The effects of glucose, peptone, KH2PO4, fruit and vegetable juice on the biomass of Flammulina velutipes were studied by response surface methodology using Box-Behnken center combination design with 4 factors and 3 levels. The results showed that the optimum medium mass fraction was glucose 2.15％, peptone 0.38％, KH2PO4 0.27％, fruit and vegetable juice 12.90％. Under the condition of optimizing the composition of the medium, the maximum yield of mycelium of Flammulina velutipes was 21.51 mg/mL and the actual measured value was 21.46 mg/mL.

以葡萄糖、蛋白胨、KH2PO4、果蔬汁用量为影响因素,应用响应面分析法探讨灰树花液体发酵的最优条件,并以菌丝体生物量为指标,测定体外抗氧化活性.实验结果表明,100 mL液体培养基,接种量10％时,最优培养基的配方:葡萄糖25％ (w·v-1),蛋白胨05％ (w·v-1),KH2PO4 0.1％ (w·v-1),果蔬汁15％ (v·v-1).在此条件下菌丝体生物量预测值为19.06 mg·mL-1,与实际测量值(18.12±0.214) mg·mL-1在误差范围内.抗氧化结果表明,灰树花菌丝体具有较强的清除能力,当质量浓度为1.5 mg·mL-1时,DPPH自由基的清除率达到69.78％±6.17％;ABTS自由基的清除率达到82.11％±7.24％;羟基自由基清除率达到59.73％ ±3.15％.因此,灰树花液体发酵培养的菌丝体可以作为潜在的抗氧化剂.

A response surface experiment was conducted to optimize the fermentation of Flammulina velutipes for the extracellular polysaccharides (EPS).Liquid media with varied amounts of glucose,peptone,KH2PO4,fruit and vegetable juices were used for the experimentation.At end of the process,the antioxidant activity of EPS in each liquid suspension was determined as the criterion for optimization.The results showed that (a) the effect of ingredients in medium on the antioxidant activity ranked as peptone＞KH2PO4 ＞fruit/vegetable juices＞glucose;(b) the medium containing 2.46％ glucose,0.5％ peptone,0.1％ KH2PO4 and 15％ fruit/vegetable juices produced the highest EPS in the suspension at 0.83 mg · mL-1;(c) at concentrations exceeding 2 mg · mL-1,EPS obtained from the fermentation exhibited a strong scavenging effect on DPPH and ABTS free radicals;(d) at a same concentration level,EPS had a greater DPPH free radical scavenging rate than Vc;and,(e) at concentrations higher than 1.5 mg · mL-1,EPS exhibited a scavenging rate on ABTS free radicals similar to Vc,reaching 99.87％.

冷却肉一般而言是指的就是在经过一系列的相关部门的专业检测之后,获得了屠宰许可之后的生猪肉被进行冷却处理的一个过程,该类猪肉务必要在24小时之内降到0-4℃这一个区间,在后续的加工、零售的过程当中,温度必须保持不变.冷鲜肉在经过加热处理之后,其的蛋白质也能够得到降解,无论是从肉质还是从嫩度看来,都是尤为不错的.所以说,如今的冷鲜肉的保鲜已经受到了人们的广泛关注.

本文主要选取两种不同的火腿肠系列进行亚硝酸盐含量测定,选取722型分光光度计作为主要测定工具,通过实验测出准确亚硝酸盐含量. 实验部分 仪器试剂及试样 设备名称:722型分光光度计;榨汁机;抽滤泵;电子天平. 选用药剂:Na2B407,·10H20、亚铁氰化钾、ZnSO4·7H20、对氨基苯磺酸、盐酸萘乙二氨、NaNO2、活性炭粉等以上试剂均为分析纯,水均用二次蒸馏水.