Milk Powder Samples Research Articles

Screening of a High-Affinity Aptamer for Aflatoxin M1 and Development of Its Colorimetric Aptasensor

Aflatoxin M1 (AFM1), a secondary metabolite of Aspergillus spp., is highly toxic and widely present in food matrices. Therefore, the detection of AFM1 is of great importance for the protection of food safety. In this study, a five-segment sequence was designed as the initial library. Graphene oxide-SELEX (GO-SELEX) was applied to screen AFM1. After seven rounds of repeated screening, affinity and specificity assays showed that aptamer 9 was the best candidate for AFM1. The dissociation constant (Kd) of aptamer 9 was 109.10 ± 6.02 nM. To verify the efficiency and sensitivity aptamer for the detection of AFM1, a colorimetric sensor based on the aptamer was constructed. The biosensor showed good linearity in the range of AFM1 concentration of 0.5-500.0 ng/mL with a detection limit of 0.50 ng/mL. This colorimetric method was successfully used for the detection of AFM1 in milk powder samples. Its detection recovery was 92.8-105.2%. This study was conducted to provide a reference for the detection of AFM1 in food.

Colorimetric Sensing of the Peroxide Number of Milk Powder Using CsPbBr3 Perovskite Nanocrystals

In this study, a wavelength-shift-based colorimetric sensing approach for the peroxide number of milk powder using CsPbBr3 perovskite nanocrystals (CsPbBr3 NCs) has been developed. Through the fat extraction, REDOX reactions and halogen exchange, as well as the optimized experimental conditions, a colorimetric sensing method was established to determine the peroxide number of milk powder samples. The integrated process of milk powder fat extraction and the REDOX process greatly shortened the determination time. This colorimetric method has a good linear correlation in the range of the peroxide number from 0.02 to 1.96 mmol/kg, and the detection limit was found to be 3 μmol/kg. This study further deepens the application prospect of wavelength-shift-based colorimetric sensing using CsPbBr3 NCs.

One-pot synthesis of a novel conductive molecularly imprinted gel as the recognition element and signal amplifier for the selective electrochemical detection of amaranth in foods

Herein, we prepared a self-crosslinked conductive molecularly imprinted gel (CMIG) using cationic guar gum (CGG), chitosan (CS), β-cyclodextrin (β-CD), amaranth (AM) and multi-walled carbon nanotubes (MWCNTs) by a simple one-pot low temperature magnetic stirring method. The imine bonds, hydrogen-bonding interactions and electrostatic attractions between CGG, CS and AM facilitated CMIG gelation, while β-CD and MWCNTs enhanced the adsorption capacity and conductivity of CMIG, respectively. Next, the CMIG was deposited onto the surface of a glassy carbon electrode (GCE). After selective removal of AM, a highly sensitive and selective CMIG-based electrochemical sensor was obtained for AM determination in foods. The CMIG allowed specific recognition of AM and could also be used for signal amplification, thus improving the sensitivity and selectivity of the sensor. Due to the high viscosity and self-healing properties of the CMIG, the developed sensor was very durable retaining a 92.1% of original current after 60 consecutive measurements. Under optimal conditions, the CMIG/GCE sensor showed a good linear response for AM detection (0.02–150 μM) with a limit of detection of 0.003 μM. AM recovery tests were performed in milk powder and white vinegar samples, yielding satisfactory recoveries (89.00%–111.00%). Furthermore, the levels of AM in two kinds of carbonated drinks were analyzed with the constructed sensor and an ultraviolet spectrophotometry method, with no significant difference found of the two methods. This work demonstrates that CMIG based electrochemical sensing platforms allow the cost-effective detection of AM, with the CMIG technology likely being widely applicable to the detection of other analytes.

Radionuclides in commercial children's food consumed in Croatia

This work presents first results of radioactivity measurements in selected early children's food (<year) which are commercially available, widespread, and typically consumed in Croatia. The samples are categorized according to growth of a child, from its first nourishment, adapted powdered milk, to its first solid food, cereal porridge powder, homogenized fruit porridge and finally mushed meals with vegetables and/or meat. Natural 4 K is detected and quantified in all of the samples (from 30 Bq/kg up to over 250 Bq/kg), with highest values in powdered milk (150–200 Bq/kg) and cereal porridge (maximum value 262 Bq/kg in the sample containing oats). 226 Ra was visible in all types of foods in the majority of the samples in small amounts, not exceeding 0.92 Bq/kg. 137 Cs was detected only in some of the powdered milk samples with maximum measured activities (0.65 ± 0.32 Bq/kg and 0.38 ± 0.14 Bq/kg) found in the samples where 4 K showed largest values, too. 90 Sr was detected in majority of samples of fruit, vegetable and meat meals, reaching up to 0.065 ± 0.025 Bq/kg in vegetable porridge containing potatoes and carrot. It was detected only in one sample of powdered milk, and in none of the cereal porridge samples. All of the presented results are within the values reported by other studies around the world. The results are used to estimate the ingestion doses to evaluate the radiological health risk, which is calculated to be 0.72 mSv/year. The contribution of 4 K prevails with about 72%. The biggest part comes from intake of fruit (34%), followed by intake of milk (24%) and cereals (20%). The contribution of radioactivity in water, taken from previous studies is also considered. Even the maximum possible value of the annual dose for infants still doesn't exceed the recommended limit of 1 mSv. • Results of radioactivity measurements results in baby food in Croatia are presented. • 4 K, 226 Ra, 90 Sr and 137 Cs are found and quantified in most of the samples. • The ingestion doses for infants are estimated to be 0.72 mSv/year. • Contribution of 4 K prevails with about 72% to the ingestion dose. • Highest contribution comes from intake of fruit (34%), milk (24%) and cereals (20%).

Application of Three-Dimensional Digital Photogrammetry to Quantify the Surface Roughness of Milk Powder.

The surface appearance of milk powders is a crucial quality property since the roughness of the milk powder determines its functional properties, and especially the purchaser perception of the milk powder. Unfortunately, powder produced from similar spray dryers, or even the same dryer but in different seasons, produces powder with a wide variety of surface roughness. To date, professional panelists are used to quantify this subtle visual metric, which is time-consuming and subjective. Consequently, developing a fast, robust, and repeatable surface appearance classification method is essential. This study proposes a three-dimensional digital photogrammetry technique for quantifying the surface roughness of milk powders. A contour slice analysis and frequency analysis of the deviations were performed on the three-dimensional models to classify the surface roughness of milk powder samples. The result shows that the contours for smooth-surface samples are more circular than those for rough-surface samples, and the smooth-surface samples had a low standard deviation; thus, milk powder samples with the smoother surface have lower Q (the energy of the signal) values. Lastly, the performance of the nonlinear support vector machine (SVM) model demonstrated that the technique proposed in this study is a practicable alternative technique for classifying the surface roughness of milk powders.

Bisphenol A in Fluid and Powdered Milk Samples and Associated Child Dietary Exposures

Bisphenol A in Fluid and Powdered Milk Samples and Associated Child Dietary Exposures

Green synthesis of gardenia seeds-based carbon dots for bacterial imaging and antioxidant activity in aqueous and oil samples.

In this work, luminescent carbon dots with gardenia seeds as carbon precursors (GCDs) were synthesized using a one-step mild pyrolysis process and were then used as probes for imaging of bacterial (Escherichia coli). The GCDs showed a strong emission at 430 nm when excited at 370 nm. The relative fluorescence quantum yield of GCDs was found to be 1.13% in an aqueous medium. Rapid internalization of the GCDs by bacteria was confirmed by three colors (blue, green, and yellow) images that were obtained using confocal fluorescence microscopy. In addition, GCDs were noted to exhibit potent scavenging activities against DPPH˙, ˙OH, and ˙O2- free radicals. GCDs were also assayed as antioxidants in an oil sample by volumetric determination of the peroxide value. Thus, GCDs exhibited good antioxidant properties both in aqueous and oil media. In addition, a free fatty acid quantification kit in the presence of GCDs showed enhanced fluorescence detection of palmitic acid with a remarkably good limit of detection of 0.08 μM, which is lower than that in the absence of GCDs (0.76 μM). The proposed fluorescence method was then successfully used to determine the concentration of palmitic acid spiked in milk powder samples, with spiked recoveries of 82.6-109.6% and relative standard deviations of 0.9-4.6%.

First-Order Derivative Spectrophotometry Method with Triapine as Chelating Agent for Simultaneous Determination of Barium(II) and Lead(II)

A simple, selective and sensitive first-order spectrophotometric method was used for the simultaneous determination of Ba(II) and Pb(II) with triapine as chelating agent. When triapine reagent was mixed with Ba(II) and Pb(II) solutions, it produces a light green colour in a basic medium. Maximum peaks for both Ba(II) and Pb(II) were observed at pH 8.5 (basic buffer solution) between 350 and 395 nm. Ba(II)-triapine has a molar absorbance of 5.276 × 106 L mol-1 cm-1 and a Sandell’s sensitivity of 0.000189 g/cm2. Similarly, they are 9.421 × 105 L mol-1 cm-1 and 0.00106 g/cm2 for Pb(II)-triapine, respectively. The stability constants of Ba(II)-triapine and Pb(II)-trapine complexes are 3.207 × 104 and 5.118 × 104, respectively. The effects of Ba(II)-triapine and Pb(II)-triapine concentrations on amplitude were also studied. The detection and quantification limits for Ba(II)-triapine are 0.0882 g/mL and 0.746 g/mL, respectively. Similarly, detection and quantification values were 0.089 g/mL and 0.745 g/mL for Pb(II)-triapine, respectively. The developed or proposed method was used to examine biological samples of carrots, onions, beans, paints, milk powder and alloys. The sample results were close to the certified reference values for the ICP-AES, FDA and AAS methods.

Synthesis of crystallinity covalent organic framework and its ratiometric fluorescent detection of trace water

The sensitive and accurate detection of trace water in solid food products is of great significance for the protection of their stability and quality. Herein, a novel crystalline COF TAPT-BPTA with fluorescence was prepared via Schiff-base condensation reaction between 4,4′,4″-(1,3,5-Triazine-2,4,6-triyl)trianiline (TAPT) and 2,5-bis(2-propyn-1-yloxy)-1,4-benzenedicarboxaldehyde (BPTA). The fluorescence of TAPT-BPTA was sensitive to trace water and can be quenched due to the disruption of intermolecular charge transfer (ICT) process by water molecules. Hence, COF TAPT-BPTA was successfully applied for sensing of trace water in common organic solvents including acetone, acetonitrile, THF and DMF with rapid response (less than 3 s) and good sensing ranges (0.05–20 v/v% for acetone, 0.10–25 v/v% for THF, 0.05–15 v/v% for ACN, and 0.05–10 v/v% for DMF). The limit of detection of water in acetone, ACN, DMF, THF were 0.0585%, 0.0631%, 0.0185% and 0.0718% (v/v), respectively. Additionally, using TAPT-BPTA as signal probe and tris(2,2′-bipyridyl)ruthenium (II) dichloride with red fluorescent as reference, a ratiometric fluorescent sensor was prepared and successfully used for the sensing of trace water in milk powder samples.

Application of LC-MS/MS method for the determination of cyproheptadine in dietary supplements

Cyproheptadine is an H1 antihistamine, that is often illegally added in dietary&amp;nbsp;supplements to stimulate appetite and gain weight in children, currently banned for use in&amp;nbsp;health supplements according to the provisions of Circular 10/2021-BYT. The method was&amp;nbsp;using the Agilent Triple Quadrupole 6460 with fragments 288.1 &amp;rarr; 96.1 and 288.1 &amp;rarr; 191.2&amp;nbsp;selected for quantitative and qualitative. The separation was carried out on XBridge C18&amp;nbsp;column (100 mm &amp;times; 2.1 mm, 3.5 &amp;micro;m) with a mobile phase consisting of acetonitrile and 0,1%&amp;nbsp;formic acid. The analyte was extracted with methanol and cleaned up by d-SPE technique&amp;nbsp;using a mixture of PSA and C18 powder. The recovery was in the range of 80-110%, the&amp;nbsp;accuracy met the requirements of AOAC for method validation at spiked concentrations on&amp;nbsp;three matrices of dietary supplements (granules, syrup, and powdered milk). Limits of&amp;nbsp;detection and quantification were achieved at 0.08 mg/kg and 0.25 mg/kg with the syrup;&amp;nbsp;0.15 mg/kg and 0.50 mg/kg with granule and powdered milk samples. The method has been&amp;nbsp;applied to analyze 30 samples and detected cyproheptadine in a syrup sample at 1.67&amp;nbsp;mg/dose of 10 mL. This method can be applied to analyzing cyproheptadine in dietary&amp;nbsp;supplements on the market as well as developing for simultaneous determination of other&amp;nbsp;adulterants with similar properties and effects in our next studies.

Comparative study of some macro &amp; micro elements in milk samples from Abuja, Nigeria using microwave plasma atomic emission spectroscopy (MP-AES) and flame atomic absorption spectroscopy (F-AAS) methods

A comparative study was carried out for the determination of calcium, magnesium, iron and zinc contents in two brands of powdered milk samples, using the Microwave Plasma Atomic Emission Spectroscopy (MP-AES) and Flame Atomic Absorption spectroscopy (F-AAS) methods. The powdered milk samples were collected and placed in a muffle furnace at 550°C for 6 hours, and the ash contents obtained was used for the sample preparation. The percentage recoveries for the spikes were as follows: for MP-AES determination; the recoveries for the milk samples were within the range (116.9 – 163.1%) for calcium; (51.8 – 78.8%) for magnesium; (110.9 – 125.4%) for iron; (90.7 – 92.9%) for zinc. For FAAS determination; the recoveries for the milk samples were within the range (51.1 – 83.6%) for calcium; (52.2 – 61.9%) for magnesium; (77.7 – 84.8%) for iron; (46.5 – 71.7%) for zinc. The percentage recoveries showed a better recovery with MP-AES than the F-AAS method. The analysis of variance conducted using One way ANOVA method shows that there is no significant difference between the two methods used for the analysis, as the P-values (calculated probability) obtained were higher than 0.05. The values obtained for Ca, Mg, Fe and Zn content shows that only Ca was found to be within WHO/FAO standard, while Mg, Fe and Zn were found to be below the WHO/FAO standard. It is highly recommended that a 100g of any of the powdered milk used for the research work be consumed per day in order to meet up with the RDA per day, or other sources of these elements to be considered.Â

An ultra-sensitive photothermal lateral flow immunoassay for 17β-estradiol in food samples

Hormone residues in food and drinking water endanger human health, therefore, on-site analysis techniques of superior performance are important for monitoring this risk. In this study, an ultra-sensitive photothermal lateral flow immunoassay (LFIA) for quantification of 17β-estradiol (E2) has been developed. Anti-E2 antibody modified black phosphorus-Au (BP-Au) nanocomposite was developed as a photothermal contrast signal probe and the temperature at test-zone was recorded with an infrared camera. Under the irradiation of 808 nm laser at test-zone, it gave temperatures negatively related to the concentrations of E2 in samples. Under optimal detecting conditions, the developed photothermal LFIA exhibited a limit of detection of 50 pg mL−1, over 100-fold more sensitive than visual LFIA, and a linear range of 3 orders of magnitude. This method has been successfully applied to water, milk, and milk powder samples.

Amino Acid Fingerprinting of Authentic Nonfat Dry Milk and Skim Milk Powder and Effects of Spiking with Selected Potential Adulterants.

A collaborative study was undertaken in which five international laboratories participated to determine amino acid fingerprints in 39 authentic nonfat dry milk (NFDM)/skim milk powder (SMP) samples. A rapid method of amino acid analysis involving microwave-assisted hydrolysis followed by ultra-high performance liquid chromatography-ultraviolet detection (UHPLC-UV) was used for quantitation of amino acids and to calculate their distribution. The performance of this rapid method of analysis was evaluated and was used to determine the amino acid fingerprint of authentic milk powders. The distribution of different amino acids and their predictable upper and lower tolerance limits in authentic NFDM/SMP samples were established as a reference. Amino acid fingerprints of NFDM/SMP were compared with selected proteins and nitrogen rich compounds (proteins from pea, soy, rice, wheat, whey, and fish gelatin) which can be potential economically motivated adulterants (EMA). The amino acid fingerprints of NFDM/SMP were found to be affected by spiking with pea, soy, rice, whey, fish gelatin and arginine among the investigated adulterants but not by wheat protein and melamine. The study results establish an amino acid fingerprint of authentic NFDM/SMP and demonstrate the utility of this method as a tool in verifying the authenticity of milk powders and detecting their adulteration.

Quantitative PCR Assays for the Strain-Specific Identification and Enumeration of Probiotic Strain Lacticaseibacillus rhamnosus X253.

Probiotics are universally recognized for their health benefits, despite the fact that their effects depend on the strain. Identification and enumeration of probiotic strains are required prior to evaluating their effectiveness. Lacticaseibacillus rhamnosus X253 is a potential probiotic strain with antioxidant capacity. Comparative genomics and single nucleotide polymorphisms (SNPs) were used to identify a strain-specific locus within the holA gene for strain X253 that was distinct in 30 different L. rhamnosus strains. Using quantitative PCR, the primers and probe designed for the locus were able to distinguish L. rhamnosus X253 from the other 20 probiotic strains. The chosen locus remained stable over 19 generations. The sensitivity of the assay was 0.2 pg genomic DNA of L. rhamnosus X253, or 103 cfu/mL bacteria of this strain. In terms of repeatability and reproducibility, relative standard deviations (RSD) were less than 1% and 3%, respectively. Additionally, this assay achieved accurate enumerations of L. rhamnosus X253 in spiked milk and complex powder samples. The strain-specific assay could be used for quality control and compliance assessment of dairy products.

Cherenkov radiation technique for the determination of fission product 90Sr in milk

ABSTRACT Monitoring of the anthropogenic radionuclides (90Sr, 135Cs and 137Cs) in different components such as spinach, milk, meat, soil and the grass is important for the environmental radiological survey. Nuclear weapons testing in the atmosphere, nuclear power plant accidents and leaks from the nuclear fuel cycle are the main sources of these radionuclides. The amounts of 90Sr/90Y detected in the environment are mostly due to fallout from nuclear weapons testing. Because of its long physical (28.5 years) and biological half-lives (approximately 12 years) and high fission yield, the measurement of 90Sr is also necessary for radiation protection purposes. It accumulates in bone tissue when ingested by humans through the food chain, and 90Y, a daughter nuclide of 90Sr, emits high-energy beta particles, raising the risk of bone cancer. Strontium has been widely measured in milk samples by using various classical methods. In this study, the procedure we used is based on the separation of 90Y by HDEHP extraction and counting the Cherenkov radiation using a liquid scintillation spectrometer, Quantulus 1220. Prior to analyses, spiked milk samples were dried and prepared as milk powder. The microwave ashing programme was optimised, and recovery of the radiochemical separation steps was tested for spiked milk powder samples before routine analysis. This method is found to be applicable for the routine analysis of 90Sr in milk samples after validation of the method by measuring IRMM milk powder samples, too. A lower limit of detection of about 0.02 Bq.kg−1 was obtained for samples in the case of 84–99% Y chemical yield, 1.45 cpm reagent blank, 4 × 60 minutes counting time and about 83.5 ± 2.1% counting efficiency.

Fluorescence determination of chloramphenicol in milk powder using carbon dot decorated silver metal-organic frameworks.

Carbon dot decorated silver metal-organic frameworks (CD-MOFs) were successfully synthesized at room temperature by adding CDs during the formation of Ag-MOFs. The CD-MOFs have excellent optical property, stability, and good fluorescence intensity in water compared with other solvents. The fluorescence intensity of CD-MOFs was relatively stable in the range of pH 5-9. It was used to construct a sensitive and reliable fluorescent sensor for the determination of chloramphenicol (CAP). When the CAP was introduced into the CD-MOFs, the fluorescence at 427nm was quenched at the excitation wavelength of 332nm. Wide linear relationships were established for CAP with a limit of detection of 44 nM. The fluorescent sensor has been applied to determine CAP in milk powder sample with satisfied recoveries (104 to 109%) and good precision (< 4%). The photoinduced electron-transfer is the most important mechanism contributing to the fluorescence quenching. The synthesized CD-MOFs provide a new orientation for fluorescence determination of chloramphenicol in real samples.

Testing for total bacteria in dairy powder - Comparison of test incubation temperatures (a case study)

The dairy industry uses the aerobic plate count (APC) to enumerate mesophiles (30 °C) and thermophiles (55 °C). However, there are some dairy-associated bacteria with optimal growth outside the temperature range used. Seventy milk powder samples were tested for APC at 30, 37, 55 and 65 °C. There was no significant difference (p > 0.05) between the number of bacteria capable of growth at 30 and 37 °C in all samples. However, bacterial growth at 55 °C (1.78 log cfu g−1) was significantly higher (p < 0.05) than growth at 65 °C (1.54 log cfu g−1). Bacillus licheniformis was found to be the dominant bacterium in the dairy powder samples when testing was done at 30 and 37 °C. Geobacillus stearothermophilus and Anoxybacillus flavithermus were found to be dominant in dairy powder samples when tested at 55 and 65 °C. These results indicate that the current testing temperatures are satisfactory.

Eco-friendly and affordable trace quantification of riboflavin in biological and food samples using a supramolecular solvent based liquid–liquid microextraction

Reduction of organic solvent usage has been the preliminary force impressive the development of safer, and more environmentally friendly techniques. The present work applied a green supramolecular solvent-based liquid–liquid microextraction (Ss-LLME) method for preconcentration and quantification of riboflavin (RB) spectrofluorimetrically. The outstanding physicochemical properties of supramolecular solvents (Ss) make them very noteworthy in replacing the organic solvents in LLME. The recommended method was based using 1-decanol/THF as supramolecular solvent phase and the riboflavin extracted into the supramolecular solvent phase, and finally, the extraction recovery (%ER) was calculated. The impact of main variables in the extraction procedure, including pH, ultrasonic mixing time, the volume of 1-decanol, and THF, were examined and optimized by central composite design (CCD). Under the selected conditions, linear range, detection limit, and extraction repeatability (the relative standard deviation) were 5–700, 1.35 ng mL−1, and 4.3% (n = 4). The optimized method was successfully applied to determine RB in urine, soft drink, and milk powder samples as biological and food samples with recoveries between 86.7% and 101.5%. This study prospects the efficacy of the eco-friendly Ss-LLME method to enrichment and quantifies trace amounts of riboflavin in complicated matrixes.

A novel polymeric fluorescence sensor based on acrylated citric acid for detection of melamine adulteration: Application in milk powder

Melamine selective acrylate citric acid (ACA) based polymeric membrane sensor was prepared by radical polymerization method and the sensor was characterized. The sensor showed a selective fluorescent response to melamine (λex/λem = 388/425 nm). The sensor response is linear in the concentration range of 3.96 × 10−9 to 7.93 × 10−8 mol L−1, the optimum pH value is 6.0 and response time is less than 1 min. Limit of detection (LOD) and limit of quantification (LOQ) were calculated as 2.32 × 10−10 mol L−1 and as 7.74 × 10−10 mol L−1, respectively. The sensor showed great selectivity towards melamine in the presence of a large number of molecules and ions. The performance of sensor was also confirmed by determining of melamine in milk powder sample and the results were compared with HPLC results and acceptable results were obtained. As a conclusion, the results revealed that the proposed sensor is an interesting alternative for melamine determination.

Histopathological Modifications due to Intake of Powdered Milk

Milk is considered as one of the healthiest diet because it contins proteins, calcium, iron, vitamin D and other macro and micro nutrients. But people often use powdered milk due to unawareness of its side effects on the development and growth of body. Powder milk has all of bioactive elements which effect on body weight by deposing fats in adipose tissues. In this experimental work, two powdered milk samples: nido and eveyday. Powdered milk samples were converted into liquid by treating with distilled water. For experiment albino mice (Mus musculus) were selected and dose was given orally for four weeks. The histopathological results of hepatic and renal tissues were found striking even onset of tumrogenesis was observed. The alterations in both hepatic and renal tissues related to necrosis, glomerulai size, blood vessels’ diameter and their wall thickness, lobules, bile duct and nuclear enlargement were observed. From current study it was concluded that powdered milk of any brand is not suitable for health and growth and in this regard, organized efforts of general public awareness are required.