Inactivation of peroxidase and lipoxygenase in carrots, green beans, and green peas by combination of high hydrostatic pressure and mild heat treatment

The efficiency of high hydrostatic pressure (HHP) with the combination of mild heat treatment on peroxidase (POD) and lipoxygenase (LOX) inactivation in carrots, green beans, and green peas was investigated. In the first part of the study, the samples were pressurized under 250–450 MPa at 20–50 °C for 15–60 min. In the second part, two steps treatments were performed as water blanching at 40–70 °C for 15 and 30 min after pressurization at 250 MPa and 20 °C for 15–60 min. Carrot POD was decreased to 16% residual activity within the first 30 min at a treatment condition of 350 MPa and 20 °C and then it decreased to 9% at 60 min. When the carrots were water blanched at 50 °C for 30 min after HHP treatment of 250 MPa at 20 °C for 15 min, 13% residual POD activity was obtained. For green beans, the most effective results were obtained by two steps treatment and approximately 25% residual POD activity was obtained by water blanching at 50 °C for 15 min after pressurization at 250 MPa and 20 °C for 60 min. An effective inactivation of POD in green peas was not obtained. For carrots, LOX activity could not be measured due to very low LOX activity or the presence of strong antioxidants such as carotenoids. After pressurization at 250 MPa and 20 °C for 15 or 30 min, water blanching at 60 °C for 30 min provided 2–3% residual LOX activity in green beans. The treatment of 250 MPa for 30 min and then water blanching at 50 °C for 30 min provided 70% LOX inactivation in green peas.     

利用固定化谷氨酰胺转氨酶生产彩椒花色内酯豆腐条件的研究

利用响应面法研究添加固定化谷氨酰胺转氨酶生产彩椒花色内酯豆腐的最佳工艺条件。结果表明:当豆浆与蔬菜汁的比例为3∶1,固定化酶与葡萄糖酸内酯的比例为3∶7,固定化酶在60℃下作用40min时,花色内酯豆腐的凝胶强度与感官指标皆为最优值。     

In vitro testing to assess the UVA protection performance of sun care products

The UVA protection delivered by sunscreens is an issue of increasing importance due to the increasing knowledge about UVA-induced skin damage. In Europe there is no officially accepted method available to determine the degree of UVA protection. Therefore, the objective of the present study was to design a protocol combining the merits of an in vitro model, which are simple and reproducible, with aspects known to be relevant from in vivo studies. The principle is: an UV-transparent support to which the test product is applied, a (pre)irradiation and a transmission measurement. Transpore(R) tape (standard support for SPF determinations) was found to be incompatible with many preparations on prolonged contact times. Roughened quartz was adopted as a suitable alternative. Transmission measurements on this support are not reliable with a layer of 2 mg cm(-2) (standard for SPF) due to detection limitations of spectrophotometers, hence a reduced layer of 0.75 mg cm(-2) was adopted. Overall, it is very difficult to apply products in a reproducible thin layer on appropriate substrates. As a consequence, absolute parameters derived from the transmission profile show relatively large dispersion, whereas relative parameters, such as critical wavelength lambda(c)[1] or UVA/UVB ratio are much less sensitive to unavoidable variations in layer thickness. An increase in deviations was observed when the samples were irradiated before measurement. It is crucial to control the output carefully (spectral distribution and even more importantly, irradiance and dose delivered) of the light source. By doing so and also taking into account the previous learning steps, a protocol was drafted and tested in a ringtest (four samples in six laboratories). The results are encouraging and show that if relative parameters (e.g. lambda(c), UVA/UVB ratio) are considered, the intra- as well as interlaboratory reproducibility is clearly better than can be obtained in vivo. In general, we describe a suitable method, which can be considered in any future official discussions about the methodology to determine UVA protection.     

天然高钙复曲豆酱及其营养分析

以大豆为主料、鲜畜禽骨泥为辅料,理化诱变优良菌株 ＡＳＰ．ｏｒｙｚａｅ,ＣＪ９９０及与其各种酶互补的四种曲霉,通过分别制曲、混曲共酵新工艺生产天然高钙（含钙 ９６０mg／１００g）豆酱。在营养成分分析的基础上进行了营养学意义分析。     

冷榨豆饼制作腐乳试验报告

本文主要介绍了利用40%冷榨痘 饼和60%黄豆制作腐乳的可行性及工艺过程中需要注意的问题,实验结果,腐乳质量理想,并可降低产品成本。     

Dephosphorylation of phytate compounds by means of acid phosphatase from Aspergillus niger

A non-purified preparation of intracellular acid phosphatase (EC 3.1.3.2) from a waste mycelium of Aspergillus niger was utilised for dephosphorylation of phytate compounds present in food and feed ingredients. The enzymic hydrolysis of p-nitrophenylphosphate was used for assaying acid phosphatase activity, expressed in standard units (u). The hydrolysis of phytate phosphorus in wheat bran, soya bean meal and fully formulated feedstuffs for broilers (Galus galus; ‘Cornish’ × White Rock') was carried out at 40°C, a pH value of 4.5 and an enzyme dosage ranging from 12 to 30 u g^?1. Complete dephosphorylation of soya bean protein isolates was performed at 60°C, a pH value of 4.5 and an enzyme dosage of 12 u g^?1. In the gastrointestinal tract of broilers the in-vivo dephosphorylation of phytates present in feed was observed when the preparation of acid phosphatase was added to the diet.     

微带共形天线阵在遥测系统中的设计应用

论述了微带共形天线阵的设计方法,分析了设计中存在的微带天线保护涂层设计与微带天线宽带化等关键技术,仿真设计与实际测试结果表明设计满足系统要求。     

绿豆皮牡荆素对H2O2损伤HUVEC细胞的预防和治疗作用

目的：研究绿豆皮牡荆素对过氧化氢（H2O2）损伤人脐静脉内皮细胞（HUVEC）的保护作用。方法：H2O2诱导建立HUVEC细胞损伤模型,设置空白组、绿豆皮牡荆素低、中、高剂量组、VC对照组,噻唑蓝和试剂盒法分别测定细胞存活率、目标成分(MDA、 GSH、SOD、 LDH、GSH- Px)。结果：最佳H2O2损伤浓度为900 μmol/L此时细胞存活率为51.32% ;剂量组浓度为60、80、100 μg/ mL时,细胞存活率分别为110.61、122.30、131.68%,不同剂量组均能显著降低细胞及培养液中MDA含量,增加 GSH含量,提高SOD、GSH- Px活性;能显著提高细胞中LDH活性,降低培养液中LDH活性;绿豆皮牡荆素质量浓度为100 μg /mL时,细胞保护能力与同浓度下VC相当。结论：绿豆皮牡荆素能促进HUVEC细胞增殖,抑制自由基生成,增强抗氧化酶活性,降低细胞氧化损伤程度,且存在剂量依赖关系。     

加工方式对红小豆粉理化性质及预估血糖生成指数的影响

淀粉的理化性质受其品种来源、加工条件的影响,并直接影响到其在人体中的消化吸收.本研究以低预估血糖生成指数(eGI)红小豆粉的制备为目标,考察了蒸煮加工、微波加工、滚筒加工、挤压加工对红小豆粉理化性质和eGI的影响.从不同加工方式对红小豆粉理化性质的影响上看,4种加工方式下淀粉的糊化程度从低到高依次为:微波红小豆粉、蒸煮...     

综合指数与粗糙集联用法评价豆制品质量安全

目的 采用综合指数与粗糙集联用法评价豆制品的质量安全.方法 以沈阳市2012—2015年豆制品监测数据为研究对象,通过指数分级标准,建立质量评价(综合指数法)与风险评价(粗糙集理论)联用的评价方法.结果 豆制品综合质量指数(food quality index,FQIt)值为0.139,评价为优级.2012—2014年...