查看更多>>摘要：The milk containing only A2 beta-casein (called A2 milk) is globally popular because of its unique health benefits. Traditionally, genetic testing (such as gene sequencing) is used to identify the cows with A2 beta-casein gene that can only produce A2 milk, which is a time-consuming and costly method. The objective of this study was to directly identify A1 and A2 milk from a large quantity of milk using mid-infrared (MIR) spectroscopy and chemometrics without genotyping cows. Before establishing the predictive model, we firstly genotyped the A1 beta-casein and A2 beta-casein of cows from blood as reference values. Further, the MIR spectra of the milk collected from these cows were obtained using a dairy product analyzer. The MIR spectroscopy data and the reference values were used as the independent and dependent variables, respectively, to establish a category classification model for A1 and A2 milk. Seven preprocessing methods were combined with two feature extraction algorithms to establish the model. Subsequently, partial least squares discriminant analysis (PLS-DA) and support vector machine (SVM) models were developed. The average accuracy of the test set of the two models were 94.9% and 94.4%, respectively, while the PLS-DA model exhibited better effect, and the accuracy of training set and test set reached 96.6% and 96.0%, respectively. We used a set of independent samples for the external validation of the PLS-DA model, and the prediction accuracy was 95.2%. Overall, the proposed prediction models based on MIR spectroscopy can be used for low-cost, rapid, and large-scale classification of A1 and A2 milk, which may be extremely beneficial in milk production industries.
查看更多>>摘要：Flavonoids in Sedum aizoon L. (FSAL) have been used traditional medicine due to its antibacterial properties and anti-inflammatory. In this study, the molecular mechanisms involved in the action of FSAL on Pseudomonas fragi (P. fragi) were investigated for the first time using the transcriptome. The results showed that FSAL treatment (1.0 MIC) disrupted the intracellular sulfate assimilation pathway and led to disturbances in glutathione redox homeostasis. A total of 298 genes were found to be responsive to FSAL, including 233 up-regulated and 65 down-regulated. The highlighted changes were those related to sulfur metabolism, ABC transporters, aminobenzoate degradation and benzoate degradation. In summary, the intervention of FSAL resulted in the disturbance of cellular metabolic processes and redox homeostasis, which inhibited P. fragi. The results revealed the mechanism of P. fragi inhibition under FSAL treatment, which could be helpful for the application of FSAL in food industry and food safety.
Birke, R. R.Causon, T.Turetschek, R.Emerstorfer, F....
7页
查看更多>>摘要：The quantification of nitrate and nitrite in molasses is an emerging requirement for the sugar industry. The establishment of a validated analytical methodology is necessary to comply with the EU-guidelines on maximum permissible levels currently under discussion. In the present study, validation of an anion exchange chromatographic method to determine nitrate and nitrite in molasses was performed determining key validation parameters via several stages of an interlaboratory comparison for the first time. Since a stable, homogeneous sample material was necessary for establishing quantitative accuracy, a nitrite-spiked molasses material was prepared and evaluated independently across two laboratories in a parallel study. This preliminary study revealed that quantification of nitrate and nitrite content in molasses could be achieved with excellent precision under repeatability conditions of measurement (1.21% RSD for nitrate; 1.26% RSD for nitrite) in independent laboratories but requires preservation of samples at -20 degrees C for long-term (>several days) storage prior the analysis. A subsequent stage involving five different participating laboratories was then undertaken to evaluate anion exchange chromatography with conductivity detection for this application within a round robin study. The first phase focused on the analysis of nitrite-spiked molasses to optimize the individual analytical practices of laboratories and to elaborate a harmonized sample preparation protocol. In the second phase the participating laboratories analyzed seven molasses samples with different pH-value, dry substance, factory origin, with nitrate levels ranging from 2931 mg/kg - 6436 mg/kg and nitrite levels ranging from 25.3 mg/kg - 109 mg/kg. The determination of precision of reproducibility conditions of measurement revealed average relative interlaboratory standard deviations of 2.5% for nitrate and of 13% for nitrite. The present study clearly demonstrates the necessity of harmonization and standardization regarding measurement and data evaluation procedures applied for controlling nitrate and nitrite in molasses.
查看更多>>摘要：Protozoan parasites have emerged as a cause of disease associated with fresh produce and berry fruits, and are of particular concern for both public health and the food industry. For example, contamination with Cryptosporidium oocysts, whether directly from faeces or through water used in food production and processing, has led to widespread foodborne outbreaks of cryptosporidiosis. The main foodstuffs implicated so far have been fresh produce (especially leafy greens), fruit juice, milk and dairy products. There is an international standard, ISO 18744:2016, based on microscopy, for the detection of oocysts from leafy green vegetables and berry fruits, but verification and validation data that have been published for this and alternative methods can be difficult to compare due to differences in artificial contamination protocols. There is a lack of reporting of the efficiency and performance of methods used in sample surveys, hampering understanding of parasite occurrence. To improve the consistency and comparability of assays and surveys reporting the results of such artificial contamination experiments, we have developed guidance for artificial contamination procedures and analysis that can be applied to food within the category fresh produce and fruits, with particular attention to leafy greens. Information gathered through an opinion survey revealed that molecular detection would be a valuable development, but that standardised methods and improved validation data were required. A market survey revealed that the provision of oocysts for artificial contamination studies has focused on meeting requirements for microscopy detection. An insight-generation workshop provided the background knowledge synthesised into best practice guidance for artificial contamination studies using either microscopical or molecular detection. This should contribute to better method development and reporting, and improved food safety.
查看更多>>摘要：Pine-mushrooms is rich in bioactive compounds, possess a unique aroma profile for culinary art. In China, pinemushroom has been produced in Southwest and Northeast area. However, the discrepancy of volatile profiles in pine-mushrooms from two regions was unclear due to different extraction and detection method applied in research. This study attempted to compare the volatile profiles of four pine-mushrooms from Southwest (LS) and Northeast (HEB, SY, MDJ) using Headspace Solid Phase Microextraction coupled with Gas Chromatography Mass Spectrometry (HS-SPME/GC-MS) and Electronic nose (E-nose). Results showed a significant difference in aroma profiles among samples. A total of 100 volatile compounds were identified, and separated into 11 classes. Benzaldehyde and hexanal were detected in all samples, which could be the pivotal aroma components in pinemushrooms. Aromatic components, were present in LS pine-mushroom from Southwest China, including abundant of methyl (Z)-N-hydroxybenzenecarboximidate, benzaldehyde, and methyl 3-phenylprop-2-enoate. Meanwhile, some alcohols (such as oct-1-en-3-ol, hexan-1-ol) were characteristic compounds present in HEB, SY and MDJ samples. Principal component analysis (PCA) of E-nose data showed a clear distinction among samples. In addition, this study also highlighted the correlation between key volatile compounds detected by GC-MS and Enose sensors, which could be benefit for further explanation to the origin of differences in sensory quality of pinemushrooms.
查看更多>>摘要：The purpose of this review is to explore prior research on the food safety perspectives and practices of consumers and vendors in Nigeria, Africa's most populous country. Through a systematic search and review process, 87 relevant studies were identified. The results of the review indicated that most studies were concentrated in urban areas and in the southwest, south, and central regions. Most of the studies (64.4%) focused only on vendors; only one study focused on both consumers and vendors. The most common food category studied was prepared readyto-eat foods, and 81% of studies did not focus on any specific food safety hazard, instead examining general food safety issues. Sixty studies (69%) used a single data-collection method, most commonly an individual-level structured survey. In terms of topics, most studies focused on the respondent's food safety-related knowledge (66.7%) or self-reported practices (63.2%). Eleven studies (12.6%) examined actual practices via observations, while nine (10.3%) included observations of the food preparation or sale environment. Studies tended to find participants' knowledge to be better than their self-reported practices, with observed practices being worse than self-reported practices. Studies suffered from certain methodological weaknesses. Based on the results of this review, it is concluded that future research on food safety in Nigeria would benefit from greater focus on fruits and vegetables and traditional markets, less reliance on closed-ended survey questions and self-reported data, and more focus on understanding individuals' food safety motivations, beliefs, and values within specific cultural contexts.
查看更多>>摘要：Bread consumption has declined in recent years due to the loss of its sensory quality. To identify the key sensory attributes for the consumer, in this study will provide to the bakery industry with a powerful tool to design products adapted to the consumer preferences will be provided to the bakery industry. For identifying the key attributes 7 Galician breads were evaluated by a trained panel using 22 attributes using the Quantitative Descriptive Analysis. In addition, a sensory acceptance test carried out by 97 consumers provided hedonic evaluations. The results of the joint analysis (trained panel and consumers) demonstrated that the loaves with the moistest bread crumb, with a predominance of large cells, and an alveolation with non-uniform distribution were the ones that presented the greatest acceptance. The use of an artisanal production process (sourdough and long fermentation time) and the incorporation into the recipe of indigenous flour (around 40%) improved the acceptance of the Galician bread.
查看更多>>摘要：Casein and ethyl cellulose (Cas + EC) complexes were fabricated and used for encapsulation of curcumin (Cur). Physicochemical properties of Cas + EC/Cur along with its antibacterial activity when used in combination with blue LED irradiation were investigated. Encapsulation efficiency of microparticles at Cas:EC of 1:1 was the highest at 92.4%, with average particle size of 1.47 mu m and zeta-potential of -21.40 mV. Fourier transform infrared spectroscopy revealed that Cur was well encapsulated in Cas + EC by electrostatic interactions; more hydrogen bonds were also formed. At optimal encapsulation condition, Cur exhibited good thermal stability; its water solubility improved 69 folds, while its release rate in oily food mimic reached 76%. Cas + EC/Cur in combination with blue LED irradiation could rapidly inactivate Escherichia coli ATCC 43894, Staphylococcus aureus ATCC 23235 and Pseudomonas aeruginosa MCC-208. Such desirable activities are attributed to the production of reactive oxygen species, which caused increased membrane permeability and reduced bacterial cell integrity.
查看更多>>摘要：The monitoring of phenolic compounds in mead is a useful tool for the evaluation of its quality and potential adulteration because the profile and content of phenolic compounds strongly depend on the amount and type of honey used for mead production and on the technological process. Therefore, the aim of this study was the optimization of rapid reversed-phase high performance liquid chromatography coupled to tandem mass spectrometry for the determination of 23 phenolic compounds in 22 mead samples. The isolation of monitored phenolic compounds was performed using liquid-liquid extraction with a mixture of diethyl ether and ethyl acetate. 3,4-dihydroxybenzoic, 4-hydroxybenzoic, caffeic, p-coumaric, salicylic, chlorogenic, gentisic, gallic and ferulic acids, together with apigenin, quercetin and 3,4-dihydroxybenzaldehyde were the most frequently occurred phenolic compounds in mead extracts. The instrumental limits of detection and quantification were for all compounds below 20 mu g/L and 65 mu g/L, respectively. Among the samples studied, four meads contained a low total amount of phenolic compounds (below 10 mg/L), and two of them did not even exceed 2 mg/L. Moreover, a very high concentration of vanillin as a flavouring was observed in one of those samples.
查看更多>>摘要：Food fraud is an increasingly acknowledged problem that can cause unfair competition in the market, contribute to the grey economy, cause financial losses and threaten the health of consumers. Even so, little research exists on food-related criminal cases. The aim of this study was to characterize Finnish food-related criminal cases in order to improve understanding of the prevention of food-related crime. We investigated 127 cases resolved by the police, prosecutors, or district courts under the titles of food offence, health offence or marketing offence from 2008 to 2019. The analysis revealed that the incidence of cases was low and varied regionally, which may be due to varying abilities to detect cases and differences in reporting them to the police. The most common non compliances in the cases we analysed were unapproved or unregistered premises or activities (43.3%), false or misleading information provided on food products (39.4%), and insufficient or incorrect, false or misleading documents (31.5%). Safety hazards were associated with 45.7% of cases, while 2.4% involved verifiable instances of illness, which demonstrates that preventing food crime is important for consumer safety. The majority of cases (51.2%) were detected during food control inspections, highlighting the importance of performing inspections on-site. In addition, tip-offs to food control authorities about possible food-related crime (29.1% of cases) were an important mode of detection and could possibly be even more important if Finland were to have a centralized anonymous whistleblowing system. In total, 59.8% of cases led to a conviction or a sanction, and the most common type of punishment was a fine. Nevertheless, the fines tended to be rather low, and the proceeds of crime were recovered in only a few cases. More training for food control inspectors on the detection of food related crime, harmonized reporting practices, and increased legal praxis throughout the country could improve the detection and prevention of food crime in the future.
NSTL
Elsevier