小麦中嘧菌酯残留及膳食摄入风险评估

为对嘧菌酯在小麦生产上应用的安全性进行评价,采用田间试验,使用QuEChERS方法进行样品前处理,气相色谱法电子捕获检测器进行定量分析,对嘧菌酯在小麦中的残留动态及最终残留量进行了研究,并对小麦籽粒中嘧菌酯残留量进行了膳食摄入风险评估。结果表明,在0.01~1.0mg·kg~(-1)添加水平范围内,嘧菌酯在植株、籽粒空白添加的平均回收率为87.9%~108.4%,相对标准偏差为1.1%~6.2%,其最小检出量为5×10~(-12)g,植株、籽粒中的最低检测浓度均为0.01mg·kg~(-1)。该检测方法准确度、灵敏度高,重复性好,可满足嘧菌酯在小麦植株及籽粒中的残留分析要求。消解动态研究表明,嘧菌酯在小麦植株中的消解半衰期为3.3~4.3d。最终残留试验表明,20%嘧菌酯可湿性粉剂按施药剂量180、270g a.i.·hm~(-2),连续喷药2~3次,施药间隔7d,药后7、14、21d,嘧菌酯在小麦籽粒中的最终残留量均≤0.354mg·kg~(-1)。普通人群嘧菌酯的国家估算每日摄入量是2.43mg,占日允许摄入量的19.0%左右,因此,按本试验方式进行施药,不会对一般人群健康产生不可接受的风险。     

Effect of Cooking and Processing on CIPC Residue Concentrations in Potatoes and Processed Potato Products

Residue concentrations of the sprout suppressant chlorpropham (or CIPC) were determined in raw and cooked potatoes and processed potato products, 48 h after CIPC aerosol treatment and after 30 days of subsequent storage at 4 or 12 °C. In the raw (uncooked) tuber, 48 h after CIPC treatment, the CIPC residue in the peel was 4.7 mg kg^-1, while in the peeled tuber it was 0.1 mg kg^-1. Boiling resulted in a decrease in residue concentration in the peel, but no significant differences in the residue concentration of the peeled tuber were observed. Pressure cooking resulted in a significantly increased residue concentration in the peel, but no significant change in the peeled tuber, whereas microwave cooking also did not increase the residue concentration in the peel significantly compared with that in raw tubers. Also the trend towards increases in residue concentration in microwave-cooked peeled tubers was not significant. The CIPC residue concentration detected in peeled tubers was 0.4–0.7 mg kg^-1 after boiling, 0.4–1.5 mg kg^-1 after pressure cooking and 0.4–3.8 mg kg^-1 after microwave cooking. The highest values were always found for tubers stored for 30 days at 4 °C. Processed products such as crisps, French fries, dehydrated sliced potatoes and starch contained different concentrations of CIPC residue, which was also detected in the cooking water and frying oil. The highest residue concentrations detected were 0.7, 4.7, 1.3 and 0.2 mg kg^-1 in crisps, French fries, dehydrated sliced potatoes and starch, respectively. The highest CIPC residue concentration observed in raw potatoes was much lower than the maximum residue level of 10 mg kg^-1 prescribed by the European Union.     

Effect of Cultivar, Year Grown, and Cropping System on the Content of Tocopherols and Tocotrienols in Grains of Hulled and Hulless Barley

In a three-year period (2000–2002) total tocols (tocopherols and tocotrienols), content of vitamin E and its isomers (α-, β+γ-, δ-tocopherols and tocotrienols) were assessed in grain of 13 barley genotypes. The highest content of tocols (60.3–67.6 mg kg⁻¹) and content of vitamin E (Vitamin E equivalent—18.0–20.1 mg kg⁻¹) were determined in the waxy varieties Wanubet, Wabet, and Washonubet. Standard varieties, i.e. of a malting type (Krona and Kompakt), had statistically significantly lower content of tocols (49.9 and 53.6 mg kg⁻¹) and vitamin E (15.7–16.1 mg kg⁻¹) compared to the waxy varieties. The hulless waxy variety Washonubet had statistically significantly higher total content of tocols (67.6 mg kg⁻¹) and α- tocotrienols isomer (42.1 mg kg⁻¹) versus all other genotypes in the set. Chemical treatment and fertilization statistically significantly increased the content of tocols (by 4.7 mg kg⁻¹), vitamin E (by 1.9 mg kg⁻¹), isomer α-tocopherol (by 0.9 mg kg⁻¹) and isomer α- tocotrienols (by 3.3 mg kg⁻¹). The average values of α-tocopherols and α-tocotrienols in the set were 6.7 mg kg⁻¹ and 29.7 mg kg⁻¹, respectively. Some of the reciprocal lines created by us from the malting and waxy varieties are suitable for food use for high contents of all tocopherols and α-tocotrienols.     

萎锈灵在大麦和土壤中的残留及安全性评价

为探明萎锈灵在大麦上的残留特性和安全性,通过田间试验和室内检测,研究了萎锈灵在大麦和土壤中残留的检测方法、萎锈灵在土壤中的消解动态及其在大麦和土壤中的最终残留量。结果表明,本检测方法对萎锈灵的最小检出量为0.002ng,萎锈灵在大麦植株、籽粒和土壤中的最低检测浓度分别为0.005、0.002、0.001mg·kg~(-1),添加回收率分别为78.9%~94.0%、92.4%~98.6%和90.6%~101.3%;相对标准偏差分别为1.3%~7.9%、1.8%~4.7%和0.9%~4.8%。萎锈灵在土壤中的半衰期为6.5~7.1d,药后14d消解率大于93%。400g·L~(-1)萎锈·福美双悬浮剂120、180g a.i.·100kg~(-1)种子拌种,收获期大麦籽粒中萎锈灵残留量均低于0.002mg·kg~(-1),说明400g·L~(-1)萎锈·福美双悬浮剂在大麦上使用是安全的。     

Studies on potato sprout suppressants. 5. The effect of chlorpropham contamination on the performance of seed potatoes

Summary Potatoes of cv. Désirée and Pentland Crown, treated in February at 0, 0.6, 1.2, 2.5, 5, 10, and 20 mg kg¹ chlorpropham adsorbed on alumina, were sampled for analysis immediately before planting at the beginning of May. Chlorpropham was extracted using hexane as the solvent in the presence of anhydrous sodium sulphate. Emergence and yield data showed that low levels of chlorpropham (<0.3 mg kg⁻¹) that had little effect on total emergence, increased the mean emergence time and reduced yield. High levels of chlorpropham drastically reduced total emergence and yield.

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Zusammenfassung Chlorpropham (Isopropyl-N-(3-chlorophenyl) carbamat) ist ein weitverbreitetes Keimhemmungsmittel, das niemals bei Pflanzkartoffeln angewendet wird, da es ein die Zellteilung hemmendes Gift ist. Zuf?llige Kontamination kann jedoch erfolgen und es war daher der Sinn dieses Versuches, die Mengen an Chlorpropham zu bestimmen, die nachweislich den Auflauf, den Ertrag und die Gr?ssenverteilung der nachfolgenden Ernte beeinflussen. Zwei Proben von je 7,5 kg der Sorten Désirée und Pentland Crown wurden mit Chlorpropham in den Aufwandmengen von 0, 0,6, 1, 2, 2,5, 5, 10 und 20 mg/kg best?ubt. Nach der Lagerung bei 10°C in fest verschliessbaren Beh?ltern wurden sie zwei Wochen vor dem pflanzdatum vorgekeimt und 1 kg für die Rückstandsanalysen abgenommen. Der Rest wurde gepflanzt und Auflauf und Ertrag bestimmt. Die Extraktion von Chlorpropham erfolgte nach der Methode von Cerny & Blumenthal (1972) und es wurde eine neue Reinigungsmethode entwickelt, die den Einsatz eines Gaschromatographen mit einem Flammenionisationsdetektor erlaubt. Tabelle 1 zeigt die Rückstandswerte und die entsprechenden Angaben für den Feldbestand. Der Einfluss von Chlorpropham war bei der Sorte Pentland Crown deutlicher, aber allgemein verl?ngerten sehr kleine Rückstandswerte (<0.3 mg/kg) bereits die durchschnittliche Auflaufzeit und verringerten leicht den Ertrag, obwohl die gesamte Auflaufrate nahe bei 100% blieb. H?here Werte (0,3–1 mg/kg) verz?gerten den Auflauf und reduzierten den Ertrag. Rückst?nde über 1 mg/kg führten zu geringem Auflauf und einer drastischen Ertragseinbusse. Lagerh?user in denen Chlorpropham angewendet wird oder in denen behandelte Knollen gelagert werden sind offensichtlich Quellen der Kontamination mit geringen Mengen.

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Résumé Le chlorprophame (isoprophyl-N-(3 chlorophenyl) carbamate) est un inhibiteur de germination très employé mais jamais sur pomme de terre de semence parce que c'est un poison mitotique. Une contamination accidentelle peut avoir lieu et l'objet de cette expérimentation était de déterminer les taux de chlorprophame qui affectent de fa?on significative la germination, le rendement et la distribution par calibre de la culture suivante. Une expérimentation à 2 répétitions a été faite avec du chlorprophame par poudrage à différentes concentrations: 0, 0,6, 1,2, 2,5, 5, 10, et 20 mg/kg sur des échantillons de 7,5 kg pour les variétés Désirée et Pentland Crown. Ces échantillons ont été conservés à 10°C dans des bo?tes fermées hermétiquement et prégermés pendant 2 semaines avant la date de plantation tandis qu'un échantillon de 1 kg a été prélevé pour une analyse de résidus. Les tubercules restants ont été plantés et les notations de levée et de rendement ont été effectuées. La méthode de Cerny & Blumenthal (1972) a été employée pour extraire le chlorprophame et une nouvelle technique de lavage a été imaginé afin d'obtenir des échantillons adaptés á la chromatographie en phase gazeuse utilisant la détection thermoionique. Les teneurs en résidus et les notations au champ correspondantes sont indiquées dans le tableau 1. L'effet du chlorprophame était plus accentué pour les variétés Pentland Crown mais, en général, de faibles taux en résidus (<0,3 mg/kg) retardaient la durée de levée moyenne et réduisaient légèrement les rendements quoique la levée totale approchait 100%. Les taux de résidus plus élevés (0,3 → 1,0 mg/kg) retardaient également la levée et diminuaient les rendements. Les résidus supérieurs à 1,0 mg/kg provoquaient une mauvaise levée et des réductions sérieuses de rendement. Les locaux utilisés pour l'application du chlorprophame ou pour la conservation de tubercules traités sont indiscutablement des sources faibles de contamination.

     

Residues of free and bound maleic hydrazide in potato tubers

Summary The method of Vadukul (1991) for determining maleic hydrazide (MH) was modified and gave recoveries of free MH of 89%±4%. The values recorded on individual tubers ranged from 2–14 mg kg⁻¹. Maleic hydrazide was evenly distributed throughout the tuber (peel, outer and inner flesh) but concentration increased slightly as tuber size increased. The concentration of free MH decreased from 7 to 3 mg kg⁻¹ over the storage period of 5 1/2 months. Acid hydrolysis released substantial amounts of MH particularly from older potatoes (13 mg kg⁻¹) compared with 6 mg kg⁻¹ from new potatoes, implying that free MH is gradually converted to a bound form with time after treatment. No evidence was found for the presence of a β-glucoside of MH.     

Studies on potato sprout suppressants. 4. The distribution of tecnazene in potato tubers and the effect of processing on residue levels

Summary Tecnazene (1, 2, 4, 5-tetrachloro-3-nitrobenzene) treated potato tubers analysed by a gas chromatographic method were found to contain tecnazene residue levels ranging from 8.2 mg kg¹ near the surface of the tubers to approximately 0.2 mg kg¹ near the centre of the tubers. Residue levels in laboratory and commercially treated samples were examined at various stages during a commerical crisp manufacturing process. Peeling removed 85–95% of the total residue, leaving 0.14 0.21 mg kg¹ in the sliced sample. There was a further loss of tecnazene during the cooling stage. Frying increased the residue level to 0.55–0.60 mg kg¹ due to the effect of water loss. The final product after packaging contained 0.25 mg kg¹ tecnazene. The frying oil becomes contaminated with tecnazene whilst processing treated tubers and this contamination canbe transferred to untreated batches.

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Zusammenfassung Tecnazen (1, 2, 4, 5-Tetrachlor-3-Nitrobenzen) wird immer mehr von den Kartoffelverarbeitern verwendet, weil es die Wundheilung nicht hemmt und deshalb schon bei der Einlagerung der Knollen angewendet werden kann. Wegen dieser steigenden Verwendung wurde die vorliegende Untersuchung vorgenommen, um mehr Information zu beschaffen über die Tiefe, bis zu der Tecnazen in die Knolle eindringt, und über das Verhalten der Tecnazen-Rückst?nde w?hrend der Chips-Fabrikation. 10 mm dicke Schichten wurden wiederholt von Knollen entfernt, die mit Tecnazen bei empfohlener Dosis von 135 mg a.i. kg¹ behandelt und w?hrend 4 Monaten bei 10°C eingelagert wurden. Jede Schicht wurde dann mittels Gaschromatographie analysiert. Die sich daraus ergebenden Rückstandsgrade sind in Tabelle 1 aufgeführt. Die Einflüsse der Chips-Fabrikation auf die Rückstandsgrade wurden untersucht, indem in verschiedenen Stadien der verarbeitung von im Handel und im Labor behandelten Knollenpartien Muster entnommen wurden. Die Ergebnisse sind in Tabelle 2 aufgeführt. Es wurde festgestellt, das 85–95% des Gesamtrückstandes in einer Knolle durch Sch?len entfernt werden kann. Zurück bleiben 0.14 0.21 mg kg¹ in dem in Scheiben geschnittenen Muster. Backen erh?ht den Rückstandsgrad auf 0.55 0.60 mg kg¹ infolge des Wasserverlustes. Das Endprodukt eines Handelsmusters enthielt nach der Verpackung 0.25 mg kg¹ Tecnazen. Das Back?l wurde w?hrend der Verarbeitung von behandeltem Material mit Tecnazen verseucht, und diese Verseuchung wurde auf eine nachfolgende unbehandelte Partie übertragen.

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Résumé Le tecnazène (1, 2, 4, 5-tetrachloro-3-nitrobenzene) est de plus en plus utilisé par les industriels de la pomme de terre car il n'empêche pas la cicatrisation des blessures et peut donc être appliqué lors du remplissage des cellules de conservation. La présente étude a été entreprise en raison de cet accroissement d'emploi, afin d'obtenir davantage d'informations sur la profondeur de pénétration du tecnazène et sur l'évolution des résidus de tecnazène au cours de la fabrication des chips. A plusieurs reprises, des tranches de 10 mm d'épaisseur sont prélevées sur des tubercules traités au tecnazène, à la dose recommandée de 135 mg m.a. kg¹, et conservés à + 10 °C pendant 4 mois. Une analyse par chromatographie en phase gazeuse est alors effectuée sur chaque tranche; les teneurs en résidus figurent au tableau 1. L'effet de la transformation en chips sur le niveau de résidus est étudié en échantillonnant à différents stades de la fabrication industrielle et sur des lots de tubercules traités au laboratoire. Les résultats figurent au tableau 2. Ils montrent que 85 95% du total des résidus du tubercule disparaissent à l'épluchage. Il ne reste dans l'échantillon découpé en tranches que 0,14–0,21 mg kg¹. La friture augmente la teneur en résidus à 0,55–0,60 mg kg¹ en raison de la déshydratation. Le produit fini, extrait d'un échantillon du commerce, contient 0,25mg kg¹ de tecnazène après emballage. L'huile de friture se charge en tecnazène pendant la fabrication, et peut contaminer les lots non traités.

     

The effects of high-concentrate diets and pasture on the concentration of conjugated linoleic acid in beef muscle and subcutaneous fat

Abstract In view of the evidence indicating several potential benefits of high intakes of conjugated linoleic acid (CLA) on human health, an experiment was conducted to examine the effects of the diet of beef cattle on the total CLA concentration in muscle and subcutaneous fat. High‐concentrate [steers consumed 515 g concentrates and 485 g grass silage kg^?1 dry matter (DM) for 8 weeks followed by 887 g concentrates and 113 g grass silage kg^?1 DM for 14 weeks until slaughter] and high‐forage (steers consumed 803 g grass silage and 197 g concentrates kg^?1 for 8 weeks followed by grass silage only for 10 weeks and then grazed perennial ryegrass‐based pasture for 23 weeks until slaughter) treatments were imposed on 48 steers, which were crosses of continental beef breeds (initially 414 kg live weight) The concentrates were based on barley, extracted soyabean meal, molassed sugarbeet pulp and maize meal. The silages were of medium to low digestibility and contained 117–137 g crude protein kg^?1 DM and 83–158 g ammonia‐N kg^?1 total N. The pasture was of high quality and contained 168 g crude protein, 234 g acid‐detergent fibre and 222 g water‐soluble carbohydrate kg^?1 DM. Samples of muscle were taken post slaughter from the m. semimembranosus, m. gluteobiceps, m. longissimus and m. deltoideous muscles, and subcutaneous fat was taken from over the m. longissimus. Concentrations of total CLA in the tissues were for the high‐concentrate and high‐forage treatments, respectively (mg 100 g^?1 fresh tissue), m. gluteobiceps 18 and 47 (s.e. 3·5); m. semimembranosus 9 and 20 (s.e. 1·6); m. longissimus 15 and 35 (s.e. 3·2), m. deltoideous 20 and 59 (s.e. 4·3); subcutaneous fat 584 and 1975 (s.e. 138·7). It is concluded that muscle and subcutaneous fat tissue from grass‐fed cattle contained three times as much CLA as those from concentrate‐fed cattle, and that the consumption of beef from grass‐fed cattle should be effective in increasing the intake of CLA by humans.     

Alpha‐tocopherol and β‐carotene in legume–grass mixtures as influenced by wilting,ensiling and type of silage additive

Effects of wilting, ensiling and type of additive on α‐tocopherol and β‐carotene contents in legume–grass mixtures were examined. Swards of birdsfoot trefoil + timothy (Bft + Ti), red clover + timothy (Rc + Ti) and red clover + meadow fescue (Rc + Mf) were harvested as a first regrowth in August 2005. Forage was wilted to a dry‐matter (DM) content of 273 g kg^?1 and ensiled without additive or with an inoculant or acid. Wilting decreased α‐tocopherol concentration by 30% in the Bft + Ti mixture (P = 0·015). Untreated Bft + Ti silage had higher α‐tocopherol content than red clover silages (56·9 vs. 34·2 mg kg^?1 DM; P = 0·015). The α‐tocopherol concentration of Bft + Ti forages increased during ensiling from 41·1 mg kg^?1 DM in wilted herbage to 56·9, 65·2 and 56·8 mg kg^?1 DM in untreated, inoculated and acid‐treated silage respectively (P = 0·015). The inoculant increased α‐tocopherol content in the red clover silages (50·1 vs. 34·2 mg kg^?1 DM; P = 0·015) compared with untreated red clover silages. Red clover mixtures had lower β‐carotene content than Bft + Ti (32·3 vs. 46·2 mg kg^?1 DM; P = 0·016), averaged over treatments. In conclusion, wilting had small effects but the use of bacterial inoculant as an additive and a Bft + Ti mixture increased α‐tocopherol concentration in the silage.     

Dimethylnaphthalene and diisopropylnaphthalene for potato sprout control in storage: 1. Application methodology and efficacy

Dimethylnaphthalene (DMN) and diisopropylnaphthalene (DIPN) isomers applied as sprout suppressants to stored potatoes (cv. Russet Burbank) were evaluated for effects on sprout length and weight compared to chlorpropham (CIPC). One application of CIPC at 22 mg a.i. kg^-1 of tuber fresh weight (f.w.), and one or two applications of DMN and DIPN at 100, 200, and 300 mg a.i. kg^-1 f.w. were applied as thermal aerosol fogs. Two applications of DIPN at 300 mg a.i. kg^-1 f.w. were as effective as CIPC in suppressing sprout growth during ten months of storage. DMN also suppressed tuber sprout growth but was not as effective as two applications of DIPN or one application of CIPC. One application of DIPN or DMN at 300 mg a.i. kg^-1 f.w. was an effective suppressant of sprout growth on a short-term basis. Whole tuber residue analyses were also conducted. After ten months in storage, DMN and DIPN residue concentrations were equal to or less than those of CIPC.     

Tetrodotoxin concentrations in Pleurobranchaea maculata: temporal, spatial and individual variability from New Zealand populations

Tetrodotoxin (TTX) is a potent neurotoxin that has been identified in a range of phylogenetically unrelated marine and terrestrial organisms. Tetrodotoxin was recently detected in New Zealand in Pleurobranchaea maculata (the grey side-gilled sea slug). From June 2010 to June 2011 wild specimens were collected from 10 locations around New Zealand. At one site (Narrow Neck Beach, Auckland) up to 10 individuals were collected monthly for 6 months. Attempts were also made to rear P. maculata in captivity. Tetrodotoxin was detected in samples from eight of the ten sites. The highest average (368.7 mg kg⁻¹) and maximum (1414.0 mg kg⁻¹) concentrations were measured in samples from Illiomama Rock (Auckland). Of the toxic populations tested there was significant variability in TTX concentrations among individuals, with the highest difference (62 fold) measured at Illiomama Rock. Tetrodotoxin concentrations in samples from Narrow Neck Beach varied temporally, ranging from an average of 184 mg kg⁻¹ in June 2010 to 17.5 mg kg⁻¹ by December 2010. There was no correlation between TTX levels and mass. The highest levels correspond with the egg laying season (June–August) and this, in concert with the detection of high levels of TTX in eggs and early larval stages, suggests that TTX may have a defensive function in P. maculata. Only one larva was successfully reared to full maturation and no TTX was detected.     

Determination of thiabendazole residues in potatoes using high pressure liquid chromatography

Summary This paper describes a method for the extraction, purification and quantification by high pressure liquid chromatography using fluorimetric detection, of thiabendazole residues from potatoes. Bonded silica sorbent extraction columns (diol phase) are used for sample clean up, resulting in a rapid and accurate analysis. The average recovery was 93.8%±2.1%. Levels of about 0.0004μg of TBZ, equivalent to 0.033 mg kg⁻¹ in potatoes (on fresh weight basis), were readily detected from deliberately contaminted potatoes.     

Total Phenolics Level,Antioxidant Activities and Cytotoxicity of Young Sprouts of Some Traditional Korean Salad Plants

The aim of this investigation was to study the antioxidant and anticancer activities of young sprouts of some traditional Korean salad plants. Total phenolics, antioxidant and anticancer activities of the methanol extracts from young sprouts of 11 salad plants were determined. The highest amount of phenolics was found in methanol extracts of Euonymus alatus (235.7 mg kg⁻¹), followed by Hypericum ascyron (197.1 mg kg⁻¹), Zanthoxylum piperitum (194.1 mg kg⁻¹) and Zanthoxylum schinifolium (142.5 mg kg⁻¹). Methanol extracts of E. alatus, H. ascyron, and Z. piperitum at 63 mg kg⁻¹ exhibited the highest dose-depend DPPH radical scavenging activity by 91.2, 91.2 and 83.9%, respectively. According to the MTT results, the methanol extracts from Stellaria aquatica, Eleutherococcus sessilifolrus and Z. schinifolium showed the highest anticancer activities against Calu-6 (IC50 < 25.0 μgml⁻¹) and from S. aquatica—the highest anticancer activities against SNU-601 (153.3 μgml⁻¹), following by E. sessilifolrus (196.7 μg ml⁻¹) and Amaranthus mangostanus (303.1 μgml⁻¹). Total phenolics were highly correlated with the DPPH, suggesting that they contribute to the antioxidant properties of the studied plants. In conclusion: young sprouts of Korean salad possess antioxidant and anticancer properties and could be used as a supplement to proper drugs.     

The effects of sward characteristics and supplement type on the herbage intake and milk production of summer-calving cows

High (H; 27 350 m^?1:) or low (L. 13 300 m-¹) tiller density perennial ryegrass swards were created in the mid- and late grazing season by imposing different sward heights in the spring. Summer-calving cows then grazed these swards from 6 June to 2 September 1992 and were offered 5 kg fresh weight hd^?1 d^?1 of either a barley (S) or a molassed sugar beet pulp (F) based supplement. The factorial combination of sward and supplement types resulted in four experimental swards being grazed by thirteen Holstein/Friesian cows each. Supplement F contained more crude fibre (110 vs. 58 g kg^?1) and less metabolizable energy [12–5 vs. 13–2 MJ kg^?1 dry matter (DM)] than supplement S. Herbage on the H sward contained more metabolizable energy (11–9 vs. 104 MJ kg^?1 DM) and crude protein (232 vs. 205 g kg^?1 DM), had fewer rejected areas f 16–5 vs. 26–9%) and a higher live-dead tiller ratio (4–6 vs. 2–1) than that on the L sward. Sward, but not supplement type, significantly affected the intake of grazed herbage (P<0–001). On average, the herbage intakes of cows grazing II swards were higher than for L swards (14–5 vs. 11 6kg DM d^?1) and those of cows on the S and F supplements were 12–6 and 13–5 kg DM d^?1 respectively. Averaged over the grazing period, sward and supplement had no significant effects on milk yield, milk composition or yield of constituents. When expressed on an average weekly basis, cows grazing an L sward and offered the F supplement on occasions had significantly lower milk yields and higher milk fat contents (P<005) than those grazing an H sward and offered the S supplement. There were no significant effects on cow live weight or condition score change. The results suggested that grazing swards with a high density of live tillers increased herbage intakes and on occasions milk yield, relative to low density swards. However, small increases in energy intake from sward and supplement effects were used primarily to ameliorate liveweight loss.     

Tetrodotoxins (TTXs) and Vibrio alginolyticus in Mussels from Central Adriatic Sea (Italy): Are They Closely Related?

Tetrodotoxins (TTXs), potent neurotoxins, have become an increasing concern in Europe in recent decades, especially because of their presence in mollusks. The European Food Safety Authority published a Scientific Opinion setting a recommended threshold for TTX in mollusks of 44 µg equivalent kg⁻¹ and calling all member states to contribute to an effort to gather data in order to produce a more exhaustive risk assessment. The objective of this work was to assess TTX levels in wild and farmed mussels (Mytilus galloprovincialis) harvested in 2018–2019 along the coastal area of the Marche region in the Central Adriatic Sea (Italy). The presence of Vibrio spp. carrying the non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes, which are suspected to be involved in TTX biosynthesis, was also investigated. Out of 158 mussel samples analyzed by hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry (HILIC-MS/MS), 11 (7%) contained the toxins at detectable levels (8–26 µg kg⁻¹) and 3 (2%) contained levels above the EFSA safety threshold (61–76 µg kg⁻¹). Contaminated mussels were all harvested from natural beds in spring or summer. Of the 2019 samples, 70% of them contained V. alginolyticus strains with the NRPS and/or PKS genes. None of the strains containing NRPS and/or PKS genes showed detectable levels of TTXs. TTXs in mussels are not yet a threat in the Marche region nor in Europe, but further investigations are surely needed.     

Nutrient composition of the leaves and flowers ofColocasia esculenta and the fruits ofSolanum melongena

The nutrient composition, ofColocasia esculenta flowers (CF) and leaves (CL), and the green fruits ofSolanum melongena (SM) were carried out as a means to determine their nutritional potential. Results showed that these food materials had high moisture and fiber levels which ranged between 888 and 906 g·kg^–1; and 204 and 303 g·kg^–1 dry weight (dw) for moisture and fiber respectively. The calorific values were between 3889 and 4001 kcals·kg^–1 dw, while the total lipids ranged from 53 in CF to 71 g·kg^–1 dw in SM. The leaves ofColocasia esculenta had the highest crude protein value of 307 g·kg^–1 dw. The flowers had 149 g·kg^–1 dw while SM had 138 g·kg^–1 dw. The amino acid profile in the flowers and leaves ofColocasia esculenta in contrast to SM were balanced comparable to the reference FAO pattern. Ash values were high (ranging from 76 in SM to 98 g·kg^–1 in CL) with potassium being the principal element. Iron and Zinc levels were also high especially in CF (with 303 and 82 mg·kg^–1 dw respectively). These foods also contained moderate quantities of calcium, phosphorus and magnesium but were poor in manganese and copper.     

Selenoamino Acid-Enriched Green Pea as a Value-Added Plant Protein Source for Humans and Livestock

Selenium deficiency in various degrees affects around 15% of the world’s population, contributing to a variety of health problems. In this study, we examined the accumulation and biotransformation of soil applied Se-supplementation (sodium selenite and sodium selenate forms) at different concentrations, along with growth and yield formation of green pea, in a greenhouse experiment. Biotransformation of inorganic Se was evaluated using HPLC-ICP-MS for Se-species separation in the above ground parts of green pea. Results showed 3 mg kg^?1 Se^IV increased green pea growth biomarkers and also caused an increase in protein content in leaves by 17%. Selenomethionine represented 65% of the total selenium content in shoots, but was lower in pods and seeds (54 and 38%, respectively). Selenomethionine was the major species in all plant parts and the only organic selenium form in the lower Se^IV concentration range. Elevating the dose of Se^IV (≥30 mg kg^?1) triggered detrimental effects on growth and protein content and caused higher accumulation of inorganic Se in forms of Se^VI and Se^IV. Selenocysteine, another organic form of proteinogenic amino acid, was determined when Se^IV (≥10 mg kg^?1) was applied in higher concentrations. Thus, agronomic biofortification using the appropriate chemical form and concentration of Se will have positive effects on green pea growth and its enriched shoots and seeds provide a value-added protein source for livestock and humans with significant increased selenomethionine.     

Dimethylnaphthalene as a sprout suppressant for seed and ware potatoes

Summary Dimethylnaphthalene (DMN) was shown to be an effective sprout suppressant. In the laboratory and in a commercial seed potato store, a DMN isomer mixture applied at 100 mg kg⁻¹ controlled sprout growth as effectively as tecnazene applied at 135 mg kg⁻¹. When seed tubers, treated at 100 mg kg⁻¹, were aired for 4 to 7 weeks before planting, subsequent emergence and total yield were not adversely affected but treatment at 300 mg kg⁻¹ delayed emergence and reduced yield. Treatment with DMN at 100 mg kg⁻¹ increased the yield of medium sized tubers more than did that by tecnazene at 135 mg kg⁻¹. One initial application of DMN (200 mg kg⁻¹) did not maintain adequate sprout control in a long-term, higher temperature, ventilated store of tubers intended for processing where reapplication or continuous application would be required.

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Zusammenfassung Eine Mischung von Dimethylnaphthalin-(DMN)-Isomeren wurde als Keimhemmer eingestuft. Verschiedene Mengen der Mischung wurden auf einem Tonerdetr?ger auf eingelagerte Knollen gebracht und 14 Wochen sp?ter die Keiml?nge gemessen. Die Ergebnisse (siehe Tabelle 1) zeigen, dass die kleinste wirksame Anwendungsrate der Isomermischung 100 mg kg⁻¹ betr?gt. Die Wirkungen des DMN bei 100 mg kg⁻¹ auf das nachfolgende Wachstum der behandelten Pflanzknollen wurden dann mit den Wirkungen von Tecnazen (1,2,4,5-Tetrachlor-3-Nitrobenzol) und mit unbehandelten Kontrollen verglichen. DMN wurde auch mit einer Menge von 300 mg kg⁻¹ angewendet, um die Wirkungen einer unausgeglichenen Anwendung oder einer zuf?lligen Ueberdosis zu vergleichen. Alle 4 Verfahren wurden vor dem Auspflanzen 3 verschiedenen Kombinationen von Behandlungsdauer/Belüftungsdauer unterworfen. Der Einfluss der 4 chemischen Verfahren auf die Keiml?nge am Ende einer 17 Wochen dauernden Behandlungszeit sind in Tabelle 2 aufgeführt. Die Gesamtwirkungen der chemischen Verfahren auf das nachfolgende Auflaufen und die Ernte gehen aus Tabelle 3 hervor. Die Wirkungen der verschiedenen Kombinationen von Behandlungsdauer/Belüftungsdauer für die 4 chemischen Verfahren auf eine Sorte sind in Tabelle 4 dargestellt. Die Auswirkungen von DMN auf die nachfolgende Pflanzgutleistung wurden ebenfalls in einem handelsüblichen Modellversuch untersucht. Dafür wurde Standardpflanzgut unter üblichen landwirtschaftlichen Produktionsbedingungen verwendet. Die Ergebnisse dieses Versuches sind in Tabelle 5 aufgeführt. Diese beiden Untersuchungen zeigen, dass DMN als Keimhemmer an Pflanzkartoffeln ideal geeignet ist. Die behandelten Knollen werden vor dem Auspflanzen 4–7 Wochen bei 10°C belüftet; das nachfolgende Auflaufen und der Gesamtertrag werden nicht ernsthaft beeinflusst. Die Behandlung wird jedoch eine kleine Reduktion im Ertrag von grossen Knollen und eine entsprechende Zunahme im Ertrag von mittleren und kleinen Knollen innerhalb des Gesamtertrages hervorrufen. Das Ausmass dieser Wirkung ist jedoch geringer als dasjenige, das von Tecnazen erzeugt wird. Die keimhemmenden Eigenschaften von DMN wurden auch in einem grossen, belüfteten Speisekartoffellager untersucht. Die Chemikalie wurde in verschiedenen Mengen angewendet und die Knollen w?hrend 27 Wochen bei 7–8°C gelagert. Unter diesen Bedingungen war der Grad der erreichten Keimbek?mpfung (siehe Tabelle 6) unzul?nglich, selbst wenn 200 mg kg⁻¹ DMN verwendet wurden. Unter diesen Bedingungen ware Wiederanwendung oder fortgesetzte Anwendung der Chemilakie notwendig.

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Résumé Un mélange d’isomères de dimethylnaphthalène (DMN) a été étudié en tant qu’inhibiteur de germination par application de différentes quantités de ce mélange (support d’alumine) sur tubercules stockés, puis en évaluant la longueur des germes 14 semaines plus tard. Les résultats (voir tableau 1) montrent que la dose efficace minimale du mélange d’isomères est de 100 mg kg⁻¹. Les effets du DMN à 100 mg kg⁻¹ sur la croissance ultérieure des semences traitées sont ensuite comparés aux effets du tecnazène (1,2,4,5-tetrachloro-3-nitrobenzène) et avec des témoins non traités. DMN est aussi appliqué à 300 mg kg⁻¹ pour rechercher les effets d’une application irrégulière ou d’un surdosage accidentel. Les 4 traitements sont soumis à 3 durées de ventilation avant plantation. Les effets des 4 traitements chimiques sur la longueur des germes à la fin de la période de 17 semaines sont indiqués au tableau 2, et les effets du traitement sur la levée et le rendement figurent tableau 3. Les effets des différentes durées de ventilation combinées aux 4 traitements chimiques sur une variété sont indiqués au tableau 4. L’effet du DMN sur le rendement de semences a été également étudié dans une expérimentation à l’échelle commerciale utilisant les standards de la production du plant. Les résultats de ces essais sont indiqués au tableau 5. Ces deux expérimentations montrent que le DMN convient très bien pour inhiber la germination des plants et si les tubercules sont ventilés pendant 4 à 7 semaines à 10°C avant la plantation, la levée et le rendement total ne sont pas sérieusement affectés. Le traitement peut cependant entrainer une petite réduction du rendement en gros calibres et un accroissement correspondant du rendement en moyens et petits tubercules, à l’intérieur du rendement total. Cet effet est cependant moins marqué qu’avec le tecnazène. Les propriétés inhibitrices du DMN sont également étudiées sur pomme de terre de consommation dans un vaste local ventilé. Le produit est appliqué à différentes doses et les tubercules sont stockés pendant 27 semaines à 7–8°C. Dans ces conditions, l’inhibition de la germination obtenue (voir tableau 6) est insuffisant, même quand le DMN est appliqué à 200 mg kg⁻¹. Pour ces conditions, un nouveau traitement, ou une application continue (en nébulisation) serait nécessaire.

     

Chemical composition and nutritive value of leaves and stems of tropical weed Chromolaena odorata

Chromolaena odorata (Siam weed) has been classified as a weed plant in West Africa. Data from C. odorata foliage after 4, 6, 8, 10 and 12 weeks of regrowth showed that the leaf fraction had a crude protein content above 194 g kg^–1 dry matter (DM) and an average leaf to stem ratio of 2·1:1. Chemical analysis of the leaf fraction of an 8‐week‐old regrowth indicated a high crude protein content (258 g kg^–1 DM) and a high degradable nitrogen content (60·7 g N kg^–1 digestible organic matter), but low neutral‐detergent fibre (331 g kg^–1 DM), acid‐detergent lignin (53·1 g kg^–1 DM), total extractable phenolic (37·1 g kg^–1 DM), extractable tannin (0·72 absorbance at 550 nm) and extractable condensed tannin (1·4 g kg^–1 DM) contents. In sacco degradability analysis of the 8‐week‐old regrowth leaf sample showed a high 48 h organic matter (935 g kg^–1 DM) and crude protein (953 g kg^–1 DM) degradability. The leaf sample had an organic matter degradability of 670 g kg^–1 DM as estimated by cumulative gas production in vitro after 24 h incubation. There was little or no phenolic‐related antinutritive factors in C. odorata. Additionally, leaf samples had no effect on rumen protozoa activity estimated as the rate of [¹⁴C]leucine Selenomonas ruminantum bacterial protein breakdown. Data from this study suggest that C. odorata leaves are of high nutritive value and might have the potential to be used as a protein supplement to ruminants. There is need for further investigation to test whether C. odorata leaves may have any deleterious effect on the host animal.     

Seasonal dynamics of bioenergy characteristics in grassland functional groups

Semi‐natural grasslands (SNG) are considered as bioenergy resources, either for combustion or for biogas production. To provide information on the seasonal (June–August) dynamics of herbage quantity and chemical composition, we studied the effects of factors on the proportions of four plant functional groups, chemical composition and total biomass yield at twelve sites representing three Estonian SNG types. Biomass yield increased only in alluvial meadows with the largest contribution of sedges/rushes (39%). Grasses dominated in dry‐to‐mesic meadows (62%) and other forbs in wooded meadows (55%). Concentration of fibre was highest in grasses and sedges/rushes (682 and 645 g NDF kg^?1), and lignin was highest in legumes and other forbs (103 and 113 g kg^?1). Legumes contained more C and N (447 and 25 g kg^?1) and grasses more Cl (1 g kg^?1). The highest concentrations of Mg, K and ash were in other forbs (4, 18 and 80 g kg^?1), and Ca in legumes (16 g kg^?1). The results are discussed in the context of suitability of different functional groups and SNG types for bioenergy conversion. Grasses and sedge‐/rush‐rich biomass are considered suitable for methane production. Biomass harvesting in July and minimizing the problems with N and Cl during combustion need to be considered. Forb‐rich biomass should be pre‐treated before direct combustion.