abby asked in 社會與文化語言 · 1 decade ago


Measurement of relative leakage rate

Relative leakage rate was determined by the method of Li (2000). Litchi pericarp discs, (1 g), from 10 fruits were rinsed and incubated in 60 ml of distilled water for 4 h, and then the initial electrolyte leakage was monitored with a conductivity meter (DDS-11A, China).

Each sample was continually rinsed for 2 h after being boiled for 5 min, and the final electrolyte leakage (total electrolyte) was again monitored. Relative leakage rate was defined as percent of initial electrolyte.

Enzyme assay

Litchi pericarp (2 g) from 10 fruits was homogenized with 25 ml of 50 mM sodium phosphate buffer (pH 7.0) containing 0.25 g of polyvinylpyrrolidone (PPVP,Sigma). After centrifugation at 18,000g for 20 min, the supernatant was used as enzyme extract. POD (EC1.11.1.7) activity was based on the determination of guaiacol oxidation at 470 nm by H2O2. The change in absorbance at 470 nm was followed every 30 s by spectrophotometer(GBC Centra-10, Australia) (Lacan &Baccou, 1999). POD activity was defined as DA470/min/g FW (Li, 2000). Total SOD (SOD, EC was assayed according to the method of Oberley and Spitz (1985), based on the ability of SOD to inhibit the reduction of nitroblue tetrazolium (NBT, Sigma).

The absorbance was monitored at 550 nm. One unit of SOD is the amount of extract that gives 50% inhibition of the reduction rate of NBT.

Malondialdehyde (MDA) determination

MDA determination was followed the method described by Li (2000). Litchi pericarp, (1 g), from 10 fruits was homogenized in 15 ml of 10%TCA. The homogenate was centrifuged at 10,000g for 20 min, and then 2 ml supernatant of sample was reacted with 2 ml of 0.6% 2-thiobarbituric acid. The absorbance was monitored at 600, 532 and 450 nm, respectively. Calculation of MDA was based on the following formula:

C(μm/l) = 6.45(A532 - A600) -0.56 A450.

1 Answer

  • 1 decade ago
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    有關的漏泄率被李的方法確定 ( 2000 ) . 荔枝樹pericarp 光碟,(1 克) ,從10中水果被為4 h 沖洗並且在蒸餾水的60 ml孵化, 然後最初電解液滲漏被一傳導性米(DDS-11A,中國)監控 .

    在煮5分之後,每個樣品被連續為2 h 沖洗,以及最後的電解液滲漏(總電解液) 再次被監控。 親戚漏泄率確定當時百分之姓名的大寫首字母電解液。


    荔枝樹pericarp(2 克) 從10種水果中被50裡鈉磷酸鹽緩沖區的25 ml 均勻(pH值7.0) 包含0.25 克polyvinylpyrrolidone(PPVP,總和) . 在centrifugation在18,000 克適合20分之後,supernatant被用作酵選出。 莢(EC1.11.1.7) 活動因為H2O2以470納米基於guaiacol 氧化的決心。 變化在吸光度在470納米遵循每30 s 以spectrophotometer(GBC Centra-10,澳洲) (Lacan &Baccou,1999) . 莢活動被定義為DA470 /分/ 克FW(李,2000) . 總草地(草地,EC 活動被根據Oberley 和斯皮茨的方法分析 ( 1985 ) ,基於抑制nitroblue tetrazolium(NBT,總和)的減少的草地的能力 .

    吸光度被以550納米監控。 一單位草地是給NBT的減速率的50%的抑制的選段的數量。

    Malondialdehyde(MDA) 決心

    MDA 決心被遵循李描述的這種方法 ( 2000 ) . 荔枝樹pericarp,(1 克) ,從10中水果在10%的TCA的15 ml 均勻。 homogenate被以10,000 克離心分離20分, 然後樣品的2 ml supernatant被與0.6%的2-thiobarbituric酸的2 ml起回應。 分別,吸光度被在600,532 和450納米監控。 MDA的計算基於下列公式︰

    C( /l) =6.45(A532-A600) -0.56 A450。

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