Dairy flavor is a product of the synergistic interaction between microbial metabolism and processing techniques,with its unique sensory characteristics being critical determinants of product competitiveness and quality control.This review systematically summarizes the formation mechanism of dairy flavor and the principles and applications of major identification,screening,and quality evaluation technologies,with a focus on the advantages,limitations,and complementary relationships of gas chromatography-mass spectrometry,liquid chromatography-mass spectrometry,near-infrared(NIR)spectroscopy,nuclear magnetic resonance,and intelligent sensory technologies.Based on a systematic comparison of existing techniques,a"technology characteristic-detection objective-application scenario"matching framework is proposed,aiming to shift the current research paradigm from reliance on"single-technology identification"toward an integrated approach based on"multi-technology fusion perception".This shift provides a theoretical foundation and technical support for establishing a standardized and intelligent dairy flavor evaluation system.Future developments are expected to focus on the construction of multi-technology collaborative platforms,in-depth interpretation of complex data using artificial intelligence algorithms,and online quality control enabled by miniaturized devices.
The standards for infant and young child formulae of China,the Codex Alimentarius Commission(CAC),the European Union(EU),Australia and New Zealand(ANZ),and the United States were compared with respect to energy,protein,fat,and optional ingredients to identify differences in nutritional requirements.It was found that China has established stringent standards for infant,follow-on,and young child formulae.The Chinese and CAC standards for infant and follow-on formulae are highly consistent,with nearly identical limits set for essential nutrients such as energy,total fat,total carbohydrates,protein,and vitamins.The major difference between them is that the addition of inositol and L-carnitine is mandated by the CAC,while these compounds are classified as optional ingredients in China.The limits set by China for essential ingredients such as energy,fat,and carbohydrates are consistent with those from the EU standards,while the limits for 13 nutrients including vitamins A and D are higher than those from the EU standards.Additionally,the EU has mandated the addition of inositol,L-carnitine,and docosahexaenoic acid,and has approved seven human milk oligosaccharides(HMOs)for use in infant formula.In contrast,only two HMOs have been approved in China.These variations can be attributed to differences in breast milk composition data,infant dietary patterns,nutritional deficiency status,and regulatory philosophies among countries.This paper clarifies the similarities and differences in the nutritional requirements of domestic and international standards for infant and young child formulae,providing crucial insights for refining China's regulatory revisions and guiding consumers in selecting products that meet the nutritional needs of local infants and young children.
The proliferation of small intestinal epithelial cells is fundamental to intestinal development and barrier function maintenance in infants and young children. To investigate the effects and mechanisms of u03C9-3 polyunsaturated fatty acids (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)), commonly used in infant formula, on this process, this study employed the rat intestinal epithelial cell line 6 (IEC-6) as a model. After DHA and EPA treatment at different combinations of concentration (1, 10, 50, 100 u03BCmol/L) and duration 12, 24, 36, 48 h, cell viability was assessed using the cell counting kit-8 and 5-ethynyl-2u2019-deoxyuridine assays, and the mRNA and protein expression of key molecules involved in the Wnt/u03B2-catenin signaling pathways were analyzed via real-time quantitative polymerase chain reaction and Western blot. The results showed that both DHA and EPA significantly promoted the proliferation of IEC-6 cells, with optimal concentrations of 100 and 10 u03BCmol/L, respectively, and an optimal treatment duration of 24 h. Specifically, treatment with 100 u03BCmol/L DHA and 10 u03BCmol/L EPA for 24 h increased cell viability by nearly 4- and 3.5-fold compared to the control group (P u0026lt; 0.001), respectively. Both DHA and EPA activated the Wnt/u03B2-catenin signaling pathway, significantly upregulating the mRNA and protein expression of cell proliferation-related genes such as cyclin D1 and u03B2-catenin (P u0026lt; 0.05, P u0026lt; 0.01, or P u0026lt; 0.001). These findings indicate that DHA and EPA enhance intestinal epithelial cell proliferation by activating the Wnt signaling pathway.
The effects of heat sterilization and microwave sterilization on the stability and casein structure of fresh camel milk were compared.The microwave sterilization conditions were optimized using single factor experiments and response surface methodology based on Box-Behnken design.Changes in the structure and properties of camel milk casein after sterilization were investigated using a differential scanning calorimeter,a Fourier transform infrared spectrometer,and a scanning electron microscope.The centrifugal sedimentation rate of protein and the total number of colonies were taken as response variables,the optimum conditions were determined as follows:pH 7.0,microwave power 560 W and microwave irradiation time 120 s.After microwave treatment under these conditions,the centrifugal sedimentation rate of protein was 6.96%,and no bacterial colonies were detected.Differential scanning calorimetry(DSC)plot showed that microwave treatment resulted in higher enthalpy of camel milk casein compared with heat sterilization,indicating a lower degree of denaturation and higher stability.The results of scanning electron microscopy showed that both sterilization methods destroyed the micellar structure of casein to varying degrees,resulting in cross-linking and aggregation.However,after microwave sterilization,the casein showed ordered aggregation,forming small aggregates that assembled into an ordered network structure.Appropriately increasing the pH of camel milk before sterilization was conducive to its stability.Different sterilization methods had a significant effect on the secondary structure of camel milk casein.Both microwave and heat sterilization reduced the relative contents of α-helix and β-turn in the casein.The relative content of β-sheet in heat-sterilized camel milk casein was the highest,indicating the most significant change in the secondary structure of the protein.In summary,this study revealed the stability of camel milk and the structural change of camel milk casein under different sterilization conditions,which can help address the poor stability of thermally sterilized camel milk at this stage.
Based on previous research suggesting that milk exosomes specifically express miR-26a,this study optimized the miR-26a encapsulation efficiency of liposomes through ultrasonic treatment,and it also evaluated the in vitro digestion performance of the ultrasonic-treated liposomes and compared its anti-inflammatory activity with that of natural milk exosomes.Single-factor experiments were conducted to optimize the molar charge ratio of cationic liposome vector to nucleic acid(N/P),ultrasonication time,and ultrasonic power for the preparation of miR-26a-encapsulated liposomes.The results demonstrated that when the N/P ratio was 4,ultrasonication time was 15 min,and ultrasonic power was 300 W,the encapsulation efficiency reached its peak of(89.51±1.37)%,with uniform particle size distribution and homogeneous morphology.In vitro simulated digestion experiments showed that the retention rate of miR-26a in the ultrasonic-treated liposomes(58%)was higher than that in the conventional liposomes(24%).Cell function experiments confirmed that the ultrasonic-treated liposomes not only enhanced the viability of normal Caco-2 cells but also effectively inhibited lipopolysaccharide(LPS)-induced inflammatory responses,significantly restoring cell viability under inflammatory conditions.Additionally,it reduced NO release and down-regulated the secretion of the inflammatory cytokines interleukin 6(IL-6),tumor necrosis factor α,and IL-1β,while effectively controlling the generation of reactive oxygen species.Notably,the ultrasonic-treated liposomes showed no significant differences from milk exosomes in terms of cell viability regulatory and inflammation inhibitory effects.In summary,this study demonstrates that ultrasonic can significantly improve the miR-26a delivery efficiency of liposomes.
A novel strain of Ligilactobacillus cholophilus,designated BD7642,was isolated from pickled potherb mustard(Brassica juncea Coss.)in Shanghai.The complete genome sequence of the strain was obtained using a combination of PacBio and Illumina sequencing.To characterize this strain and explore its potential probiotic functions,we performed comprehensive genomic analyses.The results showed that the genome of L.cholophilus BD7642 was 1 587 935 bp in size and encoded 1 530 genes(no plasmids detected).Functional annotation and secondary metabolite synthesis analysis revealed that L.cholophilus BD7642 contained gene clusters for the biosynthesis of the bacteriocin mutacin 1140 and type III polyketide synthases and possessed a great capacity for environmental adaptation.ResFinder analysis indicated the absence of antibiotic resistance genes.Comparative genomics uncovered the genomic uniqueness of L.cholophilus BD7642.This study provides a deep understanding of L.cholophilus BD7642 and offers a reference for exploiting its probiotic potential.
Fresh cheese is rich in nutrients but is highly susceptible to mold contamination,resulting in a short shelf life and poor long-term storage stability.This study investigated the effects of three lactic acid bacterial(LAB)strains with mold-inhibiting properties,Lactiplantibacillus plantarum HH-LP56(L1),Lactobacillus acidophilus HH-LA26(L2),and Limosilactobacillus reuteri PB-LR09,on the quality characteristics of fresh cheese during storage.The results indicated that compared with the nisin supplemented group and the control group without any preservative added,addition of any of the three antifungal strains significantly improved the quality characteristics of fresh cheese during storage.In terms of antibacterial properties,the LAB groups performed excellently.After 60 days of storage,the total colony counts in groups L1 and L2 were significantly lower than those in the L3,nisin,and control groups(P<0.05),and the mold counts did not exceed the limit stipulated by the Chinese national standard(≤50 CFU/g).The mold count in group L1 remained within the limit after 90 days,whereas the mold counts in the L3,nisin,and control groups exceeded the limit after 60 days of storage.With regard to quality characteristic,the LAB groups showed brighter color(higher brightness value,lower redness and yellowness values),superior texture,and richer milky aroma.The abundance of volatile flavor compounds was evidently higher in the LAB groups than in the control group.In total,66 volatile flavor compounds were detected in group L1,with a richer and mellower flavor.In conclusion,the three LAB strains exhibited stronger antifungal effects than did nisin,with L1 showing the best performance.These strains can effectively extend the shelf life of fresh cheese while maintaining its desirable flavor and texture.
To address the issue of the long detection cycle and difficult quantitative analysis of molds in fermented milk,this study developed a systematic method for the detection of molds in commercial fermented milk by using droplet digital polymerase chain reaction(ddPCR)to absolutely quantify the copy number of target sequences in samples.The optimal ddPCR reaction system and amplification program were determined.The proposed method performed well in terms of specificity,sensitivity and quantitative accuracy.It specifically amplification target molds(Aspergillus niger,Penicillium citrinum,and Penicillium chrysogenum),with no cross-reactivity with yeasts,lactic acid bacteria,or pathogenic bacteria.Sensitivity tests indicated that at the minimum detectable concentration(0.625 ng/μL),the positive copy number was 9 copies/μL.In addition,this method established linear equations between bacterial suspension concentration and DNA concentration,as well as between DNA concentration and gene copy number,with correlation coefficients greater than 0.99,and based on them,a linear equation between bacterial suspension concentration and gene copy number was developed.The results of the ddPCR method for artificially contaminated samples were consistent with those of the national standard method(GB 4789.15-2016).Moreover,the method enables absolute quantification without the need for a standard curve,effectively shortening the detection cycle.
Milk protein, a crucial natural raw material in the dairy industry, possesses multiple physiological activities. However, natural milk protein has deficiencies in key functional properties such as thermal stability, solubility, and gel characteristics, which restrict its application in dairy processing. To address this issue, modulation of the molecular structure of milk protein through protein modification technology can not only enhance its basic functionalities but also explore and impart novel functional characteristics to it. This review focuses on the precise regulation of milk protein functional properties and systematically reviews four modification technologies: 1) enzymatic modification such as hydrolysis and cross-linking; 2) physical modification such as non-thermal processing and microencapsulation; 3) chemical modification such as glycosylation, phosphorylation (dephosphorylation), and acylation (deacylation); and 4) combined modification. It discusses these technologies in terms of mechanisms, functional characteristics, and advantages and disadvantages. In light of current research progress, this article also points out that the field still faces several challenges, such as the likelihood of chemical modification causing reagent residues, the high cost of enzyme preparations, the limited effectiveness of single physical modification, and insufficient understanding of the structure-function relationship at the molecular level. Finally, it is proposed that further research should focus on developing targeted green combined modification technologies, investigating the safety and nutritional properties of modified products, and expanding the application of milk protein in high value-added special diets such as infant formula and nutritional products for the elderly, with the aim of providing a theoretical basis and technical support for promoting the high-value utilization of milk protein.
To addresses technical bottlenecks such as the complexity of the camel milk matrix and the interference of endogenous proteins with target detection,this study established an analytical method to detect exogenous bovine insulin in camel milk using dispersive liquid-liquid microextraction(DLLME)coupled with high performance liquid chromatography(HPLC).The extraction conditions and the instrumental parameters were optimized.The results showed that efficient enrichment and accurate quantification of target analytes in complex milk matrices were achieved by HPLC combined with DLLME using 0.01 mol/L HCl as the extractant,volume fraction 60%aqueous acetone as the extraction solvent,and n-hexane as the separation phase.The method exhibited good linearity for bovine insulin over the concentration ranges of 5-500 μg/mL(R2=0.999).Recoveries for blank sample of Bactrian camel milk from Dabancheng District,Ürümqi ranged from 64.1%to 86.9%at spiked levels of 5,50 and 500 μg/mL,with relative standard deviations(RSDs)of 4.9%-12.4%.The limit of detection and limit of quantification were 0.5 and 5 μg/mL,respectively.The DLLME-HPLC method is characterized by simple operation,short pretreatment time,and high analytical efficiency,providing technical support for rapid screening of exogenous bovine insulin in camel milk.
Constipation is a prevalent functional gastrointestinal disorder.Conventional laxative therapies for constipation often entail risks of dependence and adverse effects.With the growing recognition of the crucial role of gut microbiota dysbiosis in its pathogenesis,gut microbiota modulation has emerged as a core strategy in novel therapies.Synbiotics,a combination of probiotics and prebiotics,demonstrates significant therapeutic potential through synergistic mechanisms:prebiotics selectively promote the colonization and proliferation of probiotics,and they synergistically optimize gut microbiota composition,enhance the production of short-chain fatty acids,and subsequently improve intestinal barrier function,regulate immune responses,and stimulate intestinal motility.Clinical evidence indicates that specific synbiotic formulations outperform single-component interventions in improving stool frequency,consistency,and overall symptoms.This advantage stems from the"nutrition-microbiota-metabolism"multiple-pathway synergistic effect.Future research should prioritize the development of personalized synbiotic regimens based on gut microbiota functional prediction,conduct large-scale clinical trials for functional validation,and explore their integration with novel delivery systems and functional food carriers,thereby advancing the development of constipation treatment toward the integration of precision microbiota-based intervention and enhancing its clinical utility and patients'quality of life.
Per-and polyfluoroalkyl substances(PFASs)have emerged as potential health risks in milk and dairy products due to their chemical inertness and bioaccumulative properties.This paper systematically reviews the detection methods,migration and transformation mechanisms,and pollution control strategies for PFASs in milk and dairy products.Sample preparation techniques including liquid-liquid extraction,solid-phase extraction,QuEChERS(quick,easy,cheap,effective,rugged,and safe),supercritical fluid extraction,and metal-organic framework-based dispersive solid-phase extraction have been widely applied in conjunction with liquid chromatography-tandem mass spectrometry and high-resolution mass spectrometry to achieve precise quantification of PFASs at trace to ultra-trace levels.PFASs migrate through the"environment-feed-cattle-milk"pathway,with significant differences in accumulation and transfer efficiency between short-chain and long-chain PFASs.In dairy cows,PFASs primarily distribute in serum protein-bound forms,and some novel PFASs exhibit uncertainties in biotransformation.During dairy processing,thermal treatment and contact materials may cause redistribution or migration of PFASs.Finally,a comprehensive pollution control strategy combining source control,production process interventions,and active removal technologies provides a scientific basis for reducing exposure to PFASs from dairy products.This review aims to offer theoretical references and practical guidance for dairy product safety regulation,risk assessment,and pollution prevention.
Water-soluble vitamins,as essential micronutrients for the human body,play a vital role in maintaining normal physiological functions,and their deficiency may lead to metabolic disorders and related health issues.Infant formula is fortified with these vitamins through nutrient fortification technologies to support the healthy growth and development of infants and young children.Due to the matrix complexity of infant formula and the instability of water-soluble vitamins,it is a great challenge to accurately analyze and detect multiple water-soluble vitamins in infant formula.In this paper,we review the latest developments in extraction and separation(protein precipitation,acid hydrolysis,and enzymatic hydrolysis)and detection(microbiological method,liquid chromatography,and liquid chromatography-mass spectrometry)techniques for water-soluble vitamins in infant formula,and we discuss future prospects in this field.Through this review,we aim to provide a reference for relevant researches.
The rapid identification of Salmonella,a significant foodborne pathogen,is of significant importance.To establish a new method for identifying Salmonella based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS),this study optimized culture medium type,incubation time,bacterial lysis methods,and instrumental parameters.The results showed that compared to the national standard method GB/T 33682-2025 General microorganism identification method with matrix-assisted laser desorption/ionization time of flight mass spectrometry,the recovery rate increased from 54.7%to 84.7%after replacing the culture medium with nutrient agar.Increasing the incubation time from 24 to 48 h increased the average identification score by 7.0%,from 2.203 to 2.355.Optimizing lysis methods elevated the average identification score by 19.0%,from 1.898 to 2.259.When the instrumental parameters were adjusted to 50%laser energy and a laser wavelength of 370 nm,the average identification score increased to 2.211.Compared to its original version specified in GB/T 33682-2025,the established MALDI-TOF/TOF MS method exhibited improved accuracy and reliability in Salmonella identification.
This study aimed to establish a rapid method for identifying three common foodborne pathogenic Gram-negative bacteria(Vibrio parahaemolyticus,Enterobacter cloacae,and Acinetobacter baumannii).We explored the effects of different pretreatment methods,media,and culture durations on the results of bacterial identification using matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS).We optimized the MALDI-TOF/TOF MS(tandem TOF MS)method with respect to culture medium and time.Formic acid-acetonitrile extraction was found to be the most suitable pretreatment method.The single-stage TOF MS spectra showed significant differences in identification scores,the number of characteristic peaks,and morphology among strains grown on different media.The number of major ion peaks decreased with culture time,leading to reduced matching accuracy.The tandem TOF MS spectra showed no significant changes in the characteristic peaks of strains at different culture times,indicating that the tandem TOF MS method was less affected by the external environment,exhibiting higher specificity.The single-stage TOF MS method had high accuracy for identifying strains cultured in specific environments for short durations.However,as the culture environment changed and the culture time increased,the results of single-stage TOF MS became unstable,while those of tandem TOF MS changed little.When they were applied to identify Gram-negative bacteria,compared with single-stage TOF MS,tandem TOF MS gave more stable results with fewer interfering peaks,thereby serving as an effective supplement to the existing microbial identification methods.
Benzalkonium chloride and didecyl dimethyl ammonium chloride residues in infant formula milk powder sold from 2022 to 2024 were detected and statistically analyzed.Based on the European Union's allowable daily intake for benzalkonium chloride and the German Federal Institute for Risk Assessment's allowable daily intake for didecyl dimethyl ammonium chloride,a point estimation method was used to provide estimated values applicable to the percentiles of the available sample quantities.The detection rates of C12-benzalkonium chloride C14-benzalkonium chloride,C16-benzalkonium chloride,and didecyl dimethyl ammonium chloride in infant formula milk powder were 23.3%,16.8%,15.4%,and 16.0%,respectively;the average residue levels from lower bound(LB)to upper bound(UB)were 10.96-12.18 and 3.71-4.13 μg/kg,respectively.The average exposure levels(LB-UB)to benzalkonium chloride for infants and young children aged 0-6,7-12,and 13-36 months were 0.281-0.297,0.036-0.047,and 0.026-0.032 μg/(kg mb·d),respectively.The average exposure levels(LB-UB)to didecyl dimethyl ammonium chloride were 0.091-0.095,0.007-0.011,and 0.013-0.016 μg/(kg mb·d),respectively.The hazard quotient(HQ)for both substances was less than 1.The contamination levels of benzalkonium chloride and didecyl dimethyl ammonium chloride in infant formula milk powder sold from 2022 to 2024 were found to be at an acceptable level.
The fat in breast milk exists in the form of fat globules,which are enveloped by a unique biophysical membrane called the milk fat globule membrane.The absence of fat globules will affect the structure and stability of fat droplets,which will in turn affect lipid digestion and absorption.In an effort to make the nutritional composition of milk powder approximate as closely as possible to that of breast milk,an extensive literature has developed concerning the fat globule membrane of cow's milk,goat's milk and other milks both domestically and internationally.With the aim of providing a reference for the resource development and application of milk fat globule membrane resources,this article reviews recent progress in understanding the composition of the milk fat globule membrane as well as the factors affecting the structure and functional characteristics of the milk fat globule membrane such as lactation stages,feeding regimes and milk sources as well as separation,thermal processing,homogenization and non-thermal processing,and it summarizes recent advances in breast milk fat globule membrane simulation and its application in infant formula and milk products for middle-aged and elderly people.
Protein is an important nutrient in the food system,and active ingredients(such as polyphenols,flavonoids,and terpenes)have a variety of physiological effects because of their unique chemical structures,such as antioxidant,antitumor,and chronic disease-preventive effects.They form complexes through covalent or noncovalent interactions,thus changing their functional structure,nutritional properties,and bioavailability.In this review,we summarize the application of multispectral methods,including ultraviolet-visible(UV-vis)absorption,fluorescence,Fourier transform infrared(FTIR),circular dichroism(CD)spectra,and molecular simulation techniques(molecular docking and molecular dynamics simulation)in the study of protein-active ingredient interaction.The principles,features,and examples of these techniques in the study of the interaction between protein and active ingredients are briefly described.This review also focuses on the application of molecular simulation in delivering active ingredients,regulating food flavor,and monitoring food quality based on protein-active ingredient systems,hoping to provide scientific reference for further study of the interaction between protein and active ingredients.
The milk fat globule membrane(MFGM)is a three-layered membrane that surrounds milk fat globules.Its main components include proteins,carbohydrates,and lipids,which are mainly derived from the mammary gland cell membrane.Different milk sources vary in the composition of MFGM proteins,which have good emulsifying properties,gastrointestinal stability and safety.Some MFGM proteins have diverse bioactivities including anti-inflammatory,antiviral and intestine regulatory effects and enhancing the exercise performance of muscles.This paper reviews the composition,physicochemical properties and bioactivities of MFGM proteins,which will provide a reference for the research and application of MFGM proteins in the dairy industry and related food additives.
In this study,a prediction model based on Fourier transform mid-infrared spectroscopy was developed for the rapid detection of β-lactoglobulin in milk.The content of β-lactoglobulin in 260 different batches of milk samples was determined as reference by high performance liquid chromatography(HPLC),and the mid-infrared spectra of raw milk were collected using an Fourier transform mid-infrared spectrometer.The effective wavebands were selected,and the background noise was eliminated by Savitsky-Golay(SG)smoothing,first-order derivative or second-order derivative pretreatment before the establishment of the β-lactoglobulin prediction model by using partial least squares regression(PLSR).The results showed that SG five-point smoothing second-order derivative was the optimum preprocessing method.The PLSR model exhibited good prediction accuracy with correlation coefficient(R2)of 0.932 for the calibration set,root mean square error of calibration(RMSEC)of 0.049%,R2 of 0.923 for the calibration set,and root mean square error of prediction(RMSEP)of 0.057%.
