High Nitrite Content Research Articles

Catalytic degradation of "trinitrogen" by Fe-Ce-SiO2 /TiO2 aerogel.

The "trinitrogen" [ammonia nitrogen (NH4+ - N), nitrate nitrogen (NO3- - N), and nitrite nitrogen (NO2- - N)] from industrial or domestic wastewater can lead to eutrophication of water bodies. When ammonia nitrogen is converted into nitrate nitrogen, it will cause high nitrogen oxygen demand, which will also lead to hyperammonemia. High nitrite content in water bodies will increase the risk of human cancer. In this paper, Fe-Ce bimetallic-doped composites (Fe-Ce/SiO2 and Fe-Ce-SiO2/TiO2) were synthesized using SiO2 aerogel as a carrier for the adsorption and degradation of "three nitrogen."SiO2/TiO2 was prepared by dipping method, and Fe and Ce bimetals were loaded on the surface of SiO2/TiO2 material, and the effect of photo-Fenton oxidation on the degradation rate of three nitrogen under different materials was explored. The results showed that when the dosage of catalyst was 0.01g, pH value was 11.0, and the concentration of H2O2 was 80mmol/L, the photocatalytic efficiency was the best, and the degradation efficiency of three nitrogen remained above 70%.

Monitoring of ecotoxicological parameters in the floating net cage area in Buluhcina Village, Kampar District, Riau Province, Indonesia

Net cages culture activities produced organic pollutant that are distributed in the surrounding area and thus affects the water’s ecotoxicological parameters. This research was conducted along the Kampar River in the village of Buluhcina during the period of May to July 2023. Water samples were collected three times and the parameters measure were TSS, DO, COD, pH, Nitrite and Total P. Results indicate that in general, the water quality of the Kampar River’s was less contaminated (Pollution Index 1.19). The most polluted area was in Station 1 (PI 1.35) as indicated by high TSS and nitrite content that were more than the standard level. Relatively high nitrate content was also found in Station 3 (0.08 mg/l). In Station 2, however, the water quality was relatively good (PI 0.87), and the COD level was slightly above the standard value (0.5 mg/l). Based on data collected, it can be concluded that the water quality in the study site can be categorized as good and it may be used to conduct aquaculture activities.

Characterization of the Sediment Bacterial Community Structure and Composition in Najafgarh Lake and Adjoining Dhansa Barrage.

This study was undertaken to assess the changes in the community structure, diversity, and composition of sediment bacteria in a shallow lake, Najafgarh Lake (NL), that receives untreated sewage effluent through drains connected to it. These changes were analyzed by comparing the sediment bacterial community structure of NL to the sediment bacterial community structure of Dhansa Barrage (DB), which receives no such effluents. 16S rRNA amplicon was used for bacterial community analysis. Water and sediment samples were also analyzed and compared revealing high conductivity, ammonia, nitrite content, and low dissolved oxygen in NL. The organic matter content is also higher in the sediments of NL. Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria are the predominant phyla in both sites and account for 91% of total bacterial abundance in DB and only 77% in the case of NL. Proteobacteria have the highest relative abundance, accounting for around 42% of the total bacterial population in the case of DB and Firmicutes has the highest relative abundance in Najafgarh at 30%. The diversity analysis found significant differences in the community structure at the two sites. The variation in the bacterial communities in the two wetlands is significantly associated with two water parameters (conductivity and temperature) and two sediment parameters (Sediment Nitrogen and Sediment Organic Matter). Correlation Analysis showed that high ammonia, nitrite, and conductance in NL resulted in bacterial communities shifting towards phyla abundant in degraded ecosystems like Acidobacteria, Choloroflexi, Caldiserica, Aminicenantes, Thaumarchaeota, and Planctomycetes.

Investigation of the Possibility of Listeria monocytogenes Growth in Alternatively Cured Cooked Sausages—A Case Study

The aim of this study was to investigate the possibility of Listeria monocytogenes growth in cooked sausages produced in the same meat processing plant without or with a direct nitrite addition (alternatively cured, AC, and nitrite cured, control). The AC and control sausages were inoculated with a mix of three L. monocytogenes strains. Products (n = 24 sausages for each product type) were vacuum-packed and stored for 10 days at 6 °C. Residual nitrite and salt contents, water activity and the number of L. monocytogenes were determined in products. A higher nitrite content was found in the control (44.9 mg/kg) compared with AC (12.1 mg/kg). Significantly higher L. monocytogenes counts at the 6th and the 8th day were noted in AC sausages, however at the 10th day they did not differ significantly between the treatments (2.96 and 3.27 log10 CFU/g in the control and AC, respectively). AC sausages showed a growth potential value of 0.64, which indicates the possibility of L. monocytogenes growth on the surface of alternatively cured products. In contrast, a growth potential value of 0.21 was found in control sausages, which indicates that nitrite cured sausages did not support the pathogen growth at 6 °C.

Changes and Driving Mechanism of Microbial Community Structure during Paocai Fermentation

Fermentation of paocai is a dynamic process of the microbial community structure, and the interaction between community structure and physicochemical factors endows paocai with unique taste and flavor. The study of bacterial and fungal community structure changes and the driving mechanism of physicochemical factors induced changes in community structure, showing that Pseudomonas belonging to Proteobacteria and Lactobacillus belonging to Firmicutes were the dominant bacteria in the process of paocai fermentation. The correlation analysis of physicochemical factors with bacterial community showed that titratable acid was significantly positively correlated with Lactobacillus and negatively correlated with Pseudomonas, while nitrite was the opposite. Redundancy analysis (RDA) showed that pH was positively correlated with the bacterial community in the early fermentation stage, amino acid nitrogen was positively correlated with the bacterial community in the middle fermentation stage, and titratable acid was positively correlated with the bacterial community in the late fermentation stage. Variance partitioning analysis (VPA) showed that environmental factors, pH and metabolites, were the main driving forces of bacterial community diversity, which jointly explained 32.02% of the bacterial community structure variation. To study the glucolysis and nitrogen metabolism in the process of paocai fermentation, we found that in the early stage of the fermentation, the nitrite reductase enzyme of Pseudomonas activity was high, with high nitrite content in the prophase, but by the end of fermentation, lactic acid bacteria rapidly increased, the content of L−lactic acid through the glycolysis pathway, making paocai fermentation environment become acidic, then Pseudomonas decreased. Ascomycota and Basidiomycota were the main phylum fungi in the fermentation process. RDA analysis showed that the fungal community was positively correlated with pH, nitrite, and soluble protein at the early fermentation stage, amino acid nitrogen was positively correlated with the fungal community at the middle fermentation stage, titratable acid and reducing sugar were positively correlated with the fungal community at the late fermentation stage. VPA analysis showed that metabolites were the main driving force of fungal community diversity and accounted for 45.58% of fungal community diversity. These results had a certain guiding significance for the production and preservation of naturally fermented paocai.

Small Ruminants Grazing as a Rehabilitative Land Management Tool in the Negev Highland; Soil, Geomorphological and Topographical Perspectives

The ‘wadis’ (ephemeral incised channels in arid regions) concern badlands with low agriculture utilisation that expands to neighbouring cultivated areas. They are noticeable and unique landforms characterised by vegetation patches and seasonal flood flows with scenic beauty that must be conserved. The wadi characteristics have influenced the way of life of their indigenous residents from ancient times until now. The main one is grazing with small ruminants (SR). The authorities and public consider grazing in these areas as a destructive land management practice that should be reduced. To assess the viability of grazing in such regions, we hypothesised that fluvial and biological flows tightly correlate with the wadis’ landforms, channels and slopes. The site of study is located in the Yeroham mountains nearby the Rahma planned Bedouin village. Five different transects of channels and slopes were located over representative wadis, including those exposed to grazing. The finding indicates that a herbaceous vegetation expansion uphill was observed only in grazed transects, while the wadi slope patterns affect its patterns. It contains an increased soil water content (from a similar value of 5% until 13% change in the grazed transect), 1.5% higher soil organic matter, 0.08 mg Kg−1 higher Nitrite content and 1–2% higher clay content in the grazed transects, up to 4 m ahead from the channel. The novelty of this finding suggested that the SR influences the organic matter to reach the wadi channel and facilitate the adherence of aggregated clay and the formed colluvial layer that serves as a substrate to the expanded vegetation growth. Adequate implementation of these grazing patterns may rehabilitate degraded ‘wadis’ and increase their tourism eligibility.

Ameliorating effect of nitrate on nitrite inhibition for denitrifying P-accumulating organisms

Lowered air supply and organic carbon need are the key factors to reduce wastewater treatment costs and thereby, avoid eutrophication. Denitrifying PO43−- removal (DPR) process using nitrate instead of oxygen for PO43− uptake was started up in the sequencing batch reactor (SBR) at a nitrate dosing rate of 20–25 mg N L−1 d−1. Operation with a real municipal wastewater supplied with CH3COONa, K2HPO4 and KNO3 succeeded in the cultivation of biomass containing denitrifying polyphosphate accumulating organisms (DPAOs). The durations of SBR process anaerobic/anoxic/oxic cycles were 1.5 h, 3.5 h and 1 h, respectively. SBR operation resulted in a maximum PO43−-P uptake of 17 mg PO43−-P g−1 MLSS. The highest TN and PO43− removal efficiencies were observed during the first half of reactor operation at 77 (±10) % and 71 (±5) %, respectively. An average COD removal rate of 172 (±98) mg g−1 MLSS and a high average removal efficiency of 89 (±4) % were achieved.Nitrite effect with/without nitrate as DPR electron acceptor was investigated in batch-scale to show possibilities to use high nitrite and nitrate contents simultaneously as electron acceptors for the anoxic phosphate uptake. Nitrate attenuation against nitrite toxicity can be economically justified in full-scale treatment applications in which wastewater has a high nitrogen content. Nitrate attenuated nitrite toxicity (caused by nitrite content at 5–100 mg NO2−-N L−1) when using supplemental additions of nitrate (at concentrations of 45–200 mg NO3−-N L−1) in batch tests. Illumina sequencing emphasized that during biomass adaption microbial community changed by lowered aerobic cycle length and by lowered nitrate dosing towards representation of key DPAO/PAO- organisms, such as Candidatus Accumulibacter, Xanthomonadaceae, Comomonadaceae, Saprospiraceae and Rhodocyclaceae. This study showed that DPAO biomass adaption to nitrate maintained an efficient COD, nitrogen and phosphorus removal and the biomass can be applied for treatment of wastewater containing high nitrite and nitrate content.

Investigating the root cause of N-nitrosodimethylamine formation in metformin pharmaceutical products

ABSTRACT Background FDA limited N-nitrosodimethylamine (NDMA) – a carcinogenic impurity formed during metformin (MET) tablets manufacturing – level to 96 ng/day; a step which led to recall of MET products. This work aims to investigate the root cause of NDMA formation during MET tablets manufacturing. Research design and methods We focused on three main contributing causes: use of water and heat during intra-granulation, and the nitrite/nitrate quantities in excipients. Thirteen MET tablet formulations (immediate or sustained-release) were manufactured, on batch level. Each batch was manufactured using one excipient and excluding one cause at a time and NDMA level was assayed. Results NDMA traces were undetectable in MET tablets manufactured using polyvinyl pyrrolidone or hydroxypropyl cellulose SSL, even when water and/or heat were employed during intra-granulation. Levels of NDMA in MET tablets with hydroxypropyl methyl cellulose (HPMC) E5 or carboxymethyl cellulose sodium 4000 were 67.08 ± 2.3 and 66.21 ± 2.5 ng/day, in the presence of water and/or heat. No impact of employing extra-granular PolyoxTM, HPMC E5 or HPMC K15 on NDMA formation, despite the high nitrite and nitrate content in these excipients. Conclusions Water, heat, and excipients’ nitrite and nitrate levels are the key players, which should collectively exist, to cause NDMA formation during MET tablets manufacturing.

Thiosulphate driven autotrophic denitrification via nitrite using synthetic wastewater

AbstractBACKGROUNDThe removal of biological nitrite from wastewater can occur by both heterotrophic and autotrophic bacteria. Autotrophic denitritation can be implemented by using different sulphur forms (e.g., S2−, S0 or S₂O₃2−) as electron donors, and there is no need for organic carbon availability, as is required in heterotrophic denitrification. This work investigated an alternative biochemical pathway for nitrite removal from synthetic wastewater with high nitrite content, using thiosulphate as electron donor. The process was examined for 170 days in three identical 1 L sequencing batch reactors (SBR) that were inoculated with filtrate originating from the aerobic filters of the desulphurization unit of a wastewater treatment plant (WWTP).RESULTSThe SBR units were able to remove approximately 98% of the initial nitrite concentration of 70–80 mg N L−1, operating under an HRT of 5d. The batch experiments showed autotrophic denitritation rates (NUR) with average values between 0.91 and 1.50 mg NO₂‐N gVSS−1 h−1 during the whole duration of the experiment, with a remarkable increase on the NUR after the initial lag time of the process, where rates of up to 4.74 mg NO₂‐N gVSS−1 h−1 were measured.CONCLUSIONThe daily monitoring of the three SBR units showed that denitritation via thiosulphate can be effective enough for nitrite removal without carbon source addition. The lag phase of the process, as well as the loss of alkalinity and pH drop during denitritation, are disadvantages that can be counterbalanced with the cost savings resulting from not needing a carbon source addition when treating wastewater with low C/N ratio. © 2021 Society of Chemical Industry

Nano-modified concrete at sub-zero temperatures: experimental and statistical modelling

In cold regions, concrete practitioners face challenges when trying to achieve quality results with concrete produced under low temperatures. The addition of nano-silica, which has vigorous reactivity, to concrete can produce mixtures with a dense microstructure and improved hardened properties under cold temperatures. Thus, this research focused on gaining a fundamental understanding of the performance of nano-modified concrete which was mixed, cast and cured at a temperature of −5°C, without any method of heating or insulation. This study adopted the response surface method as a statistical modelling approach to assess the effect of different parameters on the performance of 28 mixtures. Four factors were implemented in this model – water/binder ratio, fly ash content (0–25%), nano-silica dosage (0–4%) and type of antifreeze admixtures – followed by optimisation scenarios. The mixtures’ performance was assessed based on multiple responses: initial and final setting times, early- and late-age compressive strengths and resistance to freezing–thawing cycles. In addition, mercury intrusion porosimetry, thermogravimetry and backscattered scanning electron microscopy were conducted to capture the microstructural evolution of the mixtures. Nano-modified mixtures with and without fly ash, especially with a low water/binder ratio (0·32) and high calcium nitrite content, showed promising performance when cast under cold weather conditions without any protection method.

453 Association of processed meat and sodium intake with atopic dermatitis in adults: A pooled analysis of three cross-sectional studies in China and validation in NHANES 2005-2006

Intake of processed food that contains high content of salt and nitrite are associated with poorer health outcomes. A recent study indicated that salt could stimulate Th2 cell differentiation in vitro experiment, and might link atopic dermatitis (AD). The study aimed to investigate intakes of processed meat, pickles, and estimated salt and nitrite with adult AD in three population-based studies among rural residents, civil servants, and workers in China. Intakes of processed meat and pickles during the past year were inquired through a food frequency questionnaire. Daily intake of salt was estimated according to food nutrition content and validated by urine sodium concentration-based estimates through the Tanaka equation. AD was ascertained by dermatologists during the field survey. NHANES 2005-2006 data was used to validate the results. AD in NHANES was defined as self-reported eczema with elevated IgE levels (>333 IU/ml). A mixed model was used to deal with the intra-cluster correlation, and to estimate the effect size in terms of adjusted odds ratio (AOR). A total of 15062 Chinese participants was analyzed. Intake of pickles for at least 1 time per week was associated with AD (AOR=1.35; 95% CI: 1.06–1.70). Intake of processed meat for at least 1 time per week was associated with AD (AOR=1.44; 95% CI: 1.11–1.87). In NHANES 2005-2006, intakes of bacon (AOR=4.47; 95% CI: 1.21–16.6) and sausage (AOR=8.59; 95% CI: 2.03–36.4), but not pickles (AOR=0.55; 95% CI: 0.07–4.67) for at least 3 times per week, were significantly associated with AD. In both Chinese and US population, cubic spline showed that the estimated daily sodium intake was linearly associated with the risk of AD. Processed meat, possibly through a mechanism involving sodium, may increase the risk of AD in adults.

Study on the Change of Nitrite Content of Yutang Pickles under Different Storage Conditions

Objective: To study the determination conditions of nitrite in pickles by spectrophotometry, select the best experimental conditions, determine the content of nitrite in pickles under different storage conditions, and find a better storage method for pickles. Methods: A certain amount of pickle was homogenized. Saturated boric acid and deionized water were added. The water bath was cooled to room temperature. Potassium ferrocyanide and zinc acetate were added and filtered to obtain a backup filtrate. The nitrite was used as a standard to determine the pickle sample solution at 538 nm. Absorptance at place. Results The nitrite concentration of the sun-dried sample: 1.8435 mg/kg dry; 0.3441 mg/kg with pickling solution; the nitrite concentration of the indoor light sample during the day: 0.5462 mg/kg dry; 0.2048 mg/kg with pickling solution; Nitrite concentration of samples in cabinets protected from light: dry 1.84 mg/kg; with pickling solution 1.2973 mg/kg; nitrite concentration of samples at high temperature (27 °C): 1.2973 mg/kg; room temperature (20 °C) samples Nitrate concentration: 0.7511 mg/kg; Nitrite concentration at low temperature (7 °C): 0.2048 mg/kg. Conclusion: The dry sample has a higher nitrite content than the pickled solution sample, the dark sample has a higher nitrite content than the strong light sample, and the high temperature sample has a higher nitrite content than the low temperature sample. Therefore, storage conditions such as pickling solution, proper light and low temperature are selected.

Evaluation of physicochemical properties and volatile compounds of Chinese dried pork loin curing with plasma-treated water brine

The application of dielectric barrier discharge cold plasma (DBD-CP)-treated water as a novel curing process for manufacturing Chinese dried pork loin was investigated. The treatment time of DBD-CP was optimized based on the pH and nitrite level of the plasma-treated water (PTW). PTW treated for 3 min had an alkaline environment and a higher nitrite content than that at the other lengths of treatment time. Pork loins were marinated in control or PTW brine at 4 °C for 24 h and then dry-ripened for 15 days. PTW with a higher treatment voltage significantly decreased lipid oxidation of the products and led to an increased a* value (redness) and an increased residual nitrite content in products that was still within the range of use (all P < 0.05). The contents of each free amino acid increased with increasing treatment intensity (P < 0.05). There were 22 new volatile compounds generated in PTW-cured products, such as 3-methyl-butanol, hexanal and 2,3-octanedione, while six substances were lost, such as 2-pentylfuran, compared with those in the control. This study indicates that using PTW as a curing method can be a potential and effective way of producing dried pork meat products.

Isolation of nitrite-degrading strains from Douchi and their application to degrade high nitrite in Jiangshui.

Excessive nitrite in food is potentially harmful to human health because of carcinogenic effects caused by its nitroso-derivatives. Douchi, which widely distributed throughout the country, is a traditional solid fermented soybean food with low nitrite content. In this study, bacteria which can degrade nitrite were isolated from Douchi and identified from their 16S rDNA sequences. Acinetobacter guillouiae, Acinetobacter bereziniae, Bacillus subtilis, Bacillus tequilensis, Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus aryabhattai and Bacillus methylotrophicus were selected. It was shown that all strains were able to degrade nitrite to some extent, including Bacillus subtilis NDS1, which was able to degrade 99.41% of nitrite. The enzyme activities of these strains were determined at 24 and 48 h and were shown to correspond with their nitrite degradation rates. The strains were used to inoculate Jiangshui, a kind of traditional fermented vegetable from northwest China that often has a high nitrite content. Of the strains tested, Bacillus subtilis NDS1, Bacillus tequilensis NDS3, Acinetobacter bereziniae NDS4, Bacillus subtilis NDS6, and Bacillus subtilis NDS12 were able to degrade nitrite in Jiangshui more rapidly, with Acinetobacter bereziniae NDS4 degrading almost all nitrite in 48 h compared with 180 h of control. These results indicate that the selected strains have potential to be used as nitrite-degrading agents in food. © 2018 Society of Chemical Industry.

Comparative transcriptome analysis reveals the gene expression profiling in bighead carp (Aristichthys nobilis) in response to acute nitrite toxicity

ObjectiveNitrite exposure induces growth inhibition, metabolic disturbance, oxidative stress, organic damage, and infection-mediated mortality of aquatic organism. This study aimed to investigate the mechanism in responses to acute nitrite toxicity in bighead carp (Aristichthys nobilis, A. nobilis) by RNA-seq analysis. MethodsBighead carps were exposed to water with high nitrite content (48.63 mg/L) for 72 h, and fish livers and gills were separated for RNA-seq analysis. De novo assembly was performed, and differentially expressed genes (DEGs) between control and nitrite-exposed fishes were identified. Furthermore, enrichment analysis was performed for DEGs to annotate the molecular functions. ResultsA total of 406,135 transcripts and 352,730 unigenes were tagged after de novo assembly. Accordingly, 4108 and 928 DEGs were respectively identified in gill and liver in responses to nitrite exposure. Most of these DEGs were up-regulated DEGs. Enrichment analysis showed these DEGs were mainly associated with immune responses and nitrogen metabolism. ConclusionsWe suggested that the nitrite toxicity-induced DEGs were probably related to dysregulation of nitrogen metabolism and immune responses in A. nobilis, particularly in gill.

Fermented garlic extract decreases blood pressure through nitrite and sGC-cGMP-PKG pathway in spontaneously hypertensive rats

Garlic (Allium sativum L.) has long been used as an anti-hypertensive. The study investigated the effect of fermented garlic extract (Fgarlic) on systolic blood pressure (SBP) and its molecular basis using spontaneously hypertensive rats (SHRs). Fgarlic contained high content of stable nitrite (0.975 mg nitrite/ml). Acute feeding of different amounts (0.3, 0.6, and 0.9 ml) of concentrated Fgarlic (9.75 mg nitrite/ml) reduced SBP dose-dependently. Chronic feeding of Fgarlic (containing 27 mg nitrite/day) for 12 days reduced SBP with increased expressions of eNOS and PKG proteins in aortic tissues, which were attenuated by a soluble guanylyl cyclase (sGC) inhibitor. The relaxation responses of thoracic aorta to acetylcholine and sodium nitroprussside were improved in SHRs fed Fgarlic. These results suggest that nitrite in Fgarlic, which converts to NO in the body, functions as an anti-hypertensive molecule and its effect is mediated through sGC-cGMP-PKG pathway.

惠州梅菜的营养与安全研究

梅菜是广东惠州的特产，具有消食健胃、降脂、降压等保健功效，深受大众喜爱。传统梅菜腌制需食盐量大，长期食用易导致高血压。另外其传统加工条件恶劣，亚硝酸盐含量较高，难以满足现代消费者对健康食品的要求。本文主要从梅菜的营养与降低亚硝酸盐的方法这两方面进行综述以期为梅菜的研究与加工提供一定的参考。 Meicai vegetable as a specialty of Guangdong Huizhou has health effect of digestive, lipid-lowering, antihypertensive and is loved by people. The much salt during the traditional pickling can lead to high blood pressure for people who consume it for a long time. Moreover, the harsh processing conditions and high content of nitrite are difficult to meet the requirements of modern consumers for health food. This article mainly reviews the plum food nutrition and nitrite reduction methods to provide certain reference for the preserved vegetable research and processing.

Preliminary nitrite, nitrate and colour analysis of Malaysian edible bird’s nest

The high nitrite content in edible bird’s nests is a major concern to the local swiftlet industry. It lowers the price of the edible bird’s nests and it brings severe health hazards to consumers and farmers. This research investigated the nitrite and nitrate contents of eight types of local edible bird’s nests by using ion chromatography system and evaluating its colour using the CIE system in L∗a∗b∗ parameters. The nitrite content obtained ranged from 5.7μg/g for the house nests to 843.8μg/g for the cave nests. The nitrate content for the house and cave nests was 98.2μg/g and 36,999.4μg/g, respectively. The cave nests with darker and redder colour had higher nitrite and nitrate contents than the brighter and more yellow house nests. This likely suggests that the nitrite and nitrate contents have correlations with edible bird’s nests colour. Correlations studies suggested that the nitrite content had high correlations with colour parameters, L∗a∗b∗ of edible bird’s nests at significant level of P<0.10. These findings suggest that edible bird’s nests’ colour may be a useful indicator for measuring nitrite and nitrate contaminations.

Improvement of fermented Chinese cabbage characteristics by selected starter cultures.

Traditional fermented vegetables have inconsistent quality and high nitrite content, whereas a commercial starter culture could overcome these problems. A total of 34 lactic acid bacteria strains were screened from 2 homemade naturally fermented Chinese cabbages. Fermented characters of single starter or mixed cultures were examined, including acidification, growth rate, and nitrite depletion ability in the fermented culture. As a result, the combined starter culture (Lactobacillus delbrueckii IWQ and Lactobacillus paracasei J21) was selected. The fermented Chinese cabbage resulted from this mixed starter culture had higher sugar content residue (30.5 mg/mL for mixed culture and 22 mg/mL for control). And the titratable acid of the cabbage fermented by the mixed starter was 110°T, which was twice higher than that of control sample. The selected starter culture also had a better texture and sensory qualities than that the starter cultures from a local fermented Chinese cabbage plant, especially for its significantly lower nitrite content (3.00 mg/kg for mixed culture and 4.49 mg/kg for control). The findings of this study form a database for further studies on the development of starter cultures for fermented cabbage production and could replaced the local plant starter culture. LABs were screened from traditional fermented food. The fermented characteristics of selected LABs were better than that of starter cultures from a local Chinese cabbage plant. Selected LAB can decrease nitrite content in fermented cabbage. The Chinese cabbage fermented by the selected LAB had the good flavor and texture.

Phytotoxic effects of fungicides, insecticides and nonpesticidal components on pepper depending on water quality

Modern agriculture relies on simultaneous application of fungicides, insecticides, fertilizers and adjuvants. The selection of compounds for tank-mixes has been rarely studied and it presents a risk in the application of pesticides but the quality of water should also be considered. The aim of this study was to assess the phytotoxic effects of several fungicides, insecticides, a complex fertilizer, an adjuvant and their mixtures on pepper (Capsicum annuum L.) as a test plant, depending on water quality. The effects of the pesticides: azoxystrobin (Quadris, 0.75 l/ha), mancozeb (Dithane M-70, 2.5 kg/ha), thiamethoxam (Actara 25-WG, 0.07 kg/ha) and cypermethrin (Cipkord EC-20, 0.3 l/ha), a complex fertilizer (Mortonijc plus /hereinafter: M+/ 3kg/ha), an adjuvant (Sillwet 77-L, 0.1 l/ha) and their mixtures, were assessed depending on the quality of water (well water - slightly alkaline, very hard and with high nitrite content; tap water - neutral and slightly hard; surface water - alkaline, slightly hard and with high content of nitrite and ammonia) using a puncture method. The effects were assessed after seven days by measuring the diameter of chlorosis and/or necrosis around puncture sites, and were expressed in mm2. The significance of differences between treatments was analyzed using a one-way ANOVA (LSD 0.05 %). In the slightly alkaline and very hard well water, all spray liquids containing Dithane M-70 caused a significant increase in leaf chlorosis area (from 6.0 to 25.2 mm2), compared to the control and other treatments. In the neutral and slightly hard tap water, all spray liquids containing Dithane M-70 caused a significant increase in leaf chlorosis (5.3 to 7.9 mm2) compared to the control and the other spray liquids, although its phytotoxicity in that water was at a lower level than it was in well water. However, in the weakly alkaline and slightly hard surface water from the river Sava, Dithane M-70, Dithane M-70 + Actara WG-25, Dithane M-70 + Sillwet L-77, and Dithane M-70 + Actara 25-WG + M+ showed a significant increase in phytotoxicity, compared to the control.