Exogenous nitric oxide treatment delays the senescence of postharvest mung bean sprouts by regulating ascorbic acid metabolism.

BACKGROUND: This study evaluated the effects of nitric oxide (NO) treatment on ascorbic acid (AsA) metabolism and mung bean sprout quality. It examined changes in the AsA content, enzyme activity associated with AsA metabolism, antioxidant capacity, cell membrane composition, and cellular structure to clarify the effects of NO on mung bean sprouts. RESULTS: Nitric oxide treatment preserved mung bean sprout quality by enhancing significantly the activity of enzymes involved in the l-galactose pathway (including guanosine diphosphate (GDP)glutathione (-d-mannose pyrophosphorylase, GDP-mannose-3',5'-epimerase, GDP-l-galactose phosphorylase, l-galactose-1-phosphate phosphatase, l-galactose dehydrogenase, and l-galactose-1,4-lactone dehydrogenase) and the AsA-glutathione (GSH)(Beijing Solarbio Science and Technology Co.,Ltd., Beijing, China) cycle (including ascorbate peroxidase, ascorbic acid oxidase, glutathione reductase, dehydroascorbate reductase, and monodehydroascorbate reductase) during the germination and storage stage. Increased enzyme activity led to an increase in AsA content and enhanced antioxidant capacity, and reduced the membrane lipid damage in mung bean sprouts. This was demonstrated by higher levels of DPPH radical scavenging capacity, unsaturated fatty acids and phospholipids, along with lower levels of hydrogen peroxide, superoxide anions, and malondiadehyde, in NO-treated mung bean sprouts. Scanning electron microscopy also revealed that NO treatment maintained the integrity of the cellular structure of the mung bean sprouts. CONCLUSION: Nitric oxide accelerates AsA metabolism effectively by regulating the biosynthesis and regeneration of AsA in mung bean sprouts. These changes increased AsA levels, alleviated membrane lipid damage, delayed senescence, and maintained the quality of mung bean sprouts during storage. © 2024 Society of Chemical Industry.

Natural exosomes-like nanoparticles in mung bean sprouts possesses anti-diabetic effects via activation of PI3K/Akt/GLUT4/GSK-3ß signaling pathway.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by hyperglycemia and insulin resistance. Mung bean sprouts are traditionally considered a "folk" hypoglycemic food and their pharmacological effects and underlying mechanisms warrant further investigation. PURPOSE: This study aimed to investigate the anti-diabetic effects of the exosomes-like nanoparticles in mung bean sprouts (MELNs) and explore the related molecular mechanisms. RESULTS: MELNs were isolated using a differential centrifugation-polyethylene glycol (PEG) method, and the identification of MELNs were confirmed by PAGE gel electrophoresis, agarose gel electrophoresis, thin-layer chromatography (TLC), and transmission electron microscopy (TEM). In the high-fat diet/streptozotocin (HFD/STZ) mouse model, MELNs ameliorated the progression of T2DM by increasing oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) results, decreasing the fasting blood glucose level, and reducing the serum triglycerides (TG) and total cholesterol (TC). Histopathological examinations indicated MELNs diminished inflammatory infiltration of hepatocytes and amplified the area of islet B cells. In addition, MELNs decreased the oxidative stress levels in liver tissue and had good biocompatibility. In vitro experiments verified that MELNs improved the viability of glucosamine (GlcN) induced insulin-resistant hepatocytes. Furthermore, this study also revealed that MELNs upregulated GLUT4 & Nrf2 and down-regulated GSK-3ß via activating the PI3K/Akt signaling pathway, promoting the production of antioxidant enzymes, such as HO-1 and SOD, to reduce oxidative stress. CONCLUSION: MELNs mitigated the progression of type 2 diabetes in HFD/STZ mouse model. The underlying molecular mechanism is related to PI3K/Akt/GLUT4/GSK-3ß signaling pathway.

The conjugative transfer of plasmid-mediated mobile colistin resistance gene, mcr-1, to Escherichia coli O157:H7 and Escherichia coli O104:H4 in nutrient broth and in mung bean sprouts.

The emergence of mobile colistin resistant gene (mcr-1) in Enterobacteriaceae has become a global public health concern. Dissemination of the mcr-1 gene through conjugation of bacteria associated with food may occur. This research investigated the transfer frequency of the mcr-1 gene among Escherichia coli in liquid media and during growth of mung bean sprouts. The donor strain E. coli NCTC 13846 (mcr-1 positive) and recipient strains of E. coli O157:H7 and E. coli O104:H4 were used. Mating experiments in vitro were conducted at 4, 25, and 37 °C for up to 36 h. The in vivo mating experiments (growing sprouts) were conducted in a sprout growth chamber with irrigation of 1 min/h over 6 days following inoculation of mung bean seeds with the donor and a recipient. The highest transfer frequencies in TSB media, 2.86E-07 and 3.24E-07, occurred at 37 °C after mating for 24 h for E. coli O104:H4 and E. coli O157:H7, respectively. Transconjugants were not detected in liquid media at 4 °C. Moreover, transfer frequency (5.68E-05 per recipient) of mcr-1 was greater during mung bean sprout growth for E. coli O104:H4 compared to E. coli O157:H7 (1.02E-05 per recipient) Day 3 to Day 6. This study indicates that the transfer of antibiotic resistant gene(s) among bacteria during mung bean sprout production may facilitate the spread of antibiotic resistant bacteria in the environment and to humans.

[TWO CASES OF ALLERGY WITH MUNG BEAN SPROUTS].

Patient 1 was a female patient in her teens who presented with swelling of the lips and oral discomfort after consuming mung bean sprouts. She had a history of this reaction since the age of 6 years and showed positive on a prick-to-prick test for mung bean sprouts. Patient 2 was a male patient in his twenties who also showed positive for mung bean sprouts as well as soybean sprout. Both patients were positive for IgE specific to birch, Gly m4, and Bet v1.Mung beans belong to the PR-10 family because they contain the allergenic component, Vig r1. A cross reaction to mung bean may occur in a patient with birch allergy as in the present cases. Mung bean sprouts are a cheap and common dietary item in Japan where, however, only a few cases of mung bean sprouts allergy have been reported. Mung bean sprouts allergy should be diagnosed with appropriate testing; if the patient has allergic reactions for this food item, an allergologist should provide detailed dietary guidance for avoiding pollen-food allergy syndrome.

Monodispersed mesoporous SiO2@metal-organic framework (MSN@MIL-101(Fe)) composites as sorbent for extraction and preconcentration of phytohormones prior to HPLC-DAD analysis.

The monodispersed mesoporous SiO2@metal-organic framework (MSN@MIL-101(Fe)) composites were prepared by grafting MSN-NH2 onto MIL-101(Fe) particles with a solvothermal method. The adsorption ability of the composites was greatly improved compared to that of pristine MSNs or MIL-101(Fe) for phytohormones (Phys). The MSN@MIL-101(Fe) composites were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometer, and mapping analysis. Using MSN@MIL-101(Fe) composites as sorbent, a dispersive solid-phase extraction procedure (dSPE) was developed to extract three endogenous Phys (abscisic acid (ABA), indole-3-aceticacid (IAA), and indole-3-butyric acid (IBA)) and two exogenous Phys (1-naphthylacetic acid (1-NAA) and 2-naphthylacetic acid (2-NAA)) prior to HPLC-DAD analysis. The experimental parameters including sample volume, sorbent amount, adsorption time, adsorption pH, desorption time, and desorption solvent on extraction efficiency were optimized and evaluated. Under optimized conditions, the working range of 0.08 to 0.45 ng mL-1 with enrichment factors from 144 to 207 were achieved. The linear range is 0.75-200 ng mL-1 for IAA, 0.20-200 ng mL-1 for ABA, and 1.0-200 ng mL-1 for IBA, 1-NAA, and 2-NAA. With MSN@MIL-101(Fe) as sorbent for extraction of Phys and determination by HPLC-DAD, two endogenous Phys (IAA and ABA) were detected from mung bean sprouts which were made in a laboratory, and the results were further confirmed by high-resolution mass spectrometry. The composites can be applied to extract other small molecules, which have similar chemical structures with Phys in biological, environmental, and food samples. Graphical abstract Schematic presentation of a dispersive solid-phase extraction using monodispersed mesoporous SiO2@metal-organic framework composites (MSNs@MIL-101(Fe)) as the sorbent for extraction, clean-up, and preconcentration of phytohormones in mung bean sprouts prior to HPLC-DAD analysis.

Bio-Derived Co2 P Nanoparticles Supported on Nitrogen-Doped Carbon as Promising Oxygen Reduction Reaction Electrocatalyst for Anion Exchange Membrane Fuel Cells.

Recently, nonnoble-metal catalysts such as a metal coordinated to nitrogen doped in a carbon matrix have been reported to exhibit superior oxygen reduction reaction (ORR) activity in alkaline media. In this work, Co2 P nanoparticles supported on heteroatom-doped carbon catalysts (NBSCP) are developed with an eco-friendly synthesis method using bean sprouts. NBSCP can be easily synthesized through metal precursor absorption and carbonization at a high temperature. It shows a very large specific surface area with various dopants such as nitrogen, phosphorus, and sulfur derived from small organic molecules. The catalyst can exhibit activity in various electrochemical reactions. In particular, excellent performance is noted for the ORR. Compared to the commercial Pt/C, NBSCP exhibits a lower onset potential, higher current density, and superior durability. This excellent ORR activity and durability is attributable to the synergistic effect between Co2 P nanoparticles and nitrogen-doped carbon. In addition, superior performance is noted on applying NBSCP to a practical anion exchange membrane fuel cell system. Through this work, the possibility of applying an easily obtained bio-derived material to energy conversion and storage systems is demonstrated.

Rapid monitoring of plant growth regulators in bean sprouts via automated on-line polymeric monolith solid-phase extraction coupled with liquid chromatography tandem mass spectrometry.

An automated on-line solid-phase extraction (SPE) following liquid chromatography tandem mass spectrometry was established for the fast determination of plant growth regulator residues in soybean sprout and mung bean sprout. The crude extracted specimens were directly purified on a poly (2-(dimethylamino) ethyl methacrylate-co-ethylene dimethacrylate) monolithic column which was well-defined as the on-line SPE adsorbent. Under the optimized conditions, the developed method gave the linear range of 0.3-50 ng/mL for gibberellin and 2,4-dichlorophenoxyacetic acid, 0.2-50 ng/mL for 4-chlorophenoxyacetic acid, and 0.5-50 ng/mL for 1-naphthaleneacetic acid (r ≥ 0.998). The detection limits (S/N = 3) ranged from 1.0 to 2.5 µg/kg and the recoveries for spiked soybean sprout samples were in the range of 75.0-93.3%. Besides, the total time for one analysis was 16 min. The reusability of the monolith was up to 600 extractions. The proposed process facilitated fully automated SPE and accurate determination in one step with rapidity, simplicity, and reliability. Graphical abstract ᅟ.

Ca2+ influxes and transmembrane transport are essential for phytic acid degradation in mung bean sprouts.

BACKGROUND: Phytic acid is considered as an antinutrient. Ca2+ addition during germination has been proved to be an effective method for reducing phytic acid content in seeds. In this study, mung bean sprouts were treated with LaCl3 (La), verapamil (VP), ruthenium red (RR), and CaCl2 to explore the effect of Ca2+ influxes on phytic acid degradation. RESULTS: CaCl2 (6 mmol L-1 ) significantly improved extracellular and intracellular calcium precipitates and calcium content, elevated phytase and acid phosphatase activity, and further enhanced phytic acid degradation. Conversely, La, VP, or RR induced the opposite results. Among them, RR exhibited the most significant inhibitory effect. Decreased PA, PAP, MIPP, and ALP gene expression after VP or RR treatment was also observed. Enhanced or weakened extracellular Ca2+ influx or intracellular Ca2+ efflux was detected with increased or decreased calcium precipitates distributed in different compartments. However, CaCl2 addition differentially reversed the inhibitory effects of all channel blockers. CONCLUSION: CaCl2 enhanced Ca2+ influxes and accumulation in cells, which contributed to the regulation of phytic acid degradation. This study demonstrates that calcium channels play an essential role in mediating phytic acid degradation in mung bean sprouts, and both extracellular and intracellular Ca2+ -regulation were involved in phytic acid degradation. © 2017 Society of Chemical Industry.

Polyamines regulating phytic acid degradation in mung bean sprouts.

BACKGROUND: Polyamines are essentially involved in cell division and differentiation. Transport of polyamines is adenosine triphosphate (ATP)-dependent, while phytic acid is the major reserve of phosphate essential to the energy-producing machinery of cells. Thus polyamines might enhance phytic acid degradation during mung bean germination. In this study, different polyamines (putrescine (Put), spermidine (Spd) and spermine (Spm)) and dicyclohexylamine (DCHA, an inhibitor of Spd synthesis) were applied to investigate the function of polyamines on phytic acid degradation. RESULTS: Spd exhibited the best effect at the same concentration. Simultaneously, exogenous Spd improved sprout growth and enhanced the accumulation of gibberellin acid 3 (GA3 ), indole-3-acetic acid (IAA), abscisic acid (ABA) and cytokinin (CTK). This must be due to the increased endogenous polyamine contents. Apart from dramatically reducing phytic acid content, Spd resulted in the up-regulation of PA, PAP, MIPP and ALP transcript levels and the enhancement of phytase and acid phosphatase activities. However, DCHA application caused the opposite results, because it decreased endogenous polyamine contents. Furthermore, Spd alleviated the DCHA-induced inhibitory effect to some extent. CONCLUSION: Overall, polyamines, especially Spd, could accelerate phytic acid degradation in mung bean sprouts by inducing the synthesis of endogenous polyamines and phytohormones and enhancing the growth of sprouts. © 2017 Society of Chemical Industry.

Application of electrolyzed water on reducing the microbial populations on commercial mung bean sprouts.

The efficacy of acidic electrolyzed water (AEW) for reducing total bacteria, coliforms, yeast and mold counts on commercial mung bean sprouts was investigated. The impact of pH, available chlorine concentration (ACC) and the cleaning method on antimicrobial efficacy of AEW was studied. AEW with a pH of 4.47 reduced the total bacterial, coliform, and yeast and mold counts on mung bean sprouts by 1.23, 1.42 and 1.25 log CFU/g, respectively. The efficacy of AEW increased with increasing ACC, and further studies showed that its antimicrobial ability was based on a combination of pH and ACC values. Cleaning using ultrasonic waves enhanced the antimicrobial activity of electrolyzed water, achieving reduction of 2.46, 2.13 and 2.92 log CFU/g for total bacterial, yeast and mold, and coliform counts, respectively. These results have indicated that using ultrasonic waves as a cleaning method, combined with AEW, could be a promising way to reduce the microbial populations on mung bean sprouts.

Engineering analysis of the high-density heterotrophic cultivation of mung bean sprouts.

This study investigated the heterotrophic growth behavior of mung beans cultivated in an individual bed under water supply. The fresh weight of mung beans in the bed was estimated, and changes in temperature, and oxygen and carbon dioxide concentrations were recorded during the cultivation period. The specific growth rate, oxygen uptake rate, and carbon dioxide evolution rate, based on the fresh weight in the bed, were calculated. Growth under heterotrophic cultivation can be classified into the following three stages. Reductions in specific oxygen uptake rate, specific carbon dioxide evolution rate, and specific energy production rate corresponded to that of specific growth rate. Indicators of biological activity related to oxygen and carbon dioxide were evaluated quantitatively for beds under high-density heterotrophic cultivation. Moreover, the results obtained from this study successfully demonstrate that there is a relationship between the growth of mung beans and indicators of biological activity.

Growth of healthy and sanitizer-injured Salmonella cells on mung bean sprouts in different commercial enrichment broths.

The ability of nine commercial broths to enrich healthy and 90% sanitizer-injured Salmonella Typhimurium and Salmonella cocktail on mung bean sprouts was evaluated to select an optimum broth for detection. Results showed that S. Typhimurium multiplied faster and reached a higher population in buffered peptone water (BPW), Salmonella AD media (AD) and ONE broth-Salmonella (OB), compared with other broths. Healthy and 90% sanitizer-injured Salmonella at low concentrations increased by 4.0 log CFU/ml in these three broths. However, no Salmonella growth was observed in lactose broth (LB). Further investigation showed that during incubation, pH of LB dropped from 6.7 to 4.2, due to production of lactic (66 mM) and acetic acids (62 mM) by lactic acid bacteria that were identified as dominant microbiota in bean sprouts. Though no cell membrane damage was detected by propidium monoazide combined with real-time PCR, it was found that LB inhibited Salmonella growth, especially from low inoculum levels. This study suggests that in consideration of effectiveness and cost, BPW would be a suitable enrichment broth to use for isolating and detecting Salmonella on mung bean sprouts, while using LB might cause false negative results in Salmonella detection by either PCR or standard cultural method.

Effects of ultraviolet irradiation, pulsed electric field, hot water and ethanol vapours treatment on functional properties of mung bean sprouts.

The present investigation was conducted with the objective to study the effects of various treatments and storage conditions on ascorbic acid, total phenols, antioxidant activity and polyphenol oxidase activity of mung bean sprouts. The sprouts subjected to various treatments viz., pulsed electric field (PEF) (10,000 V for 10 s), hot water dip (HWD) (50 °C for 2 min), ethanol vapours (1 h) and UV-Irradiation (10 kJm(-2) in laminar flow chamber for 1 h); and then stored at room (25 ± 1 °C) and low (7 ± 1 °C) temperature conditions. The sprouts were analyzed regularly at 24 h interval till end of shelf life. Different treatments given to sprouts resulted in differential effect on various parameters. The ascorbic acid, total phenols and antioxidant activity were highest in ethanol vapours treated sprouts. There was a general decrease in polyphenol oxidase activity by various treatments. During storage ascorbic acid, total phenols and antioxidant activity of sprouts first increased and then decreased significantly, however, for polyphenol oxidase activity a progressive increase with increase in storage period was observed. The trends were similar at room and low temperature storage conditions. Thus, it can be concluded that the ethanol vapours significantly improved the ascorbic acid content, total phenols and antioxidant activity of mung bean sprouts, both at room as well as low temperature conditions of storage.

Effects of ultraviolet irradiation, pulsed electric field, hot water dip and ethanol vapours treatment on keeping and sensory quality of mung bean (Vigna radiata L. Wilczek) sprouts.

The objective of this research work was to evaluate the effects of UV- irradiation, pulsed electric field (PEF), hot water dip (HWD) and ethanol vapours on the quality and storage life of mung bean sprouts (Vigna radiata L. Wilczek). The sprouts were subjected to various treatments viz., UV-Irradiation (10 kJm(-2) in laminar flow chamber for 1 h), PEF (10,000 V for 10s), HWD (50 °C for 2 min) and ethanol vapours (1 h); and then stored in thermocol cups wrapped with perforated cling films at room (25 ± 1 °C) and low (7 ± 1 °C) temperature conditions. The sprouts were analyzed regularly at 24 h interval for sprout length, sprout weight, total soluble solids (TSS), titratable acidity, non-enzymatic browning, total plate count and overall acceptability. Sprout length and weight increased during storage. There was no significant effect of various treatments on sprout length and weight, except in ethanol treatment, where suppression was observed. HWD showed higher TSS and acidity than that of control. The least browning was observed in ethanol treatment. The total plate count was not significantly affected by various treatments. Overall acceptability under various treatments decreased during storage period both at room and low temperature. Hot water and ethanol vapour treated sprouts showed higher acceptability than other treatments. However, the acceptability scores for sprouts remained within the acceptable range (≥6) up to 72 h at room temperature and 120 h at low temperature conditions.

An interlaboratory study on the detection method for Escherichia albertii in food using real time PCR assay and selective agars.

Escherichia albertii is an emerging enteropathogen. Although E. albertii-specific detection and isolation methods have been developed, their efficiency on food samples have not yet been systematically studied. To establish a series of effective methods for detecting E. albertii in food, an interlaboratory study was conducted in 11 laboratories using enrichment with modified E. coli broth supplemented with cefixime and tellurite (CT-mEC), real-time PCR assay, and plating on four kinds of selective agars. This study focused on the detection efficiency of an E. albertii-specific real-time PCR assay (EA-rtPCR) and plating on deoxycholate hydrogen sulfide lactose agar (DHL), MacConkey agar (MAC), DHL supplemented with rhamnose and xylose (RX-DHL), and MAC supplemented with rhamnose and xylose (RX-MAC). Chicken and bean sprout samples were inoculated with E. albertii either at 17.7 CFU/25 g (low inoculation level) or 88.5 CFU/25 g (high inoculation level), and uninoculated samples were used as controls. The sensitivity of EA-rtPCR was 1.000 for chicken and bean sprout samples inoculated with E. albertii at low and high inoculation levels. The Ct values of bean sprout samples were higher than those of the chicken samples. Analysis of microbial distribution by 16S rRNA gene amplicon sequencing in enriched cultures of bean sprout samples showed that approximately >96 % of the population comprised unidentified genus of family Enterobacteriaceae and genus Acinetobacter in samples which E. albertii was not isolated. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a high inoculation level of E. albertii was 1.000 and 0.848-0.970, respectively. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a low inoculation level of E. albertii was 0.939-1.000 and 0.515-0.727, respectively. The E. albertii-positive rate in all colonies isolated in this study was 89-90 % in RX-DHL and RX-MAC, and 64 and 44 % in DHL and MAC, respectively. Therefore, the sensitivity of RX-supplemented agar was higher than that of the agars without these sugars. Using a combination of enrichment in CT-mEC and E. albertii isolation on selective agars supplemented with RX, E. albertii at an inoculation level of over 17.5 CFU/25 g of food was detected with a sensitivity of 1.000 and 0.667-0.727 in chicken and bean sprouts, respectively. Therefore, screening for E. albertii-specific genes using EA-rtPCR followed by isolation with RX-DHL or RX-MAC is an efficient method for E. albertii detection in food.

Discrimination of untreated and sodium sulphite treated bean sprouts by Fourier transform infrared spectroscopy and chemometrics.

Sprouts of black beans (Phaseolus vulgaris L.), soybeans (Glycine max L.) and mung beans (Vigna radiata L.) are widely consumed foods containing abundant nutrients with biological activities. They are commonly treated with sulphites for the preservation and extension of shelf-life. However, our previous investigation found that immersing the bean sprouts in sulphite might convert the active components into sulphur-containing derivatives, which can affect both the quality and safety of the sprouts. This study explores the use of FTIR in conjunction with chemometric techniques to differentiate between non-immersed (NI) and sodium sulphite immersed (SI) black bean, soybean and mung bean sprouts. A total of 168 batches of raw spectra were obtained from NI and SI-bean sprouts using FTIR spectroscopy. Four pre-processing techniques, three modelling assessment techniques and four model evaluation indices were examined for differences in performance. The results show that the multiplicative scatter correction is the most effective pre-processing method. Among the models, the accuracy rate of the three models was as follows: radial basis function neural network (95%) > convolutional neural network (91%) > random forest (82%). The overall findings indicate that FTIR spectroscopy, in conjunction with appropriate chemometric approaches, has a high potential for rapidly determining the difference between NI and SI-bean sprouts.

Untargeted metabolomics combined with vitro antioxidant to comprehensively evaluate the effect of sodium sulfite immersion on the holistic quality of mung bean sprouts.

Mung bean sprouts are widely consumed as a seasonal fresh vegetable, renowned for their affordability and richness in antioxidants and bioactive compounds. This study employed ultra-high-performance liquid chromatogram-Q-Exactive HF mass spectrometry (UHPLC-QE-MS) and multivariate statistical analysis to comprehensively evaluate the chemical profile of mung bean sprouts following sulfite immersion. The findings revealed a significant alteration in the overall chemical composition of mung bean sprouts following sodium sulfite immersion. Eleven components, including four sulfur-containing compounds, were identified as characteristic markers distinguishing between non-immersed and sodium sulfite-immersed mung bean sprouts. Esterification and addition reactions were inferred to occur during sodium sulfite immersion, leading to the transformation of flavonoid and saponin sulfates. Commercial samples analysis indicated that sulfur-containing compounds were detectable in 9 of 11 commercial mung bean sprouts. Meanwhile, when sodium sulfite concentration exceeded 3.00 mg/mL and immersion time exceeded 360 min, the contents of total polyphenol and flavonoid were significantly reduced and the antioxidant activity was adversely influenced.

Efficacy of chlorine and peroxyacetic acid on reduction of natural microflora, Escherichia coli O157:H7, Listeria monocyotgenes and Salmonella spp. on mung bean sprouts.

Sprouts-related outbreaks have risen due to increased raw sprouts consumption. To minimize such cases, chemical sanitations are applied. While chlorine is commonly used, concerns with its effectiveness and health implication have prompted researchers to seek alternatives. Peroxyacetic acid (PAA) has shown efficacy in inactivating foodborne pathogens on fresh vegetables, and hence could be considered as an alternative. Thus, the objective of this study was to compare the efficacy of chlorine and PAA in inactivating Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., and natural microflora on mung bean sprouts. Resistance of non- and acid-adapted pathogens to these sanitizer treatments was also evaluated. Un-inoculated and inoculated sprouts were treated with chlorine at 106, 130 and 170 ppm and PAA at 25, 51 and 70 ppm for 90 and 180 s at room temperature. Overall, the greater log reductions were obtained with the increase in the sanitizer concentration. For 180 s, chlorine treatment at 170 ppm reduced 2.0, 1.3, 1.5, 0.9-logs and PAA treatment at 70 ppm resulted in 2.3, 1.8, 2.1, 1.1-log reductions for non-adapted E. coli O157:H7, L. monocytogenes, Salmonella spp., and natural microflora, respectively. These results revealed that the efficacy of PAA was significantly better than or similar to that of chlorine. For acid-adapted cells, these sanitizer treatments were less effective with the ranges of 1.0-1.2-log reductions for chlorine and 1.1-1.6-log reductions for PAA compared to non-adapted cells, indicating that acid-adapted cells were more resistant to the sanitizing treatment. These data suggest that PAA may replace chlorine in the disinfection of mung bean sprouts and that acid-adapted pathogens should be used to design an effective sanitizing strategy.

Miniaturized point discharge optical emission spectrometry coupling with solid phase extraction: A robust approach for sensitive quantification of total mercury in mung bean sprout growth.

In this work, a portable chemical vapor generation point discharge optical emission spectrometry (CVG-PD-OES) system was designed for trace Hg2+ monitoring in mung bean sprout samples. The system incorporated selective solid phase extraction (SPE) to enhance the detection sensitivity. Gold nanoparticles (AuNPs) were prepared and utilized to extract trace amounts of Hg2+ by forming gold amalgam. Subsequently, the amalgam was desorbed using 5% HCl and introduced into a low-power PD-OES system analysis via CVG. A low limit of detection (LOD) of 0.16 ng mL-1 was obtained with a linear range of 0.5-6 ng mL-1. The well-designed system was successfully utilized for monitoring trace Hg2+ in the growth of mung beans. The results indicated that the Hg2+ in mung bean sprouts was continuously decreased during growth based on the metabolism. Furthermore, the risk assessment conducted implied a negligible hazard quotient, suggesting that the observed levels of exposure posed minimal risk.

Effects of Typical Antimicrobials on Growth Performance, Morphology and Antimicrobial Residues of Mung Bean Sprouts.

Antimicrobials may be used to inhibit the growth of micro-organisms in the cultivation of mung bean sprouts, but the effects on mung bean sprouts are unclear. In the present study, the growth performance, morphology, antimicrobial effect and antimicrobial residues of mung bean sprouts cultivated in typical antimicrobial solutions were investigated. A screening of antimicrobial residues in thick-bud and rootless mung bean sprouts from local markets showed that the positive ratios of chloramphenicol, enrofloxacin, and furazolidone were 2.78%, 22.22%, and 13.89%, respectively. The cultivating experiment indicated that the production of mung bean sprouts in antimicrobial groups was significantly reduced over 96 h (p < 0.05). The bud and root length of mung bean sprouts in enrofloxacin, olaquindox, doxycycline and furazolidone groups were significantly shortened (p < 0.05), which cultivated thick-bud and rootless mung bean sprouts similar to the 6-benzyl-adenine group. Furthermore, linear regression analysis showed average optical density of 450 nm in circulating water and average production had no obvious correlation in mung bean sprouts (p > 0.05). Antimicrobial residues were found in both mung bean sprouts and circulating water. These novel findings reveal that the antimicrobials could cultivate thick-bud and rootless mung bean sprouts due to their toxicity. This study also proposed a new question regarding the abuse of antimicrobials in fast-growing vegetables, which could be a potential food safety issue.