查看更多>>摘要：Sulfoxaflor and flupyradifurone, two pesticides belonging to sulfoximins and butenolides, are widely used to treat crops and fruits. In order to amplify the detection of pollutants, we aimed to identify also molecules deriving from the parent pesticides. We studied their photoinduced transformation and identified their main transformation products by applying a laboratory simulation and by employing HPLC-HRMS to characterize them. We detected three transformation products from sulfoxaflor, whose formation involved the conversion of cyanamide group into a ureic group and the detachment of the side chain. Flupyradifurone transformation proceeded through the formation of seven transformation products and three of them were recognized in this study for the first time; it involved hydroxylation and breakage of the molecule with the detachment of the pyridine or furan ring. These results will allow enlarging the extent of TPs to be screened in food matrices. Pesticides and their transformation products were then determined in 67 samples of fruits, leaves, honey and pollen by applying QuECHERs for sample pre-treatment and HPLC-MS/MS for their quantification. The presence of flupyradifurone was detected in different samples of honey at concentration level of 10-15 mu g/kg.
查看更多>>摘要：High pressure processing (HPP) is one of the most successful nonthermal technique adopted by the meat industry. Raw beef and poultry meat commercially produced using HPP are processed at intense pressure levels for microbiological safety purposes, which, however, have been associated with impact on quality attributes, e.g., texture, appearance/color, and oxidation of proteins and lipids. Research over the last decade has shown that HPP may be operated at mild settings without compromising bacterial inactivation when combined with plantorigin essential oils (EOs). This review discusses 1) the effects and the underlying mechanisms of HPP on bacterial inactivation and on meat quality, 2) the antimicrobial activities of individual or mixed EOs when combined with HPP, and 3) the development of statistical models for foodborne pathogen reduction using HPP involving multiple parameters, e.g., pressure level, holding time, temperature, concentrations of antimicrobial agents, etc.; which may assist in process optimization of HPP-based hurdle technologies.
查看更多>>摘要：The migration of various plastic additives (antioxidants: BHT, Ionox 220, Irgafos 168; UV absorber: Uvinul 3039; plasticizers: TBAC and TOTM) from polypropylene and polylactic acid was investigated in a series of experiments conducted over a period of 13 days. As fatty food simulants, both ethanol 95 v/v% and isooctane were used. NonFickian behaviour was observed on multiple occasions. The kinetic curves of both migration concentrations and swelling were evaluated using variography, to determine objectively the starting points of long-lasting plateaus as well as short halts in the increase. A strong correlation between migration and swelling was observed: the kinetic curves showed that migration always followed swelling. Also, more intensive swelling results in the increased migration of the additivies. Consequently, migration testing can be improved by considering the swelling of the plastic.
查看更多>>摘要：The COVID-19 pandemic situation has altered consumers' behaviour in food purchasing and consumption. This study, as a first attempt, assesses how the COVID-19 lockdown affects Chinese consumers' purchasing and consumption behaviour from a sustainability point of view. To reach this objective, a semi-structured questionnaire is designed, collecting data from 1006 participants. The food purchasing behaviour towards the importance of sustainable attributes (P), sustainable and healthy diets (D), and food waste (W) as three dependent variables are measured, and three binary logistic regressions are estimated. The results suggest that gender and age are relevant factors affecting sustainable behaviour. Household size has a significant effect on the healthy diet shift and food waste reduction. Risk attitude has a negative and significant impact on the sustainable purchase decision. In addition, consumers' food security, financial, and health risk perceptions are highly important factors in understanding consumers' sustainable purchasing and consumption behaviour. Consumers' subjective and objective knowledge levels regarding COVID-19 influence consumers' sustainability shift during the lockdown. The findings provide some practical implications for policymakers and stakeholders to carry out more socially acceptable policy actions that ensure consumers' sustainable purchasing and consumption behaviour during the COVID-19 pandemic.
查看更多>>摘要：Understanding the bacterial behavior in response to sublethal stresses is crucial for the optimization of antimicrobial treatments, particularly in food processing. However, the data regarding the effect of sublethal concentrations of essential oils (EOs) on microbial cells are still scarce. In this study, we evaluated the response of Listeria monocytogenes ATCC 7644 to the sublethal concentration of 1.25 mu L/mL Origanum vulgare L. EO at 30 degrees C for 1 h, by means of Phenotype Microarray, modelling the kinetic data obtained by inoculating the control and treated cells into GEN III microplates (Biolog Inc.) for 96 h after EO removal. The results showed important differences regarding the growth dynamics in the presence of carbohydrates and environmental conditions often encountered in food products and that normally sustain the growth of the pathogen (i.e. pH 6.0, pH 5.0, NaCl 1-8%, presence of lactic acid and sodium lactate). In detail, the lag phase of the treated cells was extended, the growth rate was slowed down and the maximum concentration was often significantly reduced. Interestingly, the susceptibility to antimicrobials such as vancomycin, lincomycin and rifamycin was restored after EO application and removal, suggesting a potential role in combating antibiotic resistance. Confocal laser scanner microscopy showed a diffuse aggregation of the treated cells, as a response to the stress encountered. In conclusion, a single exposure to a sublethal concentration of O. vulgare EO causes a stressing effect that persists after its removal. This outcome should be better investigated for potential applications both in food production, to combine low EO concentrations with other hurdles to guarantee food safety, and in medicine, to restore the sensitivity to antibiotics.
查看更多>>摘要：The global demand for home meal replacement (HMR) products has been increasing because of changing consumer behavior toward convenience foods. Although the quality of food products is the most important factor in the decision to purchase, packaging also has a decisive influence on customer choice. Therefore, the importance of packaging technology in the HMR industry has increased significantly. Depending on the packed food requirements, appropriate packaging technology can provide significant benefits to both producers and consumers. Active packaging technology, such as modified atmosphere and antimicrobial packaging, has received considerable attention because of its potential to prolong the product shelf-life, while intelligent packaging technology such as colorimetric indicators and radio-frequency identification labels can monitor the real-time condition of the packed food and communicate with consumers. Packaging technology keeps evolving in response to the growing challenges from industry and society. This review aims to provide information about innovative and commercialized packaging technologies applied to HMR products. Recognized packaging technologies have been discussed, including easy-peel adhesive, microwave susceptor, and intelligent packaging. In addition, the influence of external factors, such as modern consumer behavior, recent global issues such as circular economy and pandemics, and emerging technology on packaging trends, are evaluated and discussed for future development.
查看更多>>摘要：Aflatoxin B-1 (AFB(1)) is a powerful carcinogen, and the pollution it causes has become a global public health safety issue. Therefore, microfluidic paper-based analytical devices (mu PADs) with smartphones to read colorimetric signals were constructed for rapid AFB(1) detection. The colorimetric mechanism of mu PADs was based on the common starch-iodine reaction, and the addition of gelatin/chitosan enhanced the colorimetric effect. During detection and analysis, the competitive analysis occurred in the process of AFB(1) monoclonal antibody's recognition of free AFB(1) and functionalized antigen. The glucose oxidase-labeled IgG was used as the secondary antibody. Hydrogen peroxide, an oxidation product of the glucose, caused a chroma change in mu PADs. Simultaneously, the change in chroma was consistent with the change in AFB1 concentration. Under the best optimized conditions, the limits of detection and quantitation of AFB(1) in the buffer were 9.45 and 12.00 ng mL(-1), respectively. A comparison of the detection performance of commercial kits with that of the method introduced herein confirmed the superiority of our method in actual food samples with known AFB(1) concentrations. This colorimetric mu PADs analysis met the detection requirements of some countries, such as China, and had great potential for development in the direction of daily extensive food safety control and environmental monitoring.
查看更多>>摘要：Pyrrolizidine alkaloids (PAs) and their corresponding N-oxides (PANOs) are natural plant toxins, which are widely distributed in various types of teas. The source of PAs contamination in tea is probably related to weeds in tea gardens. The method of simultaneously detecting PAs/PANOs in teas and weeds has not been reported. A sensitive method was developed for detecting 14 PAs/PANOs simultaneously in teas and weeds using ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Sample preparation was optimized step by step. Sulfuric acid at 0.1 M was used to extract the target compounds. Large capacity PCX column was used to enrich target compounds and remove complex matrices effectively, following by the elution solvent with methanol containing 0.5% NH4OH. The method showed good linearity for all 14 analytes with regression coefficients (R2) > 0.99. Satisfactory recoveries of target compounds spiked at three concentrations (10, 50, 100 mu g/kg) ranged from 68.6% to 110.2%, while intra-day and inter-day precision were below 18.5%. Limits of detection (LODs) and limits of quantification (LOQs) of 14 PAs/PANOs in different matrices were in the range of 0.001-0.4 mu g/kg and 1-5 mu g/kg, respectively. This method was firstly applied to monitor the occurrence of PAs/PANOs in different kinds of teas from China and weed samples collected in the local tea gardens. Seven PAs/PANOs (>LOQs) were detected in 15.32% of tea samples and maximum total PAs/PANOs content was 151.33 mu g/kg. Pollution levels and patterns of PAs/PANOs were different significantly in various types of teas. Based on the occurrence of PAs/PANOs in teas and weeds, weeds in tea garden were likely to be the source of PAs/PANOs in teas and the most relevant contaminating species of tea samples could be Crassocephalum crep-idioides (Benth.) S. Moore.
查看更多>>摘要：This research was conducted to assess the structure, mechanical, barrier and optical properties of three edible composite films based on chitosan nanoparticles. Films containing cinnamon-perilla essential oil (C-PEO) Pickering nanoemulsion had denser structure and better mechanical properties. In addition, films with anthocyanidins exhibited enhanced antioxidant activity. The results showed that both Pickering nanoemulsion and anthocyanidins could improve some properties of edible composite film based on chitosan nanoparticles. Finally, preservation experiments were carried out. Analysis of storage quality indices (sensory evaluation, microbiological analyses, pH, total volatile basic nitrogen, thiobarbituric acid values, color and texture) revealed the shelf life of fillets wrapped in three kinds of composite film was extended to 6-8 days. The preservation effect of plant essential oil compound anthocyanidin edible film for fillet was the best and anthocyanidins compound chitosan nanoparticles edible film was the best in appearance of protection.
查看更多>>摘要：Humulus lupulus (hop) cone is a key ingredient in beer, which determines its taste and aroma. The impact of ripening on the bitter acids, aroma compounds, and polyphenols of hops has been reported separately, there is no systematic study on all three components. Here, three hop varieties ('TP1', 'TP2', and 'QTF') in China were sampled to investigate the correlation between the harvest maturity and these three components, which indicated that polyphenols synthesized earlier than hop bitter acids, followed by the aroma compounds. Variety differences of the hop cultivars prompted the obvious separation in the partial least-squares discriminant analysis (PLS-DA). Among three hop cultivars. 'TP1' with the highest contents of aroma compounds contributed to flower aroma, and with higher contents of bitter acids which contributed to bitter taste. In contrast, 'TP2' has been reported to be rich in caffeic acid, salicylic acid, syringaldehyde, (+)-catechin, and (-)-epicatechin. To analyze the hop aroma characteristics, two matrices of hop tea and late-hopped beer were prepared and used for sensory evaluation. Compared to 'TP2' and 'QTF', the hop tea with 'TP1' scored best for 'strong' (P < 0.01), 'herbal' (P < 0.05) and 'citrus' (P < 0.01). While the 'strong' and 'herbal' characteristics from terpene compounds receded in the late-hopped beer, the 'citrus' and 'fruity' notes from terpenol compounds remained noticeable.
NSTL
Elsevier