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This paper proposes a strategy for the large-scale preparation of stretchable silver inks, which can be applied to fabricate a conformal on-skin electrode array via screen printing for a stable human–machine interface.

A highly sensitive and reliable fluorescence immunoassay based on the inner-filter effects (IFE) of quantum dots (QDs) was developed for the sensitive detection of norfloxacin (NOR) in animal-origin foods. Briefly, the enzymatic formation of horseradish peroxidase in conventional ELISA effectively quenched the fluorescence of QDs through IFE, and then the absorption signal of conventional ELISA was transformed to fluorescent signals, resulting in a higher sensitivity for NOR detection in animal-origin foods.The detection limit of NOR in this developed method was 0.20 µg L− 1 in standard solution, which was 12-fold more sensitive than conventional ELISA (2.50 µg L− 1). The results of specificity analysis revealed that the proposed method could not only be used for the detection of NOR, but also for the other 9 structural analogues. The recovery rates of NOR-spiked animal-origin foods ranged from 88.11–108.16%, with CV values of 1.95%-18.03%. In addition, the established method had good consistency with the commercial ELISA kits and HPLC, indicating the accuracy of the developed method for the detection of NOR in real samples. In conclusion, the established fluorescence immunoassay was sensitive and facile, and could be alternatively used for the determination of NOR residues in animal-origin foods.

Fluoroquinolones are a new class of synthetic antimicrobials, which have been widely used in clinical treatment. However, their irrational use can lead to allergic reactions, adverse reactions of the heart system and damage of the liver system. Due to the urgency of the safety risk of fluoroquinolones, it is of great significance to establish rapid, sensitive and accurate detection methods for fluoroquinolones. Molecularly imprinted polymers with specific structures synthesized by molecular imprinting technology are widely used for the detection of fluoroquinolones due to their high specificity, high sensitivity and stable performance. Besides, new functional nanomaterials with different morphology and size can provide rich sites for surface chemical reactions, thus greatly promoting the sensitivity and innovation of molecular imprinted polymer. This review summarizes the application status and development prospects of molecular imprinting technology based on novel nanomaterials labeling in the adsorption and detection of fluoroquinolones, in order to provide references for the future research on the adsorption and removal of fluoroquinolones, analysis and detection fluoroquinolones.

Norfloxacin (NOR) is a type of fluoroquinolone broad spectrum antimicrobial drug capable of treating bacterial infections leading to adverse reactions and a reduction in the efficiency for treating infection in humans. To ensure consumer safety, a facile and sensitive immunoassay using personal glucose meter (PGM) was developed for the detection of NOR in animal-derived foods in this study. In which, invertase, an enzyme that could catalyze the hydrolysis of sucrose into glucose, was conjugated with anti-NOR monoclonal antibody with the help of colloidal gold, and named as signal probes. NOR-BSA functionalized magnetic beads were used as sensing probes to compete with NOR for binding to signal probes. Based on a competitive immunoassay format, a facile method to detect NOR was performed using PGM as signal transducer. The detection limit for NOR in standard solution was 0.5 ng mL−1 with a wide linear range of 0.5–500 ng mL−1 (R2 = 0.9905). For specificity analysis, the data obtained showed no obvious PGM signal changes with other fluoroquinolones except ciprofloxacin (CIP) and enrofloxacin (ENR), indicating this method could be applied for the detection of three kinds of fluoroquinolones (NOR, CIP and ENR). The recoveries of NOR in spiked animal-derived foods ranged from 73.14 to 137.37%. Besides, the results obtained by the proposed method showed high agreement with commercial ELISA kits. In conclusion, the proposed immuno-PGM assay provided an alternative method for facile and sensitive detection of NOR in animal-derived foods.

Threonine aldolases catalyze the aldol condensation of aldehydes with glycine to furnish β-hydroxy-α-amino acid with two stereogenic centers in a single reaction. This is one of the most promising green methods for the synthesis of optically pure β-hydroxy-α-amino acid with high atomic economy and less negative environmental impact. Several threonine aldolases from different origins have been identified and characterized. The insufficient -carbon stereoselectivity and the challenges of balancing kinetic versus thermodynamic control to achieve the optimal optical purity and yield hampered the application of threonine aldolases. This review summarizes the recent advances in discovery, catalytic mechanism, high-throughput screening, molecular engineering and applications of threonine aldolases, with the aim to provide some insights for further research in this field.

In the present study, the bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against Listeria monocytogenes (L. monocytogenes) planktonic cells and biofilm on food-contact surfaces including stainless steel and glass was systematically evaluated. The results showed that SAEW (pH 5.09 and available chlorine concentration (ACC) of 60.33 mg/L) could kill L. monocytogenes on food-contact surfaces completely in 30 s, a disinfection efficacy equal to that of NaClO solutions (pH 9.23 and ACC of 253.53 mg/L). The results showed that long exposure time and high ACC contributed to the enhancement of the disinfection efficacy of SAEW on L. monocytogenes on food-contact surfaces. Moreover, the log reduction of SAEW treatment presented an increasing tendency within the prolonging of treatment time when SAEW was used to remove the L. monocytogenes biofilm formed on stainless steel and glass surfaces, which suggested that SAEW could remove L. monocytogenes biofilm effectively and its disinfection efficacy is equal to (in the case of stainless steel) or higher than (in the case of glass) that of high-ACC NaClO solutions. In addition, the results of the crystal violet staining and scanning electron microscopy also demonstrated that SAEW treatment could remove the L. monocytogenes biofilm on food-contact surfaces.

In the present work, the bactericidal efficacy and mechanism of slightly acidic electrolyzed water (SAEW) on L. monocytogenes were evaluated. The results showed that the strains of L. monocytogenes were killed completely within 30 s by SAEW whose available chlorine concentration (ACC) was higher than 12 mg/L, and it was confirmed that ACC is the main factor affecting the disinfection efficacy of SAEW. Moreover, our results demonstrated that SAEW could destroy the cell membrane of L. monocytogenes, which was observed by SEM and FT-IR, thus resulting in the leakage of intracellular substances including electrolyte, protein and nucleic acid, and DNA damage. On the other hand, the results found that SAEW could disrupt the intracellular ROS balance of L. monocytogenes by inhibiting the antioxidant enzyme activity, thus promoting the death of L. monocytogenes. In conclusion, the bactericidal mechanism of SAEW on L. monocytogenes was explained from two aspects including the damage of the cell membrane and the breaking of ROS balance.

In this study, a durable, reusable, effective and large-area molding method was proposed to fabricate hierarchical structures on the CF/PEEK composite surface. The hierarchical structures were fabricated using a combination of sandblasting and anodizing treatments on the metal surface. Subsequently, a hot-pressing process was adopted for producing structures that matched the metal templates. The rough surface was modified by (Heptadecafluoro-1,1,2,2-tetradecyl)trimethoxysilane with low surface energy to obtain superhydrophobicity. Scanning electron microscopy was utilized to observe the surface morphologies and structure. The chemical composition and roughness were analyzed by FT-IR spectroscopy and the laser microscopy, respectively. Wettability was characterized through contact angle measuring instruments, and static and dynamic sliding contact angles were obtained to be 158.23° and 8.38°, respectively. After the abrasion test, the CF/PEEK composite surface still maintained reasonable mechanical stability. Comparing with the untreated sample, CF/PEEK superhydrophobic surface exhibited excellent anti-icing performance with freezing time increasing from 54 to 514 s at − 20° and icing adhesion strength reducing to 30.5 kPa. Although the fabrication of composite surface with water repellency presented here is useful for anti-icing, it can also be applied in other applications that require superhydrophobic surfaces.

The systematic application of slightly acidic electrolyzed water (SAEW) for natural microbial reduction of buckwheat sprouts were investigated including seed-dipping, germination and sprouts-washing in the present study. The results show that all the three SAEW treatments with similar pH value (approximately 6.0) used in the study resulted in the reduction of the natural moulds and yeasts and total bacteria counts in buckwheat seeds and harvested sprouts in spite of their different available chlorine concentration (ACC, approximately 10, 28 and 92 mg/L respectively), which was equivalent or high disinfectant efficacy for buckwheat seeds and sprouts compared to NaClO solutions and acidic electrolyzed water (AEW). Moreover, SAEW treatments could control the growth of natural microbial populations during germination and decrease the E. coli O78 and L. monocytogenes counts on 8-day-old sprouts by 1.10–2.74 and 1.85–2.46 log10 CFU/g, respectively. However, too high ACC (91.96 mg/L) in SAEW had adverse effect on the sprouts length. SAEW with appropriate ACC (10–28 mg/L) could be considered in the whole process of sprouts industry because of its strong disinfection efficacy and less adverse effect on the sprouts growth than NaClO solutions and AEW.

The aim of the study was to conduct comparative analyses on drying kinetics, color, rehydration ratio, polysaccharide content and aromatic components composition of shitake mushrooms dried by using hot air drying, infrared drying and intermittent microwave assisted hot air drying. Intermittent microwave–assisted drying resulted in greatly reduced drying time and higher drying rate in comparison with the other methods. The highest polysaccharide content (240.28 mg/100 g) was achieved when microwave–assisted drying was used. Furthermore, microwave–assisted drying showed its predominance in the categories and amount of generated nitric aroma (1.17%) during drying, and it could be a method for improving fresh–like characteristics of dried vegetables due to the moderate level of aldehydes (0.26%) and ketones (4.22%) formed during drying. Shitake mushrooms treated with hot air drying showed the greatest amount of sulfuric aromatic compounds (7.7%) and the highest rehydration ability as well as a lower total color difference in the cap. Therefore, shitake mushrooms dried by hot air or combined with microwave should be considered due to their enhanced physical properties or chemical components.

Wolfberry is an important medicinal and edible plant in China that is difficult to dehydrate owing to its dense pulp and epicuticular wax. Sodium carbonate (SC) pretreatment is an efficient low-cost technology that can help improve the wolfberry drying rate. To determine the effect of SC pretreatment on drying kinetics and quality changes during hot-air drying (AD), wolfberries were dried using AD at different temperatures (40, 50, and 60 °C) with or without SC pretreatment. SC pretreatment was found to increase the effective diffusivity (Deff) and reduce the total drying time by 22–28%. SC pretreatment and low-temperature AD (40 and 50 °C) helped improve wolfberry quality and increased its total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, carotenoids content, and betaine content by 10–17%, 9–24%, 21–25%, 14–22%, 3–23%, and 17–42%, respectively. Samples dried with or without SC pretreatment showed the same trends, but a different moisture content inflexion point in the drying kinetics and different antioxidant attributes. In all drying processes, the Deff initially increased and then decreased, while the TPC, TFC, and antioxidant capacity initially decreased and then increased.

Background Lentinan can inhibit the proliferation of many kinds of tumor cells, and some studies have shown that lentinan can inhibit the growth of tumor tissue by directly killing tumor cells. The purpose of this study was to investigate the immunoprophylaxis effect and mechanism of tumor specific antigen induced by lentinan on liver cancer in mice.Methods The immunogen was prepared which was induced by lentinan. And two different mouse H22 liver cancer models (ascites tumor and solid tumor)were established after immunogen immunized. The tumor growth and immune organ index of mice in each group were measured. In order to analyze the immune mechanism, the activity of CTL cells, activation of ADCC pathway ,T lymphocyte subsets, expression of CD4 + T,CD8 + T cells and expression of DC, and surface molecular markers CD80 and CD86 in immunized mice were analyzed. The expression of cytokines such as IFN-γ and TNF-α in serum and cell supernatant of mice in each group was tested too. Finally, the immunogen was analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS), and the functional proteins were screened for further analysis.Results The liver, spleen and thymus of the mice immunized with immunogen were protected to a certain extent. In immunized mice, the proportion of CD4 + T cells increased, the proportion of CD8 + T cells decreased, the ratio of CD4 + T/CD8 + T increased, and the killing activity of T lymphocytes increased significantly. The expression of CD80 in mature DC cells of immunized mice increased and cytokines increased significantly. The results of protein mass spectrometry analysis of immunogen showed that immunogen produced protein properties that inhibit cancer.Conclusion The H22 whole-cell cleavage vaccine induced by lentinan is effective in the immunity of mouse hepatoma H22 and has development value in the future.

Microwave technology has been widely used in the food industry, but the effect of microwave-heated food on human health is being questioned. Female KM mice were chosen to be treated with microwave-heated milk (MM), and reproductive markers such as litter size, birth rate, survival rate, and ovarian index were evaluated. With longer term feeding, the reproductive status (body weight, birth rate, litter size, neonatal survival rate, interpregnancy interval, and brain superoxide dismutase and catalase activity) of KM mice treated with MM did not significantly change except for the ovarian index of first-generation mice, which was decreased significantly compared with the control group and the group given electrically heated milk. Longer term consumption of MM can affect the ovarian index of reproductive mice. HIGHLIGHTS

Previous work has demonstrated that slightly acidic electrolyzed water (SAEW) can promote growth and nutrient enrichment of buckwheat sprouts. In this study, iTRAQ-based quantitative proteomic analysis of SAEW-induced buckwheat sprouts was conducted to explore its mechanism of action. The results showed that 11, 10 and 14 differentially expressed proteins (DEPs) related to energy metabolism, oxidative stress and flavonoid biosynthesis accumulated upwards and downwards, respectively, in SAEW-treated buckwheat. Bioinformatics analysis revealed 118 GO categories were in relation to molecular function. In the SAEW group, a total of 9 DEPs (5 up-regulated) were mapped to 10 significantly enriched KEGG pathways. SAEW induced flavonoid enrichment by modulating zymoproteins (e.g. phenylalanine ammonialyase and flavonol synthase) in phenylpropanoid biosynthesis pathway. qRT-PCR results had consistency with abundance levels of their corresponding proteins. These findings are likely to reveal the molecular mechanisms underlying the biochemical enrichment of buckwheat sprouts by SAEW.

Previous research found that slightly acidic electrolyzed water (SAEW) promoted the growth of buckwheat sprouts and the accumulation of bioactive γ‐aminobutyric acid (GABA), but mechanisms had not been reported. At present study, the effects of pH and available chlorine concentration (ACC) of SAEW on buckwheat sprouts were investigated. It showed that SAEW1 with moderate pH (5.71 ± 0.03) resulted in the highest accumulation of GABA ((113.5 mg/100 g) in comparison with SAEW 2 (pH 5.01 ± 0.05) and SAEW 3 (pH 6.41 ± 0.04) treatments. Moreover, the higher ACC of SAEW was, the more content of GABA it accumulated, which suggested that ACC played an important role during germination of buckwheat. The above results were demonstrated by the investigation of glutamic acid decarboxylase activity during germination of buckwheat. However, it showed that higher ACC of SAEW had adverse impact on the growth of buckwheat sprouts while pH of SAEW had no adverse impact on the growth of buckwheat sprouts. Generally, appropriate pH and ACC of SAEW should be considered in the application of the production of buckwheat sprouts. PRACTICAL APPLICATIONS: SAEW that had neutral pH (5.0–6.5) and lower ACC (10–30 mg/L) had been used in the production of sprouts. SAEW could promote the dual accumulation of GABA and rutin in tartary buckwheat sprouts. Obtaining the specific parameters of SAEW would beneficial for the most accumulation of these functional components when it is used for sprouts production.

As food industry flourished, the use of EW as a novel sanitizing agent has gained interest worldwide. The chapter reviews recent progress in the application of EW in fruits and vegetables industry, summarizing its efficacy on disinfection and pesticide removal during their processing, and disease control along with inhibiting moth infestation throughout storage as well as the effect on physiochemical properties, chemical components, and postharvest physiology. Furthermore, it specially generalized the application of EW in the field of sprouts vegetables (our researching focus) to open up a new way for the development of functional food. It indicated that EW has sufficient obliterating efficacy on spoilage or pathogenic microorganisms, pesticide residues, and some insect pests existing on fruits and vegetables without compromising sensory and nutritional quality of them in most occasions. Besides, the employment of EW to sprouts vegetables makes those healthful components such as CABA and flavonoids accumulated. However, optimal processing parameters such as washing time along with physiochemical properties of EW need further selection. And, hurdle technology should not be tolerated to maximize treatment efficacy and prolong the shelf life of fresh produce. In brief, EW has a promising prospect in future utilization of fruits and vegetables.

The disinfection efficacy of slightly acidic electrolyzed water (SAEW) has been recognized in food industry. However, the application of single SAEW limited its disinfection potential. The efficacy of the two-step disinfection with SAEW for the reduction of L. monocytogenes contamination on different food raw materials was evaluated compared to the one-step disinfection with SAEW in this study. Results demonstrated that SAEW could reduce both the natural aerobic bacterial count and inoculated L. monocytogenes population on endive and chicken immediately after processing and SAEW with approximately 60 mg/L of available chlorine concentration (ACC) had equal or higher antibacterial efficacy compared to NaClO solutions with approximately 150 mg/L of ACC. Moreover, SAEW treatments could control the growth of microbial populations of L. monocytogenes during storage and the efficacy on the microbial reduction was associated to the initial populations. In addition, the SAEW-treated food raw materials were stored and disinfected again after storage and the results showed that the two-step disinfection method could decrease the survival populations of L. monocytogenes by 24.8%–99.6% compared to the one-step disinfection of SAEW. Therefore, considering storage habits, the two-step disinfection of SAEW may be a better choice in the disinfection of non-consumed-directly food raw materials.

Photodynamic treatment is a nonthermal disinfection technology, which uses photosensitizers under specific light conditions to inactivate microorganisms. Curcumin, a component of turmeric and with many medicinal properties, has been used as food additive in many countries. In the study, curcumin was used as a photosensitizer. A controllable LED photodynamic apparatus with a wavelength of 460–465 nm was prepared from a 96-well plate, an LED dimmer and a transformer. The photodynamic activity of curcumin-loaded chitosan against Staphylococcus aureus and its biofilms on stainless-steel were investigated. The results showed that photodynamic inactivation effects relied on curcumin concentration, co-incubation time and illumination time. When 25 μmol/L curcumin-loaded chitosan was co-incubated with Staphylococcus aureus suspension (approximately 6.0 log CFU/mL) for 10 min, the viable count was reduced by 5.0 log CFU/mL, after 10 min exposure to light. On the surface of stainless-steel coupons coated with S. aureus biofilm, the viable count was significantly reduced by more than 5.0 log CFU/cm2 (initial number 5.6 logCFU/m2), after spraying with curcumin (50 μmol/L)-loaded chitosan and 10 min light treatment. So, curcumin photodynamic technology is expected to show great potential application for the inactivation of microbials on the surface of food equipment and fresh food products.

In the present study, the disinfection efficacy of slightly acidic electrolyzed water (SAEW) and strongly acidic electrolyzed water (AEW) was tested on three bacteria, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis and the disinfection mechanism was discussed. The results showed that SAEW had a stronger antibacterial efficacy against these tested bacteria in comparison with AEW. The results also showed that both SAEW and AEW treatments could damage the cell membrane, which was demonstrated microcosmically by scanning electron microscopy (SEM), thus causing leakages of protein, DNA, RNA, and ATP, resulting in the death of microbes. Moreover, AEW treatment could not cause the degradations of DNA and RNA, and nucleic acids including DNA and RNA are not the target point of its bactericidal efficacy. However, SAEW could maybe cause the degradation of RNA, and RNA may be the target in its antibacterial activity. We suggested that the differences in antibacterial efficacy between SAEW and AEW could be explained by the different impacts on RNA of tested strains.

The accumulation of γ-aminobutyric acid and the microbial decontamination are concerned increasingly in the production of sprouts. In this work, the effect of the treatment by slightly acidic electrolyzed water on the accumulation of γ-aminobutyric acid in the germinated brown millet was evaluated by high performance liquid chromatography during germination. The results showed that slightly acidic electrolyzed water with appropriate available chlorine (15 or 30 mg/L) could promote the accumulation of γ-aminobutyric acid by up to 21% (P < 0.05). However, the treatment with slightly acidic electrolyzed water could not enhance the sprouts growth of the germinated brown millet. The catalase and peroxidase activities of the germinated brown millet during germination were in agreement with the sprouts growth. Our results suggested that the accumulation of γ-aminobutyric acid was independent of the length of sprouts in germinated grains. Moreover, the treatment with slightly acidic electrolyzed water significantly reduced the microbial counts in the germinated millet (P < 0.05) and the treatment with high available chlorine concentration (15 and 30 mg/L) showed stronger anti-infection potential in the germinated brown millet than that of lower available chlorine concentration (5 mg/L). In conclusion, the treatment with slightly acidic electrolyzed water is an available approach to improve the accumulation of γ-aminobutyric acid and anti-infection potential in the germinated brown millet, and it can avoid too long millet sprouts.

The physico-chemical properties and free amino acids profiles of six wolfberry cultivars from Zhongning County were characterized and compared. Fructose and glucose were found to be the predominant soluble sugars, citric acid was the most abundant organic acid. The values of total free amino acids (TFAA) were 278.07–505.12 mg/100 g FW, the essential amino acids accounted for 17 %–30 % of TFAA. NQ7 was the best for drying processing, because it showed moderate size, higher content of total carotenoids, betaine, tartaric acid, and citric acid, relatively high essential amino acids content, lower alkaline amino acids content and relatively low reducing soluble sugars content. Principal component analysis (PCA) allowed the six cultivars to be differentiated clearly based on all these physico-chemical properties and free amino acids profiles determined in the study.

In the present study, the disinfection efficacy on fresh-cut cilantro of the combination of strongly acidic electrolyzed water (AcEW) and alkaline electrolyzed water (AlEW) was evaluated, in comparison with single slightly acidic electrolyzed water (SAEW) and single AcEW treatments. The populations of E. Coli O78 on inoculated cilantro treated by AlEW 5 min + AcEW 5 min, was not detected while 3.43 and 3.73 log10 CFU/g in the AlEW 2.5 min + AcEW 2.5 min and AcEW 2 min + AlEW 2 min + AcEW 2 min treatments respectively. Our results implied that the bactericidal abilities of the combination of AlEW and AcEW treatments were higher than that of single AcEW and SAEW, which also was demonstrated microscopically by scanning electron microscopy (SEM). Moreover, the efficacy of combination of AcEW and AlEW in reducing natural micro flora on fresh-cut cilantro was also evaluated compared with single AcEW and SAEW. The results showed that the combination of AlEW and AcEW had stronger sterilization ability than single AcEW and SAEW. Considering the utilizations of AlEW and disinfection efficacy, we suggest that the combination of AlEW and AcEW may also be a better choice in fresh-cut produce.

Leafy vegetables are the major source of nitrite intake in the human diet, and technological processing to control nitrite levels in harvested vegetables is necessary. In the current work, the effect of electrolyzed oxidizing water (EOW) on the nitrite and nitrate levels in fresh spinach during storage was studied. EOW treatment, including slightly acidic electrolyzed water and acidic electrolyzed water, was found to effectively reduce nitrite levels in fresh spinach during storage; levels in the late period were 30 to 40% lower than that of the control. However, the nitrate levels in fresh spinach during storage were not influenced by EOW treatment. The reduction of nitrite levels in EOW-treated fresh spinach during storage can be attributed to the inactivation of nitrate reductase directly and to the reduction of bacterial populations. Our results suggest that treatment with slightly acidic electrolyzed water may be a better choice to control nitrite levels in fresh vegetables during storage. This study provided a useful method to reduce nitrite levels in fresh spinach.

The producers of broccoli sprouts have become increasingly interested in improving their sulforaphane content. This study has evaluated the effects of slightly acidic electrolyzed water (SAEW) with different available chlorine concentrations (ACC) on broccoli sprouts: their content of some bioactive compounds such as glucosinolates, their morphology, and their total bacterial counts. The results have shown that SAEW might affect the content of sulforaphane by influencing the content of glucosinolates and the activity of myrosinase. SAEW inhibited the growth of broccoli sprouts: their fresh weight decreased as the available chlorine concentration (ACC) of the SAEW increased, but the different solutions did not affect their dry weight. The number of microorganisms on the broccoli sprout decreased by 1.71logCFU/g after using the SAEW with ACC value of 50mg/L treatment compared with tap water treatment. Overall, although SAEW adversely affected the morphology of broccoli sprouts, with a suitable ACC it can be a useful tool for enhancing the amount of secondary metabolites and reducing the microbial counts on broccoli sprouts intended for fresh consumption as a functional food.