酶法提取鲍鱼内脏多糖工艺的优化

【目的】优化鲍鱼内脏多糖酶解工艺条件,为鲍鱼内脏多糖的提取和高值化利用提供技术支持。【方法】以杂交鲍内脏为原料、多糖提取率为评价指标,从6种蛋白酶中筛选出提取鲍鱼内脏多糖的适宜酶制剂,并在单因素试验的基础上,利用响应面法对多糖提取率影响较大的蛋白酶作用条件进行优化,依据回归分析确定其最适作用条件。【结果】胰蛋白酶是提取鲍鱼内脏多糖的适宜酶制剂;各因素对鲍鱼内脏多糖提取率的影响排序为料液比>p H>加酶量,料液比与p H的交互作用对多糖提取率影响显著(P<0.05),而料液比与加酶量、p H与加酶量的交互作用对多糖提取率影响不显著(P>0.05)。胰蛋白酶提取鲍鱼内脏多糖的最适工艺条件为:料液比1∶49(g/m L)、p H 8.6、加酶量2.1%、酶解时间2 h、酶解温度37℃,在此条件下,鲍鱼内脏多糖提取率为6.97%,与预测值(6.99%)接近。【结论】通过响应面试验优化的胰蛋白酶酶解工艺可有效提取鲍鱼内脏多糖,建立的回归模型可用于实际生产预测。

鲍鱼内脏多糖分离纯化与抗氧化活性评价

【目的】分离纯化鲍鱼内脏多糖(Abalone viscera polysaccharide,AVP),并评价其抗氧化活性,为AVP的高值化利用提供参考依据。【方法】以鲍鱼内脏为原料,采用酶法提取并初步纯化出AVP,测定其DPPH自由基清除率、羟自由基(OH自由基)清除率和还原力3个抗氧化指标,评价AVP抗氧化能力;同时用葡聚糖凝胶G-100柱层析分离AVP,并对分离出的组分进行抗氧化能力比较。【结果】AVP质量浓度在1～10 mg/mL时,DPPH自由基清除率线性方程为y=9.715x+1.0182(R^2=0.9958),半抑制浓度(IC_(50))为5.04 mg/mL;OH自由基清除率线性方程为y=6.2778x-8.5275(R^2=0.9603),IC_(50)为9.32 mg/mL;还原力线性方程为y=0.0782x+0.0045(R2=0.9989),A_(700,0.2)为2.50 mg/mL。AVP具有一定的抗氧化能力,但与抗坏血酸(Vc)相比,其抗氧化能力较弱。AVP经葡聚糖凝胶G-100柱层析可分离出两个组分(AVP1和AVP2),AVP1和AVP2均具有一定的抗氧化活性,且AVP1抗氧化能力强于AVP2。【结论】通过葡聚糖凝胶柱层析可从AVP中有效分离出AVP1和AVP2两个组分,其中AVP1的抗氧化能力更强,在抗氧化添加剂及保健品等领域具有较好的开发利用前景。

土壤调控剂与硅肥配施对镉污染土壤的改良效果及水稻吸收镉的影响

【目的】本研究为稻米Cd污染阻控技术提供理论依据和技术支撑。【方法】通过田间试验,研究了土壤调控剂T1(纳米活性炭+硅钾钙镁肥)、T2(火山石+钙镁磷肥)和Si(叶面硅肥)单一及组合共5种不同调控措施(T1、T2、Si、T1+Si、T2+Si)对云南个旧矿区稻田镉污染土壤的修复效应及对稻米镉累积的影响。【结果】土壤调控措施均能提高土壤pH,T2处理调控效果最好,较对照提高0.80个单位;调控剂处理后,土壤酸可提取态Cd都有不同程度的降低,残渣态有不同程度的增加,T1+Si处理对土壤酸可提取态调控效果最好,较对照降低了31.6%。经调控措施处理后水稻产量有不同程度的提高,组合调控处理的增产效果优于单一调控措施,T1+Si、T2+Si组合处理较对照分别增加27.2%、29.7%。不同处理水稻根系Cd含量有不同程度的降低,但茎叶中Cd含量有不同程度的上升,糙米中Cd含量均有不同程度的降低,符合国家食品污染物限量标准(GB 2762-2012),其中T1+Si处理糙米中Cd含量较对照降低45.3%。【结论】采用纳米活性炭+硅钾钙镁肥基施以及在水稻灌浆期和抽穗期分别喷施叶面硅肥不仅可以有效修复个旧矿区镉污染土壤,而且可以明显降低糙米中镉的含量,提高矿区稻米安全质量。

部分紫色蔬菜中酚类物质及维生素C含量分析

以紫甘蓝、紫背天葵、红苋菜、紫薯、紫茄、紫洋葱为样品,测定其花青素、总花色苷、总黄酮、总酚、维生素C含量并分析其差异。结果表明,紫甘蓝、紫背天葵、紫洋葱中均检出有矢车菊素,紫甘蓝中含量最高,为44.52 mg/100 g,显著高于紫背天葵和紫洋葱(p <0.05);飞燕草素仅在紫茄皮中有检出,含量为38.72 mg/100 g;紫薯中同时检出有5.10 mg/100 g芍药素及少量矢车菊素;红苋菜及紫茄肉中均未有目标花青素检出。总花色苷含量在紫甘蓝中最高,为98.01 mg Cy3G/100 g,其次为紫茄皮,紫薯、紫洋葱以及紫背天葵含量较低且差异不显著。紫甘蓝中VC含量显著最高,为22.52 mg/100 g(p <0.05),其次为红苋菜、紫洋葱和紫薯。紫茄皮、紫甘蓝及红苋菜中总黄酮含量均较高。紫洋葱中总酚含量显著最高,为96.55 mg GAE/100 g(p <0.05),其次为紫甘蓝,紫茄皮。综合分析,在所测营养成分中紫甘蓝营养品质最高。紫色蔬菜中花青素、总花色苷、总黄酮、总酚及维生素C含量特点可作为特定人群蔬菜消费的选择依据,同时亦可为居民营养成分饮食摄入评估提供基础数据。

植物内生菌在食用农产品质量安全与营养品质调控中的研究进展

食用农产品是食品的基础原料,直接关乎人类日常生活和健康,对其质量安全和营养品质调控是农业和食品领域研究的重大课题。植物内生菌是健康植物体内的共生菌,菌体及其代谢产物能对调控植株生长发育以及环境胁迫适应等方面产生重要影响。目前对植物内生菌的研究已渗透到农业生产过程中的各个领域,其应用价值逐渐崭露头角,成为助推农业生产和提升农产品品质的潜在辅助手段,特别在食用农产品质量安全与营养品质调控上具有独特优势。本文就植物内生菌在食用农产品生产过程中产地环境危害物、农药投入品危害物、病虫害以及营养品质指标等调控方面的最新研究状况进行系统综述,并就植物内生菌在食用农产品质量安全与营养品质指标调控研究上的技术瓶颈以及未来可拓展的研究和应用展开探讨,为食用农产品质量安全与营养品质调控领域研究提供最新的有参考价值的文献资料和潜在技术创新思路。

脉络膜黑色素瘤的影像诊断

目的探讨脉络膜黑色素瘤影像检查的诊断价值。方法采用超声、CT、MRI检查诊断脉络膜黑色素瘤14例。其中超声与CT 6例,超声与MRI 8例。结果 B超及CT显示半圆形密度均等肿块,MRI提示T1加权像中到高信号,T2加权像为低信号。结论 B超检查结合CT、MRI的联合应用能充分显示脉络膜黑色素瘤的影像特征,对脉络膜黑色素瘤的诊断具有重要的临床价值。

四种鲍鱼肌肉营养成分分析与品质评价

文中对皱纹盘鲍(Haliotis discus hannai)、杂色鲍(Haliotis diversicolor)、绿鲍(Haliotis fulgens)和杂交鲍4种不同品种鲍鱼肌肉中的一般营养成分、氨基酸、脂肪酸、无机盐及微量元素进行测定分析,并对其营养价值进行了评价。结果表明,4种鲍鱼肌肉蛋白含量在18.92%~21.63%,无显著差异(p>0.05);4种鲍鱼脂肪含量均较低,在0.04%~0.09%,无显著差异(p>0.05);总糖差异显著(p<0.05),其中杂交鲍含量最高4.81%,皱纹盘鲍含量最低3.39%;氨基酸组成基本一致,共17种,氨基酸总量在16.24~18.12 g/100g,其中必需氨基酸8种,含量为4.78~5.08 g/100g,鲜味氨基酸与总氨基酸的比值(UAA/TAA)在43.35%~43.97%,胶原蛋白含量除杂色鲍(9.27%)外,其他3种在17.60%~17.96%。以氨基酸评分(AAS)和化学评分(CS)数据分析,杂交鲍营养价值高于其他3种。4种鲍鱼均含有丰富的棕榈酸、EPA和K、Ca、Zn等元素。因此,鲍鱼是一种高蛋白、低脂肪、营养价值高的优质海产品。

花椰菜不同品种类型间营养成分差异及烹饪对其含量的影响

为探明花椰菜不同品种类型间营养成分及抗氧化活性差异及烹饪对其影响,采集白花菜、松花菜、青花菜以及罗马花椰菜四种花椰菜样品,检测其维生素C、总胡萝卜素、总黄酮、总酚等营养成分含量及其抗氧化活性,并研究水煮、蒸制、微波及清炒烹饪过程对其营养成分含量的影响。结果表明:花椰菜不同品种类型间营养成分及抗氧化活性具有较大差异,其中罗马花椰菜中维生素C、总胡萝卜素及总黄酮含量最高,分别为75.67 mg/100 g、39.24μg/100 g以及4.34 mg RE/100 g。青花菜总酚含量最高,为38.04 mg GAE/100 g,总胡萝卜素及总黄酮含量仅次于罗马花椰菜,松花菜除总酚含量低于白花菜外,其它均高于白花菜;青花菜的DPPH及ABTS自由基清除能力均为最高,分别为68.40%和28.00%,罗马花椰菜次之,而白花菜和松花菜的FRAP还原能力较高,且二者差异不显著(P>0.05)。烹饪处理花椰菜对其营养成分及抗氧化活性具有不同影响,维生素C含量不同程度损失,总胡萝卜素既有损失又有提升,总黄酮和总酚含量整体为提升,DPPH及ABTS自由基清除能力提升,FRAP还原能力下降。不同烹饪处理中蒸制方式对于花椰菜营养成分及抗氧化活性保持或提升作用较好,其次为微波、水煮及清炒。本实验获得的花椰菜不同品种类型营养成分及抗氧化活性特点可为特定人群花椰菜消费以及烹饪方式选择提供依据,同时亦可为居民通过花椰菜饮食营养物质摄入风险评估提供基础数据。

Determination of Indoxacarb Residue in Foodstuffs of Plant and Animal Origin by GC-ECD and LC-MS/MS

An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and pork] was developed using gas chromatography （GC-ECD） and liquid chromatography tandem mass spectrometry （LC-MS/MS）. Samples were extracted using acetone and n-hexane mixed solvent （1：2, v/v） and then purified using solid-phase extraction （SPE） columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring （MRM） scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits （LODs） of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits （LOQs） were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations （RSDs） of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.

Degradation of Chlorpyrifos and Fipronil in Rice from Farm to Fork and Risk Assessment

Degradation of pesticide residues （chlorpyrifos and fipronil） in rice from farm to fork and risk assessment for human health were studied to reveal the magnitude of risks faced by different populations of interest, so that appropriate measures can be taken to control the risks, and to refine and update the human health risk assessment data while helping to determine the maximum residue level （MRL） value and harvest interval. Different dosages and treatments were used in field trials for the harvest residue test. Residue levels of postharvest-applied chlorpyrifos and fipronil during storage, exposure to sunlight, washing and boiling processes （boiled rice） were investigated for brown rice. The dietary exposure evaluation model （DEEM） was employed to estimate acute and chronic risks faced by different populations of interest. Percent of reference dose （POR） and margin of exposure （MOE） were calculated. A positive correlation between pesticide residues and the dosage and application frequency of pesticide was found in the field trials. Risk quotients indicate that multiple applications and double dosages of chlorpyrifos increase the risks to the entire population and prolong exposures to toxic concentrations. The concentration of pesticide residues decreased as a function of time, after sunlight exposure, storage, washing, and boiling processes. 91.6 and 96.16% degradations were achieved at the end of the experimental period for fipronil and chlorpyrifos, respectively. The boiling process played an important role in the degradation of these pesticides. The result of risk assessment to human health showed that harvest residues of chlorpyrifos in rice and acute dietary risks of chlopyrifos were of concern. The acute dietary （food only） risk estimated for chlorpyrifos as percent of acute population adjusted dose （aPAD） was frequently over 100%. The risk faced by boys under the age of 14 was higher than that for girls of the same age. For the subpopulation above age 14, the risk reversed. The chronic dietary risk from food alone showed that dietary exposures with fipronil were below the level of concern for the entire population, including children. The risk faced by rural residents was more serious than that for urbanite residents with the most sensitive populations being children and male residents who faced higher acute dietary risk than the other subpopulation groups. The harvest interval was found to be the critical measure to mitigate risk for all populations for safe rice eating. All risk levels decreased to acceptable levels when the harvest interval was extended to 14 d. To address these risks, a number of measures including reduced application rates （should not be doubled at single application）, increased retreatment intervals （longer than 7 d） and extended interval of harvest （at least 14 d） will be needed. The MRL for fipronil in rice is recommended to be 0.01 mg kg 1 in accordance with Codex （ref）.

Development of Anti-Isoproturon Polyclonal Antibody

A competitive enzyme-linked immunosorbent assay （ELISA） suitable for the determination of the urea herbicide isoproturon, 3-（4-isopropylphenyl）-l,l-dimethylurea, in food and environmental samples was developed. Two haptens named 1-（3- carboxypropyl）-3-（4-isopropylphenyl）-1-methylurea （hapten 4C） and 1-（5-carboxypentyl）-3-（4-isopropylphenyl）-1- methylurea （hapten 6C） were synthesized. The haptens were coupled to bovine serum albumin （BSA） and ovalbumin （OVA）, respectively, using the N-hydroxysuccinimide reaction. The hapten 6C-BSA conjugate was used as the immunogen, with which a high-titer anti-isoproturon polyclonal antibody （pAb） was successfully obtained by immunization of New Zealand white rabbits. The hapten 4C-OVA conjugate was used as coating antigen and a method of the indirect competitive ELISA for isoproturon was established. The haptens were confirmed with TLC, IR, and 1H NMR. The conjugation molar ratios of hapten 4C to OVA and hapten 6C to BSA were 36：1 and 46：1, respectively, as calculated by a UV spectrophotometry. The highest titer of the anti-isoproturon sera determined by a non-competitive indirect ELISA procedure was 1.6 × 10^5. The optimal concentrations of the coating antigen and the dilution of the anti-isoproturon sera used in the ELISA were 0.1 mg·L^-1 and 1.0 × 10^5, respectively. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 0.07 mg·mL^-1. The cross-reactivities of six urea herbicides including chlorbromuron, fluometuron, monolinuron were lower than 0.1%. Isoproturon is a small molecule without immune activity and active functional group for attaching to carrier protein. To produce an antibody against isoproturon with high titer and high specificity is the most important step in the development of an immunochemical method for the determination of isoproturon in food and environmental samples. The two haptens synthesized in this study have carboxyl groups and accommodate different lengths of spacer arms, and the phenyl and isopropyl groups are fully exposed. An anti-isoproturon polyclonal antibody with high titer and high specificity was successfully obtained by immunization of rabbits with the conjugate of the hapten attached to the protein carrier.

Antioxidant Activities of Nine Selected Culinary Spices from China

The antioxidant activities and the total phenolic contents of the water and/or ethanol extracts of the nine selected culinary spices from China were systematically investigated. Both ethanol extracts and water extracts had high ability of 1, 1-diphenyl-2-picrylhydrazyl（DPPH） radical scavenging, 2, 2＇-azinobis（3-ethylbenzthiazoline-6-sulphonic acid）（ABTS） radical scavenging and ferric reducing antioxidant power（FRAP）. The ethanol extract of Sichuan pepper showed the highest ability of DPPH radical scavenging. The extract with the highest ABTS radical scavenging effect was that of ethanol extract of cinnamon. Both ethanol and water extracts of cinnamon possessed the high ferric reducing antioxidant power（FRAP） with the values of 4 541.87 and 1 134.52 μmol of Fe（Ⅱ）/g. The extracts with high hydroxyl radical-mediated deoxyribose degradation were all the ethanol extracts as follows： cinnamon, bay leaf, Sichuan pepper, star anise and fennel. The extracts with high antioxidant activities also had the high contents of the phenols. The study indicated that these spices might be potentially be used as natural antioxidants in food.

Development and evaluation of immunoassay for zeranol in bovine urine

基于抗体的酶连接了的高亲密关系 polyclonal 免疫吸着剂试金(ELISA ) 在牛的尿为 zeranol 的数量化离子被开发。根据尿矩阵研究，生产不足道的矩阵干扰的优化冲淡因素在预告的处理作为 1:5 被选择。在改进 ELISA，线性反应范围在 0.02 之间；1 μ g /ml，；察觉限制是为试金的 0.02 μ g /ml。全面恢复；变化(CV ) 的系数在 82%～ 1 的范围 27% ；3.5%～ 8 .8% 分别地。与 zeranol 刺的 36 件牛的尿样品(从 0.2 ～ 10 μ g /ml ) 被 ELISA 检测；液相色层分析法(LC ) 方法，；好关联在二个方法之间被获得(R [2 ]=0.9643 ) 。我们断定这改进 ELISA 是为屏蔽的集体 zeranol 的合适的工具；能是为为在牛的尿的 zeranol 的常规 LC 方法的一种选择。

Potential influence of carbohydrate and amino acid intake by adults on the population dynamics of Cnaphalocrocis medinalis(Lepidoptera: Crambidae)

Cnaphalocrocis medinalis is a key lepidopteran pest of rice. However, little is known about the nutritional requirements of the adult or the effects of adult-derived nutrients on reproduction. The aim of the present study was to evaluate the effects of carbohydrates and amino acids on the reproductive and demographic parameters of C. medinalis. Different feeding solutions significantly influenced adult survival and reproduction. All the sources of carbohydrates used in the treatments(fructose, glucose, and sucrose) were sufficient to increase adult longevity and fecundity, and benefited the development of ovaries in the adult stage. The positive impact of carbohydrates on lifetime fecundity was due to the prolonged oviposition period and the increased daily fecundity. The intrinsic rate of increase(rm) of C. medinalis increased from 0.103 in waterfed individuals to approximately 0.138 when adults were fed with solutions containing carbohydrates. In contrast, amino acid intake by adult insects exhibited no effect on the longevity, fecundity, ovarian development or population growth, even showing an impact of decreasing longevity of females. As nectar secreted by the flowering plant is generally rich in sugars, the potential effects of nectar on the adults of C. medinalis and other pests have to be considered during the development of biological control by applying flowering plants as a microhabitat and food source for natural enemies in rice fields.

面向智慧工厂的双光融合车间人员行为识别方法

为弥补传统的单一成像监控方式的不足,对车间人员实行智能化的行为管控,提出了一种决策级的双光融合行为识别算法。在实地调研车间环境后采集了6类异常行为和3类工作行为,自建车间可见光-红外行为样本库,重新训练YOLOv5网络获取可见光和红外模型。建立了一种决策级的融合策略,能够同时识别双光数据中的目标并融合,得到最终的行为识别结果。在自建数据集上进行实验,结果表明融合算法的识别精度达到了93.04%,推理速度满足实时的识别要求。与仅使用单一数据源的算法相比,精度分别提升3.43%和0.84%;与其他5种特征级融合检测算法相比,精度均有大幅提升,证明了该融合方法的优越性。该方法可以有效地规范车间生产行为,并对异常行为进行及时预警,具有实际的工程应用价值。

未矫正老视所致近视力损害情况的调查分析

目的了解未矫正老视所致近视力损害的患病率及其不良影响。方法采取多阶段分层随机整群抽样方法,对受试者进行上门调查,登记受试者姓名、性别、年龄、受教育程度、框架眼镜使用情况等。采用《12项视觉功能问卷》进行视觉功能评估,侧重评估视觉障碍对心理健康、社会功能完整性、任务导向型的日常视觉功能的影响。结果 84.82%受检者无矫正视力的眼镜。2.74%无视物困难,11.71%轻度视物困难,41.60%中度视物困难,41.09%重度视物困难,2.86%极度视物困难。分级评估中0~30分者440人(25.14%),31~60分者645人(36.86%),61~90分者499人(28.51%),90分以上166人(9.49%)。受检者中,中度以上视物困难者对于近距离工作有不同程度的影响,工作难度增加和工作效率低下;重度视物困难、极度视物困难者明显影响近距离的工作和日常生活以及眼部极易疲劳。没有矫正视力的受检者中,62.26%(924/1 484)认为不矫正视力经常会影响其近距离工作,32.08%(476/1 484)经常需要别人的帮助,经常感到眼部疲劳。结论 45.82%(680/1 484)未矫正老视造成的视力损害对人们的职业生活和眼部健康产生明显的不良影响。