Sports Diet and Oral Health in Athletes: A Comprehensive Review

Food and fluid supply is fundamental for optimal athletic performance but can also be a risk factor for caries, dental erosion, and periodontal diseases, which in turn can impair athletic performance. Many studies have reported a high prevalence of oral diseases in elite athletes, notably dental caries 20-84%, dental erosion 42-59%, gingivitis 58-77%, and periodontal disease 15-41%, caused by frequent consumption of sugars/carbohydrates, polyunsaturated fats, or deficient protein intake. There are three possible major reasons for poor oral health in athletes which are addressed in this review: oxidative stress, sports diet, and oral hygiene. This update particularly summarizes potential sports nutritional effects on athletes' dental health. Overall, sports diet appropriately applied to deliver benefits for performance associated with oral hygiene requirements is necessary to ensure athletes' health. The overall aim is to help athletes, dentists, and nutritionists understand the tangled connections between sports diet, oral health, and oral healthcare to develop mitigation strategies to reduce the risk of dental diseases due to nutrition.

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.

The effects of Trametes versicolor fermented Rosa roxburghii tratt and coix seed quild on the nutrition, sensory characteristics and physical and chemical parameters of yogurt

Trametes versicolor can produce aromatic flavor in growth and development, widely used in food fermentation. This study used a One-Factor-at-a-Time (OFAT) test and response surface analysis to study the optimum fermentation parameters of Rosa roxburghii tratt and coix seed yogurt by Trametes versicolor. The best fermentation process is as follows: skim milk powder 17 %, sucrose content 4 %, Rosa roxburghii tratt and coix seed liquid 36 %, fermentation temperature 39 °C, inoculum 2 %, strain ratio 2:1:1(LB12: BLH1: Q-1), fermentation time 9.5 h. Under this fermentation process, the sensory score was 82.11, the contents of vitamin C, GABA, and total live bacteria in this yogurt were 13.89, 2.58, and 1.02 times higher than in common yogurt. Correlation analyses showed a significant contribution of the leavening agent to the GABA content of yogurt. This study provides a foundation for producing Rosa roxburghii tratt and coix seed yogurt with high sensory and nutritional value.

A comparison of milk fat globule membranes and whey proteomes: New insight into variation nutrient differences between Buffalo, Cow, Goat, and Yak

In this study, the whey and milk fat globule membrane (MFGM) proteomes of buffalo, cow, goat, and yak milk were analyzed using label-free proteomic technology. Totally, 1,292 MFGM proteins and 686 whey proteins were identified from these four species, and GO analysis revealed there were specific proteins with different functions in both whey (376) and MFGM (982) proteomes. The principal component analysis showed that ALB, TF, CSN1S1, and GLYCAM1 are characteristic markers of the milk for each of the four species. Furthermore, the conserved and differential in the expression of whey and MFGM proteins across the four species were identified by limma, and subsequent KEGG pathway analysis showed that immune-related proteins are both conserved and species-specific in the four species. These results provide a deepening of the understanding of the characteristics of proteins in whey and MFGMs from these four common dairy animals and new insight into developing dairy production.

Casein structures differently affect postprandial amino acid delivery through their intra-gastric clotting properties

We aimed to assess if casein structure affects its digestion and its subsequent amino acid delivery kinetic. Higher nitrogen levels were recovered in dialysates after in vitro digestions of sodium caseinate (SC, formed of small aggregates) compared to micellar casein (MC, native form of casein) and calcium caseinate (CC, intermediate structure). Likewise, plasma indispensable amino-acid concentration peak was higher after SC compared to MC or CC ingestion in healthy volunteers in a randomized, double blind, cross-over study. In pigs, gamma-scintigraphy using labelled meals revealed that SC was mainly localized in the proximal part of the stomach whereas MC was distributed in the whole gastric cavity. Caseins were found in both solid and liquid phases and partly hydrolyzed casein in the solid phase shortly after SC drink ingestion. These data support the concept of slow (MC) and rapid (SC) casein depending of casein structure, likely due to their intra-gastric clotting properties.

Differential effects of milk proteins on amino acid digestibility, post-prandial nitrogen utilization and intestinal peptide profiles in rats

OBJECTIVE

The aim of this study was to analyze the protein digestibility and postprandial metabolism in rats of milk protein matrices obtained by different industrial processes.

MATERIAL AND METHODS

The study was conducted on Wistar rats that consumed a meal containing different ¹⁵N-labeled milk proteins. Four milk matrices were tested: native micellar caseins (C1), caseins low in calcium (C2 low Ca²⁺), a matrix containing a ratio 63:37 of caseins and whey proteins (CW2) and whey proteins alone (W). Blood and urine were collected during the postprandial period and rats were euthanized 6 h after meal intake to collect digestive contents and organs.

RESULTS

Orocaecal digestibility values of amino acids ranged between 96.0 ± 0.2% and 96.6 ± 0.4% for C1-, C2 low Ca²⁺- and W-matrices, while this value was significantly lower for CW2 matrix (92.4 ± 0.5%). More dietary nitrogen was sequestered in the splanchnic area (intestinal mucosa and liver) as well as in plasma proteins after ingestion of W matrix, especially compared to the C1- and C2 low Ca²⁺-matrices. Peptidomic analysis showed that more milk protein-derived peptides were identified in the caecum of rats after the ingestion of the matrices containing caseins compared to W matrix.

CONCLUSION

We found that demineralization of micellar caseins did not modify its digestibility and postprandial metabolism. The low digestibility of the modified casein-to-whey ratio matrix may be ascribed to a lower accessibility of the protein to digestive enzymes due to changes in the protein structure, while the higher nitrogen splanchnic retention after ingestion of whey was probably due to the fast assimilation of its protein content. Finally, our results showed that industrial processes that modify the structure and/or composition of milk proteins influence protein digestion and utilization.

Alteration of the allergenicity of cow's milk proteins using different food processing modifications

Milk is an essential source of protein for infants and young children. At the same time, cow's milk is also one of the most common allergenic foods causing food allergies in children. Recently, cow's milk allergy (CMA) has become a common public health issue worldwide. Modern food processing technologies have been developed to reduce the allergenicity of milk proteins and improve the quality of life of patients with CMA. In this review, we summarize the main allergens in cow's milk, and introduce the recent findings on CMA responses. Moreover, the reduced effects and underlying mechanisms of different food processing techniques (such as heating, high pressure, γ-ray irradiation, ultrasound irradiation, hydrolysis, glycosylation, etc.) on the allergenicity of cow's milk proteins, and the application of processed cow's milk in clinical studies, are discussed. In addition, we describe the changes of nutritional value in cow's milk treated by different food processing technologies. This review provides an in-depth understanding of the allergenicity reduction of cow's milk proteins by various food processing techniques.

Quantification of Casein in Baked Food Products by Selective Analysis of Phosphorylated Peptides Using Fluorous Derivatization with Liquid Chromatography-Tandem Mass Spectrometry Method

Casein is one of the allergen proteins present in milk. Therefore, a quantification method for the selective analysis of casein using fluorous derivatization with LC-tandem mass spectrometry (LC-MS/MS) was developed. After two allergen proteins (α_S1-casein and β-casein) extracted from baked sugar cookies were tryptic digested, the obtained phosphorylated peptides were selectively derivatized by β-elimination with Ba(NO₃)₂ under basic condition and Michael addition with perfluoroalkylthiol (1H,1H,2H,2H-perfluorooctanethiol, PFOT). In this study, YKVPQLEIVPN(pSer)AQQR (104-119 fragment from α_S1-casein) and FQ(pSer)EEQQQTEDELQDK (33-48 fragment from β-casein) obtained by tryptic digestion were selected as target peptides. The phosphorylated serine residue in each peptide was converted to a perfluoroalkyl group by derivatization. The obtained fluorous-derivatized peptides were analyzed by LC-MS/MS, to which a fluorous LC column was connected. Therefore, it was possible to analyze casein without being affected by the matrix components in the baked food sample. When the present method was applied to cookies with arbitrary amounts of α_S1-casein and β-casein, the obtained quantification values were in good agreement with the arbitrary amounts spiked. The quantification limits of α_S1- and β-casein in cookie analysis were 246 and 152 ng/g, respectively. Hence, this method can be used to analyze trace amounts of allergen proteins present in the baked food.

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.

Progress in micellar casein concentrate: Production and applications

Micellar casein concentrate (MCC) is a novel ingredient with high casein content. Over the past decade, MCC has emerged as one of the most promising dairy ingredients having applications in beverages, yogurt, cheese, and process cheese products. Industrially, MCC is manufactured by microfiltration (MF) of skim milk and is commercially available as a liquid, concentrated, or dried containing ≥9, ≥22, and ≥80% total protein, respectively. As an ingredient, MCC not only imparts a bland flavor but also offers unique functionalities such as foaming, emulsifying, wetting, dispersibility, heat stability, and water-binding ability. The high protein content of MCC represents a valuable source of fortification in a number of food formulations. For the last 20 years, MCC is utilized in many applications due to the unique physiochemical and functional characteristics. It also has promising applications to eliminate the cost of drying by producing concentrated MCC. This work aims at providing a succinct overview of the historical progress of the MCC, a review on the manufacturing methods, a discussion of MCC properties, varieties, and applications.

Recent perspective on cow's milk allergy and dairy nutrition

Cow's milk is a highly nutritious biological fluid that provides nourishment and immunity to infants when breastfeeding declines. However, some infants, children, and adults are allergic to cow's milk because milk contains potential allergens in the form of proteins. Casein and whey proteins and their coagulated sub-fractions in the milk such as αS₁-casein, αS₂-casein, β-casein, κ-casein and α-lactalbumin, β-lactoglobulin, bovine serum albumin, immunoglobulins, lactoferrin, respectively are the major etiological determinant of cow's milk allergy (CMA). Moreover, milk processing techniques such as homogenization and pasteurization alter the milk fat and whey protein's molecular structure and serve them as allergens to the immune system of allergic individuals. Strict exclusion of nutrient-rich milk and other dairy products from diet puts children with CMA at higher nutritional risk. Thus, regular nutritional monitoring, the inclusion of protein and mineral-rich supplements as a substitute for cow's milk, management of animal genetics (sheep, goats, buffaloes, camel, mare, donkey, yak), and milk processing to produce non-allergenic milk by inactivating allergic proteins for designer nutrition is essentially required. This review paper details the prevalence, molecular profiling of milk allergens (proteins), body immune response against CMA, consequences of milk processing, treatment, and novel role of galectins as potentially allergy suppressors.

Milk Ingredients in Meat Products: Can Autoclaving and In Vitro Gastroduodenal Digestion Mitigate Their IgE-Binding Capacity?

The food industry commonly uses milk ingredients as technological aids in an uncounted number of products. On the other hand, milk contains allergenic proteins causing adverse allergic reactions in sensitized/allergic individuals. This work intends to evaluate the effect of autoclaving and in vitro digestion on the allergenicity of milk proteins incurred in meat products. Protein profiles of raw and autoclaved sausages without and with the addition of 10% of milk protein concentrates were analyzed by gel electrophoresis and liquid chromatography–mass spectrometry. Additionally, residual IgE-reactivity was evaluated by immunoblot analysis using pooled sera of cow’s-milk-allergic individuals followed by bioinformatic analysis. Results showed that autoclaving led to an increase in protein fragmentation (higher number of short peptides) and consequently to a higher digestion rate, that was found to be more pronounced in β-casein. The IgE-binding capacity of milk proteins seems to be reduced after autoclaving prior to digestion, with a residual reactivity in caseins, but was eliminated following digestion. This study highlights the importance of autoclaving as a processing strategy to produce hypoallergenic formulas.

Optimisation and comparison of orthogonal methods for separation and characterisation of extracellular vesicles to investigate how representative infant milk formula is of milk

Many infants are fed infant milk formula (IMF). However, IMF production from skim milk (SM) involves harsh treatment. So, we hypothesised that the quantity and/or quality of extracellular vesicles (EVs) in IMF may be reduced. Thus, firstly, we aimed to optimise separation of EVs from IMF and SM and, secondly, we aimed to compare the EV isolates from these two sources. Prior to EV isolation, abundant casein micelles of similar sizes to EVs were removed by treating milk samples with either acetic acid or hydrochloric acid. Samples progressed to differential ultracentrifugation (DUC) or gradient ultracentrifugation (GUC). EV characterisation included BCA, SDS-PAGE, nanoparticle tracking (NTA), electron microscopy (TEM), immunoblotting, and imaging flow cytometry (IFCM). Reduced EV concentrations were found in IMF. SM-derived EVs were intact, while IMF contained disrupted EV-like structures. EV biomarkers were more abundant with isolates from SM, indicating EV proteins in IMF are compromised. Altogether, a suitable method combining acid pre-treatment with GUC for EV separation from milk products was developed. EVs appear to be substantially compromised in IMF compared to SM.

In Vitro Assessment of the Impact of Industrial Processes on the Gastrointestinal Digestion of Milk Protein Matrices Using the INFOGEST Protocol

The goal of this study was to determine the impact of industrial processes on the digestion of six milk protein matrices using the harmonized INFOGEST in vitro static digestion protocol. First, this method was optimized to simple protein matrices using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and size exclusion chromatography (SEC) to compare the intestinal protein hydrolysis obtained with increasing quantities of pancreatin. Similar results were achieved with the originally required pancreatin amount (trypsin activity of 100 U.mL⁻¹) and with a quantity of pancreatin equivalent to a trypsin activity of 27.3 U.mL⁻¹, which was thus used to perform the in vitro digestion of the milk matrices. Molecular weight profiles, peptide heterogeneity from LC-MS/MS data, calcium, free amino acid, and peptide concentrations were determined in the gastric and intestinal phases to compare the milk protein digests. Results showed that the industrial process affected not only the protein distribution of the matrices but also most likely the protein structures. Indeed, differences arose in terms of peptide populations generated when the caseins were reticulated or when their calcium concentrations were reduced.

Critical review on proteotypic peptide marker tracing for six allergenic ingredients in incurred foods by mass spectrometry

Peptide marker identification is one of the most important steps in the development of a mass spectrometry (MS) based method for allergen detection, since the robustness and sensitivity of the overall analytical method will strictly depend on the reliability of the proteotypic peptides tracing for each allergen. The European legislation in place issues the mandatory labelling of fourteen allergenic ingredients whenever used in different food formulations. Among these, six allergenic ingredients, namely milk, egg, peanut, soybean, hazelnut and almond, can be prioritized in light of their higher occurrence in food recalls for undeclared presence with serious risk decision. In this work, we described the results of a comprehensive evaluation of the current literature on MS-based allergen detection aiming at collecting all available information about proteins and peptide markers validated in independent studies for the six allergenic ingredients of interest. The main features of the targeted proteins were commented reviewing all details available about known isoforms and sequence homology particularly in plant-derived allergens. Several critical aspects affecting peptide markers reliability were discussed and according to this evaluation a final short-list of candidate markers was compiled likely to be standardized and implemented in MS methods for allergen analysis.

Anti-inflammatory effects of a casein hydrolysate and its peptide-enriched fractions on TNFα-challenged Caco-2 cells and LPS-challenged porcine colonic explants

Bioactive milk peptides are reported to illicit a range of physiological benefits and have been proposed as potential functional food ingredients. The objective of this study was to characterize the anti-inflammatory properties of sodium caseinate (NaCAS), its enzyme hydrolysate (EH) and peptide-enriched fractions (5 kDa retentate [R], 1 kDaR and 1 kDa permeate [P]), both in vitro using a Caco-2 cell line, and also ex vivo using a porcine colonic tissue explant system. Caco-2 cells were stimulated with tumour necrosis factor alpha (TNFα) and co-treated with casein hydrolysates for 24 h. Following this, interleukin (IL)-8 concentrations in the supernatant were measured using enzyme-linked immunosorbent assay. Porcine colonic tissue was stimulated with lipopolysaccharide and co-treated with casein hydrolysates for 3 h. The expression of a panel of inflammatory cytokines was measured using qPCR. While dexamethasone reduced the IL-8 concentration by 41.6%, the 1 kDaR and 1 kDaP fractions reduced IL-8 by 68.7% and 66.1%, respectively, relative to TNFα-stimulated Caco-2 cells (P < 0.05). In the ex vivo system, only the 1 kDaR fraction elicited a decrease inIL1-α,IL1-β,IL-8,TGF-β andIL-10 expression (P < 0.05). This study provides evidence that the bioactive peptides present in the 1 kDaR fraction of the NaCAS hydrolysate possess anti-inflammatory properties in vitro and ex vivo. Further in vivo analysis of the anti-inflammatory properties of the 1 kDaR is proposed.

MS-based characterization of α(s2)-casein isoforms in donkey's milk

The primary structure of four α(s2)-casein (CN) isoforms, present as minor components in the dephosphorylated CN fraction of a milk sample collected in Eastern Sicily from an individual donkey belonging to the Ragusano breed at middle lactation stage, was determined, using the known donkey's α(s2)-CN (GenBank Acc. No. CAV00691; M(r) 26,028 Da) as reference. Proteins, with experimentally measured M(r) of 25,429, 21,939, 25,203 and 21,713 Da, were isolated by the combined use of reversed-phase high-performance liquid chromatography (RP-HPLC) and two-dimensional polyacrylamide gel electrophoresis. The major spot of each gel, corresponding to a single protein, was digested by trypsin, α-chymotrypsin and endoproteinase Glu-C. The resulting peptide mixtures were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and capillary RP-HPLC/nano-electrospray ionization tandem mass spectrometry, and the data obtained were used for the sequence determination. The isoforms are produced from differential splicing events involving exons 4, 5 and 6 and parts of the exon 17.

Analysis of binding interaction between (-)-epigallocatechin (EGC) and β-lactoglobulin by multi-spectroscopic method

The binding interaction between (-)-epigallocatechin (EGC) with bovine β-lactoglobulin (βLG) was investigated by fluorescence, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy methods. The binding parameters were determined by Stern-Volmer equation and the thermodynamic parameters were calculated according to the van't Hoff equation. The results suggested that βLG was bound by EGC, which resulted in change of native conformation of βLG. van der Waals interactions and hydrogen bonding probably played major roles in the binding process. Our study is helpful for further elucidation of binding interactions between catechins with milk proteins, which would contribute to the development of novel milk products.