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• The structural impact on anthocyanins' UV–Vis molar absorptivity was studied; • A quantitative strategy based on the molar relative response factors was proposed; • An online database for 617 anthocyanins was developed to support the approach; • Our strategy provided improved quantitative results for anthocyanins in food. The effects of anthocyanin's substitution groups on the UV–Vis molar absorptivity were examined by analyzing a group of 31 anthocyanidin/anthocyanin reference standards with ultra-high performance liquid chromatography-diode array detector (UHPLC-DAD). The substitution groups on aglycones were found to associate with molar absorptivity variations, often neglected in anthocyanin quantitation, resulting in significant analytical errors. A simple yet comprehensive strategy based on the molar relative response factors (MRRFs) and a single master reference calibration (i.e., cyanidin-3-glucoside) was proposed to quantify anthocyanins in red cabbage, blueberry, and strawberry samples with improved analytical accuracy. The results indicate this approach provides an effective, inexpensive, and accurate analytical method for anthocyanins in food materials without using individual reference standards. MRRFs of 617 anthocyanins/anthocyanidins were calculated, and the information is freely available at https://BotanicalDC.online/anthocyanin/. This study could be critical to developing new reference methods for anthocyanin analysis and harmonizing results and data from various sources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel smartphone-based methods for wine analysis were developed. • Developed methods were applied for the determination of bioactive compounds in wines. • Smartphone-based detection facilitates in-field analysis. • Proposed solution can be used in routine food quality assessment. • The obtained results were comparable to those obtained with UV/Vis spectrophotometry. A set of simple smartphone-based methods of bioactive compounds determination were developed for wine analysis. Procedures for smartphone-based determination of the total content of phenolic compounds, flavonoids, anthocyanins and biogenic amines, as well as measurement of antioxidant activity were developed and fully validated. The experimental setup is based on smartphone and 3D-printed device, though it is very simple and can be conveniently applied in lab and in field. The proposed solutions have satisfactory figures of merit with R2 in the range of 0.9860–0.9981 for linear range. The recoveries were in range 98.6–102%, RSDs up to 4.2% and LODs below 2.3 mg/L. In order to demonstrate the applicability of the proposed procedures, wine samples were analysed using spectrophotometry and newly developed methods. The results of application of smartphone and spectrophotometer are comparable, in terms of validation parameters and measured concentrations in real samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two fusion tracers with alkaline phosphatase (ALP) tagged at one terminus of scFv. • The fusion tracers ALP-scFv and scFv-ALP retain good bifunctional activities. • Colorimetric and chemiluminescent immunoassays based on ALP-scFv for zearalenone. • Both methods are reliable for rapid and sensitive detection of zearalenone in food. Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin and seriously threatens food safety, which requires rapid and sensitive detection methods for monitoring ZEN in agro-products. Herein, an alkaline phosphatase-tagged single-chain variable fragment fusion protein (ALP-scFv) was used as a bifunctional tracer to develop a colorimetric enzyme immunoassay (CEIA) and a chemiluminescent enzyme immunoassay (CLEIA) for ZEN. In addition, the interactions between scFv and ZEN were exploited by computer-assisted simulation, and four key amino acid sites were preliminarily identified. After optimization, the CEIA and CLEIA exhibited a limit of detection of 0.02 and 0.006 ng/mL, respectively. Furthermore, both methods showed favorable accuracy in recovery experiments and good selectivity in cross reactions. Moreover, the detection results of the actual samples from both methods correlated well with those from high-performance liquid chromatography. Overall, the ALP-scFv fusion tracer-based CEIA and CLEIA are demonstrated as reliable tools for ZEN detection in food. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel approach of digital-image based method combined to SPE. • In-situ Cu(II) desorption and spot color development using iodide-starch reagent for DIB imaging. • Development of a new magnetic SPE adsorbent for copper preconcentration. • The method provided low detection limit sufficient for trace copper analysis in food and water. • An adsorbent with a more than fifteen-fold cycle life. A new analytical method for measuring copper in food and water was developed and validated, employing a solid-phase extraction (SPE) technique combined with digital-image-based (DIB) detection. A novel magnetic adsorbent of zinc ferrite/ Citrullus colocynthis biochar (ZF@C.BC) was used to preconcentrate copper. A magnetic tip was used to separate the copper-loaded adsorbent from the extraction medium and to dispense it to the DIB plate. In-situ desorption and development of the spot color with iodide-starch reagent were carried out, and a digital image of the developed spots was captured using a smartphone and processed using ImageJ software. The copper adsorption capacity was 91.3 mg g−1. Desorption was effected using a 0.3 mol L-1 hydrochloric acid. The preconcentration factor was 300, the limit of detection was 4.8 μg L-1, the linearity was 16–600 μg L-1 and the sample throughput was 12 h−1. The developed approach was validated by analyzing food and water samples, confirming recoveries ≥ 91 % and 88 %, respectively, with RSD ≤ 8.4 %, n = 3. [ABSTRACT FROM AUTHOR]

A portable smartphone-based fluorescence sensing platform can realize the on-site rapid quantification of sulfite in food. [Display omitted] • A chromogenic and fluorogenic dual-mode probe was developed for the detection of sulfite. • The probe specifically recognizes sulfite with fast response and low detection limit. • A portable sensing platform can on-site visually determine sulfite in various food. • The probe achieved high accuracy and good anti-interference ability. Sulfur dioxide (SO 2) and its derivatives (HSO 3 − and SO 3 2−) are widely used in food-processing. Whereas excessive consumption of sulfur dioxide and its derivatives (>0.70 mg·kg−1day−1) severely endangers human health. In this work, we rationally constructed a practical dual-mode probe (dicyanomethylene)-1-methyl-1,4-dihydroquinolin-2-yl)vinyl)-1-methylquinolinium (QMN), which underwent a specific 1, 4-Michael addition with sulfite to afford a noticeable color change from pale yellow to red along with a high-contrast fluorescence turn-on response at 598 nm. QMN has the advantages of rapid response, high signal-to-noise ratio, excellent selectivity, good water-solubility, large Stokes shift and low detection limit (LOD = 31.9 nM). QMN has been successfully used to on-site visually determine sulfite in a diversity of foods with satisfactory recoveries (91.33–111.33 %) and high accuracy (93.74–98.71 %). Furthermore, a portable smartphone-based fluorescence sensing platform was fabricated for on-site determination of sulfite in food with good performance. [ABSTRACT FROM AUTHOR]

• Utilization of biodegradable polymers ensures the safety of food and the environment. • Bioactive compounds and natural colorants are incorporated for smart functioning. • Natural colorants can be used as a pH indicator as well as active ingredient in packaging. • Smart packaging possesses dual functions; food preservation and quality indication. • Natural colorants incorporation by appropriate techniques is crucial for real-time indications of food spoilage. The current synthetic plastic-based packaging creates environmental hazards that impact climate change. Hence, the topic of the current research in food packaging is biodegradable packaging and its development. In addition, new smart packaging solutions are being developed to monitor the quality of packaged foods, with dual functions as food preservation and quality indicators. In the creation of intelligent and active food packaging, many natural colorants have been employed effectively as pH indicators and active substances, respectively. This review provides an overview of biodegradable polymers and natural colorants that are being extensively studied for pH-indicating packaging. A comprehensive discussion has been provided on the current status of the development of intelligent packaging systems for food, different incorporation techniques, and technical challenges in the development of such green packaging. Finally, the food industry and environmental protection might be revolutionized by pH-sensing biodegradable packaging enabling real-time detection of food product quality and safety. [ABSTRACT FROM AUTHOR]

• A total of seventy-five garlic samples from different geographical origins were analysed. • Garlic samples from different geographical origins have distinct metabolite compositions. • Polish garlic has the highest content of allyl organosulfur compounds. • Chinese garlic has low sugar content but high amino acid and choline content. • Madeira garlic is rich in free carbohydrates, betaine, and amino acids. Garlic is one of the most popular vegetables worldwide, which contains many bioactive compounds. The chemical composition of garlic varies significantly depending on conditions in the growing locality and other factors. In this paper, the garlic samples were classified based on their geographical origin using principal component analysis (PCA), and significant differences in metabolite composition were found. Quantitative analysis highlighted that Polish garlics have the highest level of sulfur components, similar to Spanish garlic Egyptian garlic exhibited the lowest content of identified metabolites, while Madeira garlic was rich in carbohydrates and amino acids. Chinese garlic had low sugar content but a higher quantity of amino acids and choline. The findings highlight the association between food composition and environmental conditions and can be used to classify garlic based on its origin. [ABSTRACT FROM AUTHOR]

[Display omitted] • Solid-phase microextraction of fluorides on layered double hydroxide nanoparticles. • Cotton rotating disk packed with layered double hydroxide (LDH) nanoparticles. • LDH nanoparticles for in situ formation of the alizarin complexone-Al3+-F– complex. • Layered double hydroxides for smartphone digital image colorimetry. • First procedure for the determination of F– in milk by smartphone-based colorimetry. A novel smartphone digital image colorimetry-based approach was developed for fluoride ion determination, using layered double hydroxide (LDH) nanoparticles (Mg 2 Al(OH) 7) as sorbents for analyte preconcentration and as a source of a central metal ion for a colored complex formation. A cotton rotating disk provided effective retention of the LDH nanoparticles during solid-phase microextraction and elution, excluding time-consuming centrifugation process. In the proposed procedure, the nanoparticles acted as aluminum ion source for alizarin complexone-Al3+-F– complex formation. An image of Eppendorf tube, containing the colored complex solution was obtained by a smartphone and converted, using the RGB model for fluoride ion determination. The procedure had a linear range of 0.20–20 mg L−1 with a limit of detection of 0.06 mg L−1. The developed procedure provided effective fluoride separation from various matrices for its determination by a smartphone without additional sample pretreatment. [ABSTRACT FROM AUTHOR]

• Using LSC to measure 226Ra and 228Ra in food samples simultaneously. • Overall efficiencies of 226Ra and 228Ra were 68.4–79.4% and 30.1– 35.8%, respectively. • The MDA of 226Ra and 228Ra were 11.3 mBq/g and 33.4 mBq/g, respectively. • Method was validated by reference materials and compared to data from γ-spectrometry. The 228Ra and 226Ra isotopes of radium are significant contaminants in food, raising public concern because of their radiotoxicity. Several methods are available for determining 228Ra and 226Ra. However, the application of these procedures is not focused on food but only on water and environmental matrices. In this study, a cost-effective method for the simultaneous determination of 226Ra and 228Ra radioactivity in food samples using liquid scintillation counting was developed. The overall efficiencies of 226Ra and 228Ra in the food samples are 69.4–78.4% and 30.1–35.8%, respectively. The minimum detectable activities of 226Ra and 228Ra are 11.3 mBq/g and 33.4 mBq/g, respectively, in our food sample, obtained using a 1.0 g ash sample and 60 min of counting time. The method was validated using IAEA-certified reference materials and compared with data obtained using gamma spectrometry in tea, kelp, and oyster samples. [ABSTRACT FROM AUTHOR]

• Oil refining causes hydrolysis of epoxy fatty acids to the corresponding diol. • The epoxy-to-diol ratio might be a new marker to asses authenticity of virgin oils. • Fried and highly processed foods contain high oxylipin concentrations. • The total amount of oxylipin consumed per portion ranges from 2 to 80 mg. Several oxylipins are potent lipid mediators and are discussed to be absorbed after oral intake. However, information about their concentrations in oils and processed foods are scarce. Here, we analyzed the concentrations of mono-, di- and multihydroxy- as well as epoxy-PUFA in virgin and refined oils as well as in different foods/meals. Oil refining causes hydrolysis of epoxy-PUFA and thus high dihydroxy-PUFA concentrations (e.g. 15,16-DiHODE 290 µg/g in refined vs. 15 µg/g in virgin rapeseed oil), making the epoxy-to-diol ratio a potential marker for refined oils. Low oxylipin levels were found in foods with high amounts of saturated fatty acids such as Hamburger patties (around 30 µg/g). High concentrations (up to 1200 µg/g, 80 mg per serving) and high oxylipin/precursor-PUFA ratios were found in fried falafel and processed foods such as vegetarian sausage/fish fingers. Our study provides first insights in the oxylipin concentrations of our daily food, indicating a relevant intake. [ABSTRACT FROM AUTHOR]