核桃花食用价值的研究与分析

分析测定了核桃花的营养成分，并与干蕨菜和脱水白菜的营养成分进行比较，结果表明，核桃花中蛋白持含量高达２１％，在１８．２２％的总氨基酸中，必需氨基酸４１．２％，谷氨酸２３％，色氨酸８．７％，支链氨基酸的含量也较高，但含硫氨基酸含量偏低，为第一限制氨基酸，ＣＢＶ４１．４８％，粗纤维不到干蕨菜的一半，但灰份比干蕨菜的高一倍多，Ｋ，Ｆｅ，Ｍｎ，Ｚｎ的含量比蕨菜和脱水白菜高，Ｋ／Ｎａ高达５００多，β－胡萝卜     

固定化增殖酵母酒精发酵新技术研究：第四报 薯类原料固定化增殖…

在前文基础上，利用Ｖ＝１１ｍ＾３传统发酵罐改造为并流型固定床反应器，进行木薯干原料固定化增殖酵母酒精发酵工业性试验。糖化醪糖化率Ｙｓ≥５０％，载体填充率８０Ｌ．ｇｅｌ／ｍ＾３反应器，发酵时间Ｔ１６．５ｈｒ，成熟醪乙醇浓度９．２２％，总糖利用率Ｕｗ＝９２．７％，糖醇化系数ＹＥ／ＳＰ＝０．４７１７，反应器容积乙醇产率ＰＶ＝４．５ｋｇ，Ｅｔ－ＰＨ／ｍ＾３．ｈｒ载体乙醇产率Ｐｃ＝５８．１８ｋｇＥｔ－ＯＨ／     

酸性脲酶反应动力学研究

用Ｂｅｒｔｈｌｏｔ法测定酸性脲酶酶反应过程产物ＮＨ＋４的浓度变化。实验表明，酸性脲酶反应是按Ｍｉｃｈａｅｌｉｓ机理进行。其最佳反应条件是ｐＨ＝４．５，反应温度６０℃，反应活化能Ｅａ＝３７．３４ｋＪ／ｍｏｌ，米氏常数Ｋｍ＝０．２８６８ｍｍｏｌ／Ｌ，Ｖｍ＝０．１７４４ｍｍｏｌ／Ｌ·ｍｉｎ．     

水溶性聚酯的溶液性质和粘结性能

对水溶性聚酯的溶液性质和粘结性能初步研究表明，水溶性聚酯溶液的表面张力为５４．５￣６４．６ｍＮ／ｍ，浸透速率为０．０２２３￣０．０５２１ｃｍ＾２／ｓ；它对涤纶织物的粘结力强，剥离强度为７．５３￣２５．６Ｎ／ｃｍ，最高值可达ＰＶＡ的８￣９倍，其平衡吸湿率为５．４１￣１２．７％，随分子结构而变化 。     

金樱子、魔芋复合果汁颗粒饮料的加工工艺

１前言金樱子（ＲｏｓａＬａｅｖｉｓａｔａＭｉｃｈｘ），又名糖罐子、蜂糖罐、黄茶瓶等，属蔷做科普微属常绿蔓性灌木野生果树。金樱子果实成熟时显黄色或红黄色，果实呈倒卵形或近球形，表面有细小直刺、萼片宿存，单果平均重量为４．３ｇ，可食部分占６３．７％，种子及萼片占３６．３％。果实含丰富的营养物质；Ｖｃ含量达１１８７．３ｍｇ／１００ｇ，是猕猴桃Ｖｃ含量的２．４～５．９倍，糖含量为２３．９６％；含有１９种氨基酸，其中包括８种人体必需氨基酸，含有１８种无机盐及微量元素，其中Ｆｅ、Ｚｎ、Ｃｕ、Ｍｎ等有保健疗效…     

树头发的成分分析

采用反相高效液相色谱法、葸酮比色法分别对树头发的氨基酸、水溶性维生素、町济性糖等成分进行分析。结果表明，除色氨酸被水解破坏而未检出外，树头发蛋白中含有16种氨基酸，9种必需氨基酸，其氨基酸的总含量达179．652μg／mg，总必需氨基酸含量为63．546μg／mg，必需氨基酸含量占总含量的35．37％；树头发中可溶性糖含量为2．93％，粗纤维含量为7．55％，维生素的含量：维生素C 1．484mg／g，烟酸1．096mg／g，维生素B1 0．586mg／g，维生素B2 0．096mg／g．     

四川小麦地方品种营养品质分析

为了评价四川小麦地方品种籽粒蛋白质的营养价值，本文通过化学分析法研究了67个四川小麦地方品种的蛋白质和氨基酸含量及其组成特性。结果表明：蛋白质含量平均为11．86％；18种氨基酸中谷氨酸、脯氨酸、亮氨酸和天门冬氨酸含量丰富，而色氨酸、蛋氨酸和半胱氨酸含量较少；必需氨基酸和总氨基酸含量分别为3．65％和11．68％；必需氨基酸含量与氨基酸总量之比为31．25％；必需氨基酸含量与蛋白质总量之比为30．78％；氨基酸评分表明，赖氨酸和蛋氨酸＋半胱氨酸的氨基酸评分平均值最低分别为47和70，因此赖氨酸和蛋氨酸＋半胱氨酸分别为第1和第2限制性氨基酸；必需氨基酸指数平均值为60。67个小麦地方品种中7个品种其赖氨酸含量相对较高，赖氨酸的氨基酸评分都在60以上；11个品种的必需氨基酸指数较高、均大于65，具有较为平衡的氨基酸组成；13个品种的必需氨基酸含量与氨基酸总量之比超过36％。是蛋白较为优质的小麦品种。结论：与WHO模式比较，四川小麦地方品种中存在部分优质营养品质资源。     

多重抗药性突变株中α－淀粉酶高产菌株选育

以解淀粉芽孢杆菌（Ｂａｃｉｌｌｕｓａｍｙｌｏｌｉｑｅｆａｃｉｅｎｓ）Ａ－４为出发菌株，经诱变处理，选育多重抗药性突变株。研究结果表明，抗药性突变株α－淀粉酶产量提高的正变率和正变幅度明显大于非抗药性突变株，负变率和负变幅度也较高。经ＮＴＧ和ＮＴＧ－ＵＶ诱变处理，获得一株林可霉素、Ｄ－环丝氨酸和万古霉素多重抗性突变株ＬＣＶ＿５（Ｌｉｎ￣ｒ，Ｃｓ￣ｒ，Ｖｍ￣ｒ），其α－淀粉酶活力比出发菌株Ａ－４提高３２．５％，发酵周期短，摇瓶为４０ｈ，酶活力达４６１ｕ／ｍｌ．     

聚吡咯修饰生物传感器的制备及应用

用电化学方法制备了聚吡咯－抗坏血酸传感器,研究了传感器制制备的条件,表征了传感器的电化学行为特征及其对抗坏血酸的Ｎｅｒｎｓｔ响应特性。传感器对抗坏血酸 Ｎｅｒｎｓｔ响应线性范围为５．０＊１０＾－１－５．０＊１０＾－８ｍｏｌ／Ｌ,为５７．５ｍＶ／ＰＶｃ,检测下限为１．０＊１０＾－８ｍｏｌ／Ｌ。电极的稳定性好,响应快、,寿命较长。可用于饮料中抗坏血酸含量的测定。     

醋蛋液的营养成分分析

对醋蛋液的营养成分进行了分析和评价，主要对一般营养成分、游离氨基酸组成及其无机质含量进行了检测和分析。结果表明：醋蛋液中的蛋白质含量较高，为3．17g／100ml；脂肪含量较低；游离氨基酸中必需氨基酸种类齐全，其中谷氨酸和赖氨酸含量最高，分别占到总量的13．55％和10、27％；无机质含量丰富，尤其是常量元素钙（180．8mg／100ml）。因此，醋蛋液是一种营养价值较高的饮品。     

脉冲电场对啤酒大麦萌发性质的影响

在啤酒麦芽制备过程中引入脉冲电场(PEF)技术,对浸渍后的大麦种子进行不同电场强度的处理,以了解PEF对大麦萌发性质的影响。结果表明,PEF处理有利于提高大麦萌发活力和相关理化性质。大麦籽粒经电场强度1.5、3.0、4.5、6.0、7.5 kV/cm处理后,萌发大麦的芽长、根长、根数、鲜重、干重、发芽势、发芽率、简化活力指数、还原糖含量、β-葡聚糖酶活力、α-淀粉酶活力、β-淀粉酶活力、可溶性蛋白质和氨基态氮含量等指标与对照组比较均有明显提高,发芽势、根长、β-葡聚糖酶活力、α-淀粉酶活力和β-淀粉酶活力提高的幅度分别为38.96%、43.33%、21.46%、26.48%和23.57%。对14项指标进行主成分分析的结果表明,当电场强度为6.0 kV/cm时,脉冲电场对大麦萌发的促进效果最好。     

高压静电场对大肠杆菌蛋白酶活力的影响

利用自制的试验装置,探讨了直流高压静电场对大肠杆菌蛋白酶活力的影响,结果表明:高压静电场对蛋白酶活力的影响有活化和钝化两种情况。电场强度为0～10kV/3cm场强范围,酶活力提高,在30℃,场强3kV/3cm,处理15min,最大能提高29.9%,而超过10kV/3cm后,酶活力逐渐降低,降幅可达13.2%。     

Effects of pulsed electric field (PEF) treatment on physicochemical properties of Panax ginseng

Effects of pulsed electric field (PEF) technology on physicochemical properties of raw Panax ginseng roots were investigated in this study. PEF treatment was conducted with different electric field strength (0.5, 1.5, and 2.5 kV/cm) and pulse width of 25 μs. Ginseng cell and vacuole membranes were significantly affected by PEF treatment at field strengths >1.5 kV/cm. Changes in membrane systems due to PEF treatment were verified by increased ion leaching and increased cell membrane disintegration (conductivity disintegration index Z value). Observation by electron microscopy revealed vacuole destruction and plasma membrane separation following PEF treatment. Texture profile analysis showed a significant decrease in hardness (by 44%) and chewiness (by 45%) at 2.5 kV/cm. PEF treatment had little effect on proximate composition and crude saponin content of ginseng roots. However, total phenolic content (by 11%) and antioxidant activity (by 21.4% for DPPH and 3.64% for ABTS) were significantly increased.Industrial relevanceRaw ginseng is normally steamed and dried to make white ginseng and red ginseng. However, using these methods is time consuming and requires much energy. Pulsed electric field (PEF) can induce the changes in physicochemical properties of ginseng with less energy for a short period of time. By using this technology, we can obtain ginseng products with high cell permeability and high antioxidant ability by tailoring the microstructure. This potentially increases the extraction of bioactive compounds in ginseng and significantly enhances the mass transfer during subsequent processing, thereby improving the efficiency of the whole process. These results could be used as basic study for the production of high-quality ginseng products using non-thermal technologies.     

Inactivation and conformational change of horseradish peroxidase induced by pulsed electric field

Effects of pulsed electric field (PEF) on the structure and activity of horseradish peroxidase (HRP) in buffer solution were studied. The results showed that activity of HRP decreased with the increase in applied electric field strength (5–25 kV/cm) and pulse numbers (207–1242 pulses). 16.7% and 34.7% reduction of HRP relative activity was achieved immediately after PEF treatment at 25 kV/cm for 207 pulses and 22 kV/cm for 1214 pulses, respectively. The temperature of buffer solution did not increase above 40 °C during PEF treatment. The relative activity exhibited a slow reduction after 24 and 48 h of storage at 4 °C. The HRP conformation changed after PEF treatment, as suggested by CD analysis and fluorescence spectroscopy analysis. α-Helix relative content in the HRP decreased by 35.1% and 57.7% after PEF and heating at 100 °C for 5 min, respectively. The intrinsic relative fluorescence intensity (RFI) increased after PEF treatment. The inactivation of PEF-treated HRP was related to the conformational change of α-helix and the increase of RFI.     

高压脉冲电场对抗氧化肽荧光特性的影响

以前期研究所得的Gln-Trp-Phe-Met(QWFM,652.78)和Lys-Trp-Phe-Met(KWFM,610.78)抗氧化四肽为研究对象,探究高压脉冲电场技术(pulsed electric field,PEF)对抗氧化肽荧光特性的改变。研究表明,在PEF作用下QWFM和KWFM的荧光强度发生了不同程度的改变,由于两条结构相似的抗氧化四肽中色氨酸前端所连接的氨基酸不同,在相同的PEF处理条件下,QWFM的荧光强度变化更为显著,在电场频率为1 800 Hz和电场强度为15 k V/cm时,其荧光强度变化最显著。通过监测经PEF处理后2 h抗氧化四肽荧光强度的变化,发现抗氧化四肽荧光强度的变化随着时间的延长而逐渐减弱。通过圆二色谱分析和核磁共振波谱技术分析发现维持QWFM中β-折叠的氢键含量有所改变从而导致了β-折叠结构的含量有所减少。这些变化表明PEF技术可能通过改变抗氧化肽的化学结构而改变其荧光特性,为PEF技术应用于抗氧化肽的研究提供了理论基础。     

Effects of high voltage electric field on storage life and antioxidant capacity of whole pomegranate fruit

The objective of this study was to investigate the effects of high voltage electric field (HVEF) on the antioxidant system in stored pomegranate fruit. The experiments were conducted at cold storage for two months under three selected electric field levels (0, 1.5 and 3 kV/cm). Results showed that non-enzymatic antioxidant contents including phenols and ascorbic acid were better preserved by 1.5 kV/cm treatment than control after 60 days of storage. While the activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) in pomegranate fruit were significantly enhanced with 1.5 kV/cm treatment compared to control, Guaiacol peroxidase (G-POX) levels in the control group increased steadily and were highest at the end of the storage. Although the results obtained from 3 kV/cm treatment were acceptable till the end of the first month, due to oxidative damage of reactive oxygen species (ROS) produced in response to HVEF stress, their results come close to the control group at the end of the second month. These data suggest that the optimum electric field intensity for enhancing antioxidant contents in stored pomegranate fruits was 1.5 kV/cm.     

Effect of high intensity pulsed electric fields and heat treatments on vitamins of milk

The effects of high intensity pulsed electric field (HIPEF) treatments at room or moderate temperature on water-soluble (thiamine, riboflavin, ascorbic acid) and fat-soluble vitamins (cholecalciferol and tocopherol) were evaluated and compared with conventional thermal treatments. Vitamin retention was determined in two different substrates, milk and simulated skim milk ultrafiltrate (SMUF). Samples were subjected to HIPEF treatments of up to 400 micros at field strengths from 18.3 to 27.1 kV/cm and to heat treatments of up to 60 min at temperatures from 50 to 90 degrees C. No changes in vitamin content were observed after HIPEF or thermal treatments except for ascorbic acid. Milk retained more ascorbic acid after a 400 microstreatment at 22.6 kV/cm (93.4%) than after low (63 degrees C-30 min; 49.7% retained) or high (75 degrees C-15s; 86.7% retained) heat pasteurisation treatments. Retention of ascorbic acid fitted a first-order kinetic model for both HIPEF and thermal processes. First-order constant values varied from 1.8 x 10.4 to 1.27 x 10(-3) micros(-1) for the HIPEF treatments (18.3-27.1 kV/cm) and, for thermal processing ranged from 5 x 10(-3) to 8 x 10(-2) min(-1) (50-90 degrees C). No significant differences were found between the results obtained after applying HIPEF treatments at room or moderate temperature. However, results depended on the treatment media. A beneficial effect of natural skim milk components, mainly proteins, was observed on the preservation of ascorbic acid, since skim milk retained more ascorbic acid than SMUF after HIPEF treatments.     

Influence of Pulsed Electric Field and Thermal Treatments on the Quality of Blueberry Juice

Fresh blueberries were selected as trial materials. Two blueberry juice samples were sterilized using pulsed electric field and thermal treatments respectively. Their qualities were analyzed and compared by evaluating the microorganisms in the samples. The changes in the quality of fresh blueberry juice samples during storage were also assessed. The results showed that the inactivation of Escherichia coli increased as electric field strength and treatment time increased. Pulsed electric field treatments at 35 kV/cm and 82 μs reduced E. coli by 5.12 logarithms. Pulsed electric field had less effect on juice quality, but after heat treatment, the vitamin C of blueberry juice sample was reduced by 14.78%, whereas its anthocyanin content was reduced by 3.64%. After sterilization, no significant change was observed in the relative reducing sugar, total acid, phenol contents, and Brix value. The vitamin C and anthocyanins contents of the fresh blueberry juice samples treated with pulsed electric field were higher than those treated with heat sterilization.     

新鲜葡萄酒高强电磁场人工催陈研究

通过采用高强电场处理设备对2002年产新鲜干红葡萄酒进行了人工催陈研究，发现当处理电场强度为3KV／cm，频率为1000Hz，处理时间5min时，与对照相比，酒体变得陈香明显加强，口感柔和协调，更加饱满。     

Enhancement of the solid-liquid extraction of sucrose from sugar beet (Beta vulgaris) by pulsed electric fields

A systematic study of the impact of pulsed electric fields (PEF) parameters (1–7 kV/cm, 5–40 pulses, specific energy of 0.006–0.19 kJ/kg per pulse, pulse frequency of 1–10 Hz, pulse width of 2–5 μs, square and exponential decay pulses) on the kinetics of the sucrose extraction from sugar beet at different temperatures (20–70 °C) has been carried out in this investigation. The efficiency of the solid-liquid extraction was independent of the frequency, as well as of the pulse width, and the pulse shape at 7 kV/cm, and it was influenced by the electric field strength applied and by the temperature of the extracting medium. Sucrose yield increased with both field strength, time of extraction, and temperature. The effect of the field strength was higher the lower the temperature. The application of 20 pulses at 7 kV/cm (3.9 kJ/kg) increased the maximum yield by 7 and 1.6 times, compared to non-PEF-treated samples, at 20 and 40 °C, respectively. A mathematical expression was generated, which enabled to evaluate the influence of the electric field strength (from 0 to 7 kV/cm) and temperature (from 20 to 70 °C) on the sucrose extraction efficiency and the extracting time in a solid-liquid PEF-assisted sucrose extraction process. Based on this equation, for 80%-sucrose extraction in 60 min, the temperature could be reduced from 70 °C to 40 °C, when 20 pulses of 7 kV/cm were applied.