不同清洗剂对水果四种残留农药的洗涤效果研究

探讨不同清洗剂对水果在模拟体系中污染的四种农药残留的洗涤效果,得到日常生活中简便易行的去除水果农残的方法.分别采用清水、2％食盐水和2％ NaHCO3水溶液对圣女果、李子、马奶提葡萄上的四种残留农药进行清洗,然后用气相色谱测定各种农药的含量.清水、2％食盐水和2％ NaHCO3水溶液对水果中百菌清的平均洗脱率分别为32％、49％和48％,对敌百虫的平均洗脱率分别为31％、34％和40％,对毒死蜱的平均洗脱率分别为20％、36％和33％,对高效氯氰菊酯的平均洗脱率分别为6％、8％和16％.实验结果显示,清水、2％食盐水和2％ NaHCO3水溶液对水果中残留农药的平均洗脱率分别是22％、32％和34％,食盐和NaHCO3水溶液的洗脱效果优于单独使用清水的洗脱效果,使用这两种清洗剂可作为日常去除带皮食用水果中农残的有效方法.     

不同清洗剂对水果四种残留农药的洗涤效果研究

探讨不同清洗剂对水果在模拟体系中污染的四种农药残留的洗涤效果,得到日常生活中简便易行的去除水果农残的方法。分别采用清水、2%食盐水和2%NaHCO3水溶液对圣女果、李子、马奶提葡萄上的四种残留农药进行清洗,然后用气相色谱测定各种农药的含量。清水、2%食盐水和2%NaHCO3水溶液对水果中百菌清的平均洗脱率分别为32%、49%和48%,对敌百虫的平均洗脱率分别为31%、34%和40%,对毒死蜱的平均洗脱率分别为20%、36%和33%,对高效氯氰菊酯的平均洗脱率分别为6%、8%和16%。实验结果显示,清水、2%食盐水和2%NaHCO3水溶液对水果中残留农药的平均洗脱率分别是22%、32%和34%,食盐和NaHCO3水溶液的洗脱效果优于单独使用清水的洗脱效果,使用这两种清洗剂可作为日常去除带皮食用水果中农残的有效方法。      

发酵过程对橙皮渣中农药残留的影响

利用热带假丝酵母(Candida tropicalis)1254和宇佐美曲霉(Aspergillus usamii)对甜橙皮渣进行发酵处理,研究发酵过程对皮渣中16种农药残留含量的影响。结果显示:酵母和曲霉发酵处理对甜橙皮渣中百菌清和敌敌畏残留的降解最显著,降解率达到了72.87%～100%;除氧化乐果外,其他有机磷农药残留的降解率为27.95%～62.28%,显著高于对照,也高于相应处理中的三氯杀螨醇、腐零利和菊酯类农药残留的降解率。此外,酵母发酵处理对皮渣中农药残留降解的总体效果要好于曲霉处理。     

柑橘皮渣生物转化燃料乙醇的研究进展

利用柑橘皮渣生物转化燃料乙醇是一种生产乙醇的安全可再生的方法。以柑橘皮渣为原料,通过酶或酸进行水解成可发酵糖液,利用糖酵解途径发酵乙醇的微生物将其转化为乙醇,提取脱水到99.5%浓度即得到燃料乙醇。这旨在解决柑橘产业大量副产物皮渣造成的环境污染资源浪费,同时生产乙醇作为枯竭的石油能源替代品。柑橘皮渣转化乙醇中,D-柠檬烯严重抑制微生物发酵,但合理控制各种影响因素可达到较高的乙醇产量。文中对柑橘皮渣生物转化燃料乙醇的过程及影响因素等进行了综述。     

我国主产地柑橘的农药残留现状研究

我国柑橘生产使用农药种类多、剂量大,对产品质量安全有一定影响。文中采用气相色谱和高效液相色谱检测技术,对我国6省(市)柑橘产地抽取的198个鲜果样品进行了26种农药残留的检测与评价。10种农药残留检出,包括禁限用农药,其中1个样品有1种农残超标,超标率为0.47%,各省(市)柑橘鲜果样品的农药残留检出率均在48.9%以上,我国柑橘质量安全存在潜在风险。     

平菇及其培养料中5种拟除虫菊酯类农药的残留消解动态

在确证平菇培养料中联苯菊酯、甲氰菊酯、高效氟氯氰菊酯、高效氯氰菊酯和溴氰菊酯5种拟除虫菊酯类农药多残留分析方法的基础上,研究供试拟除虫菊酯类农药在平菇和培养料中的消解动态规律。结果表明:5种供试拟除虫菊酯类农药在平菇和培养料中的消解半衰期分别为3.01～5.06、25.48～54.59d。平菇培养料的灭菌会显著减少其中拟除虫菊酯类农药的残留量,降解率达18.80%～61.16%。平菇在含有联苯菊酯等5种拟除虫菊酯类农药的培养料中栽培42、62、83、103d后,培养料中供试农药残留量仍较高,分别为1.29～7.40、1.55～6.81、0.32～1.78、0.14～1.76mg/kg,同步采集的平菇子实体中均未检测到供试农药的残留量。因此,平菇培养料中供试拟除虫菊酯类农药残留不会向平菇子实体转移,对食用菌产品质量安全的影响较小。     

“检出农药残留”跟“危害健康”不是一回事

农药残留控制在国家标准内,几乎没有健康风险根据这份用466项欧盟农残标准检测出现的榜单显示,混合农残的问题仍旧不容乐观,每种蔬菜平均混合5种以上的农残。对于这份榜单农科院专家有如下表示。第一,＂检出农药残留＂与＂危害健康＂不是一回事。任何农药都需要达到一定的量才会产生危害。这个＂不产生危害的量＂是由国家标准来进行规范的。     

柑橘皮渣生物转化利用研究进展

柑橘皮渣生物转化利用主要转化为燃料乙醇、沼气、饲料、酶制剂、食品和食品添加剂,通过微生物和酶作用,实现资源再利用,这既能提高柑橘副产物利用率,又能开发各种新型生物转化产品。本文就柑橘皮渣生物转化利用的国内外研究现状进行综述,并提出以后的研究方向。     

我国北方三省(区)几种常见野生食用菌营养成分分析

为了解野生食用菌的营养价值,本实验以我国北方三省(自治区)(内蒙古自治区、辽宁省、吉林省)群众喜食的几种常见野生食用菌为材料,与市场上常见的平菇和香菇作对比,以比较不同食用菌间的营养成分差异。结果表明,11种野生食用菌在灰分含量方面大大高于人工栽培的食用菌;蛋白质含量、氨基酸综合评价方面平菇(CK1)和香菇(CK2)高于吉-2、吉-3,低于其他地区食用菌。在多糖、粗纤维方面,平菇(CK1)和香菇(CK2)处于中等水平。总体来说,尽管野生蘑菇营养成分差异较大,但与栽培食用菌相比野生食用菌开发具有一定的价值。     

多菌灵和灭蝇胺在平菇及培养料中的残留及消解动态

目的研究多菌灵和灭蝇胺农药在平菇和培养料中的消解动态规律。方法在大棚中开展平菇及其培养料残留消解动态实验,采用超高效液相色谱(ultra performance liquid chromatography,UPLC)检测平菇和培养料中的农药残留量。结果在培养料中低浓度(1 g/kg)和高浓度(1.5 g/kg)的多菌灵消解半衰期分别为35.4 d和40.1 d,低浓度(0.25 g/kg)和高浓度(0.375 g/kg)灭蝇胺的消解半衰期分别22.5 d和24.2 d。平菇培养料的灭菌会显著减少其中多菌灵和灭蝇胺农药的残留量,低浓度和高浓度的灭蝇胺降解率分别为17.52%和8.04%,低浓度和高浓度的多菌灵降解率分别为43.17%和62.87%。平菇在含有灭蝇胺农药的培养料中栽培,同步采集的平菇子实体中均未检测到灭蝇胺的残留量;平菇在含有多菌灵农药的培养料中栽培,同步采集的平菇子实体中多菌灵的残留量在0.394 mg/kg以上。结论平菇培养料中灭蝇胺农药残留不会向平菇子实体转移,对食用菌产品质量安全的影响较小;平菇培养料中多菌灵农药会向平菇子实体转移,且影响平菇菌丝生长,建议慎用多菌灵。     

Mineral composition of oyster mushroom

Oyster mushroom (Pleurotus ostreatus) belongs to the best known wood-destroying fungi. In the nature it grows on trunks and stumps of deciduous trees but nowadays it is also cultivated on modified lignocellulose substrates in oyster mushroom farms. It possesses a very pleasant flavour and piquant taste. As most fungi it contains up to 90% water, but owing to its protein and amino acids content, low fat content, content of B-group vitamins and a wide spectrum of mineral substances it represents a good source of biologically valuable substances for human nutrition. The saccharidic complex of oyster mushroom is characterized by low content of digestible carbohydrates and by a relatively high content of polysaccharides which take part in formation of edible fibre. In the past mushrooms were generally regarded as less valuable foodstuffs especially for their low energetic value and high fibre content. With respect to the present knowledge their importance is coming to the foreground [1]. Although some authors report that the mineral composition of oyster mushroom is biologically highly valuable — because of its content of macroelements, but especially because of numerous microelements that began to be appreciated only recently — relatively few data are available [2–10]. This paper will contribute to enhancing information in this field.     

富硒平菇液态深层发酵试验研究

采用平菇作为富硒的载体,将亚硒酸钠(Na2SeO3)添加到液体培养基中,进行液态深层发酵试验,研究平菇对无机硒的生物转化能力.通过单因素试验及正交试验确定出液态深层发酵最优工艺参数.结果表明,在摇床频率为200r/min、培养6d的条件下,富硒平菇液态深层发酵最优工艺参数为装液量50mL,pH6.5,温度30℃,加硒浓度7.5mg/L.此时平菇总富硒量为1714μg/L.     

正交试验优化平菇面包工艺

以高筋小麦粉为主要原料,添加3种不同处理方式的平菇匀浆制作平菇面包。通过单因素和正交试验研究平菇处理方式、平菇添加量、白砂糖添加量、油脂添加量对面包品质的影响。结果表明:平菇面包最佳工艺参数为平菇蒸煮熟化匀浆处理,以高筋小麦粉质量(100%)为基准,添加12%平菇浆料、14%白砂糖、15%油脂、6%鸡蛋、2%食盐、2%酵母、3%面包改良剂、47%～48%水,在此条件下,平菇面包感官评分为90.5分。面包表皮有光泽,颜色均匀一致,面包芯质地细腻,填充物均匀分布,口感松软,除有面包特有的发酵香气外,后味香甜,有平菇香气。     

平菇馒头制作工艺研究

为了丰富平菇精深加工产品种类,提高其利用价值。以平菇为研究对象,在单因素实验基础上,采用正交优化实验,研究平菇馒头的最佳制作工艺。结果表明,在小麦粉为100g的情况下,平菇浆添加量为36 mL、酵母添加量为0.85 g以及发酵时间为55 min时,制成的平菇馒头质地均匀,形态完整,口感好,有适宜的平菇风味,馒头感官评分达到92分。     

Post-harvest physiology and storage of the white oyster mushroom Pleurotus flabellatus

Changes in the post-harvest storage of the mushroom Pleurotus jlabellatus at ambient temperature were studied. There was a decrease in respiratory rate and soluble carbohydrates along with loss in water content. With progress in period of storage, the fresh mushrooms showed an increase in the activities of 0-diphenoloxidases and proteases accompanied with decrease of total phenols and increase in free amino acids respectively. The degree of discoloration increased with the lapse of storage time.
Fresh mushrooms (200 g) packed in 25 μm thick polyethylene bags (16 × 25 cm) with one pin hole on either side stored up to a period of 24 hr at ambient temperature and up to a period of 6 days at 5 ± 2°C in the intact polyethylene bags.     

Compression properties of the fruit body of king oyster mushroom Pleurotus eryngii

To investigate the textural properties of edible fungi, raw and boiled cubic samples cut from stipe of the king oyster mushroom Pleurotus eryngii were compressed from various directions by different type utensils, and their deformed tissue structures were examined. Differences in the loads between compress directions were observed by the homogenous compression. A significant difference between the loads of the boiled upper (~10 N) and lower (~12 N) portions of stipe by intrusive compression from parallel to the growth direction was found. In the scanning electron microscopy (SEM) images, the arrangement of fibrous spawn in the lower‐portion tissue was characterised by curl‐like formations. The fibre also appeared tangled in irregular arrangements. The results of this study indicate that the firmness of mushroom tissue was produced by the complex attributes, which were the mechanical strength and physicochemical bindings of the fibre, and that the fibre arrangement and/or formation of the tissue.     

Cultivation of the oyster mushroom (Pleurotus ostreatus) on lignocellulosic waste

The establishment of a small-scale production facility for Pleurotus ostreatus is described and environmental and yield data are presented. The average yield was c. 50% fresh weight mushroom/dry weight substrate when grown on 40% cocoa shell waste, 40% softwood sawdust, 19% oatmeal and 1% carboxymethyl cellulose. The mushroom fruited when daily temperatures ranged between 11 and 27°C.     

Development of surimi gel from king oyster mushroom and cuttlefish meat paste

Effect of king oyster mushroom on the physicochemical and textural properties of cuttlefish surimi gel was investigated. Surimi gels containing 20, 30, 40, and 50%(w/w) king oyster mushroom were analyzed for color, rheological properties, and sensory attributes. Texture profile analysis of fish paste added with king oyster mushroom paste showed significant decrease on hardness, cohesiveness, and gumminess. Springiness of cuttlefish paste increased with the addition of king oyster mushroom paste. The results of the sensory evaluation showed that cuttlefish paste added with 30, 40, and 50% king oyster mushroom had higher overall acceptability compared with that of the control. However, flavor, softness, chewiness, and overall quality tended to decrease in 50% king oyster mushroom paste group. Therefore, this study suggests that king oyster mushroom paste and cuttlefish were suitable for surimi gel production and could be effective in improving the nutritional properties and functionality of surimi gel.     

Effect of some thermal and chemical pre-treatments on smoked oyster mushroom quality

The effect of different thermal and chemical pre-treatments on quality and enzyme activities of smoked mushroom was investigated. Mushrooms were blanched (water and steam) and dipped in different concentrations of SO₂, H₂O₂, ethylenediaminetetraacetic acid (EDTA) and citric acid for 10 min before smoking. Enzyme activities, colour characteristics, microbiological and sensory examinations were carried out every 2 weeks up to 8 weeks of storage at 4 °C. Smoked mushroom pre-treated with sulphites (SO₂), H₂O₂ and steam blanching had the best colour values, better scores for all sensory characteristics and lower non-enzymatic browning compared with the other pre-treatments. Pre-treatment against total aerobic bacteria, yeast and moulds was the most effective when using citric acid, EDTA and steam, followed by smoking of mushroom. The most effective pre-treatments on quality and safety of smoked mushrooms were those using H₂O₂ and steam. It can be concluded that thermal and chemical treatments followed by smoking of mushroom reduce enzyme activities and are suitable for preserving mushrooms.