Preparation of optically active trifluoromethylated (3'-indolyl) thiacarboxylic acids, novel plant growth regulators, through lipase-catalyzed enantioselective hydrolysis

Among a variety of lipases tested, that obtained from Candida antarctica (SP 435) induced enantioselective hydrolysis of trifluoroethyl 5,5,5-trifluoro-4-(3'-indolyl)-3-thiapentanoate (1c). The selectivity could be increased by optimizing the reaction conditions. Thus, good selectivity was achieved (E = 37) in a buffer containing 10% dichloroethane. In order to improve the optical yields, a sequential kinetic resolution was utilized for the preparative-scale enantioselective hydrolysis of 1c using SP 435. Hydrolysis of trifluoroethyl 6,6,6-trifluoro-5-(3'-indolyl)-4-thiahexanoate (2c) with the lipase of Pseudomonas aeruginosa (LIP) in a buffer containing 20% tert-amyl alcohol at 25 degrees C gave excellent selectivity (E=357).     

Efficacy of the insect growth regulators methoprene, fenoxycarb and diflubenzuron against Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) on maize and paddy rice

The activity of fresh deposits of methoprene, fenoxycarb and diflubenzuron against F₁ progeny of Rhyzopertha dominica on maize and paddy was compared with that on wheat, at two equilibrium relative humidities. There were differences between slopes of log concentration-probit (lc-p) lines for different compounds, and for the same compound on different grains. Judging by values of the IC_99.9, i.e. the concentration which inhibited progeny production by 99.9%, the order of activity against F₁ progeny on different grains was: methoprene, wheat and paddy > maize; fenoxycarb, wheat > paddy > maize; diflubenzuron, wheat and maize > paddy. Equilibrium relative humidity (e.r.h.) had no consistent effect on activity—at 90% e.r.h., the IC₅₀ of fenoxycarb on wheat was reduced and the IC₅₀ of diflubenzuron on maize was increased compared with 70% e.r.h., and other treatments were unaffected.

The efficacy of these compounds on maize and paddy against F₁ and F₂ progeny was evaluated during 48 weeks storage at 30°C, 70% r.h. The resolved S isomer of methoprene was also included. Slopes of lc-p lines were greater against the F₂ than against the F₁, particularly using diflubenzuron on paddy, with corresponding smaller values of the IC_99.9. Equally effective concentrations did not decline systematically over 48 weeks. Minimum effective application rates were judged as the concentrations that prevented living F₂ progeny in at least 2 of 3 replicates. Estimates for 48 weeks protection on maize were: methoprene, 2 mg kg⁻¹; S-methoprene, 1 mg kg⁻¹; fenoxycarb, 10 mg kg⁻¹; and diflubenzuron, 5 mg kg⁻¹. Corresponding estimates on paddy were 0.15 mg kg⁻¹, 0.05 mg kg⁻¹, 5 mg kg⁻¹, and 5 mg kg⁻¹.     

Effects of explant source,culture medium: Strength and growth regulators on the in-vitro propagation of three Jamaican yams: (Dioscorea cayenensis,D trifida and d rotundata)

Explants of tuber, meristem and vines from three widely cultivated yam species in Jamaica—D cayenensis, D rotundata and D trifida—were examined for their responses to mineral media strength, inorganic ammonium and growth regulator supplements. Tuber pieces (5mm³) showed some positive growth responses but did not produce in-vitro plantlets on all the media tested. Meristem tips of D trifida grew rapidly on basal media (BM) supplemented with either 0.1 mglitre^?1 6-benzylamino purine (BAP) and 0.01 mg litre^?1indole butyric acid or 0.2 mg litre^?1 BAP and 1.0 mg litre^?1 naphthalene acetic acid (NAA) producing plantlets by 28 weeks. The nodal explants grew rapidly with plantlets obtained from all the cultivars within 4 weeks. Use of young, vigorously growing vines of 8 weeks or less, as explant source, gave low contamination levels (16–25%) in culture when sterilised for 30 min in 200 g litre^?1 NaOCl in the case of D trifida and 300 g litre^?1 NaOCl in the case of D cayenesis prior to culturing. Initiation of growth was optimal when explants were taken from monopodial vines grown in October or January and placed on BM supplemented with 0.5 mg litre^?1 BAP (BM0.5BAP). Addition of 0.5 mg litre^?1 kinetin to the BM or 0.05 mg litre^?1 NAA to BM0.5BAP depressed shoot production, while 5.0 mg litre^?1 kinetin increased swelling of the nodal region in explants from sympodial shoots and from vines grown in March. The results suggest that nodal segments excised from young, fast growing vines of these species are the best explant source for the purpose of commercial micropropagation.     

Pulsed electric field (PEF) application on wheat malting process: Effect on hydration kinetics,germination and amylase expression

Wheat malt has been widely used in food industry as an important source of endogenous enzymes, such as amylases. However, malting is a time-consuming process. Thus, this work proposed pulsed electric field (PEF) application to enhance wheat hydration, germination and amylase expression. Two-step hydration of Hendrix wheat variety was studied. PEF treatments (3 kV·cm⁻¹; total energy applied of 9.9 and 19.8 kJ·kg⁻¹) were applied with wheat in the water at the beginning or after the first hydration cycle. Hydration curves were accurately described by the Weibull exponential model (R²adj > 0.98). The more intense PEF treatments enhanced hydration rate (25%), water holding capacity (15%) and germination parameters when applied before the first hydration cycle. PEF enhanced α- and β-amylase activity by up to 104% and 25%, respectively, compared to control. Therefore, PEF can be used as a clean emerging technology to improve the malting process and malt quality.Industrial relevanceGrowing concerns have gained attention regarding the use of synthetic enzymes or higher amounts of natural resources to perform enzymatic process to food applications. Malting cereals represents a clean technology to provide natural enzymes from natural resources, even though it is still considered a time- and energy-consuming method. In this sense, the use of pulsed electric fields (PEF) demonstrated to be a green and efficient technique to enhance the overall wheat malting process. Besides improving the process kinetics, the enzymatic activity and, thus, the quality of the final malt can be also improved. Because of that, malting producers can process wheat more rapidly to obtain more efficient ingredients when incorporating PEF to their processes. On the other hand, brewery and baking sector can use wheat malt stimulated by PEF as raw material with comparable technological effects as conventional malts, but in lower amounts instead.     

Fate, partitioning, and mass loading of polybrominated diphenyl ethers (PBDEs) during the treatment processing of municipal sewage

Sewage treatment plant (STP) effluents are likely a major source of contamination for PBDEs, especially in the receiving water bodies of local aquatic environments surrounding the location of these discharges. Congeners of the pentaBDE mixture, 2,2,',4,4'-tetrabromodiphenyl ether (BDE47), 2,2,',4,4',5-pentabromodiphenyl ether (BDE99), 2,2,',4,4',6-pentabromodiphenyl ether (BDE100), 2,2,',4,4',5,5'-hexabromodiphenyl ether (BDE153), and 2,2,',4,4',5,6'-hexabromodiphenyl ether (BDE154), are of great environmental concern in North America due to their persistence, potential for bioaccumulation, and >97% use of the global production of the mixture in the region. Detailed characterization of the distribution of eight PBDE congeners (2,4,4'-tribromoDE (BDE28) and BDE47, 99, 100, 138, 153, 154, and 183) was carried out at five sites along the treatment process at an activated sludge-type secondary treatment municipal STP facility. PentaBDE mixture congeners, sigma5PBDE (sum of BDE47, 99, 100, 153, and 154) accounted for >98% of the total (sigma 8) PBDE concentration at all sites, with over 80% of the composition being BDE47 and BDE99. Presence of dissolved organic matter affected the mobility of PBDEs during the initial stages of the treatment process. About 9% of the influent mass of sigma5PBDE to the facility is estimated to be discharged into the Little River (leading to the Detroit River) with the final effluent, resulting in an estimated mass loading of approximately 0.7 kg/year. The total mass loading of sigma5PBDE to the Detroit River is expected to be much larger as effluent from this facility accounts for <10% of the total STP discharges to the river.     

Effect of corona wind,current, electric field and energy consumption on the reduction of the thawing time during the high-voltage electrostatic-field (HVEF) treatment process

Electric energy plays an important role in reducing the thawing time and accelerating the entire thawing process. Corona wind speed was increased by increasing the applied voltage and current, which were 0.87 ± 0.19, 1.22 ± 0.19, 1.49 ± 0.13 m/s under 8, 10, 12 kV with 3, 5, 10 μA; 1.01 ± 0.12, 1.24 ± 0.17, 1.49 ± 0.10 m/s under − 8, − 10, − 12 kV with 5, 9, 14.5 μA. The models T1, T2, and T3 were designed to study the effects of current, corona wind and electric field on thawing, respectively. T1: a thin stainless-steel sheet covered the top of stainless-steel box with 10 g frozen distilled water; T2: a plastic sheet was placed under the stainless-steel box; T3: a plastic sheet covered the top of plastic box. Electric field alone cannot affect thawing time, which could be maximally reduced by 1/2 compared to that of air thawing.Industrial relevanceWe have studied HVEF thawing for several years because of its many advantages, such as the quick thawing of frozen meat with little energy consumption and good post-thawing quality. The mechanism of HVEF thawing and the reduction of the thawing time, which are important for the industrial application of new technology from principle to design, must be clarified. Meanwhile, this emerging technology will be beneficial for the food-thawing field.     

Dissipation kinetics of forchlorfenuron, 6-benzyl aminopurine,gibberellic acid and ethephon residues in table grapes (Vitis vinifera)

The residue dynamics of plant growth regulators (PGR) forchlorfenuron (CPPU), 6-benzylaminopurine (6-BA), gibberellic acid (GA₃) and ethephon in grape are presented, corresponding to their field applications at recommended and double doses. Random samples were collected from each treated and control plot at regular time intervals. The optimised sample preparation technique involves extraction of 10 g homogenised sample with 20 ml methanol (+1% formic acid) and measurement by LC–MS/MS multiple reaction monitoring, offering limit of quantification ?0.0025 μg/g for all except ethephon with LOQ of 0.005 μg/g. The recoveries at LOQ and above were 84.8–109.5%. Residue dissipation of all the PGRs followed non-linear two-compartment first + first-order kinetics. CPPU, 6-BA and ethephon residues dissipated with preharvest intervals (PHIs) of 33.5, 12 and 32 days at recommended dose with no PHI applicable for GA₃. The PHIs successfully minimised residue problems as observed from survey results of traceable field samples.     

Influence of plant growth regulators on key-coding genes expression associated with phytochemicals biosynthesis and antioxidant activity in soybean (Glycine max (L.) Merr) sprouts

The present study was aimed to investigate the effect of plant growth regulators (PGRs) on phytochemicals biosynthesis and antioxidant activity in soybean sprouts. _GmVTC2, _GmDHAR and _GmGLDH were investigated for the biosynthesis of vitamin C. _GmPAL, _GmCHS and _GmIFS were investigated for the biosynthesis of phenolics, flavonoids and isoflavones. Our results revealed that 6-benzylaminopurine (6-BA) treatment significantly affected the expression levels of those major genes, followed by Gibberellin (GA3) and Naphthaleneacetic acid (NAA). Moreover, the highest levels of vitamin C, polyphenolics and antioxidant activity in 6-BA and GA3 treated groups indicate the synergistic and antagonistic role of growth regulators in the biosynthesis of phytochemicals. Overall, 6-BA seems the key contributor in genes’ expression involve in the biosynthesis secondary metabolites and their antioxidant activity. Therefore, it could be the most suitable option to enhance nutritional quantity and health benefits of soybean sprouts.     

Effects of the rootstock Ramsey (Vitis champini) on ion and organic acid composition of grapes and wine, and on wine spectral characteristics

The influence of Ramsey, used as rootstock of the scion cvs Muscat Gordo Blanco (syn. Muscat of Alexandria), Shiraz (syn. Syrah), Riesling, Cabernet Sauvignon and Chardonnay, on the characteristics of the grape berries and of wine made from them was investigated, comparing ‘own-rooted’ and ‘grafted’, and comparing wine fermented as juice (without skins) and must (juice and skins). The study involved the partitioning of K+ within berries, changes in juice K+, malic and tartaric acid through fermentation, wine inorganic ion and organic acid composition, and wine spectral characteristics. K+ concentration was higher in berries from grafted than from own-rooted for all varieties except Chardonnay, and highest for grafted Shiraz. It was higher in skin than in pulp and seeds. In the pulp, it was highest for grafted Shiraz. K+ concentrations in all ferments using must (i.e. juice plus skins) increased during the initial two days after crushing, with the increase reflecting extraction from skins, being greatest for Shiraz and Muscat Gordo Blanco. Tartaric acid concentration in must also increased during the initial two days after crushing and then decreased. Malic acid concentration was higher in juice of Ramsey-grafted than own-rooted vines, especially for Shiraz; concentrations did not change markedly during the initial 12 days of fermentation, except where malo-lactic fermentation occurred. Wine made from grapes of grafted contained significantly less tartaric and more malic acid than that made from own-rooted for all varieties and for both fermentation types, with the exception of tartaric acid in wine of Muscat Gordo Blanco fermented as must. Wine made from juice had significantly higher tartaric acid and lower malic acid than that made from must for all varieties except for tartaric acid in wine from grafted Shiraz and malic acid in own-rooted Chardonnay. Wine had a smaller tartaric acid/malic acid ratio when made from must. Wine pH was positively correlated with K+ but negatively with tartaric acid and with the tartaric acid to malic acid ratio. Overall, Shiraz wine contained highest Cl?, Na+ and K+ concentrations. Red wines obtained from grafted had higher colour hue, especially those from Shiraz. Wines made from fruit borne on own-rooted Cabernet Sauvignon had the highest concentration of total anthocyanins, ionised anthocyanins and total phenolics.     

A study of the ice crystals in vacuum-packed salmon fillets (Salmon salar) during superchilling process and following storage

The aim of this work was to study the microstructure of vacuum-packed salmon fillets superchilled in an impingement freezer at −30 °C (air temperature) and 227 W/m² K (surface heat transfer coefficient, SHTC) for 2.1 min prior to storage at a superchilling storage temperature of −1.7 ± 0.3 °C for 28 days. The microstructure of vacuum-packed salmon fillets were analysed at the surface, mid-centre and centre layers. Significant differences were observed between the ice crystals formed at the surface, mid-centre and centre layers. The size of ice crystals at the centre of the superchilled fillets was 3 times larger than those at the surface layer. Significant differences were observed between the size of ice crystals formed during the superchilling process and following storage. The results further indicated that, after temperature equalisation (1 day of storage) the growth of the intracellular ice crystal was not significant at (P < 0.05) at any storage time.     

烟田斜纹夜蛾和甜菜夜蛾幼虫对几种药剂的敏感性研究

采用点滴法分别测定了12种药剂对斜纹夜蛾3龄幼虫及9种药剂对5龄幼虫的毒力,比较了不同龄期幼虫对6种药剂敏感性的差异,还测定了9种药剂对甜菜夜蛾4龄幼虫的毒力。结果表明几种药剂对斜纹夜蛾3龄幼虫的毒力大小顺序为甲维盐>茚虫威>定虫隆>毒死蜱>辛硫磷>氟虫脲>虫酰肼>丙溴磷>硫丹>多杀菌素>顺式氯氟氰菊酯>氟虫腈。对5龄幼虫的毒力大小顺序为甲维盐>溴虫腈>茚虫威>灭多威>高效氟氯氰菊酯>毒死蜱>丙溴磷>辛硫磷>硫丹。斜纹夜蛾大龄幼虫对毒力高的药剂更敏感,小龄幼虫对毒力低的药剂较敏感。溴虫腈、氟虫脲对甜菜夜蛾4龄幼虫的毒力最高,但该虫对辛硫磷、丙溴磷、毒死蜱和硫丹表现不敏感。溴虫腈、茚虫威和甲胺基阿维菌素苯甲酸盐是防治上述两种害虫的高效药剂。     

Yield improvement in Rubberwood sawmilling through the saw, dry and rip (SDR) technique

The volume recovery, product quality and process economics of Rubberwood sawmilling using the conventional live sawing process and the saw dry and rip (SDR) process is described. The results showed that the SDR process, together with high temperature drying resulted in higher volume recovery and product quality compared to the conventional live sawing process.     

Residues of azoxystrobin, fenhexamid and pyrimethanil in strawberry following field treatments and the effect of domestic washing

Residues of the pesticides azoxystrobin, fenhexamid and pyrimethanil were determined in strawberry after field treatment. The effect of 'home' washing with tap water and a commercially available vegetable detergent on residue levels was also studied. After treatment, azoxystrobin and pyrimethanil residues on strawberry were on average 0.55 and 2.98 mg kg^-1, respectively, values below the maximum residue level (MRL) fixed by the European Union (2.0 and 5 mg kg^-1, respectively), while fenhexamid residues were on average 2.99 mg kg^-1, which is very close to the MRL of 3.0 mg kg^-1, but some samples were over the MRL. Thereafter, all residues declined, with a half-life of about 8 days (azoxystrobin and fenhexamid) and 4.8 days (pyrimethanil). Washing the fruit with tap water reduced the residues of azoxystrobin and fenhexamid but did not affect pyrimethanil residues. Finally, when fruits were washed with a commercial detergent, greater amounts were removed (about 45% of azoxystrobin and pyrimethanil and 60% of fenhexamid).     

快大液肥对烤烟生长及产质量的影响

在常量施肥的基础上,苗期和大田期叶面喷施或穴施快大液肥,能改善烟叶生长状况,促使烟苗生长健壮,烟株根系发达,生长旺盛,开片良好,烟叶产量,均价,产值有不同程度的提高;烟叶钾含量增加,含氮化合物下降,刺激性减小,香气增加。     

The effect of sowing date and growth stage on the essential oil composition of three types of parsley (Petroselinum crispum)

Essential oils obtained by simultaneous distillation–extraction (SDE) from leaves, petioles and roots of three types of parsley (turnip‐rooted, plain leaf and curly leaf type), sown on three different dates, were analysed by GC‐MS (gas chromatography–mass spectrometry) analysis. Parsley plants were found to produce mainly β‐phellandrene, 1,3,8‐p‐menthatriene, α‐,p‐dimethylstyrene, myristicin, β‐myrcene and apiole. In some cases α‐ and β‐pinene were also found, whereas β‐elemene was detected, especially in the curly leaf type. The growth stage, plant tissue and date of sowing, as well as the climate conditions, all had a significant effect on the essential oil composition by altering the ratio of the above substances. Copyright © 2004 Society of Chemical Industry     

Detection and quantification of the insect pest Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) in rice by qPCR

The early detection of insects during grain storage and processing remains a major issue for the cereal industry, especially when immature stages are hidden inside the grain kernels. For this reason, we developed a qPCR method to detect and quantify one of the main pests of stored products in rice: the coleopteran internal feeder Rhyzopertha dominica. For that purpose, a specific primer set was designed to amplify artificial infestations of this pest in rice. Then, using a regression model, a standard curve was generated that correlated individuals to adult equivalent DNA quantity (inverse of the C_t value). Results revealed that the designed primer set was specific for R. dominica when tested against the other 4 common internal feeders in grain. The technique showed to be accurated (DNA was detected in more than 73% of the samples) and sensitive to insect presence (i.e. from 0.02 adults, 0.1 3rd instar to pupae or 13 egg to 2nd instar detectable per kg of rice). Moreover, the detection of R. dominica was strongly associated with a given infestation size: DNA quantity increased along with the size of the population. The use of the described qPCR protocol in grain and milling factories may enhace the critical detection and quantification of R. dominica populations in raw materials and processed food.     

PBDEs, PBBs, and PCNs in three communities of free-ranging killer whales (Orcinus orca) from the northeastern Pacific Ocean

Polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and polychlorinated naphthalenes (PCNs) were quantified in blubber biopsy samples collected from free-ranging male and female killer whales (Orcinus orca) belonging to three distinct communities (southern residents, northern residents, and transients) from the northeastern Pacific Ocean. High concentrations of sigmaPBDE were observed in male southern residents (942+/-582 ng/g Iw), male and female transients (1015+/-605 and 885+/-706 ng/g Iw, respectively), and male and female northern residents (203+/-116 and 415+/-676 ng/g Iw, respectively). Because of large variation within sample groups, sigmaPBDE levels generally did not differ statistically with the exception of male northern residents, which had lower sigmaPBDE concentrations than male southern residents, male transients, and female transients, perhaps reflecting the consumption of less contaminated prey items. Male transient killer whales, which consume high trophic level prey including other cetaceans and occasionally spend time near populated areas, had sigmaPBDE concentrations approximately equal to southern residents. No significant age-related relationships were observed for sigmaPBDE concentrations. sigmaPBDE concentrations were approximately 1-3 orders of magnitude greater than those of sigmaPBB (3.0-31 ng/g Iw) and sigmaPCN (20-167 ng/g Iw) measured in a subset of samples, suggesting that PBDEs may represent a contaminant class of concern in these marine mammals.     

Effect of the stage of growth,wilting and inoculation in field pea (Pisum sativum L.) silages,III. Changes in the herbage and silage protein profiles

BACKGROUND: The effects of stage of growth, field wilting and inoculation with lactic acid bacteria (LAB) on the protein profile of herbage and silage were studied on field peas (Pisum sativum L.) harvested at four progressive morphological stages (end of flowering, I; beginning of pod filling, II; advanced pod filling, III; beginning of ripening, IV). The herbage was field wilted to a dry matter (DM) content around 330 g kg^?1, for each stage of growth. The unwilted and wilted herbages were ensiled with (I) and without (C) a LAB inoculant. RESULTS: As a result of the advancing maturity of the crop, the main protein component was Rubisco in the early stages and seed storage proteins in the more advanced stages, due to the redistribution of organic nitrogen during seed filling. Extensive degradation of Rubisco occurred in all the silages, without any effect of inoculation or wilting. A good preservation of the proteins was observed in stage IV for both unwilted and wilted silages, without further protein preservation due to LAB inoculation. CONCLUSION: Protein protection observed in the more mature pea silage was due to the protein type and its localization and not to the level of DM at ensiling or to the inoculation. Copyright © 2007 Society of Chemical Industry