Sensitivity of three pathogenic bacteria to Turkish cemen paste and its ingredients

Pastirma is a dry cured meat product which is pasted with cemen. This paste is prepared from ground fenugreek, garlic and red hot pepper (RHPP). In this study, the cemen mix/paste and all its ingredients were tested for their inhibitory effects on Escherichia coli, Staphylococcus aureus and Yersinia enterocolitica. All samples had a varying inhibitory effect against all the bacteria tested during 4 days of storage. Complete cemen paste showed the strongest inhibitory effect on the three pathogens compared to ingredients alone. Fenugreek and RHPP had a bacteriostatic effect while the cemen paste and garlic had a bactericidal effect. S. aureus was the most sensitive bacterium while Y. enterocolitica was the most resistant. The results of this study confirmed the protective effect of cemen paste and garlic in food preservation especially against E. coli, S. aureus and Y. enterocolitica proving safety for public health. Hence it might be concluded that cemen paste is the first hurdle to prevent bacterial contamination, and a low pH (～4.83) value would also add an additional barrier to secure safety of the product. Finally, it can be suggested that similar studies should be conducted on actual meat systems to confirm these findings.     

紫甘蓝红色素的部分性能研究

从紫甘蓝叶片中提取分离了紫甘蓝色素,研究了其在不同条件下的稳定性及抑菌性。结果表明,紫甘蓝色素在pH为2的酸性水溶液中呈现原植物具有的紫红色,稳定性较好;随着pH的增高,紫甘蓝色素发生向蓝色再到绿色的转变,且最大吸收波长发生红移。紫甘蓝色素自然光照射2d后,色素的保存率在91%以上,自然光照射6d后,色素的保存率仍在79%以上;紫甘蓝色素70℃以下加热2h,色素的保存率在97%以上,90℃加热2h,色素的保存率仍在90%以上。这说明,紫甘蓝色素对光照和加热均有一定耐受性。在紫甘蓝色素溶液吸光度为0.462时,对金黄色葡萄球菌和枯草芽孢杆菌的生长就具有极显著的抑制作用,随着色素浓度的提高,抑制作用愈来愈大,但未见紫甘蓝色素对大肠杆菌生长有抑制效果。     

Pastirma加工对马肉品质的影响

按照国家标准和气相色谱法对鲜马肉和Pastirma马肉的基本理化性质、剪切力和和脂肪酸进行测定和分析。结果发现:鲜马肉和Pastirma工艺制备的p H值没有显著性变化(P0.05),亮度值L显著降低,a值显著增加,水分含量显著减少,蛋白质含量显著增加(P0.05);马肉的嫩度在Pastirma的风干过程中显著降低(P0.05);马肉脂肪含量从高到低依次为:油酸(C18:1)、棕榈酸(C16:0)、亚油酸(C18:2)、棕榈油酸(C16:1)、硬脂酸(C18:0)、肉豆蔻酸(C14:0),鲜马肉不饱和脂肪酸含量较高,加工成pastirma后不饱和脂肪酸含量显著降低。     

Light and heat sensitivity of red cabbage extract in soft drink model systems

Anthocyanins of red cabbage (Brassica oleracea L.) display colour over a larger range of pH-values than the majority of anthocyanins from other natural sources, being pink at pH 3, violet at pH 5 and blue at pH 7. Using reversed phase high-performance liquid chromatography with diode array detection, cyanidin was found to be the only anthocyanidin of red cabbage extract and, tentatively, identified as cyanidin-3,5-diglucoside and cyanidin-3-sophoroside-5-glucoside, the latter found in various acylated forms. The apparent quantum yield for photobleaching has been determined for red cabbage extract at 25°C in air-saturated McIlvaine buffer, using monochromatic light at each of the irradiation wavelengths, 313, 366, and 436 nm, in continuous photolysis experiments, in order to provide an objective measure for the sensitivity of this food colorant to ultraviolet and visible light. The quantum yield was found to depend on both pH and irradiation wavelength, ranging from 0.2×10⁻⁴ mol einstein⁻¹ for 436 nm light at pH 7.0 to 3.7×10⁻⁴ mol einstein⁻¹ for 366 nm light at pH 5.0. The thermal stability at pH 3.0 in McIlvaine buffer of four different anthocyanin extracts was compared and, for the temperature range investigated (25–80°C) the degree of stability was red cabbage>blackcurrant>grape skin>elderberry. The thermal stability of the same anthocyanin extracts was also compared for a non-carbonated soft drink medium of pH 3.0 yielding the same order of stability but with rates of degradation approximately twice as high as in buffer, which may indicate a detrimental effect of sugar and ascorbic acid. Due to the high thermal stability of red cabbage extract in solution, photobleaching will be the primary destabilising factor for red cabbage anthocyanin-coloured products in display.     

红豆沙加工工艺及功能特性研究进展

豆沙作为具有民族风味的悠久传统食品,富含多种营养素,可用于制作各种主副食品、糕点及饮品。豆沙中蛋白质、淀粉、低聚糖、矿物质及抗氧化成分对于人体有一定的食疗效果。分析豆沙的主要成分的功能特性,有助于开拓国内发展豆沙类食品的加工思路。在借鉴日本豆沙豆馅加工技术的基础上,依靠自身科技进步并结合我国人民的饮食习惯,大力发展我国豆沙豆馅产业是可行的。     

Safety evaluations on ethanolic extract of red cabbage (Brassica oleracea L.) in mice

The present study has carried out safety evaluations on an ethanolic extract of red cabbage (RC) leaves in terms of acute and subchronic oral toxicity tests as per Organisation for Economic Cooperation and Development (OECD) guidelines in Swiss albino mice. Single-dose administration of RC extract (1000, 2000, 3000, 4000, or 5000 mg/kg body weight) to Swiss albino mice did not manifest toxicity or any significant adverse behavioral alterations. Chronic administration of RC extract (1000, 2000, and 3000 mg/kg body weight) for 28 d also did not register any significant alterations in fluid intake, organ weights, plasma lipid profile, plasma creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, alanine transaminase, creatinine, electrolytes, and calcium levels, and the total blood count showed a nonsignificant change. However, significant reduction in body-weight gain, food intake, red blood cell count, and hemoglobin content along with higher alkaline phosphatase, bilirubin, and urea levels was observed in mice treated with 3000 mg/kg body weight for 28 d. Since there was no mortality up to a dose of 5000 mg/kg body weight, 50% lethal dose (LD(50)) could not be determined, and hence, it can be assumed that, LD(50) of RC extract is >5000 mg/kg. No observable adverse effect level dose of the RC extract was found to be 2000 mg/kg body weight. Hence, consumption of RC extract for various medicinal purposes is safe. Practical Application: RC is a popularly consumed foodstuff that has been ubiquitously reported to exert medicinal properties. It is mandatory to understand the highest permissible consumption limit of any food supplement to avoid toxicity. This study establishes the safe dose of RC. These results can be of relevance for the scientific fraternity as well as laymen who consume this vegetable or its phytochemical preparation.     

Pasteurization of fermented red pepper paste by ohmic heating

Ohmic heating was applied to a Korean traditional fermented food containing red pepper paste, called Gochujang with low thermal conductivity (0.458 W/m ∙ K), by varying frequencies (40–20,000 Hz) and applied voltages (20–60 V). Contrary to conduction heating, the entire sample was heated uniformly, and the specific heating rate was found to be highly dependent on the frequency, peaking at 5 kHz and 60 V. The results showed that complex differential equation and the Runge–Kutta fourth-order method are suitable for simulating the temperature profile during ohmic heating. The deactivation of vegetable cells of Bacillus strains on fermented red pepper paste by ohmic heating was indicated by a 99.7% reduction, compared with conduction heating for 8 min at 100 °C producing a 81.9% reduction. The organoleptic and physicochemical qualities of the samples pasteurized by ohmic heating were nearly the same as those of raw samples, and higher than those of conventionally heated samples.Industrial relevanceThe present study designed and implemented a novel sterilization process based on a static ohmic heating system with low-frequency AC at the laboratory scale for fermented red pepper paste with a low thermal conductivity (0.458 W/m ∙ K).The developed system was used to investigate the mechanisms and characteristics underlying the induction of ohmic heating and then, tested the pasteurization effect against microorganisms in fermented red pepper paste.Comparing with conventional heating processes, ohmic heating could provide rapid and uniform heating, thereby is more suitable for pasteurization and sterilization of viscous foods as fermented red pepper paste on industrial thermal processing.     

Antigenotoxic effects of water extract from Korean fermented soybean paste (doen-jang)

Aflatoxin B1 is a major metabolite of the toxigenic molds Aspergillus flavus and Aspergillus parasiticus. In this study, a bacterial reverse mutation assay with Salmonella Typhimurium strains TA1535, TA1537, TA98, TA100, and TA102 and an in vitro chromosome aberration test with Chinese hamster lung (CHL) cells were used to investigate the genotoxicity of water extract from Korean soybean paste (doen-jang [dwen-jahng]) and its antigenotoxic activity against aflatoxin B1. The water extract itself did not exhibit cytotoxicity or mutagenicity. The extract significantly reduced the numbers of revertants when it was added to the assay system with Salmonella Typhimurium TA100 (P < 0.05). The extract also exhibited significant inhibitory effects on chromosome aberration in CHL cells (P < 0.05). Dose-response relationships were observed between the concentration of the water extract and both its antimutagenic effect and its suppression of chromosome aberration. The results of this work indicate that water extract from Korean soybean paste could have potential as an antigenotoxic substance.     

双水相体系萃取纯化紫甘蓝色素

采用聚乙二醇(PEG)/硫酸铵双水相体系萃取纯化紫甘蓝中的花青素。通过单因素实验优化了硫酸铵、PEG、粗提液的质量分数和体系的pH,通过正交实验确定各因素对花青素选择性系数的影响程度,粗提液的质量分数 pH硫酸铵的质量分数 PEG的质量分数。实验最佳提取条件为:粗提液的质量分数为12%,硫酸铵质量分数为20%,pH为3.5,PEG的质量分数为15%,花青素的选择性系数为750.26。     

Thermal degradation of glucosinolates in red cabbage

Thermal degradation of individual glucosinolates within the plant matrix was studied. Red cabbage samples were heated at different temperatures for various times. To rule out the influence of enzymatic breakdown and to focus entirely on the thermal degradation of glucosinolates, myrosinase was inactivated prior to the thermal treatments. All identified glucosinolates degradation when heated at temperatures above 100 °C. The indole glucosinolates 4-hydroxy-glucobrassicin and 4-methoxyglucobrassicin showed the highest degree of showed degradation, even at temperatures below 100 °C.     

Preparation and antioxidant properties of water extract of propolis

A water extract was prepared from fresh propolis from Brazil. Antioxidant activity was measured using a lipid peroxidation model system. The activity was very strong and, at 1 and 5 mg/ml, higher than that of 5 mM ascorbic acid. The scavenging activity against superoxide anion radical of water extract of propolis was high, and the extracts, at 50 and 100 mg/ml, completely inhibited the production of superoxide. The extracts, at 50 and 100 mg/ml, completely inhibited the hydroxyl radical. This suggests that the water extract of propolis has potential as a pharmaceutical for patients with various diseases such as cancer, cardiovascular diseases, and diabetes.     

Effect of tumbling and multi-needle injection of curing agents on quality characteristics of pastirma

The influence of tumbling and injection of curing solution instead of dry curing on some chemical, microbiological and sensory properties of pastirma was investigated. Effect of the curing techniques on the pH value, moisture and salt contents was significant. On the other hand, tumbling increased the moisture content of dry‐cured pastirma and decreased the brine‐injected pastirma significantly. Brine injection and tumbling caused significant increase in Staphylococcus aureus, halophilic and lactic acid bacteria. The dry‐cured pastirma had higher colour and appearance score than the brine‐injected pastirma. Insignificant increases in the colour and appearance score of tumbled brine‐injected pastirma and flavour, texture and appearance score of tumbled dry‐cured pastirma were seen.     

高速逆流色谱分离纯化紫甘蓝花色苷

优化出超声波溶剂辅助法提取紫甘蓝花色苷的最佳工艺条件,并用高速逆流色谱法对其进行分离纯化,建立HSC-CC分离制备紫甘蓝花色苷类化合物的方法。采用正交试验优化超声波溶剂辅助提取紫甘蓝花色苷的工艺条件,再高速逆流色谱对其进行分离纯化。结果表明,超声波溶剂辅助提取紫甘蓝花色苷的最佳工艺条件为超声时间8min,超声辅助提取温度40℃,乙醇体积分数65%;HSCCC制备紫甘蓝花色苷类化合物的方法:溶剂系统为正丁醇-甲基叔丁基醚-乙腈-水-三氟乙酸(2:2:1:5:0.01,V/V/V/V),流速为2mL/min,主机转速设定为800r/min,紫外检测波长为254nm,在该条件下分离制备得到3种化合物。经HPLC检测其纯度分别为76.28%,45.46%,91.46%。用超声波溶剂辅助和高速逆流色谱能分离得到了高纯度的紫甘蓝花色苷,该法具有简便、快速的优点,为紫甘蓝花色苷的分离纯化提供了高效、稳定、可靠的方法。     

红小豆挤压膨化产品的质量性状分析

目的:确定红小豆挤压膨化产品质量性状与工艺参数间关系,初步构建产品质量评价指标体系,为挤压膨化产品的开发利用、质量管理及标准制定提供依据。方法:通过回归旋转实验研究物料水分、螺杆转速和膨化温度对挤压产品质量性状(膨化率、吸水性指数、水溶性指数)的影响。采用相关性分析法研究各质量性状间的相关关系。结果:挤压工艺参数影响红小豆膨化产品质量性状的顺序为膨化温度>物料水分含量>螺杆转速,膨化温度和物料水分含量显著影响产品质量性状,螺杆转速影响不显著;挤压产品质量性状中,吸水性指数与水溶性指数呈极显著负相关。结论:红小豆挤压膨化工艺参数与产品质量性状间相关性显著,在应用中要根据所需的质量要求选择恰当的工艺参数。     

超声辅助提取红甘蓝色素的研究

以新鲜的红甘蓝(东农-8D50)为原料,采用乙酸水溶液提取红甘蓝色素.通过单因素考察及正交实验优化了超声波法辅助提取红甘蓝色素的实验条件.正交实验结果显示,在70W的超声功率下,当超声时间为50min、超声温度为40℃、乙酸浓度为25%、料液比为1:4(g/mL)时,提取率为1.62mg/g,粗产品中红甘蓝色素含量为10.3%.     

紫甘蓝花色苷的热降解动力学研究

探讨在不同温度和pH条件下紫甘蓝花色苷的热稳定性和降解动力学。以80%乙醇浸提,D-101大孔吸附树脂分离纯化制备紫甘蓝花色苷,在50、60、70、80 ℃温度范围内,于不同pH(2.0~6.0)体系中测定不同时间点的花色苷含量,研究其热降解动力学参数和褐变指数。结果表明,紫甘蓝花色苷热稳定性和褐变反应受温度和pH的影响,且其降解速率与时间呈良好线性关系,符合一级动力学模型。随着温度的升高,不同pH下花色苷的半衰期t_1/2均呈下降趋势,最大值为83.51 h(50 ℃,pH3.0),最小值为4.43 h(80 ℃,pH6.0),且各pH(2.0~6.0)体系的活化能E_a依次为42.30、45.31、38.85、26.83、31.20 kJ/mol。此外,其褐变指数随热处理时间延长、温度升高及pH增大而增大。     

Evaluation of antioxidative and mutagenic properties of 50% ethanolic extract from red beans fermented by Aspergillus oryzae

Various bean products fermented by microorganisms are commonly consumed in Asian diets; however, the safety or functional properties of fermented beans can vary with different microbial species and with different processes being applied to different beans. The objectives of this study were to evaluate the antioxidative and mutagenic properties of 50% ethanolic extracts from red beans fermented by Aspergillus oryzae. The extracts' antioxidative activities, including alpha,alpha;-diphenyl-beta-picryl-hydrazyl (DPPH) radical-scavenging effects, Fe(2+)-chelating ability, and reducing power, were studied in vitro. The antioxidative effects provided by the extracts depended strongly on their concentrations. In general, antioxidative activity increased with extract concentration to a certain point and then leveled off as the concentration further increased. The fermented red bean extracts showed less of a scavenging effect on the DPPH radical and less reducing power than the commercial antioxidants alpha-tocopherol and butylated hydroxytoluene, but better Fe(2+)-chelating ability. No mutagenicity or toxicity effect on any of the tested strains (Salmonella Typhimurium TA97, TA98, TA100, TA102, and TA1535) was found for the 50% ethanolic extracts of fermented red beans with the Ames mutagenicity assay. These results suggest that the 50% ethanolic extracts were not mutagenic.     

基于图像传感技术的娃娃菜外观品质检测

目的 设计一套基于图像传感技术分析娃娃菜外观品质如尺寸、重量、瑕疵点等的检测方法.方法 搭建一套图像采集平台拍摄娃娃菜不同侧面,应用图像处理技术,分割出娃娃菜图像区域,并数字化其区域特征信息(包括:投影面积、尺寸、瑕疵点面积等).结果 建立合格娃娃菜的侧面投影面积与重量真实值间的线性关系,其相关系数为0.938,均方根...