Dissimilarities between infants and adults in food intake and digestive physiology lead to distinct patterns of proteolysis between individuals. However, such differences are not well represented in many studies on protein digestion of baby foods. The complex biological structures of baby foods and the physiology of the infant digestive system are key factors affecting proteolysis during the first two years of life. Well-controlled in vitro studies have demonstrated that varying digestion conditions alter the specificity, rate, and extent of proteolysis of baby foods. Nonetheless, these models do not completely replicate in vivo proteolysis or the complex biogeography of the gastrointestinal tract. Animal and clinical studies have revealed the fate of dietary proteins along the digestive tract and the overall health impact on subjects. Building comprehensive and annotated datasets from human infants will require innovative and standardized measurement. Now, more systematic evaluations of digestion are emerging to advance the knowledge and its translation as food design for effective diet and health management in infants.

Immunotherapy for cow's milk allergy

Oral immunotherapy (OIT) is used regularly for young children with cow's milk (CM) allergy and has been shown to be effective in several studies. However, adverse events occur frequently during OIT. Furthermore, there are only 5 randomized controlled trial studies of CM-OIT and these are low-powered single center trials. Therefore, evidence levels are also low and sometimes frequent and severe allergic events occur during the OIT. Furthermore, there are no standardized protocols in pediatric allergy guidelines from several countries and studies with long-term follow-up observations and clinical tolerance defined as sustained unresponsiveness are rare. Additionally, clinical tolerance by OIT is generally not well defined and obscure. Thus, several problems remain to be resolved, however we hope OIT in combination with omalizumab and less allergenic heated CM products will resolve these problems in the future.

Proteins and bioactive peptides from donkey milk: The molecular basis for its reduced allergenic properties

The legendary therapeutics properties of donkey milk have recently been supported by many clinical trials who have clearly demonstrated that, even if with adequate lipid integration, it may represent a valid natural substitute of cow milk for feeding allergic children. During the last decade many investigations by MS-based methods have been performed in order to obtain a better knowledge of donkey milk proteins. The knowledge about the primary structure of donkey milk proteins now may provide the basis for a more accurate comprehension of its potential benefits for human nutrition. In this aspect, experimental data today available clearly demonstrate that donkey milk proteins (especially casein components) are more closely related with the human homologues rather than cow counterparts. Moreover, the low allergenic properties of donkey milk with respect to cow one seem to be related to the low total protein content, the low ratio of caseins to whey fraction, and finally to the presence in almost all bovine IgE-binding linear epitopes of multiple amino acid differences with respect to the corresponding regions of donkey milk counterparts.

Infant Formulas for Food Allergy Treatment and Prevention

The number of infant formulas intended for food allergy treatment or prevention has been increasing. Some products fulfill the criteria for hypoallergenicity, such as extensively hydrolyzed protein (casein or whey) and synthesized amino acid formulas (elemental diet). Numerous partially hydrolyzed formulas have been derived from bovine milk, soybean, and rice. They are not hypoallergenic and are not recommended for children allergic to the parent protein, yet certain preparations have shown efficacy for allergy prevention. Soybean-derived preparations, although not hypoallergenic, have been tolerated by a majority of children allergic to bovine milk. Studies on the addition of probiotics or prebiotics to infant formulas have shown inconsistent findings. Numerous hypoallergenic formulas or milk substitutes are available for pediatricians to choose for children with food allergy. Caution is needed in prescribing formulas that are erroneously marketed as hypoallergenic.

Position document: IgE-mediated cow's milk allergy

The present document offers an update on the recommendations for managing patients with cow's milk allergy - a disorder that manifests in the first year of life, with an estimated prevalence of 1.6-3% in this paediatric age group. The main causal allergens are the caseins and proteins in lactoserum (beta-lactoglobulin, alpha-lactoalbumin), and the clinical manifestations are highly variable in terms of their presentation and severity. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems, and severe anaphylaxis may occur. The diagnosis of cow's milk allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which constitutes the gold standard for confirming the diagnosis. The most efficient treatment for cow's milk allergy is an elimination diet and the use of adequate substitution formulas. The elimination diet must include milk from other mammals (e.g., sheep, goat, etc.) due to the risk of cross-reactivity with the proteins of cow's milk. Most infants with IgE-mediated cow's milk allergy become tolerant in the first few years of life. In those cases where cow's milk allergy persists, novel treatment options may include oral immunotherapy, although most authors do not currently recommend this technique in routine clinical practice. Enough evidence is not there to confirm the efficacy of elimination diets in the mother and infant for preventing the appearance of cow's milk allergy. Likewise, no benefits have been observed with prebiotic and probiotic dietetic supplements in infants for preventing food allergy.