Sprout Samples Research Articles

Determination of fluoroquinolones residues in bean sprouts using covalent organic framework based solid-phase extraction coupled with UHPLC-MS/MS

A solid-phase extraction (SPE) method using three-dimensional covalent organic framework (COFs) coupled with ultra-high performance liquid chromatography-mass spectrometry was developed for the detection of 13 fluoroquinolones (FQs) in bean sprout samples. Critical extraction parameters influencing SPE efficiency were optimized and matrix-matched standard curves were used to eliminate matrix effects and validate the proposed method. The analytical method proved to have good linearity in the concentration range of 1.0–100 μg L–1 with correlation coefficients of r≥0.9995. The limits of detection were 0.10–0.45 μg kg–1, whereas the limits of quantification were 0.34–1.51 μg kg–1. The recoveries ranged from 92.7 % to 105 % with satisfactory precision (< 4.82 %). The COFs-packed SPE cartridge maintained recovery efficiency for the target FQs over five reuse cycles. The adsorption selectivity was mainly attributed to π–π interactions, hydrogen bonding, and electrostatic attraction between FQs and the adsorbent. Analysis of actual samples revealed the presence of enrofloxacin, ciprofloxacin, and norfloxacin in three batches of bean sprout samples. These results highlight the importance of monitoring antibiotics residues in bean sprouts.

A novel fluorescent probe based on naphthimide for detecting Zn2+ and its application in plant imaging and cell imaging

The fluorescent probe NXZ was synthesized by introducing –OH at position 1, 8-naphthalimide 4-position and benzimidazole unit at 3-position. The Stokes shift (λem − λex) of NXZ can up to 148 nm, when Zn2+ was added to the probe solution, NXZ can quickly form the complex NXZ-Zn2+ with Zn2+ in a ratio of 1: 1 within 55 s, and then quench the fluorescence intensity by 4.4 times. The complexation constant of NXZ and Zn2+ was 1.2 × 104 M−1, and the detection limit for Zn2+ was 40.3 nM, which is much lower than the maximum Zn2+ content (76 µM) stipulated in the World Health Organization (WHO). Exploring the practical application of the probe NXZ found that NXZ can be used for the quantitative detection of Zn2+ in actual water samples and qualitatively detect Zn2+ in bean sprouts samples and Hela cells. In addition, NXZ can also be made into Zn2+ test paper.

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.

Hygienic effect of modified atmosphere film packaging on ginseng sprout for microbial safety

This study evaluates the microbial safety of ginseng sprouts packaged in moss and a modified atmosphere (MA) film within Styrofoam boxes. Ginseng sprout samples were stored at 4°C for seven days, and the total fungi and aerobic bacteria counts, relative humidity, and moisture content were measured at 0, 1, 3, 5, and 7 days. During the storage period, both packaging treatments caused an increase in the total fungi and aerobic bacteria counts. However, by the seventh day, the ginseng sprouts packaged in the MA film demonstrated significantly lower counts of total fungi (3.03 log CFU/g) and aerobic bacteria (7.32 log CFU/g) than those in moss (3.66 and 7.63 log CFU/g, respectively). Moss packaging alone resulted in the total fungi count reaching up to 3.36 log CFU/g, with the aerobic bacteria count consistently exceeding 7 log CFU/g, highlighting the importance of hygienic management. Moreover, no significant differences were observed in the moisture content and relative humidity between the MA-film- and moss-packaged groups throughout storage. These findings indicate that the functional MA film is a more hygienic packaging solution for ginseng sprouts than moss.

The fate of enterohemorrhagic Escherichia coli on alfalfa and fenugreek seeds and sprouts as affected by ascaroside #18 treatments

Alfalfa and fenugreek sprouts are healthy foods, but they are occasionally contaminated with bacterial pathogens and serve as vehicles for transmitting foodborne illnesses. This study examined the efficacy of ascaroside (ascr)#18 treatment for the control of enterohemorrhagic E. coli (EHEC) growth on sprouts. Commercial alfalfa and fenugreek seeds were decontaminated with 20,000 ppm of NaClO, and residual chlorine was neutralized with Dey-Engley broth. Decontaminated seeds were treated with 1 mM or 1 μM ascr#18, a plant immunity modulator, before being dried and mixed with sandy soil inoculated with E. coli F4546 or BAA-2326 at 104–105 CFU/g. The inoculated seeds were sprouted on 1 % water agar at 25 °C for 7 days in the dark. Seed or sprout samples were collected on days 0, 1, 3, 5, and 7 for enumeration of bacterial populations. Data was fit into the general linear model and analyzed using Fisher's least significant different test of the statistical analysis software. Treatment with ascr#18 significantly (P ≤ 0.05) reduced the cell population of EHEC on sprouts. The mean EHEC populations in the 1 mM or 1 μM treatment groups were 3.31 or 1.56 log CFU/g lower compared to the control groups. Besides treatment, sprout seed type and sprouting time were also significant independent variables influencing the growth of EHEC, according to the results of type III error analysis. However, EHEC strain type was not a significant independent variable. The study suggests that ascr#18 could be potentially used to control EHEC contamination and improve the microbial safety of sprouts.

Influence of Source Materials, Concentration, Gastric Digestion, and Encapsulation on the Bioactive Response of Brassicaceae-Derived Samples against Helicobacter pylori.

Isothiocyanates may have antibacterial activity against Helicobacter pylori, but there are different variables related to Brassicaceae-derived samples that could affect their efficacy. This work studied the influence of source variety, concentration, gastric digestion, and encapsulation of samples on their bioactive response against Helicobacter pylori. The antibacterial activity of raw sprouts (red cabbage and red radish) showed the highest antibacterial effect, which was consistent with a higher amount of isothiocyanates. It decreased with gastric digestion, regardless of sample encapsulation. By contrast, adult red radish leaves became antibacterial after gastric digestion. Antioxidant activity on H. pylori-infected gastric cells was similar in all samples and followed an equivalent pattern with the changes in isothiocyanates. Raw samples decreased intracellular reactive oxygen species production, but they lost this capacity after gastric digestion, regardless whether the compounds were free or encapsulated. Red cabbage sprouts, red radish sprouts, and red radish roots produced a decrease in nitric oxide production. It was consistent with a modulation of the inflammatory response and was associated to isothiocyanates concentration. Encapsulated sprout samples retained part of their anti-inflammatory activity after gastric digestion. Adult raw red radish leaves were not active, but after digestion, they became anti-inflammatory. The results obtained in this study have shown that several variables could have a significant impact on the bioactive properties of Brassicaceae-derived samples against H. pylori, providing a starting point for the design and standardization of samples with specific bioactivities (antibacterial, antioxidant, and anti-inflammatory) potentially useful for the treatment of H. pylori infection.

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 0.16ngmL-1 was obtained with a linear range of 0.5-6ngmL-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.

Comparison of Policosanol Profiles of the Sprouts of Wheat Mutant Lines and the Effect of Differential LED Lights on Selected Lines.

Policosanols (PCs) are long-chain linear aliphatic alcohols that are present in the primary leaves of cereal crops, such as barley and wheat, sugar cane wax, and beeswax. PCs have been used as a nutraceutical for improving hyperlipidemia and hypercholesterolemia. However, the PC content in mutant wheat lines has not been investigated. To select highly functional wheat sprouts with a high content of PCs in wheat mutant lines developed via gamma-irradiated mutation breeding, we cultivated the sprouts of wheat mutant lines in a growth chamber with white LED light (6000 K) and analyzed the PC content in these samples using GC-MS. We studied the PC content in 91 wheat sprout samples: the original variety (Woori-mil × D-7; WS01), commercially available cv. Geumgang (WS87) and cv. Cheongwoo (WS91), and mutant lines (WS02-WS86 and WS88-WS90) developed from WS01 and WS87. Compared to WS01, 18 mutant lines exhibited a high total PC content (506.08-873.24 mg/100 g dry weight). Among them, the top 10 mutant lines were evaluated for their PC production after cultivating under blue (440 nm), green (520 nm), and red (660 nm) LED light irradiation; however, these colored LED lights reduced the total PC production by 35.8-49.7%, suggesting that the cultivation with white LED lights was more efficient in promoting PCs' yield, compared to different LED lights. Therefore, our findings show the potential of radiation-bred wheat varieties as functional foods against hyperlipidemia and obesity and the optimal light conditions for high PC production.

Microbial Profiles and Patterns of Antibiotic Susceptibility of Bacterial Isolates from Edible Sprouts of Flaxseeds (Linum usitatissimum L.)

Flaxseed (Linum usitatissimum L.) is a plant-based food that provides healthy fat, antioxidants, and fiber. It is referred to as a "functional food" by certain individuals, which suggests that someone can eat it to improve their health. A study on sprouted flaxseed produced in the laboratory revealed the presence of microbial flora, namely bacteria and molds, which is of concern for the health-conscious public. A total of 39 flaxseed sprout samples were cultured to evaluate microbial profiles and to determine antibiotic susceptibility patterns by the Kirby-Bauer Disc diffusion method. Bacterial isolates were tested only against 11 antibiotics, viz. Amoxycillin, Gentamicin, Ciprofloxacin, Colistin, Meropenem, Cefixime, Azithromycin, Mecillinam, Cotrimoxazole, Cefaclor, and Moxifloxacin. 39 (100%) of the 39 flaxseed sprout samples cultured tested positive for bacteria and molds. Among them, positive cultures, single bacterial growth, multiple bacterial growth, and molds were 33 (84.6%), 6 (15.4%) and 39 (100%) respectively. The most predominant organisms were Serratia marcescens, comprising 15(33.3%), followed by Citrobacter freundii 10(22.2%), Pseudomonas aeruginosa 9(20.0%), and other bacterial isolates were Enterobacter cloacae complex, Morganella morganii, and Aeromonas hydrophila, whose frequencies were 6(13.3%), 4(8.9%) and 1(2.2%) respectively. All of the bacterial isolates were 100% sensitive to Ciprofloxacin, Gentamicin, Mecillinam, and Moxifloxacin, and only two antibiotics were shown 100% resistance in Amoxicillin and Cefixime. Based on the results, it is suggested that consumers should pay attention to producing with hygienic techniques and cooking properly to avoid foodborne diseases from flaxseed sprouts&#x0D; J. of Sci. and Tech. Res. 4(1): 155-164, 2022

Au@Ag nanodome-cones array substrate for efficient residue analysis of food samples by surface-enhanced Raman scattering

A bioinspired Au@Ag nanodome-cones array (Au@Ag NDCA) surface-enhanced Raman scattering (SERS) chip was developed for efficient residue analyses of food samples. The cicada wing inspired Au@Ag NDCA chip was fabricated by a bottom-up method, Au nanocones array was firstly grown onto nickel foil by displacement reaction and cetyltrimethylammonium bromide guidance growth, and then silver shell with controllable thickness was coated onto the Au nanocones array by magnetron sputtering. The Au@Ag NDCA chip exhibited good SERS performances with high enhancement factor of 1.2 × 108, good uniformity with relative standard deviation (RSD) less than 7.5% (n = 25), good inter-batch reproducibility with RSD less than 9.4% (n = 9), and long-term stability over 9 weeks. By adapting a minimized sample preparation, Au@Ag NDCA chip combined with a 96-well plate could realize high-throughput SERS analyses of 96 samples with average analysis time less than 10 min. The substrate was applied for quantitative analyses of two food projects. One was 6-benzylaminopurine auxin residue in sprout samples with detection limit of 38.8 μg/L, recoveries of 93.3–105.4% and RSDs of 1.5–6.5%, and the other was an edible spice of 4-amino-5,6-dimethylthieno (2,3-d) pyrimidin-2(1H)-one hydrochloride additive in beverage samples with detection limit of 18.0 μg/L, recoveries of 96.2–106.6% and RSDs of 3.5–7.9%. All the SERS results were well confirmed by conventional high-performance liquid chromatographic methods with relative errors less than 9.7%. The robust Au@Ag NDCA chip exhibited good analytical performances possessed great potential for convenient and reliable analyses of food quality and safety.

Efficacy of Ascaroside #18 Treatments in Control of Salmonella enterica on Alfalfa and Fenugreek Seeds and Sprouts

A novel, natural, and effective antimicrobial intervention is in demand for improving the microbial safety of vegetable seeds/sprouts. This study assessed the efficacy of ascaroside treatment in the control of Salmonella enterica on alfalfa and fenugreek sprouts. Sanitized commercial seeds were treated with 1 mM or 1 µM ascaroside (ascr)#18, a plant immunity modulator (PIM) and dried for an hour before being inoculated with lyophilized S. Cubana or S. Stanley cells in sandy soil (104 CFU/g). Treated and untreated seeds were spouted on 1% water agar at 25°C in the dark. Seed or sprout samples were collected on days 0, 1, 3, 5, and 7, and the population of Salmonella was determined. Data were fit into the general linear arrangement, and means were separated using Fisher’s least significant difference test. Seed type, strain type, treatment type, and sprouting time were significant factors (P ≤ 0.05) influencing Salmonella growth on sprouts. The populations of Salmonella were significantly higher on fenugreek than on alfalfa sprouts. S. Stanley had a significantly higher population than S. Cubana. The population of Salmonella increased from day 0 to day 3 and reached the peak population on Day 5. Treatments with both concentrations of ascaroside significantly decreased the populations of Salmonella compared to the controls. The mean Salmonella population reduction was ca. 4 or 1 log CFU/g by treatment with 1 mM and 1 µM of the PIM, respectively. Treatment with the PIM could be potentially used to improve the microbial safety of vegetable seeds and sprouts.

Synthesis of Phenolic Compounds in Barley Seedlings Under the Influence of the Microwave Electromagnetic Field of Ultrahigh Frequency

Phenolic substances are involved in the processes of growth, morphogenesis, respiration and photosynthesis, are reserve and signaling substances, and have antioxidant properties. Spring barley (Hordeum vulgare L.) of variety Nikita was used in the experiments. In seven-day-old seedlings, phenolic substances were determined using reversed phase high-performance liquid chromatography analysis (RP HPLC) with an amperometric detector. The maximum number of phenolic compounds is registered in the chloroform extract of the endosperm of the microwave-treated grain, their number is 26 names of substances. The minimum number of individual substances is 10-11 and is found in samples of roots and sprouts of native seedlings, as well as roots of microwave-irradiated barley plants. The microwave treatment affected both the number of isolated substances and their amount in the extract. The most biochemically active anatomical part of a seven-day-old barley seedling is the endosperm: it contains significantly more substances of a phenolic nature, recorded by an amperometric detector, than in sprouts and roots. The microwave field significantly affected the amount of phenolic compounds with antioxidant properties in the endosperm. In relation to phenolic substances in the composition of barley seedlings, there is an organ-specific response, which is expressed in the difference in their quantitative and qualitative content. Individual phenolic substances are registered in all the organs of the seedling (roots, leaves, endosperm), and some have a certain localization. The total amount of phenolic substances with antioxidant properties increases after microwave treatment.

Kecambah: Agen penghidrolisis pati yang potensial

Starch is a group of complex carbohydrates containing amylose and amylopectin. Starch can be broken down into simpler molecules such as maltose, isomaltose, and glucose which is called the hydrolysis process. Starch hydrolysis is very useful in several food industries. Enzymatic hydrolysis of starch usually uses the amylase enzyme derived from saliva. However, if you are going to carry out the hydrolysis process on a large scale, it requires large amounts of enzymes. Therefore, this study aimed to examine the ability of enzymes in sprouts to hydrolyze starch and compare it with the ability of starch hydrolysis by saliva and HCl. The isolated sprout samples were added to the starch solution and then incubated at 37oC. Every 5 minutes the mixture was tested qualitatively with Benedict's test and iodine. The same treatment for saliva and HCL. However, HCl was incubated at 100oC. The results of the qualitative test using Benedict's test and the iodine test showed enzymatic process had a higher ability to hydrolyze starch than chemically with HCl. The α-amylase enzyme produced from sprouts showed a higher starch hydrolysis ability than saliva. Sprouts are a natural source that can be developed as a starch hydrolyzing agent.

Simultaneous determination of 40 plant growth regulators, fungicides, insecticides, and antibiotics in bean sprouts by QuEChERS-high performance liquid chromatography-tandem mass spectrometry

研究从豆芽质量安全监管的实际需求出发,建立了QuEChERS-高效液相色谱-串联质谱同时测定豆芽中植物生长调节剂、杀菌剂、杀虫剂和抗生素类等40种药物残留的方法。首先通过参数优化确定最佳质谱条件,然后比较不同提取溶剂(甲醇、乙腈、0.1%氨水乙腈、1%乙酸乙腈)、提取方法(超声、振荡)以及乙二胺-N-丙基硅烷化硅胶(PSA)、C18净化剂添加量时40种药物的回收率,确定最优前处理过程。样品用10 mL 1%乙酸乙腈提取两次,超声波辅助提取,100 mg C18为净化剂。选用Waters ACQUITY UPLC BEH C18色谱柱(100 mm×2.1 mm, 1.7 μm)进行分离,甲醇和0.01%甲酸水为流动相梯度洗脱,多反应监测(MRM)模式进行质谱监测,基质匹配外标法定量。结果表明,40种药物可在15 min内完成色谱分离,在2~200 μg/L的线性范围内均呈现出良好的线性关系,相关系数(r2)均大于0.99,检出限(LOD)和定量限(LOQ)分别为0.1~3 μg/kg和0.3~9 μg/kg。以阴性豆芽为基质,分别在5、10、50 μg/kg 3个水平下进行加标回收试验,40种药物的平均回收率为78.5%~115.3%,相对标准偏差(RSD)为1.3%~9.7%(n=6)。将该方法用于分析邯郸本地豆芽中40种药物的污染状况,结果显示4-氯苯氧乙酸、6-苄基腺嘌呤、多菌灵、2,4-二氯苯氧乙酸(2,4-D)、赤霉素和恩诺沙星检出率较高,分别为28.6%、19.0%、9.5%、9.5%、4.8%和4.8%,含量范围为37.5~352.4、32.4~273.1、28.8~38.7、16.1~20.2、19.9和13.6 μg/kg。研究建立的方法简单、快速,灵敏度高,适用于大批量豆芽中40种药物的快速准确测定。

Dissipation behavior and dietary exposure risk of pesticides in Brussels sprout evaluated using LC–MS/MS

In this study, the dissipation behavior and dietary exposure risk of eight pesticides in Brussels sprout were evaluated under greenhouse conditions. Brussels sprout samples were collected 0, 7, 14, and 21 days after the last pesticide treatment. Ultra-high performance liquid chromatography with tandem mass spectrometry was used for sample analysis. Recovery rates at different concentrations of pesticides (0.01 and 0.1 mg/kg) were in the range of 70.2–104.5%, and the relative standard deviations were ≤ 10.6%. The pesticide residues in Brussels sprouts were determined for each treatment. For acephate, etofenprox, imidacloprid, indoxacarb, alpha-cypermethrin, zeta-cypermethrin, fludioxonil, and oxytetracycline, the half-lives were, respectively, 11.3, 9.8, 11.3, 15.8, 10.6, 13, 9.1, and 8.2 d and the dietary intake rates were, respectively, 2.90%, 0.81%, 0.7%, 1.19%, 0.06%, 0.24%, 0.05%, and 0.36% of the acceptable daily intake. The findings of this study provide important insights into the establishment of maximum residue limits in the Republic of Korea and pesticide control measures for Brussels sprout.

Rapid Screening of 30 Plant Growth Regulators and Quinolone Antibiotics in Bean Sprout Samples

A method was developed for the simultaneous determination of 30 plant growth regulators residues and quinolone antibiotics residues in bean sprouts by ultra-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with pass-through solid-phase extraction. The samples were extracted by 90% acetonitrile containing 0.1% formic acid and purified with PRiME HLB solid-phase extraction, gradient elution with acetonitrile and water (containing 0.1% formic acid). The target compounds were separated on an Agilent SB-Aq RRHD column, then detected by electrospray positive and negative ion multiple reaction monitoring mode. The target compounds were quantified by using the matrix-matched standard calibration. The result showed that the correlation coefficients greater than 0.991 in the range of 2~500 μg/L, the detection limit was 0.04~1.67 μg/kg, the quantitative limit was 0.1~5.6 μg/kg, the average recovery was 74.0%~113.5%, and the relative standard deviation was 0.6%~7.7% (n=6). The method is simple and sensitive, can be used for rapid screening of 30 plant growth regulators and quinolones in bean sprouts.

Detection of Campylobacter jejuni from Fresh Produce: Comparison of Culture- and PCR-based Techniques, and Metagenomic Approach for Analyses of the Microbiome before and after Enrichment

In this study, we compared the efficiency of culture-based methods with or without membrane filtration, real-time PCR, and digital droplet PCR (ddPCR) for the detection of Campylobacter in fresh produce. Alfalfa sprouts, clover sprouts, coleslaw, and lettuce salad spiked with Campylobacter jejuni were enriched in Bolton broth for 48 h, and enrichment cultures were either directly inoculated onto modified charcoal-cefoperazone-deoxycholate agar or applied on membrane filters placed on the surface of plating media. In parallel, 2-mL Bolton broth cultures were taken to extract DNA for real-time PCR and ddPCR assays and bacterial community analysis. A developed primer set for ddPCR and real-time PCR was evaluated for its inclusivity and exclusivity using pure culture of C. jejuni and non-C. jejuni strains, respectively. In pure culture, the primer set reacted only with C. jejuni strains and showed negative reaction to non-C. jejuni strains. There was no significant difference (P > 0.05) in the detection efficiency of positive Campylobacter isolates from coleslaw and lettuce salad using four detection methods. However, for sprout samples, the detection efficiency of the culture method was significantly (P < 0.05) lower than those of the two PCR assays and the filtration method. The analysis also revealed the presence of Pseudomonas and Acinetobacter as the most prevalent competing microbiota in enriched culture and only Acinetobacter on agar plates in the selective culture step.

EXTRACTION AND CHARACTERIZATION OF RESVERATROL FROM VEGETABLE WASTE FROM VINES

Vine shoots resulting from vine pruning can become valuable products of interest for many industries. Research conducted to date showed that resveratrol is found in many parts of the vine. The aim of the present study was to determine the resveratrol content in Romanian vine sprouts samples by direct injection into the HPLC instrument coupled with diode array detector after being filtered through 0.45 μm PTFE membrane filters. The resveratrol content varied from 5.44 mg/100 g to 10.27 mg/100 g in ethanolic extracts. For aqueous extract, the resveratrol was found in only two samples in very low concentration. Thise paper aimed to contribute to the research on the capitalization of residual products from viticulture industry.

Effect of Red Cabbage Sprouts Treating with Organic Acids on the Content of Polyphenols, Antioxidant Properties and Colour Parameters

In recent years, there has been a great deal of consumer interest in consuming vegetables in the form of sprouts, characterized by high nutritional value. The disadvantage of sprouts is the loss of bioactive compounds during storage and the relatively short shelf life, due to the fact that they are a good medium for microorganisms, especially yeasts and molds. The aim of the study was to compare the content of polyphenols, antioxidant properties, color and microbiological quality of red cabbage sprouts preserved by the use of mild organic acids: Citric, ascorbic, lactic, acetic and peracetic. In the study, the content of polyphenols and antioxidant properties of sprouts was examined using the spectrophotometric method, instrumental color measurement was done using an “electronic eye” and the content of mold, yeast and the total number of mesophilic microorganisms was determined using the plate inoculation method. Taking into account the content of polyphenols and the antioxidant potential of sprouts, it was found that the addition of all organic acids contributed to the preservation of the tested compounds during their 14-day storage under refrigerated conditions, depending on the type of organic acid used, from 71 to 86% for polyphenols and from 75 to 96% for antioxidant properties. The best results were obtained by treating the sprouts with peracetic acid and ascorbic acid, respectively, at a concentration of 80 ppm and 1%. The conducted research on the possibility of extending the storage life and preserving the bioactive properties of fresh sprouts showed that the use of peracetic acid in the form of an aqueous solution during pre-treatment allows to reduce the content of microorganisms by one logarithmic order. Ascorbic acid did not reduce the content of microorganisms in the sprout samples tested. Considering the content of bioactive ingredients, as well as the microbiological quality of fresh sprouts, it can be said that there is a great need to use mild organic acids during the pre-treatment of sprouts in order to maintain a high level of health-promoting ingredients during their storage, which may also contribute to their prolongation durability.

Standardized Shiga-Toxin Encoding Genes Real-Time PCR Screening Methods Comparison and Development of an Internally Controlled Assay for Pan-stx2 Detection.

Various primer and probe sets have been developed and standardized, but certain sets may have low efficiency or miss some stx-subtypes. To compare the efficiency of the recommended stx screening primers and probe sets in four standardized methods and develop a new primers and probe system with an internal amplification control (IAC) for all known stx2 subtypes. The inclusivity and specificity of recommended screening primers and probe sets in four standardized methods were compared. A new pan-stx2 primer and probe set was adapted from the International Organization for Standardization (ISO) method for all known stx2 subtypes. The robustness of the new method was assessed in seven laboratories and also assessed in ground beef and bean sprout samples. None of the recommended screening primers and probe sets in the four standardized methods could efficiently amplify all the stx2 subtypes because of various mismatches in the primers or the probe sequences. A new primers and probe system adapted from the ISO method, through introducing degenerate bases in primers and probe sequences with an IAC, showed high amplification efficiency and specificity for all known stx2 subtypes in ground beef and bean sprouts samples. The specificity of the new method was assessed in seven laboratories and showed robust and consistent results. This study provided evidence for Shiga-toxin producing Escherichia coli (STEC) screening method development, and the newly developed primers and probes system should be considered in the revision of the standardized methods. None of the recommended screening primer and probe set in the four official methods could efficiently amplify all the stx2 subtypes. A new developed primer and probe set showed high amplification efficiency and specificity for all known stx2 subtypes in fresh ground beef and bean sprouts samples. The newly developed stx2 screening system showed robustness and consistency during interlaboratory study.