山苍子油含醛量分析

本文较全面介绍山苍子精油质量标准及柠檬醛的各种分析方法、并介绍了一些检测山苍子精油掺假的办法。

食用酒精含醛量测定的反滴定法

采用反滴定法测定食用酒精中的含醛量,可减少二次取样测定,只需2min测出结果,节省化验时间,提高生产的指导性。(孙悟)

花椒、肉桂对食用菜油的抗氧化作用

食用菜油的稳定性是保证油脂食品卫生质量的重要因素。本实验将添加香料的食用油在恒温(65℃)条件下静置,不同时间测定香料花椒、肉桂对食用菜油的POV(过氧化值)值。实验数据表明,花椒、肉桂对食用菜油具有抗氧化作用,而且肉桂的抗氧化性能大于花椒。产生差异的主要原因是肉桂的含醛量大于花椒,而醛类物质中与羰基直接相连的α-碳原子上具有较活泼的氢,与食用菜油中活泼的自由基形成稳定的氢过氧化物或将油脂还原,自身则形成抗氧化自由基分子,起到了较强的抗氧化作用。

山苍子果实外表颜色变化与其出油率及油质关系的研究

山苍子果实在成熟期内何时采收能使其出油率高且油质好 ,是生产经营者感到比较棘手的问题。本研究为直观起见 ,主要从果实外表颜色变化着手 ,找出其与出油率及油质的关系 ,结果表明 :山苍子果实过早或过晚采收提炼山苍子油 ,都会影响其出油率及油质 ,只有在适宜的时间采收才会使出油率高且油质好。

Analysis and Evaluation Indicator Selection of Chilling Tolerance of Different Cotton Genotypes

[Objectivc] This study aimed to investigate the chilling tolerance of seedlings of different cotton genotypes and screen appropriate indicators for assess- ing chilling tolerance, to establish reliable mathematical evaluation model for chilling tolerance of cotton, thus providing theoretical basis for breeding and promoting new chilling-tolerant cotton germplasms and large-scale evaluation of chilling tolerance of cotton varieties. [Method] Fifteen cotton varieties （lines） were used as experimental materials. The photosynthetic gas exchange parameters, chlorophyll fluorescence ki- netic parameters, chlorophyll content, relative soluble sugar content, malonaldehyde content, relative proiine content, relative conductivity and other 12 physiological indi- cators of seedling leaves under low temperature treatment （5 ℃, 12 h） and recovery treatment （25 ℃. 24 h） were determined; based on the chilling tolerance coefficient （CTC） of various individual indicators, the comprehensive evaluation of chilling toler- ance was conducled by using principal component analysis, hierarchical cluster anal- ysis and stepwise regression analysis. [Result] The results showed that the 12 indi- vidual physiological indicators could be classified into 7 independent comprehensive components by principal component analysis; 15 cotton varieties （lines） were clus- tered into three categories by using membership function method and hierarchical cluster analysis; the mathematical model for evaluating chilling tolerance of cotton seedlings was established： D =0.275 -0.244Fo1 ＋0.206Fv/Fm1＋0.326g,%-0.056SS ＋ 0.225MDA＋O.O38REC （FF=0.995）, and the evaluation accuracy of the equation was higher than 94.25%,0. Six identification indicators closely related to chilling tolerance were screened, including Fo,, Fv/Fm1, Seedling leaves of cotton varieties （lines） gs2, SS, MDA, and REC. [Conclusion] with high chilling tolerance are less dam- aged under low temperature stress, and are able to maintain relatively high photo- synthetic electron transport capacity and high stomatal conductance after recovery treatment, which is contributed to gas exchange and recovery of photosynthetic ca- pacity. Determination of the six indicators under the same stress condition can be adopted for rapid identification and prediction of the chilling tolerance of other cotton varieties, which provides basis for the breeding, promotion, identification and screen- ing of chilling tolerant germplasms.

Physiological characteristics changes of Aesculus chinensis seeds during natural dehydration

A study was conducted to determine the physiological characteristics changes of Aesculus chinensis seeds during natural dehydration in 2003. The results showed that A. chinensis seeds were recalcitrant with being highly desiccation-sensitive. The seed moisture content of fresh fruits was higher than 60%. When the seeds were naturally dried for 30 days, their moisture content declined to 30.2% and their viability was completely lost. The seed germination percentage had a small increase at the beginning of desiccation and then decreased rapidly. The relative electrical conductivity of the A. chinensis seeds increased along with a decrease in seed moisture content. However, there was an abnormal increase in relative electrical conductivity when the seed moisture content was between 53.7% and 50.9%. Superoxide dismutase （SOD） activity decreased rapidly in the period of desiccation except for an abnormality when the seed moisture content was between 53.7% and 50.9%. Malondialdehyde （MDA） content increased slowly at the early stage of desiccation and then rose rapidly after the moisture content was below 50.9%. The soluble sugar content in seeds slowly increased with the increasing period of desiccation. The seed germination percentage was at the high level when seed moisture content was in range of 47%- 60%, which suggests that this was the optimum moisture content for maintaining A. chinensis seed viability.

Antioxidant activity of chito-oligosaccharides on pancreatic islet cells in streptozotocin-induced diabetes in rats

AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.

Increased plasma malondialdehyde and fructosamine in anemic H pylori infected patients:Effect of treatment

AIM： TO unravel the possible association of malondialdehyde （MDA） and fructosamine in anemic H pylori infected patients and to observe the alteration in MDA and fructosamine levels in these patients after treatment for one month. METHODS： Fructosamine, MDA and glucose were estimated in 22 anemic H pylori infected patients and 16 healthy controls. Hematological parameters were also evaluated in both the groups using Sysmex-K-100 automated cell counter. The H pylori infected patients were randomly divided into two groups. Hpylori infected patients in Group Ⅰ received both iron supplementation and anti-H pylori therapy, while patients in Group Ⅱ received only iron supplementation. All the biochemical and hematological parameters were estimated after one month of treatment. RESULTS： In anemic H pylori infected patients, while MDA （5.41 ± 2.16 vs 2.26 ± 0.50; P 〈 0.05） and fructosamine （2.64 ± 0.93 vs 1.60 ± 0.35; P 〈 0.05） were significantly increased, iron （32.72 ± 14.93 vs 110.25 ± 26.58; P 〈 0.05）, hemoglobin （6.9 ± 2.6 vs 12.66 ± 0.74; P 〈 0.05） and ferritin （28.82 ± 16.27 vs 140.43 ± 30.72; P 〈 0.05） levels were significantly decreased compared with the controls. With partial correlation analysis, fructosamine was found to have a significant positive correlation with MDA. In Group I, while MDA level decreased significantly （3.11 ± 1.73 vs 5.50 ± 2.46; P 〈 0.05）, there was a significant increase in iron （84.09 ± 29.51 vs 36.09 ± 17.81; P 〈 0.05）, hemoglobin （10.40 ± 1.11 vs 7.42 ± 1.90; P 〈 0.05） and ferritin （116.91 ± 63.34 vs 30.46 ± 17.81; P 〈 0.05） levels after one month. There was no significant change in the levels of fructosamine in group Ⅰ after treatment. Similarly, no significant alterations were noted in the levels of IDA, fructosamine, hemoglobin or ferritin in Group Ⅱ patients after one month of treatment. CONCLUSION： An increased level of fructosamine and MDA was found in anemic H pylori infected patients. Present data supports the premise that lipid peroxides per se do play a role in the glycation of plasma proteins. Furthermore, the findings from this study indicate that treatment for both anemia and H pylori infections is required for lowering the levels of lipid peroxides in these patients.

Study on Brewing Technology of Apple Brandy

[Objective] The aim was to study the brewing technology of apple brandy. [Method] After the activated wine yeast was added to the apple juice by sizing classification, rinsing, falling to pieces and squeezing, the preceding fermentation began. Every other day, parameters of fer- mentation broth such as temperature, pH, acidity, sugar content and bubble nurdbers were detected. Once the sugar content of the fermentation suspension was approaching 5 -6 °Bx, the following fermentation would start via pouring wine. After 20 -30 days, the cider was changed into origi- nal apple brandy by distillation. The last procedure was aging which included man-made speediness aging and oak wood aging about 20 days. The physical and chemical compositions before and after aging were measured. [ Result] 22.5 kg apple resulted into 16.56 L of juice. The juice yield was about 73.6% （10 ml/kg）. The alcohol rate of distilled apple juice was 20.0%. The color of apple brandy was darker than that of original apple brandy. Alcohol level reduced, but total acidity, fixed acid, lipid and furfural content rose. [ Conclusion] The apple brandy was of particular flavor and high quality by selecting befitting fruit, activated wine yeast and feasible brewing, distillation and aging technology. It will be conductive to the development of apple processing industry and the research and development of key brandy technique.

Variations of antioxidant enzyme activity and malondialdehyde content in nemertean Cephalothrix hongkongiensis after exposure to heavy metals

The antioxidant enzyme activity and malondialdehyde(MDA) content of Cephalothrix hongkongiensis were studied to assess variations in the biochemical/physiological parameters of nemerteans under heavy metal stress.Worms were exposed to copper,zinc and cadmium solutions at different concentrations,and the activity of three antioxidant enzymes,catalase(CAT),superoxide dismutase(SOD),and glutathione peroxidase(GPX),and MDA content were measured.The results show that the activity of each enzyme changed immediately after exposure to heavy metals.CAT was invariably inhibited throughout the experimental period,while the SOD activity was significantly elevated by exposure to Cu^(2+) for 48h,but then decreased.SOD was inhibited by Zn^(2+) during the first 12h of exposure,but activated when exposed for longer periods.Under Cd^(2+) stress,SOD activity decreased within 72h.GPX activity varied greatly,being significantly increased by both Cu^(2+) and Zn^(2+),but significantly inhibited by Cd^(2+) in the first 12-24h after exposure.MDA content increased on Cu^(2+) exposure,but normally decreased on Zn^(2+) exposure.MDA content followed an increase-decrease-increase pattern under Cd^(2+) stress.In conclusion,the antioxidant system of this nemertean is sensitive to heavy metals,and its CAT activity may be a potential biomarker for monitoring heavy metal levels in the environment.

Efficacy of Betel Leaf Extracts as Antioxidant in Moisturizing Cream

This work aims to study the appropriate method for extract Betel leaf as crude extracts to prepare as a natural antioxidant in moisturizing hand cream. Betel leaf was treated by 7 methods and the optimized method was selected for preparation of Betel leaf extract. The fresh Betel leaf and dried Betel leaf were used in this study. Betel leaf extracts were analysed for total phenolic content and essential oil as eugenol content. Then Betel leaf extracts were used as the one component for moisturizing hand cream. The lipid oxidation was evaluated by measurement on malondialdehyde content. The results revealed that an extracts solution from dried Betel leaf contained total phenolic content and eugenol content more than flesh Betel leaf. The ethanol extraction method was the optimum method since this method showed the maximum total phenolic content and eugenol content in dried Betel leaf as 5.26 g/100 g and 138.95 mg/100 g, respectively. The moisturizing creams were formulated by using crude Betel leaf extracts as the one composition compare with base cream （no addition of Betel leaf extracts）. The moisturizing cream samples were analysed for malondialdehyde. its showed that the cream that contained Betel leaf extract contained malondialdehyde content lower than in cream base. Thus, crude extracts from Betel leaf showed the efficacy to reduce lipid oxidation reaction in moisturizing hand cream.