蚕体黄酮类化合物的提取及不同家蚕品种间的含量差异

为了高效提取家蚕幼虫体内的黄酮类化合物及筛选富含黄酮类化合物的家蚕品种,通过正交试验优化提取工艺条件,采用NaNO2-Al(NO3)3-NaOH比色法测定分析16个黄血蚕品种和3个普通白血蚕品种幼虫体中的黄酮类化合物含量。家蚕幼虫粉经超声波预处理20 min后以80%乙醇溶解,当原料质量浓度为25 g/L,在60℃水浴中提取6 h的效果较佳,提取蚕体总黄酮的质量比达到0.473 mg/g。黄血蚕品种幼虫体中的黄酮类化合物含量极显著高于普通白血蚕品种,两类品种样品中的总黄酮平均质量比分别为0.560、0.513 mg/g。在16个黄血蚕品种中,以来源于东南亚地区的二化性品种幼虫体中的黄酮类化合物含量较高,是富含黄酮类化合物的家蚕品种资源。     

实时荧光定量PCR检测高温即时浸酸对蚕卵中家蚕微孢子虫的灭活效果

家蚕微孢子虫(Nosema bombycis,Nb)引起的家蚕微粒子病是对蚕种生产危害最为严重的家蚕病害,蚕种浸酸处理是蚕业生产中常用的一种防病处理手段。为探明浸酸处理对家蚕微粒子病的防治效果,将家蚕二化性四元杂交组合两广二号的带毒蚕卵分别进行常规即时浸酸处理和高温即时浸酸处理,采用实时荧光定量PCR对卵龄24~240 h蚕卵中的家蚕微孢子虫进行定量检测。结果发现,常规和高温浸酸处理后每日取样蚕卵中家蚕微孢子虫的检测值较阳性对照组均显著降低,高温浸酸组又明显低于常规浸酸组,表明2种浸酸处理对蚕卵中的家蚕微孢子虫均有灭活作用,且高温处理的灭活效果更为显著。对蚕卵孵化后饲养至3龄眠和5龄起的幼虫逐条进行显微镜镜检,结果显示高温即时浸酸处理对家蚕微粒子病的相对防治效果分别为92.30%±2.95%和81.80%±0.06%。综上表明,高温即时浸酸处理带毒蚕卵对家蚕微粒子病有显著的防治作用。     

柞蚕蛹油中的脂类物质组成分析

利用正己烷、无水乙醇、乙酸乙酯和氯仿-甲醇(体积比2∶1)4种有机溶剂提取柞蚕蛹油,并对蛹油中的甘油酯、磷脂、甾醇、维生素E等脂类物质进行较为系统地分析。结果表明,柞蚕蛹油中的脂类物质主要为甘油酯,其中甘油三酯约占88%,1,3-甘油二酯(1,3-DAG)约占1%,1,2-甘油二脂(1,2-DAG)约占1.5%;脂肪酸中不饱和脂肪酸的含量高,质量分数可达到80%以上,其中α-亚麻酸占40%,油酸占29%,亚油酸占7%;脂类物质中维生素E的质量分数高达382.56μg/g,主要为α-生育酚(255.00μg/g),还含有少量β-生育酚、γ-生育酚和γ-生育三烯酚;甾醇类物质主要由胆固醇和β-谷甾醇组成,其中β-谷甾醇的质量分数达到3.36 mg/g;磷脂类物质主要由溶血磷脂酰胆碱(LPC)、溶血磷脂酰乙醇胺(LPE)、磷脂酰胆碱(PC)、磷脂酰乙醇胺(PE)和磷酯酰丝氨酸(PS)组成,其中PE含量最高,达到34.82%,PS含量最低,仅占1.28%;采用质谱鉴定出18种甘油三酯,相对含量较高的依次为二油酸棕榈酸甘油酯(POO)、二亚麻酸棕榈酸甘油酯(PLnLn)和二亚麻酸亚油酸甘油酯(LLnLn),其含量分别占总甘油三酯的21.18%、14.22%和10.54%。     

Changes during the ripening of the very late season Spanish peach cultivar Calanda: Feasibility of using CIELAB coordinates as maturity indices

Physiological maturity of peach at harvest greatly influences the post-harvest quality. Changes in colour during the last ripening stages of a very late and firm peach cultivar [Prunus persica (L.) Batsch cv. Calanda] have been studied to assess the feasibility of using reflectance colour references as non-destructive indices of maturity. The respiratory peak was simultaneous to the ethylene rise, and both induced important changes in the peaches. The physiological changes brought about a rise in polyphenoloxidase and peroxidase enzyme activity. The amount of carotenoids increased as maturity advanced and more markedly at the climacteric rise. Reflectance spectra and CIELAB coordinates reflected changes in skin and pulp colour and a^* and h_ab evolved nearly in a near linear way. Values of the b^* coordinate show changes as well. These findings agree with and extend previous results that reflectance changes can be used as reliable indices to establish the time of physiological maturity in Calanda peaches.     

大麦虫养殖效益分析

大麦虫能够对农作物秸秆,农副食品加工的废渣、果渣,餐厨余物,城市淤泥等物质消化转化,可实现物质循环、变废为宝、低值变高值的目的,解决了环境污染和蛋白质源紧缺两大难题。综述了大麦虫的生态特性、繁殖性能、药用和食用价值以及养殖效益。     

Effects of Mulberry Leaf Meal and Fermented Mulberry Leaf Meal on Slaughter Performance,Meat Quality and Cecum Microflora in Huxu Chicken

This experiment was conducted to investigate the effect of mulberry leaf meal and fermented mulberry leaf meal on slaughter performance,meat quality and cecum microflora of Huxu chicken at the late growth stage.Three hundred and ninety-two Lingnan Ⅲ Huxu chickens aged ninety-five days were assigned to seven dietary treatments randomly,they were control group,5%,10%,20% mulberry leaf meal groups and 5%,10%,20% fermented mulberry leaf meal groups.Every treatment had 4 replicates,14 chickens per replicates (7 males and 7 females).The pre-trial period was 4 days,and the formal experiment period was 28 days.The results showed as follows:① Compared with the control group,expect the 10% mulberry leaf meal group,the semi-eviscerated percentage were significantly decreased in other experimental groups (P<0.05).Adding 10% mulberry leaf meal or 20% fermenterd mulberry leaf meal extremely significantly reduced the eviscerated percentage (P<0.01) and 10% fermenterd mulberry leaf meal reduced it significantly (P<0.05).The leg muscle percentage of chickens in 5% fermenterd mulberry leaf meal group and 20% mulberry leaf meal group reduced extremely significantly (P<0.01) and significantly (P<0.05),respectively.② Compared with the control group,the shear force of chest muscle in all experimental groups,and leg muscle in all mulberry leaf meal groups decreased,but only the shear force of chest muscle in 10% mulberry leaf meal group decreased significantly (P<0.05).Adding 20% mulberry leaf meal increased the pH_{45 min} of leg muscle significantly (P<0.05).The b^* value of leg muscle reduced in all experimental groups,and only that in the 20% mulberry leaf group reduced significantly (P<0.05).③ Compared with the control group,the number of E.coli of the cecum of chickens in 5% and 10% mulberry leaf meal groups reduced extremely significantly (P<0.05),and the ratio of Lactobacillus to E.coli of cecum in all experimental groups had an increasing trend (P>0.05).All over,the content of mulberry leaf meal in Huxu chickens'diet at the late growth stage could be up to 10%,and fermented mulberry leaf meal could be up to 20%.     

开发建设项目水土保持监测方法探讨--以阿(荣旗)深(圳)高速公路粤赣段监测为例

开展水土流失监测是对开发建设项目实施水土保持监管的重要手段。通过对国家重点公路阿（荣旗）深（圳）公路粤赣段工程建设及其水土流失特点、危害的分析,结合开发建设项目的特点,对开展水土流失监测的内容、监测的方法、监测的技术进行了探讨,并就工作中的有关具体监测细节方面提出了建议。     

Effectiveness of 1-MCP treatments on ‘Bartlett’ pears as influenced by the cooling method and the bin material

Wooden bin-stored ‘Bartlett’ pears (Pyrus communis L.) were hydrocooled (HC) or forced-air cooled (FAC) and immediately treated or not with 1-methylcyclopropene (1-MCP) for 24 h. 1-MCP gas concentrations used were 0, 0.3 or 0.6 μL L^?1 (called 0, 0.3 and 0.6, respectively). Fruit were subsequently kept at 20 °C for 20 d or stored at ?0.5 °C and 95% RH for 60, 90, 120 or 150 d. After cold storage, fruit were kept at 20 °C for up to 16 d for further ripening. In another experiment, pears stored in wooden bins (W) or plastic bins (P) were all hydrocooled, treated or not with 0.5 μL L^?1 1-MCP (called 0.5 and 0, respectively), stored at ?0.5 °C and 95% RH for 0, 30, 60, 90 or 120 d, and transferred to 20 °C for further ripening. In FAC pears, increasing 1-MCP concentrations usually resulted in delayed increases in ethylene production and lower ethylene production rates, as well as delayed softening. In contrast, HC-0.3 pear firmness did not differ from that of HC-0 fruit after cold storage. Generally, HC-0.3 pears displayed higher ethylene production and lower firmness values than FAC-0.3 pears after a 7-d exposure to 20 °C, regardless the length of cold storage. FAC-0.6 pears always showed lower ethylene production rates and higher flesh firmness values than HC-0.6 fruit. Soluble solids concentration was not consistently affected by 1-MCP. FAC-0.3 and HC-0.6 fruit showed higher titratable acidity values than HC-0 fruit after 0, 60, 120 and 150 d of cold storage plus 7 d at 20 °C. Effectiveness of 1-MCP treatments on HC pears was influenced by the bin material; P-0.5 pears were firmer than W-0.5 pears after 7 d at 20 °C, regardless the length of the cold storage. HC-0.5 fruit exposed to ?0.5 °C for 90 d reached eating quality (firmness ≤23 N) by day 7 if placed in W, and by day 21 when stored in P. Results and previous evidence suggest that wet wooden bin material may represent a major though unpredictable source of 1-MCP sorption that could bind a significant percentage of the 1-MCP applied. When used at relatively low doses 1-MCP partial removal by wet wooden bins can compromise the application effectiveness for controlling ethylene action.     

芒果品种果实可溶性糖含量特点研究

用高效液相色谱法分析了46个芒果品种果实中可溶性糖的组分及含量的差异。结果表明,成熟期芒果果实中可溶性糖主要由蔗糖、果糖和葡萄糖组成,其中蔗糖含量最高,均值为20.19 mg/g.FW;不同品种之间蔗糖和葡萄糖含量存在显著差异,果糖含量差异不显著。     

Aromatic- and di-carboxylates inhibit wound-induced phenolic accumulation in excised lettuce (Lactuca sativa L.) leaf tissue

Excision of de-bladed 5-mm mid-rib segments from Romaine lettuce leaf tissue induced a five-fold rise in phenolic concentration when held at 10 °C for 48 h. Immersion in aqueous solutions of various di-carboxylates and aromatic carboxylates for 1 h reduced this wound-induced increase. The decrease was linear for di-carboxylates with increasing length from 3 to 14 carbons, with the phenolic concentration becoming less than the control for compounds with more than 6 carbons. Aromatic carboxylates with a hydroxyl at the 2 position and another at an even position produced an average reduction of 46%, while aromatic carboxylates with no hydroxyl groups, groups at odd positions, or adjacent groups produced an average 12% reduction. The decrease in wound-induced phenolic accumulation produced by 10 mM solutions of aromatic- and di-carboxylates was linearly correlated (R² = 0.91) with the rate of carbon dioxide production, indicating possible tissue damage. This possibility was supported by the fact that most effective concentrations were highly correlated with increased ion leakage, another measure of tissue damage. While delaying the application of inhibitors of wound signal synthesis (e.g., n-alcohols) decreases their effectiveness, delaying the 1 h immersion in aromatic and di-carboxylate solutions for 4 h did not significantly reduce their effectiveness. Like mono-carboxylates, aromatic and di-carboxylates do not appear to be interfering with the synthesis or propagation of a wound signal, but appear to be inhibiting phenolic synthesis and/or accumulation at some subsequent step in the wound response.