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A new nanocomposite based on alginate microbeads impregnated with novel strontium–aluminum layered double hydroxide (Sr‐Al LDH) incorporated with choline chloride‐urea deep eutectic solvent (ChCl‐U DES) was introduced. The microbeads and LDH were characterized by adsorption/desorption isotherms, Fourier‐transform infrared spectroscopy, SEM, and x‐ray diffraction. The adsorbent was employed for determining penicillin G (PENG) using dispersive solid‐phase extraction prior to HPLC analysis. The extraction efficiency of the adsorbent, compared with that of unmodified alginate, showed a 2.5‐fold increase. Significant parameters, including elution conditions, sorbent composition and mass, adsorption time, and sample pH, were optimized. The LOD was 0.4 µg kg−1, and the linear range was 1.4–500 µg kg−1. The LOQ (1.4 µg kg−1) was lower than the established maximum level for PENG by the European Union (4 µg kg−1). Enrichment factor and synthesis reproducibility were also investigated. The method's accuracy was evaluated through PENG analysis in dairy products and water, with recoveries of 81%–107% (RSDs < 7.6%). The procedure's greenness was assessed using the Analytical Eco‐scale and achieved excellent green credentials. To the best of our knowledge, this is the first report on the synthesis and application of a novel alginate composite for the extraction of PENG from dairy and water samples. [ABSTRACT FROM AUTHOR]

Considering the importance of reducing the use of chemical preservatives in food and the increasing attention of consumers to consume food products with minimal additives, the main goal of this research was to study the effect of use of chemical (calcium propionate) and biological (Lactobacillus plantarum) preservatives on increasing shelf life of yufka paste considering its physicochemical and microbial characteristics. For this purpose, three samples of yufka paste were prepared by adding concentrations of 103, 105, and 107 cfu/mL of L. plantarum individually and three samples of paste were prepared by adding the same amount of bacteria in combination with 0.3% calcium propionate and these samples were compared with the control sample (without preservative) and the sample only containing 0.3% calcium propionate. The obtained results showed that different treatments and time had a significant effect on physicochemical properties including pH, moisture, and protein of yufka paste (p <.05). The results of the survival of L. plantarum showed that with increasing time, the survival rate of bacteria increased (p <.05). The pH of the samples showed that the L. plantarum has a significant effect on controlling the chemical quality of yufka during storage. The count of mold and yeast in the combined use of L. plantarum and 0.3% propionate was lower than the single use of propionate chemical preservative, which indicated the very good effect of the green preservative in controlling the moldy spoilage of yufka. Low concentrations of bacteria showed better antimold results than treatments containing bacteria and propionate in a combined form, propionate or control treatment. [ABSTRACT FROM AUTHOR]

A novel nanocomposite based on bacterial cellulose (BC) modified by manganese sulfide (MnS) decorated graphene oxide (GO) was prepared. The hydrogel was characterized by Fourier transform infrared, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and adsorption/desorption techniques. The sorbent was employed for determining acrylamide in bread samples using micro‐solid‐phase extraction coupled with high‐performance liquid chromatography. The extraction efficiency of prepared sorbent was 1.4‐fold higher than that of BC. The important extraction factors including elution conditions (acetonitrile 300 μL, 5 min), sorbent composition and mass (50 mg), adsorption time (7 min), sample solution pH (8), and salt effect (3% w/v) were considered for optimization of the method. The analytical merit was validated by assessing the preconcentration factor (178–225), limit of detection (1.56 μg/kg), limit of quantification (5.15 μg/kg), linearity (5.15–500 μg/kg), and determination coefficient (0.9845). The adsorption isotherms and kinetic studies demonstrated that the adsorption process followed the Langmuir model and pseudo‐second‐order kinetics. The relative recoveries and relative standard deviations were 84%–106% and 2.4%–9.2%, respectively. This paper is the first report on the fabrication and use of BC doped with MnS‐GO composite for extraction of acrylamide in typical commercial bread samples. [ABSTRACT FROM AUTHOR]

Summary: Bacteria adherence to the surface and the resulting biofilm have serious harmful effects in food. Biofilm formation in foods can lead to food deterioration and disease transfer easily. Some alternative applications are being tried to remove biofilms. Among these, biosurfactants and bacteriophages are promising owing to their low toxicity, easy availability, and high activity. In our study, the action of phage and rhamnolipid, a biosurfactant, on the biofilm of Salmonella Infantis, which is an important pathogen in food, was examined. Additionally, the efficacy of phages in the biocontrol of foods was tested. It is observed that the phage significantly reduces the bacterial concentration in milk in the first 4 h at 4 °C and 25 °C and maintains its effect for 24 h at 4 °C. The p_S3 phage, rhamnolipid (RML), and p_S3 phage + RML mixture on the 48‐h biofilm decreased the biofilm mass by 44.9–81.8%, 20.8–81.1%, and 12–60%, respectively. On a 1‐week‐old biofilm, the p_S3 phage, RML, and p_S3 phage + RML mixture decreased the biofilm mass by 43–60%, 55–72%, and 49.7–61.7%, respectively. It is seen that the p_S3 phage and RML co‐administration on biofilm can be a biosafe application in food production facilities where it is a more effective application in removing the biofilm in long‐term exposure. [ABSTRACT FROM AUTHOR]

Food safety as a credence food attribute potentially leaves room for adverse selection arising from information asymmetry between consumers and suppliers. To mitigate this market inefficiency, certification works effectively when a credible control system is in place. However, in a situation where control is weak and uncoordinated, introducing certification may encounter consumer‐related behavioural barriers. The case of weak food control in an emerging market in sub‐Saharan Africa (SSA) gives us a unique opportunity to stochastically link consumers' perception of the food control system to preference for different food safety certification options. We test the hypothesis that this perception induces consumers to depend on subjective cue food safety attributes. Using choice experiment data, we estimate a hybrid choice model that includes consumers' perceptions of food control, accounting for measurement errors and endogeneity bias. Our results show that a strong preference for food safety may not translate into a positive valuation of any of the certification schemes when we control for consumer perception of food control. Consumers are likely to rely more on subjective cue attributes if they have negative perceptions of food control. When such cue attributes are susceptible to market manipulation, consumers become more vulnerable to the risk of adverse selection in the food market. We recommend combining market mechanisms with strengthened food control systems and boosting consumers' confidence in food control to address asymmetric information problems in emerging food markets. [ABSTRACT FROM AUTHOR]

A sandwich‐type electrochemical immunosensor was developed for sensitive detection of Salmonella Typhimurium (S. Typhimurium) in milk and eggs. According to the antigen‐antibody specific binding, Anti‐S. Typhimurium antibody was used to recognize the S. Typhimurium, while the HRP‐Anti‐S. Typhimurium antibody as signal probe was used to catalyze H2O2 with the assistance of thionine. The immunosensor showed wide linear range from 5.6×101 to 5.6×108 CFU/mL and low detection limit of 35 CFU/mL. The immunosensor also exhibited excellent specificity, reproducibility and stability, indicating that it had practicability in quality control of complex food samples and potential in clinical applications. [ABSTRACT FROM AUTHOR]

Summary: A rapid and simple procedure to detect irradiated food containing fat is proposed. This method is based on HS‐SPME coupled with GC‐MS to determine the presence of a radiolytic product in irradiated meats: 2‐dodecylcyclobutanone (2‐DCB) and is proposed as an alternative to EN 1785:2003, which is a long and complex procedure. The qualitative confirmation method is validated on different type of meats: chicken, turkey, duck, beef, pork on both nonirradiated and irradiated samples at different dose levels (0.05, 0.12, 0.5, 1.0 and 3.0 kGy) with a biological X‐ray irradiator. The validation parameters investigated are selectivity, minimum dose level (MDL), limit of detection (LOD), sensitivity and specificity. The MDL and LOD values were 0.5 kGy and 5.0 ng mL−1, respectively, for all matrices. No false positives or false negatives occurred, and 100% of samples were correctly identified. The results show that HS‐SPME GC‐MS is suitable for routine analysis. [ABSTRACT FROM AUTHOR]

In the present study, for the first time electromembrane extraction followed by highperformance liquid chromatography coupled with ultraviolet detection was developed and validated for the determination of tartrazine in some food samples. The parameters influencing electromembrane extraction were evaluated and optimized. The membrane consists of 1-octanol immobilized in the pores of a hollow fiber. As a driving force, a 30 V electrical field was applied to make the analyte migrate from sample solution with pH 3, through the supported liquid membrane into an acceptor solution with pH 10. Best preconcentration (enrichment factor>21) was obtained in extraction duration of 15min. Effects of some solid nano-sorbents like carbon nanotubes and molecularly imprinted polymers on membrane performance and electromembrane extraction efficiency were evaluated. The method provided the linearity in the range 25-1000 ng/mL for tartrazine (R² >0.9996) with repeatability range (RSD) between 3.8 and 8.5% (n = 3). The limits of detection and quantitation were 7.5 and 25 ng/mL, respectively. Finally, the method was applied to the determination and quantification of tartrazine from some food samples with relative recoveries in the range between 90 and 98%. [ABSTRACT FROM AUTHOR]

This paper describes an innovation of dispersive liquid-liquid microextraction enabling multiple-component analysis of eight high-priority food contaminants in two chemically distinctive families: Sudan dyes and phthalate plasticizers. To provide convenient sample handling for solid and solid-containing matrices, a modified dispersive liquid-liquid microextraction procedure used an extractant precoated frit to perform simultaneous filtration, solvent mixing, and phase dispersion in one simple step. A binary ionic liquid extractant system was carefully tuned to deliver high quality analysis based only on affordable LC with diode array detector instrumentation. The method is comprehensively validated for robust quantification with good precision (6.9-9.8% RSD) in a linear 2-1000 μg/L range. Having accomplished enrichment factors up to 451, the treatment enables sensitive detection at 0.09-1.01 μg/L levels. Analysis of six high-risk solid condiments and sauces further verified its practical applicability within a 70-120% recovery range. Compared to other approaches, the current dispersive liquid-liquid microextraction treatment offers major advantages in terms of minimal solvent (1.5 mL) and sample (0.1 g) consumption, ultra-high analytical throughput (6 min), and the ability to handle complex solid matrices. The idea of performing simultaneous analysis for multiple contaminants presented here fosters a more effective mode of operation in food control routines. [ABSTRACT FROM AUTHOR]

The potential difference induced by the interaction of samples with electromagnetic radiation in the visible region is used for food characterization. In this article we show that the above effect can be applied for the understanding of specific reactions and processes taking place in milk such as change of the acidity and changes caused by an added reagent. We also propose a technique for instantaneous detection of inhibitors of starter bacteria in milk. We suggest possible methods for quality control of milk and other foods. Instantaneous results, practically no expenses for consumables, and possibilities for field measurements will be some of the advantages of this approach. [ABSTRACT FROM AUTHOR]

A fluorescence polarisation immunoassay (FPIA) using a specific polyclonal antiserum for the detection of maduramicin (MD) was developed and optimised. The polyclonal antiserum was produced against MD linked to bovine serum albumin. Fluorescein-labelled MD (tracer) was synthesised by N-hydroxysuccinimide active ester method and purified using thin layer chromatography. The developed FPIA for MD had a dynamic range from 0.01 to 5.6 μg mL−1 with an IC50 value of 0.16 μg mL−1 and a limit of detection of 0.002 μg mL−1. Recoveries from chicken muscle, fat and egg samples spiked at 0.25, 5 and 10 μg g−1 levels were 82–130%. The FPIA results from analysis of incurred residues in chicken muscle samples showed that the simple procedure is viable. [ABSTRACT FROM AUTHOR]

Background: Undeclared allergens in foodstuffs represent a major health problem for sensitized persons. Until recently, most food control authorities were not in the position to monitor hidden allergens and to take legal measures against their presence in foodstuffs. Methods: In this study, we employed human sera-based immunoassay techniques, enabling semiquantitative detection and identification of peanut allergens in a variety of foodstuffs. Results: This study showed the presence of undeclared allergens in products belonging to various food categories, such as cereals, cookies, cakes, and snacks. The detection limit for peanut contamination was in most instances less than 50 mg peanut material per kg, i.e., less than about 5 mg peanut allergens per kg. We legally objected to products with more than one part per thousand or 1000 mg/kg of peanut contamination. Conclusions: In most cases, food producers, confronted with our results, were able to detect and eliminate the sources of the contamination. They implemented measures to prevent the presence of hidden peanut allergens in their products, increasing food safety for sensitized persons and overall food quality. [ABSTRACT FROM AUTHOR]

Summary In this work we use paramagnetic defects induced by radiation in the fruit pulp to identify gamma-irradiated kiwi, papaya and tomato. Pulp without seed, peels or stalks are treated by alcoholic extraction in order to remove water, soluble fractions and solid residue. The ESR spectra of pulp samples of irradiated fruit is composed of species A (g = 2.0045) and species C (g = 2.0201 and g = 1.9851), which are also observed in irradiated stalks and skins. In comparison with samples which are not submitted to alcoholic extraction, species C is stable enough to be used as a dose marker. Furthermore, the species C signal can be detected perfectly even in pulp samples irradiated with doses as low as 200 Gy. Irradiation doses of fruit, exposed to 200–900 Gy of a gamma rays, were estimated with an overall uncertainty of 15% using dried pulp samples. These results indicate that radicals induced in pulp have potential to be used in the identification and absorbed dose determination of irradiated fruit. [ABSTRACT FROM AUTHOR]

Summary Aquaculture in Africa accounts for less than 2% of total domestic fish production. Although its contribution has expanded significantly from 59 000 Mt in 1985 to 85 000 Mt in 1990, the estimated potential is 3.5 million Mt per year. Of the 20 major species cultured, only Nile tilapia, African catfish and common carp are farmed throughout Africa. The leading fish culture producers, Cote d'Ivoire, Egypt, Kenya, Nigeria, South Africa, Tunisia and Zambia, accounted for more than 95% of production in 1990. Production has remained static in many countries (e.g. Cameroon, Ghana and Nigeria) and has decreased in others (e.g. Madagascar, Uganda). The potential for aquaculture in the Southern African Development Community (SADC) region is 250 000 t year-1 (present production is 5000 t year-1 ). Extensive, small-scale fish farming has expanded in Malawi, Mozambique, Tanzania and Zimbabwe, where there are some 25 000 fish ponds. Fish farming has virtually ceased in Angola and is negligible in other SADC countries. In South Africa, production increased 663% between 1982 and 1992, the fastest growth in the world. Aquaculture development in South Africa has been market driven, dominated by large-scale producers and no small-scale operators. Potential health hazards from aquaculture products arise from either contaminants that find their way into the fish during the process of farming (feed additives, drugs) or loss of quality due to poor handling and processing. Poor handling is the greatest potential food safety issue in sub-Saharan Africa, because much of aquaculture production is undertaken by small-scale farmers who grow and handle relatively small quantities. About 90% of the fish from capture fisheries in Africa is preserved by means of smoking or roasting (40%) and sun drying (50%). However, the bulk of fish from small-scale rural aquaculture is sold fresh, whole and ungutted at the pond site. Although the FAO Code of Conduct for... [ABSTRACT FROM AUTHOR]