Powdered Infant Formula Milk Research Articles

Assessment of Aflatoxin M1 in human breast and powdered milk in Tehran, Iran

Aim and backgroundAflatoxins, produced by Aspergillus flavus and Aspergillus parasiticus, are among the most toxic mycotoxins. Aflatoxin M1 (AFM1) is a hydroxylated metabolite of aflatoxin B1 (AFB1), found in milk and dairy products from animals fed AFB1-contaminated feed. Consumption of AFM1 has related adverse effects on human health. Breast milk can be a source of contamination for infants due to the presence of AFM. AFM1 can also contaminate powdered milk, a significant product of the milk industry. Consequently, monitoring dairy products for these toxins is imperative. Study methodA total of 50 samples (25 samples of breast milk and 25 samples of powdered infant milk formula) were collected in Tehran from December 2021 to February 2022. HPLC method was used for the determination of AFM1 in samples. Resultsand Discussion: AFM1 was detected in 72% of breast milk samples and 96% of powdered milk samples. AFM1 levels varied significantly between the two sample types (p < 0.05). The average amount of AFM1 in breast milk samples was 25.82 ± 4.72 ng/kg, while the average amount in powdered milk samples was 40.59 ± 7.76 ng/kg. Moreover, 44% of the breast and 68% of powdered milk samples exceeded the AFM1 content limit of the European Union and the Iranian national standard. This study concludes that given the importance of breast milk and formula to maternal and infant health, monitoring and regulating the toxin levels in these products in Tehran is crucial.

Effects of radio frequency heating on the glass transition, protein structure, and volatile compounds profile of commercial powdered infant formula milk

Radio frequency (RF) has found its potential in ensuring the safety of packaged powdered infant formula milk (PIFM). PIFM was processed by RF at different temperature-holding time treatments (70 °C-115 min, 75 °C-50 min, 80 °C-25 min, 85 °C-10 min, and 90 °C-5 min) to obtain 5-log reduction of Cronobacter sakazakii, and its physicochemical characteristics were investigated. Various RF treatments possessed insignificant effects on color difference (ΔE < 1.5), solubility (>99%), crystallinity (∼5%), surface chemical composition (>30% fat, 15%–20% protein, and 45%–50% lactose), and microstructure of PIFM. Lower temperature-longer holding time treatment as 70 °C-115 min caused 51% reduction in water activity and 71% reduction in moisture content, thereby considerably increasing the glass transition temperature of PIFM from 60.3 °C to 78.4 °C. Protein secondary structures were preserved; however, 75 °C-50 min and 80 °C-25 min treatments significantly (P < 0.05) decreased the α-helix structure. All RF heating conditions significantly (P < 0.05) altered the concentration of volatile organic compounds in PIFM and increased the relative abundance of lipid oxidation substances such as (E)-2-heptenal, 2-heptanone, and n-nonanal. PIFM can be treated at 90 °C for 5 min for better quality and processing efficiency.

Dried Baby Formula as a Source of Opportunistic Members of Enterobacteriaceae for Infants

For evaluating the prevalence of Enterobacteriaceae in baby formulas, we examined 60 different samples of powdered infant milk formula and milk-cereal based infant formula that is recommended for first-day birth and from 6-month age, respectively, and collected from various supermarkets, shops, and pharmacies. Six (20.0%) and thirteen (43.3%) powdered infant milk formulas and milk-cereal based infant formulas, respectively, were contaminated by different Enterobacteriaceae involved Enterobacter cloacae ssp. cloacae, Pantoea spp., Enterobacter hormaechei, and Raoultella ornithinolytica, which were identified using traditional biochemical tests and the vitek2 compact system. Only five samples of investigating milk-cereal based infant formula type have coliforms count of 4 MPN/g. All species were susceptible to gentamycin, while all were resistant to cephalothin antibiotics. Eventually, 20.0 % of powdered infant milk formula samples were unacceptable referred to Egyptian standards (2072/2006) and most of the comparable international standards. In the study, we proved the contamination of powdered milk baby formula by Enterobacteriaceae, which mainly causes health problems in immature and immunocompromised infants. The dried infant formula factories are more needful for good hygiene and safety systems applications. This study is one of the fewest studies conducted in Egypt to isolate Enterobacteriaceae members from dried foods; especially milk-cereal based infant formula.

Surface free fat bridging contributes to the stickiness of powdered infant formula milk pasteurized by radio frequency dry heat treatment

The effects of radio frequency (RF) dry heat treatment on powdered infant formula milk (PIFM) stickiness were investigated. Commercial spray-dried PIFM with a water activity of 0.28 was treated at a constant temperature of 70 °C for 0, 23.3, 46.6, 69.9, 93.2, and 116.5 min, corresponding to 0–5 logarithmic inactivation of Cronobacter sakazakii . All RF treatments significantly reduced the water activity, while induced insignificant change in lactose crystallinity (∼2%–3%) and surface free fat content (∼0.005–0.006 g/g powder) compared with the untreated sample. The particle size of PIFM was increased markedly when the holding time reached 23.3 min, and after that changed insignificantly, suggesting that the stickiness between neighboring particles was completed at the initial stage of pasteurization. The stickiness of the powders was noted along with the flow of molten surface fat when processed for 23.3 min, but fat coverage decreased due to fat solidification as time increased from 23.3 min to 116.5 min. Compared with the untreated samples, the increased surface lactose coverage of treated PIFM reduced the critical water activity for glass transition from 0.39 to 0.31 at 25 °C. This study demonstrated that surface free fat bridges were responsible for increasing particle size after RF dry heat pasteurization. •Radio frequency treatment redistributed the surface free fat. •Surface fat bridge contributed to a significant increase in particle size. •Radio frequency distinctly increased the lactose exposure on the particle surface. • Radio frequency reduced the critical water activity for lactose glass transition.

Prevalence of Bacillus cereus in dairy powders focusing on its toxigenic genes and antimicrobial resistance

Bacillus cereus is a common environmental foodborne microorganism that is mainly found to harbor toxigenic genes with multiple antibiotic resistances and is linked to threatening the safety of dried milk in concern to powdered infant milk formula. In the current investigation, the mean value of B. cereus in 140 samples of powdered milk was 0.57 × 102 ± 0.182 × 102, 0.15 × 102 ± 0.027 × 102, 0.21 × 102 ± 0.035 × 102, and 0.32 × 102 ± 0.072 × 102 CFU/g in a percentage of 64.0 samples of whole milk powder, 43.3 of skim milk powder, 26.7 of powdered infant milk formula and 36.7 milk–cereal-based infant formula, respectively. The results revealed that B. cereus isolates were found to harbor toxigenic genes in the following percentages: 77.8, 2.0, 72.7, 16.2, and 67.7 for nhe, hbl, cytK, ces, and bceT, respectively. Despite all evaluated B. cereus strains were originated from dairy powders, they showed a significant difference (P < 0.05) in their harbored toxigenic cytK gene between whole and skim milk powders with powdered infant formula and milk–cereal-based infant formula, as well as between powdered infant formula and milk–cereal-based infant formula. All isolated B. cereus strains were resistant to cefoxitin, colistin sulfate, neomycin, trimethoprim–sulfamethoxazole, oxacillin, and penicillin. Based on the antimicrobial resistance of B. cereus strains to cephalothin, chloramphenicol, nalidixic acid, and tetracycline, there was a significant difference (P < 0.05) between powdered infant milk formula and whole milk powder strains. This survey is one of few studies proceeded in Egypt to determine the prevalence of toxigenic B. cereus strains in milk–cereal-based infant formula and powdered infant formula as well as skim milk powder.

Antibiotic Resistance and Molecular Characterization of Cronobacter sakazakii Strains Isolated from Powdered Infant Formula Milk.

Background: Cronobacter sakazakii is a new emerging foodborne bacterial pathogen associated with severe lethal diseases such as meningitis, necrotizing enterocolitis, and septicemia in infants and neonates. Powdered infant formula milk (PIFM) has been recognized as one of the main transmission vehicles and contaminated sources of this pathogen. This study aimed to investigate the prevalence rate, genotypic and phenotypic antibiotic resistance profile, and clonal relatedness of C. sakazakii strains isolated from 364 PIFM samples collected from Tehran city, Iran. Methods: Culture-based methods, Kirby–Bauer disk diffusion antibiotic resistance testing, conventional Polymerase Chain Reaction (PCR), and Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR) assays were used in this study to detect and characterize the C. sakazakii isolates. Results: We isolated 25 C. sakazakii strains from PIFM samples (6.86%). The isolates were highly resistant to amoxicillin-clavulanic acid, amoxicillin, ampicillin, cefoxitin, cefepime, erythromycin, ceftriaxone, ciprofloxacin, and chloramphenicol and susceptible to gentamicin, tetracycline, norfloxacin, and azithromycin antibiotics. The blaCTX-M-1 gene was detected in 96% of the isolates. The isolates were categorized into eight distinct clonal types using the ERIC-PCR method, showing a high genetic diversity among the isolates. However, there was a significant correlation between the genotypic and phenotypic antibiotic resistance properties of the isolates. Conclusions: Novel microbial surveillance systems for detecting multi-drug-resistant C. sakazakii are required to control the contamination of this foodborne pathogen in infant foods.

Dielectric loss mechanism of powdered infant formula milk

Dipole loss of main compositions of powdered infant formula milk (PIFM), including whey protein (WP), fat and lactose and the ionic loss of PIFM were analyzed over frequency range of 10 to 3000 MHz at temperature range of 20–80 °C. Dielectric loss factor of PIFM decreased with increasing fat content, while increased with increasing WP content and lactose content at investigated frequencies in our study. The dipole loss of WP, fat and lactose followed Debye equation which increased with increasing frequency till around 1.2,1 and 1 GHz, respectively, and then decreased. Ionic loss of PIFM was constant with increasing frequency at investigated frequencies and increased with increasing temperature. A general formula to calculate ionic loss for both solid and liquid materials was obtained. Validation experiments based on the dielectric loss factor of different compositions indicated that increasing WP proportion in PIFM can increase heating rate in radio frequency field and also result in lower lipid oxidation of treated PIFM. This provides a solution to adjust RF heating performance and product quality based on loss mechanisms of different ingredients.

Prevalence of Melamine and Cyanuric Acid in Powdered Dairy Products in Egypt.

This study was conducted to screen melamine and cyanuric acid in powdered dairy products, which becomes a high safety concern, as considered one of the scanty surveys in Egypt. A total of 140 samples (fifty whole milk powder, thirty samples of each; skim milk powder, powdered infant milk formula, and dried milk-cereal-based infant formula were collected from Egyptian markets and pharmacies. Samples were analyzed for the presence of melamine and cyanuric acid using Liquid Chromatography-Mass Spectrometry (LC-MS/MS). Melamine was detected in 15/50 of whole milk powder, 22/30 of skim milk powder, 20/30 of powdered infant milk formula, and 25/30 milk-cereal-based infant formula samples. Meanwhile, cyanuric acid couldn't be detected in any examined samples, as its concentration was < 0.05 mg/kg. This investigation initially proceeded in Egypt for melamine and cyanuric acid detection in milk-cereal-based infant formula and skim milk powder. It is targeted for re-attention from concerned authorities to these toxic chemicals.

Genotypic and antimicrobial resistance characterizations of Cronobacter sakazakii isolated from powdered milk infant formula: A comparison between domestic and imported products.

Cronobacter sakazakii, an opportunistic foodborne pathogen and a main cause of meningitis in neonates, is usually isolated from powdered milk infant formula (PMIF). At the present study, C. sakazakii were isolated from imported and domestically produced PMIF samples and identified by detection of ompA gene using real‐time PCR SYBR green melting curve following the evaluation of antimicrobial susceptibility and genotyping of the isolates employing BOX‐PCR and RAPD methods. We detected totally 5% contamination rate and a significantly higher prevalence of C. sakazakii in bulky imported domestically packaged PMIF samples. Also, our isolates were recognized as multidrug‐resistant pathogen completely resistant to ampicillin and amoxicillin; and intermediately resistant to ciprofloxacin and tetracycline antimicrobials. Genotype clustering patterns of bulky imported and imported product isolates were identical by both genotyping methods. Far genetic relatedness of domestic isolate to other isolates and the reference strain indicated higher genetic diversity of the domestic isolate genome. Multidrug resistance and diverse population genetic make complicated situation for determination of strategies for infectious disease prevention.

Effects of radio frequency on physicochemical properties of powdered infant formula milk as compared with conventional thermal treatment

Radio frequency (RF) has been proved effective in inactivating Cronobacter sakazakii in powdered infant formula milk (PIFM). For successful industrial application, the quality of PIFM after combined RF and hot air treatment (RF-HA) were further investigated based on 5-log inactivation of Cronobacter sakazakii as compared with hot water treatment (HW). Severer color deterioration was observed on HW treated samples. No significant difference existed on solubility (>99%) and crude protein content (about 13 g/100 g) after both treatments. Protein denaturation temperature obtained from the differential scanning calorimetry curves increased with decreasing moisture content of PIFM and RF-HA resulted in more stable protein structures. Fourier transform infrared spectrum further confirmed the development of Maillard reaction, which was weaker in RF-HA. Microstructure by scanning electron microscopy revealed more obvious particle agglomeration behavior induced by RF. Overall, higher water activity, 0.4 as the upper limit, was not good for maintenance of nutritional attributes, though conducive to sterilization. This study could provide useful information for PIFM quality evaluation and optimization of thermal pasteurization methods.

Thermal inactivation of Cronobacter sakazakii ATCC 29544 in powdered infant formula milk using thermostatic radio frequency

A 27.12 MHz thermostatic radio frequency (RF) system was employed to inactivate Cronobacter sakazakii in powdered infant formula milk. A proportional-integral-derivative controller achieved constant material temperature during the holding period. Hot air and similar dielectric material assistance were used to improve RF heating uniformity. The results showed that the microbial thermal resistance was reduced by increasing temperature (55–70 °C) and water activity (0.2–0.4 at 25 °C). Combined RF and hot air pasteurization (RF-HA) was more effective than single RF and material assistance due to better temperature uniformity. D70°C-value (23.3 min) of Cronobacter sakazakii at water activity of 0.2 from RF-HA was not significantly (P > 0.05) higher than that under hot water treatment (20.8 min), indicating that thermal effect led to microbial inactivation. Flow cytometry and transmission electron microscopy further confirmed that RF had no additional damage to cell membrane. The findings contribute to better understanding of RF pasteurization mechanism.

Validation of radio frequency assisted traditional thermal processing for pasteurization of powdered infant formula milk

This study validated the radio frequency assisted traditional thermal processing (RF assisted-TTP) for pasteurization of low-moisture foods. Powdered infant formula milk (PIFM) with water activity of 0.22 ± 0.01 was selected as a low-moisture food model. The cold spot during the RF heating of PIFM was found to be the center of top layer in a tray containing 312 g of PIFM. The PIFM was inoculated with Cronobacter sakazakii and 12 g inoculated sample packed in a plastic bag was placed at the pre-determined cold spot. The sample was treated until the cold spot reached 65 °C in a 6-kW, 27.12-MHz RF heating system and the sample tray was transferred to a hot air oven set at 65 °C for various holding times. Based on the microbial inactivation during holding time, D-value at 65 °C was determined. After 21 h oven holding, a 5-log reduction of C. sakazakii was achieved. The sample was also thermally treated in the same oven without any RF pre-heating. The quality analysis results indicated that both RF assisted-TTP and TTP had no significant effect on color, solubility, digestibility, and wettability, while significant changes were observed on water activity, moisture content, POV and TBArs after both treatments. Come-up time to heat up sample to 65 °C in RF system and oven was approximately 10 min and 5 h, respectively. RF assisted-TTP is more suitable for pasteurization of PIFM than TTP due to lower lipid oxidation and much shorter overall processing time. Thus, RF may provide a potential as an effective emerging technology for pasteurizing while maintaining the quality of PIFM.

Rapid supercritical fluid chromatography analysis for 18 phthalate esters and bisphenol A in dairy products

A rapid and environmental method based on supercritical fluid chromatography (SFC) was established for the simultaneous analysis of 18 phthalate esters (PAEs) and bisphenol A (BPA) in dairy products. The stationary phases, organic modifiers, back pressures and column temperatures were investigated for the optimal separation. The BEH chromatographic column (100 mm x 3.0 mm, 1.7 mm) with sub-2-micron particles was performed for the detection of target compounds. 18 PAEs and BPA can be effectively separated within 5.5 min with acetonitrile as solvent modifier at the optimal conditions. The correlation coefficients (R2) of 18 PAEs and BPA were more than 0.997 in the linear range of 0.3-10.0 mg/L, except for BMPP, DNOP and BPA in the range of 0.6-10.0 mg/L. The limits of quantification (LOQs) for PAEs and BPA were 0.15-0.60 mg/kg. The spiked recoveries and relative standard deviation (RSDs) were in the range of 88.2-120.5% and 1.55-13.51% for powdered milk infant formula samples, 89.6-114.2% and 0.69-10.06% for milk drinks samples, respectively. The SFC method can be used as a simple and efficient alternative route for the detection of 18 PAEs and BPA in dairy products.

Characterisation and quantification of protein oxidative modifications and amino acid racemisation in powdered infant milk formula

Modification of proteins in infant milk formula (IF) is of major concern to the dairy industry and consumers. Thermal treatment is required for microbiological safety, but heat, light, metal-ions and other factors may induce oxidative damage, and be a health risk. In this study protein modifications in IFs were quantified. IFs contained both reducible (disulphide) and non-reducible (di-tyrosine, lanthionine, lysinoalanine) protein cross-links. Dehydroalanine and the cross-linked species lanthionine and lysinoalanine were detected. Protein carbonyls were detected predominantly on high molecular mass materials. Oxidation products of phenylalanine (m-tyrosine), tryptophan (N-formylkynurenine, kynurenine, 3-hydroxykynurenine), tyrosine (di-tyrosine) and methionine (methionine sulphoxide) were detected, consistent with amino acid modification. Higher levels of most of the markers of protein modification were present in the hydrolysed protein brand, when compared to the conventional IF samples, indicative of increased damage during additional processing. Significant levels of racemised (D-) amino acids were present. These data indicate that amino acids in proteins in IFs are modified to a significant extent during manufacture, with hydrolysed IF being particularly prone.

Characteristics of Escherichia coli Isolated from Bovine Mastitis Exposed to Subminimum Inhibitory Concentrations of Cefalotin or Ceftazidime.

Escherichia coli is a major udder pathogen causing clinical mastitis in dairy cattle and its heat stable endotoxin in powdered infant formula milk is a potential risk factor in neonatal infections. Cephalosporins are frequently used for treatment of mastitis caused by mastitis; however, use of these antimicrobials may induce antimicrobial resistance in E. coli. The objective of this study was to explore the in vitro effect of subminimum inhibitory concentrations (sub-MIC) of cefalotin (CF) and ceftazidime (CAZ) on the morphology, antimicrobial resistance, and endotoxin releasing characteristics of 3 E. coli isolates recovered from bovine clinical mastitis. The parent E. coli isolates, which were susceptible to CF and CAZ, were exposed to CF or CAZ separately at sub-MIC levels to produce 9 generations of induced isolates. Colonies of the CAZ-induced isolates from all 3 parent E. coli were smaller on blood agar and the bacteria became filamentous, whereas the CF-induced isolates did not demonstrate prominent morphological changes. After induction by CF or CAZ, many induced isolates showed resistance to cefoxitin, CAZ, CF, kanamycin, ampicillin, and amoxicillin/clavulanic acid while their parent isolates were susceptible to these antimicrobials. Notably, 5 CAZ-induced isolates from the same parent isolate were found to produce extended-spectrum beta-lactamase (ESBL) though none of the tested ESBL related genes could be detected. All CAZ-induced isolates released more endotoxin with a higher release rate, whereas endotoxin release of CF-induced E. coli isolates was not different from parent isolates. The exposure of cephalosporins at sub-MIC levels induced resistant Escherichia coli. We inferred that cephalosporins, especially CAZ, should be used prudently for treatment of clinical E. coli mastitis.

Molecular detection of Enterobacter spp. and other related species in powdered milk infant formula and milk powder

AbstractA total of 60 powdered milk infant formula and milk powder samples were obtained from different localities in Qena Governorate, Egypt, to be evaluated for presence of Enterobacter and closely related species using FDA procedure. Ten out of 60 samples were contaminated with Enterobacter spp. and other Enterobacteriaceae. The obtained isolates were biochemically identified as Enterobacter spp., Klebsiella pneumoniae, Escherichia coli, Citrobacter spp. Further characterization was performed using 16S rRNA sequence analysis; it was a pivotal to confirm the identity of the isolates especially in imprecise identification of phenotypic method in some isolates like Enterobacter hormaechei, Klebsiella quasipneumoniae, and Acinetobacter vivianii. Results revealed the contamination of powdered milk infant formula with E. hormaechei which makes it a matter of concern. According to the best of our knowledge, Enterobacter hormaechei and Klebsiella quasipneumonia were isolated for the first time in Egypt. The phylogenetic analysis proved the close relation between our isolates in amplification of partial 16S rRNA gene.Practical applicationsAs many neonates depend on powdered infant formula in their feeding as well as milk powder is a fundamental component of many infants diet, our study evaluated these products for the presence of pathogens of safety concern. This study focused on Enterobacteriaceae family members other than Salmonella and Cronobacter sakazakii using 16S rRNA gene for identification and differentiation of the closely related species.

P-8 - Characterization and quantification of protein oxidative modifications and amino acid racemization in powdered infant milk formula

Oxidation of dairy products, and especially infant formulas (IFs), is a major concern to the dairy industry and consumers. Thermal treatment is required for microbiological safety but may contribute to oxidative damage. Such modification may be a health risk for infants with IF as the sole source of nutrition. This study quantifies the extent of modification in commercial IFs. Protein modification in commercial IFs was examined by multiple analytical techniques. Aggregated proteins containing both reducible (disulfide) and non-reducible (di-tyrosine, lanthionine and lysinoalanine) cross-links were detected. Protein carbonyls (

Optimization of drying conditions and components to reduce wall sticking during spray drying of infant formula milk

Wall sticking, which greatly reduces productivity and product quality, has been a big challenge of spray drying. Structure of drying tower and atomizer, as well as drying conditions are the main influencing factors. This research explored the possibility to reduce wall sticking by optimizing drying conditions and components to obtain higher recovery rate of powdered infant formula milk (PIFM). Response surface experimental results indicated that inlet air temperature (T), feed concentration (C), feeding speed (S), as well as interaction term of TC and quadratic terms of C2 and S2 had significant influences on recovery rate for determined milk formula. According to mixture experiments at optimized drying conditions, whey protein (P), fat (F) and lactose (L) contents, as well as interaction term FL had significant effects on recovery rate. Positive effects were observed for F and L contents on recovery rate, while negative effects were observed for P and FL. Under the optimized drying condition of 136°C, 19.80% and 4.07 mL/min, respectively, for T, C and S, the maximum recovery rate of 58.98% was obtained for PIFM with P, F and L content of 18%, 31% and 51%, respectively. Wall sticking phenomena could be reduced by optimizing drying conditions and mildly adjusting components of infant formula milk. Keywords: spray drying, drying condition, wall sticking, inlet temperature, feed concentration, feeding speed, powder recovery rate, infant formula milk DOI: 10.25165/j.ijabe.20181102.2788 Citation: Lin Y W, Liu Y H, Wang L, Xie Y K, Gao Z J, Wang S J. Optimization of drying conditions and components to reduce wall sticking during spray drying of infant formula milk. Int J Agric & Biol Eng, 2018; 11(2): 214–218.

Development of an isothermal amplification-based assay for the rapid detection of Cronobacter spp.

Cronobacter spp. is an opportunistic pathogen that is associated with rare but life-threatening neonatal infections resulting from the consumption of contaminated powdered infant formula milk (PIF). In the present study, we developed recombinase polymerase amplification (RPA) and real-time RPA for the detection of Cronobacter spp. in PIF for the first time by targeting the ompA gene. The specificity and sensitivity of the RPA and real-time RPA were validated and the practical applicability of these methods for the detection of Cronobacter spp. in artificially contaminated PIF samples was proved by comparing their reaction time, sensitivity, and efficacy with those of real-time PCR and the Chinese traditional method. The RPA and real-time RPA assays reduced the analysis time to less than 15 min and the results were as reliable as those of real-time PCR. Taken together, the RPA and real-time RPA assays served as fast, reliable, and sensitive techniques for the detection of Cronobacter spp.

To Determine the Frequency of Bacillus cereus in Powdered Milk Infant Formula Consuming in Neonatal Intensive Care Unit (NICU) in Tehran Hospitals in 2013-14

To Determine the Frequency of Bacillus cereus in Powdered Milk Infant Formula Consuming in Neonatal Intensive Care Unit (NICU) in Tehran Hospitals in 2013-14