Fresh Milk Research Articles

Chemical composition, fatty acids, amino acids, minerals and vitamins profiles of Mithun (Bos frontalis) milk reared under semi-intensive system

This study examined the composition and nutritional value of milk produced by Mithun (Bos frontalis) reared under a semi-intensive model. The study analyzed the milk's chemical composition, fatty acids, amino acids, minerals, and vitamin profiles using standard methods. The results showed that fresh Mithun milk contained (Mean ± SEM) 7.3 ± 0.48 % fat, 10.28 ± 0.13 % solids-not-fat, 4.0 ± 0.05 % protein, 5.7 ± 0.08 % lactose, and had a density of 1.20 ± 0.01 g/mL. Gas chromatography analysis revealed that the milk contained 69.08 % saturated fatty acids and 30.82 % unsaturated fatty acids. The most abundant fatty acids were palmitic, oleic, stearic, and myristic acids, while linoleic 18:2 (n-6) and linolenic acids 18:3 (n-3) were the most abundant polyunsaturated fatty acids. The study also found that Mithun milk was rich in essential amino acids, with glutamic acid, lysine, proline, and isoleucine being the most abundant. In addition, Mithun milk was found to have a high concentration of vitamins A, D, and E, as well as calcium. The study concluded that Mithun milk could serve as a nutrient-dense food and contribute significantly to the nutritional security of North East India.

Milk volatilome as affected by somatic cell count in Holstein cows

The aim of the current trial was to study the impact of a high somatic cell count (SCC) on milk volatilome of fresh raw milk, and its evolution during storage of processed fluid milk. Six Holstein cows were selected from our research dairy herd based on test-day SCC records. Three cows were used to produce low-SCC milk (20 × 103 cells/mL). The three other cows had one-quarter infected by Staphylococcus aureus. Infected and healthy udder halves were milked separately, and high-SCC milk was standardized to 400 × 103 cells/mL by mixing these two milks. The profile of milk volatile organic compounds (VOCs) was determined on raw milk and during the storage of processed milk. The processing included a standardization to 3.25% fat, followed by homogenization, and thermization (65 °C/30 min). This procedure was repeated four times over a period of 7 days. A total of 40 VOC were identified using the solid-phase microextraction technique followed by gas chromatography separation, mass spectrometry analysis, and database search. These VOC were grouped into seven different families, including alcohols (n = 4), free fatty acids (n = 5), sulfur compounds (n = 3), esters (n = 7), ketones (n = 7), aldehydes (n = 12), and aromatic hydrocarbons (n = 2). In raw milk, high SCC was associated with a tendency for lower concentrations of ethyl-hexanoate (P = 0.07), acetone (P = 0.06), and benzaldehyde (P = 0.07) and lower concentrations of trans-2 hexenal (P = 0.04). On the contrary, high SCC was associated with a tendency for greater concentrations of acetic acid (P = 0.09) and hexanoic acid (P = 0.07) and greater concentrations of 2-nonanone (P = 0.02) and pentanal (P = 0.01). Concentrations of most VOC increased during the storage of processed milk. Lower concentrations of butanoic acid (P = 0.09; tendency) and ethyl hexanoate (P = 0.04), and greater concentration of 1-ocen-3-ol (P < 0.01) were observed in high-SCC milk at all times of storage evaluated. Increases in concentrations over time were less pronounced for ethanol (P < 0.01), ethyl butanoate (P = 0.05), and propanal (P = 0.10) in high SCC as compared with low SCC milk. In conclusion, an increase in SCC has a limited effect on milk volatilome, when a SCC standard of 400 × 103 cells/mL for bulk milk is respected.

Differences in small intestinal apparent amino acid digestibility of raw bovine, caprine, and ovine milk are explained by gastric amino acid retention in piglets as an infant model.

The rate of stomach emptying of milk from different ruminant species differs, suggesting that the small intestinal digestibility of nutrients could also differ across these milk types. To determine the small intestinal amino acid (AA) digestibility of raw bovine, caprine, and ovine milk in the piglet as an animal model for the infant. Seven-day-old piglets (n = 12) consumed either bovine, caprine, or ovine milk diets for 15 days (n = 4 piglets/milk). On day 15, fasted piglets received a single meal of fresh raw milk normalized for protein content and containing the indigestible marker titanium dioxide. Entire gastrointestinal tract contents were collected at 210 min postprandially. Apparent AA digestibility (disappearance) in different regions of the small intestine was determined. On average, 35% of the dietary AAs were apparently taken up in the small intestine during the first 210 min post-feeding, with 67% of the AA digestibility occurring in the first quarter (p ≤ 0.05) and 33% in the subsequent two quarters. Overall, except for isoleucine, valine, phenylalanine, and tyrosine, the small intestinal apparent digestibility of all AAs at 210 min postprandially in piglets fed ovine milk was, on average, 29% higher (p ≤ 0.05) than for those fed bovine milk. Except for lysine, there was no difference in the apparent digestibility (p > 0.05) of any AAs between piglets fed caprine milk or ovine milk. The apparent digestibility of alanine was higher (p ≤ 0.05) in piglets fed caprine milk than those fed bovine milk. When apparent digestibility was corrected for gastric AA retention, only small differences in the small intestinal apparent digestibility of AAs were observed across milk types. Bovine, caprine and ovine milk had different apparent small intestinal AA digestibility at 210 min postprandially. When corrected for gastric AA retention, the differences in apparent digestibility across species largely disappeared. The apparent AA digestibility differed across small intestinal locations.

Value chain analysis of fresh dairy milk in Sleman Regency

The right value chain influences effectiveness and efficiency. The use of the right value chain will provide benefits in economic and environmental. The value chain that can still be maximized is the fresh dairy milk. This paper aimed to analyze the fresh dairy milk channel, marketing margin, and marketing efficiency in Pakem Subdistrict and Cangkringan Subdistrict, Sleman Regency. The research was conducted to collect data from 35 farmers, actors involved, and dairy cooperatives as respondents who were selected using purposive and snowball sampling techniques. The results showed that there are four marketing channels of fresh dairy milk but ineffective due to high marketing margins and a low Farmer’s Share (FS) value of <60. Poor marketing channels have an economic impact and environmental impact. The economic impact on decreasing farmers’ income and reducing farmers’ welfare. While the environmental impact is an increase in the use of fuel in the distribution of fresh dairy milk and the performance of the dairy industry.

Identification and prediction of milk-derived bitter taste peptides based on peptidomics technology and machine learning method

Bitter taste peptides (BPs) are vital for drug and nutrition research, but large-scale screening of them is still time-consuming and costly. This study developed a complete workflow for screening BPs based on peptidomics technology and machine learning method. Using an expanded dataset and a new combination of BPs’ characteristic factors, a novel classification prediction model (CPM-BP) based on the Light Gradient Boosting Machine algorithm was constructed with an accuracy of 90.3 % for predicting BPs. Among 724 significantly different peptides between spoiled and fresh UHT milk, 180 potential BPs were predicted using CPM-BP and eleven of them were previously reported. One known BP (FALPQYLK) and three predicted potential BPs (FALPQYL, FFVAPFPEVFGKE, EMPFPKYP) were verified by determination of calcium mobilization of HEK293T cells expressing human bitter taste receptor T2R4 (hT2R4). Three potential BPs could activate the hT2R4 and are demonstrated to be BPs, which proved the effectiveness of CPM-BP.

Effect of cold storage on human milk fat globule membrane: Microstructure and proteomic analysis

We investigated the changes in microstructure and composition of milk fat globule membrane (MFGM) in fresh human milk under different storage temperatures (-18, -3, -0.5, and 4 °C). Freezing at -18 °C resulted in the formation of ice crystals that ruptured the MFGM, leading to aggregation and increased particle size, which could potentially impact lipid digestion and absorption in infants. Conversely, storage at -3, -0.5, or 4 °C were more favorable for maintaining the stability of MFGM structure without ice crystals formation. Notably, -3 °C exhibited the highest preservation of MFGM integrity. Label-free proteomics analysis identified a total of 1525 different MFGM proteins in the initial sample (0 day) and samples preserved at varying temperatures (-18, -3, -0.5, and 4 °C) for a duration of 4 days. Principal component analysis and hierarchical clustering analysis demonstrated two distinct clusters of MFGM proteins across the different storage temperatures. Specifically, MFGM proteomic characteristics at -18 and -3 °C showed more similarities and clustered together with the 0-day samples, while -0.5 and 4 °C formed a separate cluster. Comparative analysis with the control sample (day 0) highlighted significant changes in 202 proteins, most of which played essential roles in binding, catalytic activities, and pathways related to protein, lipid, and fatty acid metabolism. Our findings highlight the superior ability of -3 °C to inhibit bacterial growth compared to 4 and -0.5 °C, and to preserve the microstructure of milk fat globules compared to -18 °C. Thus, for household storage up to 4 days, we recommend a temperature of -3±1 °C, considering temperature fluctuations in domestic refrigerators.

Effect of ultrasonic on the chemical composition of stirred yoghurt supplemented with orange peel powder

Heat treatments in dairy processing exert undesirable effects on the final product. Alternatively, a high-intensity ultrasonic technique was applied to process stirred yoghurt supplemented with orange peel powder (OPP). For this reason, OPP was added to the fresh milk at concentrations of 0.0, 1, and 2%, and then the mixture was subjected to ultrasound waves (24 kHz at 45 ± 2 °C for 30 min) before being incubated with the starter culture w/v%. Analysis of fresh and stored samples (7 and 14 days) showed that ultrasonic-treated milk (UTM) had a longer fermentation time than the heat-treated sample (HTM). No significant differences in total solid content, protein, ash, and volatile fatty acids were observed between UTM and HTM samples, while slight differences due to the addition of OPP were detected. Treating milk with ultrasound waves improved the processed yogurt’s apparent viscosity and water-holding capacity; however, adding OPP resulted in minor reverse effects. Total flavonoid and phenolic contents and antioxidant activity increased by adding OPP and were significantly higher in yoghurt made from UTM than in HTM. Overall, the application of ultrasonication in processing OPP- supplemented yoghurt resulted in better chemical and physical properties and maintained bioactive antioxidant components compared to yogurt manufactured from HTM.

Oncogenic viral DNA related to human breast cancer found on cattle milk and meat

Bovine leukemia virus (BLV) is a major cause of lymphoma in cattle and has been recently correlated to breast cancer in humans. How and whether BLV might reach humans remains unknown but it could be through cattle-derived milk and meat. Here our aim was to investigate whether BLV DNA could be found in fresh milk and raw meat destined to human consumption and whether anti-BLV antibodies could be detected in human blood at the same geographical region. Milk (n = 36) and meat (n = 54) samples were collected from cows knowingly seropositive or negative to BLV and evaluated by nested PCR targeting BLV tax gene. Human serum samples (n = 900) were tested by ELISA to detect anti-BLV antibodies. BLV DNA was detected in 39 % of the milk samples and in 32 % of meat samples from BLV positive cows. Anti-BLV antibodies were found in 4.1 % of the human serum samples. Our data further supports the hypothesis that BLV might cause a zoonotic infection and indicate that milk and meat from BLV-infected cattle might be considered a potential source of infection to humans.

Effects of Freezing Raw Yak Milk on the Fermentation Performance and Storage Quality of Yogurt.

In this study, the effects of freezing yak milk at -20 °C and -40 °C for 30, 90 and 180 days on the fermentation characteristics and storage quality of the corresponding yogurt were discussed. The results showed that, compared with that of yogurt made from fresh yak milk, the lactic acid bacteria (LAB) growth and acid production rate of the yogurt in the -20 °C group decreased at 90 d. The water-holding capacity, viscosity and hardness decreased during storage, and a sour taste was prominent, while no significant changes were observed in the -40 °C group. At 180 d of freezing, the post-acidification of the yogurt in the -20 °C and -40 °C groups increased after 21 d of storage. Compared with the -40 °C group, the -20 °C group showed a significant decrease in LAB counts, a decrease in pH value to 3.63-3.80 and poor texture and sensory quality.

INTERAKSI SOSIAL PADA RANTAI PEMASARAN SUSU SEGAR

This research was conducted in Bocek Village, Karangploso District, Malang Regency as one of the several village agribusiness centers for fresh milk around the KUD Karangploso area. The research purpose was to determine social interaction in the fresh milk marketing chain. The research method used was survey method. Type of data uses were primary data and secondary data. Primary data obtained through observation, direct interviews to dairy farmer and cooperative officer &amp; Netle representative, and documentation. While secondary data obtained from relevant documents. The theoretical approach used was the social interaction theory which it can be consist of the form of cooperation, competition as well as conflict and accommodation. Data then analyzed descriptive qualitatively. In general, there are two main characteristics of social interaction, namely associative and dissociative. The results indicated that the social interaction that was formed in the marketing of fresh milk by dairy farmers in the Karangploso KUD area was social interaction between farmers because there was an organizational relationship between members of the Karangploso KUD. The social interaction of dairy farmers with the KUD Karangploso was formed due to cooperation in marketing fresh milk. While social interaction between KUD Karangploso and PT. Nestle Indonesia is in the form of cooperation in the distribution of fresh milk on the basis of contractual cooperation.

Dilution Reduces Sample Matrix Effects for Rapid, Direct, and Miniaturised Phenotypic Antibiotic Susceptibility Tests for Bovine Mastitis.

The time-consuming nature of current methods for detecting antimicrobial resistance (AMR) to guide mastitis treatment and for surveillance, drives innovation towards faster, easier, and more portable technology. Rapid on-farm testing could guide antibiotic selection, reducing misuse that contributes to resistance. We identify challenges that arise when developing miniaturized antibiotic susceptibility tests (AST) for rapid on-farm use directly in milk. We experimentally studied three factors: sample matrix (specifically milk or spoiled milk); the commensal bacteria found in fresh bovine milk; and result time on the performance of miniaturised AST. Microfluidic "dip-and-test" devices made from microcapillary film (MCF) were able to monitor Gram-negative bacterial growth colourimetrically even in the presence of milk and yoghurt (used to simulate spoiled milk samples), as long as this sample matrix was diluted 1:5 or more in growth medium. Growth detection kinetics using resazurin was not changed by milk at final concentrations of 20% or lower, but a significant delay was seen with yoghurt above 10%. The minimum inhibitory concentration (MIC) for ciprofloxacin and gentamicin was increased in the presence of higher concentrations of milk and yoghurt. When diluted to 1% all observed MIC were within range, indicating dilution may be sufficient to avoid milk matrix interfering with microfluidic AST. We found a median commensal cell count of 6 × 105 CFU/mL across 40 healthy milk samples and tested if these bacteria could alter microfluidic AST. We found that false susceptibility may be observed at early endpoint times if testing some pathogen and commensal mixtures. However, such errors are only expected to occur when a susceptible commensal organism is present at higher cell density relative to the resistant pathogen, and this can be avoided by reading at later endpoints, leading to a trade-off between accuracy and time-to-result. We conclude that with further optimisation, and additional studies of Gram-positive organisms, it should be possible to obtain rapid results for microfluidic AST, but a trade-off is needed between time-to-result, sample dilution, and accuracy.

Efficacy assessment of prebiotic enriched camel milk along with various prebiotic combinations against metabolic syndrome using animal model

Metabolic syndrome (MetS) is a public health concern even in apparently healthy individuals. This study was conducted with the main objective to evaluate the potential role of prebiotic enriched camel milk (PECM) as a functional food, against different biomarkers of MetS in comparison to fresh camel milk (CM) and other prebiotic sources, i.e., chicory root powder (CRP) and galacto-oligosaccharides (GOS) in rat’s model. The MetS was induced through a high-fat diet and streptozotocin. The PECM, CM, CRP, and GOS were fed to rats for 8 weeks, and different biochemical parameters were measured on baseline (0th day), 20th day, and 40th day. Prebiotics were able to significantly reduce the concentration of low-density lipoprotein, triglycerides, total cholesterol, and glucose compared to the control group with PECM being the most effective of all groups, whereas liver enzymes (ALT, AST, and AP) were significantly reduced and antioxidants improved by CM and PECM than other prebiotics and control. Histopathology results revealed improvement in degeneration and hydropic atrophies in the hepatocytes of the treatment group. It is concluded that PECM is effective in the management of MetS biomarkers and can improve the parameters of hyperlipidemia, liver enzymes, antioxidants, and glycemic control.

Ultrasensitive detection of glucose oxidase and alkaline phosphatase in milk based on valence regulated upconversion nanoprobes

Fresh milk should undergo sterilization before consumption to eliminate bacteria that can cause foodborne illnesses. Additional antimicrobial measures are beneficial to extend its shelf life. The nanoprobe developed herein can not only inspect the activity of alkaline phosphatase (ALP) for evaluating the degree of pasteurization, but also detect the activity of glucose oxidase (GOD), which is added as a chemical preservative. The facile preparation of the nanoprobe involved introducing gallic acid-Fe complex (GA-Fe) into lanthanide doped upconversion nanomaterials (UCNPs). Based on the alteration of iron’s valence state in the complex through a straightforward redox reaction, both enzyme activities could be determined through colorimetric and luminometric dual-signal readouts. With detection limits of 1.669 × 10-5 for GOD and 9.81 × 10-6 U/mL for ALP respectively, this nanoprobe shows merits of easy operation and high sensitivity. Successful application in milk samples demonstrates its potential as an innovative and cost-effective approach to food safety inspection.

Levels of organochlorine contaminants in natural bovine milk marketed in Mojuí dos Campos and Belterra, Brazil

Analyzing the organochlorine pesticide (OCP) content in milk is relevantbecause it helps evaluate the quality of milk that reaches the consumer's table and also helps identify the geographical areas where there is a high possibility of contamination. Accordingly,thispilot project was aimed at determining the extent of contamination by OCP residues and their metabolites in fresh cow's milk in Mojuí dos Campos and Belterra, Pará, using solid-phase extraction (SPE) and gas chromatography coupled with electron capture detection (GC-ECD). The OCPs evaluated in this study weredichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)), hexachlorocyclohexane (HCH) (α, β, γ, and δ), endosulfanα and β, andendosulfansulfate. None of the thirty bovine milk samples analyzedshowed any contamination with OCPs.TheOCP content was within the limit of quantification of the method. The results of this study add to the existing knowledge on the quality ofbovine milk produced in these locations. However, further researchon other environmental matricesis required to confirm the results obtained in this study.

Interaction between Bovine Serum Albumin in Fresh Milk Cream and Encapsulated and Non-Encapsulated Polyphenols of Tamarillo.

The fortification of dairy products with polyphenols is known to deliver additional health benefits. However, interactions between polyphenols may form complexes and cause a loss of functionality overall. This study aimed to investigate potential interactions between polyphenols, in encapsulated and non-encapsulated forms, extracted from tamarillo fruit and bovine serum albumin (BSA) from fresh milk cream. Fortification with tamarillo extract was made at 1, 2 and 3% (w/w), and the resultant changes in physicochemical, rheological and functional properties were studied. With an increase in fortification, the absorbance of protein-ligand in the protein-polyphenol complex was decreased by up to 55% and 67% in UV and fluorescent intensities, respectively. Chlorogenic acid and kaempferol-3-rutinoside were more affected than delphinidin-3-rutinoside and pelargonidin-3-rutinoside. Static quenching was the main mechanism in the fluorescence spectra. Tryptophan and tyrosine residues were the two major aromatic amino acids responsible for the interactions with BSA. There were at least three binding sites near the tryptophan residue on BSA. The rheological property remained unaffected after the addition of non-encapsulated tamarillo extracts. Antioxidant capacity was significantly decreased (p < 0.05) after the addition of encapsulated extracts. This may be explained by using a low concentration of maltodextrin (10% w/w) as an encapsulating agent and its high binding affinity to milk proteins.

Sensitive analysis of 18 aminoglycosides in bovine milk using hydrophilic interaction chromatography combined with tandem mass spectrometry

A sensitive and selective method was developed using hydrophilic interaction chromatography combined with tandem mass spectrometry to detect 18 aminoglycosides in bovine milk. Aminoglycosides were extracted from milk using a mixture of trichloroacetic acid, ammonium acetate, ethylenediaminetetraacetic acid, and sodium chloride, and then isolated using an Oasis HLB solid-phase extraction cartridge. We evaluated the performance of chromatographic columns with different stationary phases and optimized the mobile phases to achieve satisfactory separation of the analytes. The limits of detection and quantification were 0.05–2 µg/kg and 0.1–5 µg/kg, respectively. The recoveries of the method ranged from 78.9% to 101.1%, with intra- and inter-day relative standard deviations of less than 8.1% and 9.0%, respectively. This method was applied to 30 milk samples collected from markets, and neomycin (16.8 µg/kg) was detected in one fresh bovine milk sample. The proposed method provides a powerful tool for the surveillance of aminoglycosides in bovine milk.

Elemental and In vitro Antioxidant Studies of Some Bracharia species and Milk from Bowen University Dairy Farm

This study investigated the constituent elements present in three Bracharia grasses and milk samples from the Bowen Dairy cows. Bracharia grasses and milk samples were subjected to Atomic Absorption Spectroscopy (AAS) for determination of K, Ca, Na, Mn, Fe, Cd and Cu, and in vitro antioxidant activities. Levels of K, Ca and Na in both fresh and sterilized milk were also comparable to the RDA. No levels of Cd and Cu were determined all samples. The level of Mn in fresh milk was 0.80 ± 0003 ppm, but was not determined in sterilized milk. The AAS result shows that the levels of K, Ca and Na in Brachiaria sabia methanol extract (BSME), Bracharia gayana methanol extract (BGME) and Bracharia maradu methanol extract (BMME) were lower than the RDA value. However, Cd and Cu were not determined in the three samples, except in BMME. The fresh and sterilized milk samples had better antioxidant potentials compared to quercetin standard. This study indicates that the Bracharia grasses and milk samples from Bowen University Dairy Farm are rich in K and Fe. In addition, both fresh and sterilized milk samples possess strong in vitro antioxidant capacity.

Molecular Characterization of Multi-Drug Resistant Fungal Isolates Obtained from Raw Cow Milk in Bowen University, Nigeria

Cow milk is a highly nutritious food but many factors predispose it to microbial contamination. There is paucity of information on antifungal-resistant pathogens. Hence the study investigated the fungi from fresh cow milk samples and their resistance to some antifungals. Twenty-seven (27) fungi were isolated from forty-three (n=43) milk samples on PDA (Potato dextrose agar) media, re-cultured in glucose yeast extract broth, and incubated for 24 hours at 25°C. Taxonomic characterization on the isolates was done using photomicrography. Percentage occurrence of the isolates was determined. Molecular characterization was carried out on some isolates which were 100% resistant to antifungals; ketoconazole, amphotericin B, and clotrimazole using ITS1 and ITS4 primers. Isolate sequences were subjected to BLAST analysis and compared with representatives in GenBank. Kruskal-Wallis and Mann-Whitney Tests were used to analyze the data. Phylogenetic analysis and morphological characterization identified isolates as Rhodotorula paludigena, Candida sp and Candida tropicalis which had occurrence of 31.8%, 31.8% and 36.6% respectively. Level of resistance to ketoconazole (100%) and amphotericin B (92%) was significantly higher than clotrimazole (59%) (p< 0.05), while between ketoconazole and amphotericin B, there was no significant (p> 0.05) difference. Unprocessed raw milk is a potential source of drug-resistant pathogenic fungi. Pasteurization of raw milk is highly encouraged before consumption.

Validation of the KangarooSci® Aerobic Count Plate for the Enumeration of Meosphilic Aerobic Bacteria in Selected Foods and on Stainless Steel Environmental Surfaces: AOAC Performance Tested MethodSM 062301.

The KangarooSci® Aerobic Count Plate is a sample-ready culture medium system, for direct counting of aerobic bacteria colonies after 48-72 h of incubation. The KangarooSci Aerobic Count Plate was evaluated for AOAC® Performance Tested Methods SM certification. The KangarooSci Aerobic Count Plate (ACP) was evaluated through matrix studies and product consistency/stability study and robustness testing. For the matrix study, nine food products (nonfat dry milk powder, fresh raw bovine milk, pasteurized liquid bovine milk, fresh raw ground beef, frozen uncooked chicken breast, cooked shredded pork, apple juice, ice cream, and fresh strawberries), and one environmental surface (stainless steel) were evaluated following the KangarooSci ACP product instructions and compared to the ISO 4833-1:2013-pat 1, Microbiology of food and animal feeding stuffs-Horizontal methods for the enumeration of microorganisms-Part 1: Colony count at 30 °C by the pour plate technique reference standard. The product consistency and stability testing evaluated three separate production lots of the KangarooSci ACP. The robustness testing examined three test parameters, volume of sample plated, incubation time, and incubation temperature using a factorial study design. Results from the matrix study demonstrated equivalent performance between the KangarooSci ACP and the ISO 4833-1:2013 reference standard. The product consistency and stability testing showed that the performance of the assay was equivalent over time up to 12 months and between production lots. Minor changes to the operational test conditions showed no significant impact on performance during the robustness testing. The KangarooSci ACP is an effective method for aerobic plate count for all matrixes evaluated. The KangarooSci Aerobic Count Plate allows for fast, reliable enumeration of aerobic bacteria. Utilizing the alternative method takes up less space in incubators, requiring no sample spreader, and requires less consumables compared to the reference method.

Discrimination of Milk Freshness Based on Synchronous Two-Dimensional Visible/Near-Infrared Correlation Spectroscopy Coupled with Chemometrics.

Milk is one of the preferred beverages in modern healthy diets, and its freshness is of great significance for product sales and applications. By combining the two-dimensional (2D) correlation spectroscopy technique and chemometrics, a new method based on visible/near-infrared (Vis/NIR) spectroscopy was proposed to discriminate the freshness of milk. To clarify the relationship be-tween the freshness of milk and the spectra, the changes in the physicochemical indicators of milk during storage were analyzed as well as the Vis/NIR spectra and the 2D-Vis/NIR correlation spectra. The threshold-value method, linear discriminant analysis (LDA) method, and support vector machine (SVM) method were used to construct the discriminant models of milk freshness, and the parameters of the SVM-based models were optimized by the grid search method and particle swarm optimization algorithm. The results showed that with the prolongation of storage time, the absorbance of the Vis/NIR spectra of milk gradually increased, and the intensity of autocorrelation peaks and cross peaks in synchronous 2D-Vis/NIR spectra also increased significantly. Compared with the SVM-based models using Vis/NIR spectra, the SVM-based model using 2D-Vis/NIR spectra had a >15% higher prediction accuracy. Under the same conditions, the prediction performances of the SVM-based models were better than those of the threshold-value-based or LDA-based models. In addition, the accuracy rate of the SVM-based model using the synchronous 2D-Vis/NIR autocorrelation spectra was >97%. This work indicates that the 2D-Vis/NIR correlation spectra coupled with chemometrics is a great pattern to rapidly discriminate the freshness of milk, which provides technical support for improving the evaluation system of milk quality and maintaining the safety of milk product quality.