Utilization of diverse probiotics to create human health promoting fatty acids: A review.

Many probiotics produce functional lipids with health-promoting properties, such as short-chain fatty acids, linoleic acid and omega-3 fatty acids. They have been shown to maintain gut health, strengthen the intestinal barrier, and have anti-inflammatory and antioxidant effects. In this article, we provide an up-to-date review of the various functional lipids produced by probiotics. These probiotics can be incorporated into foods, supplements, or pharmaceuticals to produce these functional lipids in the human colon, or they can be used in industrial biotechnology processes to generate functional lipids, which are then isolated and used as ingredients. We then highlight the different physiological functions for which they may be beneficial to human health, in addition to discussing some of the challenges of incorporating probiotics into commercial products and some potential solutions to address these challenges. Finally, we highlight the importance of testing the efficacy and safety of the new generation of probiotic-enhanced products, as well as the great potential for the marketization of related products.

One stone, two birds: An eco-friendly aerogel based on waste pomelo peel cellulose for the efficient adsorption of dyes and heavy metal ions.

To achieve the objective of "waste control by waste", in this study, a green aerogel adsorbent comprised of pomelo-peel cellulose and sodium alginate (PCC/SA) was prepared through dual-network crosslinking. The resulting 3D hierarchical porous structured PCC/SA aerogel exhibited good structural stability, and kept the morphological integrity during 10 days in a wide pH range (2-10), suggesting its potential for recycling in diverse complex environments. Besides, the superior adsorption capacities for methylene blue (MB) and Cu(II) were observed, with the qm values and adsorption equilibrium times were recorded to be 1299.59 mg/g (300 min) and 287.55 mg/g (120 min), correspondingly. Furthermore, the favorable reusability of the PCC/SA aerogel was also demonstrated, with the removal efficiency for MB remaining almost unchanged (about 94 %) after 10 adsorption-desorption cycles, while there was a slight reduction for Cu(II) from 85.28 % to 72.47 %. XPS and FTIR analysis revealed that electrostatic attraction, hydrogen bonding, cation exchange and coordination were the major adsorption mechanisms. Importantly, the PCC/SA aerogel can be naturally degraded in soil within 10 weeks. Therefore, the as-prepared aerogel bead derived from pomelo peel shows great promise as an adsorbent for wastewater treatment containing dye and heavy metal ions.

An RPA-Assisted CRISPR/Cas12a Assay Combining Fluorescence and Lateral Flow Strips for the Rapid Detection of Enterotoxigenic Bacillus cereus.

Bacillus cereus (B. cereus) is a foodborne pathogen that can produce tripartite enterotoxins, which can cause a variety of diseases after infection. It is critical to rapidly and accurately detect strains with enteropathogenic potential to safeguard human health. In this study, a dual-signal visualized detection platform with fluorescence assay and paper-based lateral flow assay (LFA) based on recombinase polymerase amplification (RPA), CRISPR/Cas12a system, and self-developed CRISPR nucleic acid test strips was constructed for enterotoxigenic B. cereus. The genes that encode two tripartite enterotoxins─nheA, nheB, and nheC for nonhemolytic enterotoxin and hblA, hblC, and hblD for hemolysin BL─were utilized as detection targets. The platform was capable of detecting six enterotoxin genes at the same genomic DNA level. The limits of detection for each gene were 10-3 ng/µL in fluorescence assay and 10-4 ng/µL in LFA. Furthermore, 101-102 CFU/mL of B. cereus in pure culture was detected. Additionally, a smartphone miniprogram could assist in evaluating the results in LFA. The platform demonstrated good utility by detecting B. cereus in food samples, including milk and rice. The results indicate that our RPA-CRISPR/Cas12a dual-signal visualized detection platform can quickly and easily detect B. cereus with three-component enterotoxin-producing potentials. The whole analytic process took less than 60 min without complex operation or expensive equipment.

A new strategy to generate nanobodies for the coumaphos based on the synthesized nanobody libraries.

To break through the bottleneck in preparation of nanobody (Nb) for chemical contaminants induced by the difficulties in the synthesis of immunogen, complexity and unexpectable efficiency of immunization, a novel strategy to generate Nbs based on the designed synthetic Nb libraries with final size up to 109 cfu/mL was adopted and succeeded in selection of anti-coumaphos Nb A4. Furthermore, an affinity-matured mutant Nb 3G was obtained from the secondary library. Finally, an ic-ELISA was established with the limit of detection for coumaphos low to 1.90 ng/mL, 6.4-fold improved than the parent Nb A4, and the detection range from 3.06 to 15.77 ng/mL. Meanwhile, the recovery rate of vegetable samples was from 89.9% to 98.5%. Finally, the accuracy was testified by the standard UPLC-MS/MS method with R2 up to 0.99. Overall, fully synthetic Nb libraries constructed in this work provided an alternative possibility to generate the specific Nbs for chemical contaminants.

Review of formation mechanisms and quality regulation of chewiness in staple foods: Rice, noodles, potatoes and bread.

Staple foods serve as vital nutrient sources for the human body, and chewiness is an essential aspect of food texture. Age, specific preferences, and diminished eating functions have broadened the chewiness requirements for staple foods. Therefore, comprehending the formation mechanism of chewiness in staple foods and exploring approaches to modulate it becomes imperative. This article reviewed the formation mechanisms and quality control methods for chewiness in several of the most common staple foods (rice, noodles, potatoes and bread). It initially summarized the chewiness formation mechanisms under three distinct thermal processing methods: water medium, oil medium, and air medium processing. Subsequently, proposed some effective approaches for regulating chewiness based on mechanistic changes. Optimizing raw material composition, controlling processing conditions, and adopting innovative processing techniques can be utilized. Nonetheless, the precise adjustment of staple foods' chewiness remains a challenge due to their diversity and technical study limitations. Hence, further in-depth exploration of chewiness across different staple foods is warranted.

Food-Borne Biotoxin Neutralization in Vivo by Nanobodies: Current Status and Prospects.

Food-borne biotoxins from microbes, plants, or animals contaminate unclean, spoiled, and rotten foods, posing significant health risks. Neutralizing such toxins is vital for human health, especially after food poisoning. Nanobodies (Nbs), a type of single-domain antibodies derived from the genetic cloning of a variable domain of heavy chain antibodies (VHHs) in camels, offer unique advantages in toxin neutralization. Their small size, high stability, and precise binding enable effective neutralization. The use of Nbs in neutralizing food-borne biotoxins offers numerous benefits, and their genetic malleability allows tailored optimization for diverse toxins. As nanotechnology continues to evolve and improve, Nbs are poised to become increasingly efficient and safer tools for toxin neutralization, playing a pivotal role in safeguarding human health and environmental safety. This review not only highlights the efficacy of these agents in neutralizing toxins but also proposes innovative solutions to address their current challenges. It lays a solid foundation for their further development in this crucial field and propels their commercial application, thereby contributing significantly to advancements in this domain.

Fluorescence immunosensor based on a specific monoclonal antibody for highly sensitive and rapid detection of gizzerosine in feed.

Gizzerosine is a biogenic amine produced in fish meal drying process and posted higher mortality due to gizzard erosion in poultry than histamine. However, it is difficult to obtain gizzerosine and achieve sensitive practical detection due to its simple structure. Herein, a monoclonal antibody (mAb) specific to gizzerosine was generated based on the new structural design and a fluorescence immunosensor for sensitive and on-site detection of gizzerosine in feed was first established. Molecular modeling of the three-dimensional (3D) structure and surface electrostatic potential of gizzerosine indicated that the carbonyl group of gizzerosine hapten might affect the important sites of antigen-antibody interactions. The proposed structure was used to obtain the sensitive and specific mAb with IC50 of 3.88 ng/mL in indirect competitive ELISA which was approximately 100-fold lower than that of direct competitive ELISA. Considering the practical application scenarios, a fluorescence immunosensor based on microporous dry method integrated with independent quality control line was established to improve detection stability. Under the optimum conditions, the proposed immunosensor showed a good linear relationship from 1.10 to 19.78 ng/mL and provided a low detection limit of 50 ng/g which was approximately 80-fold lower than the maximum recommended amount (0.4 mg/kg) of gizzerosine in feed. The recoveries of 6 kinds of feed ranged from 83.1 % to 114.3 %, which was in good consistence with that of UHPLC-MS/MS. Overall, this work provides a fast, cost-effective and reliable on-site tool for rapid screening of gizzerosine residues in feed samples.

De novo synthesis of a novel hapten and development of a monoclonal antibody-based immunoassay for the detection of dichlorvos and trichlorfon.

The absence of high-affinity antibodies has hindered the development of satisfactory immunoassays for dichlorvos (DDVP) and trichlorfon (TCP), two highly toxic organophosphorus pesticides. Herein, the de novo synthesis of a novel anti-DDVP hapten was introduced. Subsequently, a specific anti-DDVP monoclonal antibody (Mab) was produced with satisfying affinity to DDVP (IC50: 12.4 ng mL-1). This Mab was highly specific to DDVP, and TCP could readily convert into DDVP under mild alkaline conditions. Leveraging this insight, an indirect competitive ELISA was successfully developed for simultaneous detection of DDVP and TCP. The limit of detection in rice, cabbage and apple for DDVP /TCP was found to be 12.1/14.6 µg kg-1, 7.3/8.8 µg kg-1 and 6.9/8.3 µg kg-1, respectively. This study not only provides an effective strategy for producing a high-quality anti-DDVP Mab but also affords a reliable and cost-effective tool suitable for high-throughput detection of DDVP and TCP in food samples.

Nanobodies-based colloidal gold immunochromatographic assay for specific detection of parathion.

Parathion is one of organophosphorus pesticide, which has been prohibited in agricultural products due to its high toxicity to human beings. However, there are still abuse cases for profit in agricultural production. Hence, we established nanobodies-based colloidal gold immunochromatographic assay (GICA) in which nanobodies (Nbs) as an excellent recognition element, greatly improving the stability and sensitivity of ICA. Under the optimal conditions, the developed Nbs-based GICA showed a cut-off value of 50 ng/mL for visual judgment and a half-inhibitory concentration (IC50) of 2.39 ng/mL for quantitative detection. The limit of detection (LOD) was as low as 0.15 ng/mL which was significantly 50-fold higher sensitivity than the commercial mAb-ICA. Additionally, this method exhibited good recoveries for the detection of cabbage, cucumber, and orange samples and excellent correlation with the UPLC-MS/MS method. The results showed that this method developed in this work based on nanobody can be used in practical detection of parathion in foods and nanobody is novel prospective antibody resource for immunoassays of chemical contaminants.

Gold nanocluster-based ratiometric fluorescence immunoassay for broad-spectrum screening of five eugenols.

BACKGROUND: Eugenol compounds (EUGs), which share chemical similarities with eugenol, belong to a group of phenolic compounds primarily found in clove oil. They are highly valued by fish dealers due to their exceptional anesthetic properties, playing a crucial role in reducing disease incidence and mortality during the transportation of live fish. Despite their widespread use, the safety of EUGs remains a contentious topic, raising concerns about the safety of aquatic products. This underscores the need for efficient and sensitive analytical methods for detecting EUGs. RESULTS: Nanomaterial-based ratiometric fluorescence immunoassay has gained increasing attention due to its integration of the immunoassay's excellent specificity and compatibility for high-throughput analysis, coupled with the exceptional sensitivity and anti-interference capabilities of ratiometric fluorescence assays. In this study, we developed a sensitive ratiometric fluorescence immunoassay for screening five EUGs. This method employs a broad-specificity monoclonal antibody (mAb) as a recognition reagent, selective for five EUGs. It leverages the horseradish peroxidase (HRP)-triggered formation of fluorescent 2,3-diaminophenazine (DAP) and the quenching of fluorescent gold clusters (Au NCs) for detection. The assay's detection limits for eugenol, isoeugenol, eugenol methyl eugenol, methyl isoeugenol, and acetyl isoeugenol in tilapia fish and shrimp were found to be 9.8/19.5 µg/kg, 0.11/0.22 µg/kg, 19/36 Tilapia ng/kg, 8/16 ng/kg, and 3.0/6.1 µg/kg, respectively. Furthermore, when testing spiked Tilapia fish and shrimp samples, recoveries ranging from 84.1 to 111.9 %, with the coefficients of variation staying below 7.1 % was achieved. SIGNIFICANCE: This work introduces an easy-to-use, broad-specificity, and highly sensitive method for the screening of five EUGs at a pg/mL level, which not only provides a high-throughput strategy for screening eugenol-type fish anesthetics in aquatic products, but also can serve as a benchmark for developing immunoassays for other small molecular pollutants, rendering potent technological support for guarding food safety and human health.

Simple synthesis of flower-like ZnO@Pt composites for dual-mode colorimetric detecting Hg2+ with smartphone and UV-vis.

BACKGROUND: Mercury is one of the most toxic heavy metal contaminants that can be harmful to human health through the food chain. Recently, the colorimetric detection of heavy metals based on nanozyme catalytic activity has received extensive interest due to the simplicity, signal visibility and suitability for in situ detection. However, the majority of these nanozymes that can be utilized for detecting mercury with high synthesis temperature and complicated synthesis methods, which limited their practical application. RESULTS: In this work, flower-like ZnO@Pt composites were simply synthesized at room temperature, the flower-like structure and the high electron mobility of ZnO endow ZnO@Pt with stronger peroxidase-like activity. Consequently, dual-mode (UV-vis and smartphone) colorimetric sensors were designed to detect Hg2+. In UV-vis mode, the Hg2+ concentration linear range was 10-400 nM, and the limit of detection (LOD) was 0.54 nM. In smartphone mode, the Hg2+ concentration linear range was 50-1250 nM, and the LOD was 29.8 nM. A parallel analysis in 3 real water samples was confirmed by ICP-MS, the results showed good correlations (R2 > 0.98), indicating the practical reliability of these sensors. SIGNIFICANCE: The novel flower-like ZnO@Pt composites with high stability, catalytic activity and Hg2+ response were simply synthesized at room temperature, simplifying the synthesis steps and reducing costs. The sensitivity of the developed colorimetric sensor in UV-vis mode was 3-145 times higher than that of the similar methods. The colorimetric sensor in smartphone mode broadened the detection range and improved the portability of Hg2+ detection. Thus, the dual-mode (UV-vis and smartphone) colorimetric sensors providing new detection modes for rapid monitoring of Hg2+ in environmental water.

Enantioselectivity regulation of antibody against chiral herbicide metolachlor based on interaction at chiral center.

Enantioselective antibodies have emerged as great potential biomaterials in the fields of immunoassays and chiral separation. However, cross-reactivity of antibodies to the distomer may severely restrict the application. Comprehending the interaction mechanism between antibodies and enantiomers could be beneficial to produce superior enantioselective antibodies. In this study, a pair of recombinant antibodies (RAbs) against metolachlor enantiomers at chiral carbon (αSS-MET and αSR-MET) were generated and characterized. The αSS-MET-RAb and αSR-MET-RAb showed comparable sensitivity and specificity to the parental monoclonal antibodies by icELISA, with IC50 values of 3.45 and 223.77 ng/mL, respectively. Moreover, the complex structures of RAbs and corresponding eutomer were constructed and analyzed, and site-specific mutagenesis was utilized to verify the reliability of the enantioselective mechanism elucidated. It demonstrated that the strength of the interaction between the chiral center region of eutomer and the antibody was the key factor for the enantioselectivity of antibody. Increasing this interaction could limit the conformational adjustment of the distomer in a specific chiral recognition cavity, thus decreasing the affinity of the antibody to the distomer. This work provided the in-depth analysis of enantioselective mechanism for two RAbs and paved the way to regulate antibody enantioselective performance for immunoassays of chiral compounds.

Designing a size exclusion-based hapten and the development of a quantitative and visual time-resolved fluorescence immunochromatography assay strip for detecting dimethomorph and flumorph in a group-specific manner.

Based on the size and surface properties of dimethomorph and flumorph, we used a computer simulation-assisted size exclusion hapten design strategy to develop group-specific monoclonal antibodies that can simultaneously recognize dimethomorph and flumorph. For this, we performed quantitative and visual semi-quantitative time-resolved fluorescence immunochromatography (TRFICA) to simultaneously detect dimethomorph and flumorph in potatoes and apples. In potato samples, the visual limit of detection (vLOD) for dimethomorph and flumorph was 4 ng/mL and 8 ng/mL, respectively, whereas the quantitative limit of detection (qLOD) for dimethomorph and flumorph was 0.26 and 0.33 ng/mL, respectively. The vLOD of dimethomorph and flumorph in apple samples was 8 ng/mL, whereas the qLOD of dimethomorph and flumorph was 0.17 and 0.38 ng/mL, respectively. The average recovery of potato and apple samples ranged from 77.5% to 121.7%, which indicated that the method can be used to rapidly detect dimethomorph and flumorph in food samples.

Universal and Naked-Eye Diagnostic Platform for Emetic Bacillus cereus Based on RPA-Assisted CRISPR/Cas12a.

Emetic Bacillus cereus (B. cereus), which can cause emetic food poisoning and in some cases even fulminant liver failure and death, has aroused widespread concern. Herein, a universal and naked-eye diagnostic platform for emetic B. cereus based on recombinase polymerase amplification (RPA)-assisted CRISPR/Cas12a was developed by targeting the cereulide synthetase biosynthetic gene (cesB). The diagnostic platform enabled one-pot detection by adding components at the bottom and cap of the tube separately. The visual limit of detection of RPA-CRISPR/Cas12a for gDNA and cells of emetic B. cereus was 10-2 ng µL-1 and 102 CFU mL-1, respectively. Meanwhile, it maintained the same sensitivity in the rice, milk, and cooked meat samples even if the gDNA was extracted by simple boiling. The whole detection process can be finished within 40 min, and the single cell of emetic B. cereus was able to be recognized through enrichment for 2-5 h. The good specificity, high sensitivity, rapidity, and simplicity of the RPA-assisted CRISPR/Cas12a diagnostic platform made it serve as a potential tool for the on-site detection of emetic B. cereus in food matrices. In addition, the RPA-assisted CRISPR/Cas12a assay is the first application in emetic B. cereus detection.

Effects of frying on the surface oil absorption of wheat, potato, and pea starches.

The effects of structural changes on surface oil absorption characteristics of wheat starch, pea starch and potato starch during frying under different water content (20%, 30%, 40%, 50%) were studied. Fried potato starch with a 40% water content exhibited the highest surface oil content. When the initial moisture content reached 30%, the scattering intensity of the crystal layer structure decreased for wheat and pea starches, while the scattering peak for potato starch completely disappeared. At 40% moisture content, the amorphous phase ratio values for fried potato, wheat and pea starches were 13.50%, 11.78% and 11.24%, respectively, and the nitrogen adsorption capacity of fried starch decreased in turn. These findings that the structure of potato starch was more susceptible to degradation compared to pea starch and wheat starch, resulting in higher surface oil absorbed by potato starch during frying process.

Development of broad-spectrum immunoassay with monoclonal antibody to detect five eugenols and study of their molecular recognition mechanism.

In this study, three eugenol fragment-containing haptens were synthesized, and a monoclonal antibody (mAb) selective for five commonly-found eugenol compounds (EUGs, i.e., eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, and acetyl isoeugenol) was obtained. Based on this mAb, a broad-spectrum indirect competitive ELISA for high-throughput detection of five EUGs was developed. The detection limits for eugenol, isoeugenol, methyl eugenol, methyl isoeugenol and acetyl isoeugenol in both tilapia and shrimp samples were 25.3/ 50.6 µg/kg, 0.075/0.15 µg/kg, 0.48/0.96 µg/kg, 0.16/0.32 µg/kg, and 18.16/36.32 µg/kg, respectively. The recoveries for five EUGs ranged from 80.4 to 114.0 % with a coefficient of variation less than 11.5 %. Moreover, homology modelling and molecular docking were conducted to elucidate the interactions mechanism of mAb-EUGs. The work provides a promising tool for high-throughput screening of EUGs in aquatic products, which can serve as a benchmark for designing haptens and developing immunoassays for other small molecules.

Development of an Open Droplet Microchannel-Based Magnetosensor for Immunofluorometric Assay of Trimethoprim in Chicken and Pork Samples with a Wide Linear Range.

Trimethoprim (TMP), functioning as a synergistic antibacterial agent, is utilized in diagnosing and treating diseases affecting livestock and poultry. Human consumption of the medication indirectly may lead to its drug accumulation in the body and increase drug resistance due to its prolonged metabolic duration in livestock and poultry, presenting significant health hazards. Most reported immunoassay techniques, such as ELISA and immunochromatographic assay (ICA), find it challenging to achieve the dual advantages of high sensitivity, simplicity of operation, and a wide detection range. Consequently, an open droplet microchannel-based magnetosensor for immunofluorometric assay (OMM-IFA) of trimethoprim was created, featuring a gel imager to provide a signal output derived from the highly specific antibody (Ab) targeting trimethoprim. The method exhibited high sensitivity in chicken and pork samples, with LODs of 0.300 and 0.017 ng/mL, respectively, and a wide linear range, covering trimethoprim's total maximum residue limits (MRLs). Additionally, the spiked recoveries in chicken and pork specimens varied between 81.6% and 107.9%, maintaining an acceptable variation coefficient below 15%, aligning well with the findings from the ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique. The developed method achieved a much wider linear range of about 5 orders of magnitude of 10-2-103 levels with grayscale signals as the output signal, which exhibited high sensitivity, excellent applicability and simple operability based on magnetic automation.

Formation and Detection of Gizzerosine in Animal Feed Matrices: Progress and Perspectives.

Gizzerosine is responsible for gizzard erosion and black vomit, owing to excessive gastric acid secretion in poultry. It is a biogenic amine that forms during feed processing. Gizzerosine, a derivative of histamine, is a serious threat to animal feed safety and poultry production because it is more potent after ingestion and more harmful to poultry than histamine. The difficulty of obtaining gizzerosine and the lack of simple, rapid, and sensitive in vitro detection techniques have hindered studies on the effects of gizzerosine on gizzard health and poultry production. In this review, we evaluated the natural formation and the chemical synthesis methods of gizzerosine and introduced seven detection methods and their principles for analyzing gizzerosine. This review summarizes the issues of gizzerosine research and suggests methods for the future development of gizzerosine detection methods.

A breakthrough of immunoassay format for hapten: recent insights into noncompetitive immunoassays to detect small molecules.

Immunoassay based on the antibodies specific for targets has advantages of high sensitivity, simplicity and low cost, therefore it has received more attention in recent years, especially for the rapid detection of small molecule chemicals present in foods, diagnostics and environments. However, limited by low molecular weight and only one antigenic determinant existed, immunoassays for these small molecule chemicals, namely hapten substances, were commonly performed in a competitive immunoassay format, whose sensitivities were obviously lower than the sandwich enzyme-linked immunosorbent assay generally adaptable for the protein targets. In order to break through the bottleneck of detection format, researchers have designed and established several novel noncompetitive immunoassays for the haptens in the past few years. In this review, we focused on the four representative types of noncompetitive immunoassay formats and described their characteristics and applications in rapid detection of small molecules. Meanwhile, a systematic discussion on the current technologies challenges and the possible solutions were also summarized. This review aims to provide an updated overview of the current state-of-the-art in noncompetitive immunoassay for small molecules, and inspire the development of novel designs for small molecule detection.

Effects of crosslinking agents on properties of starch-based intelligent labels for food freshness detection.

The impact of citric acid, carboxymethyl cellulose, carboxymethyl starch, sodium trimetaphosphate, or soybean protein on the crosslinking of starch-based films was examined. These crosslinking starch films were then used to create pH-sensitive food labels using a casting method. Blueberry anthocyanins were incorporated into these smart labels as a pH-sensitive colorimetric sensor. The mechanical properties, moisture resistance, and pH responsiveness of these smart labels were then examined. Crosslinking improved the mechanical properties and pH sensitivity of the labels. These different crosslinking agents also affected the hydrophobicity of the labels to varying degrees. Soybean protein was the only additive that led to labels that could sustain their structural integrity after immersion in water for 12 h. Because it increased the hydrophobicity of the labels, which decreased their water vapor permeability, moisture content, swelling index, and water solubility by 47 %, 29 %, 52 % and 10 %, respectively. The potential of using these labels to monitor the freshness of chicken breast was then examined. Only the films containing soybean protein exhibited good pH sensitivity, high structural stability, and low pigment leakage. This combination of beneficial attributes suggests that the composite films containing starch and soybean protein may be most suitable for monitoring meat freshness.