卷烟计量型测量系统的分析

为准确了解卷烟计量型测量系统现状,将工序自检、过程巡检、出厂检验3个环节相同质量指标测量单元视为一个测量系统,采用MSA新方法对质量、圆周、长度、吸阻、硬度5个测量系统进行了分析。结果表明:5个测量系统的研究公差比(%P/T)在10%~30%之间,说明测量系统能力满足对产品质量判定的要求;除硬度测量系统外,4个测量系统的研究变异比(%RR)在10%~30%之间,说明测量系统能力满足对生产过程改进分析的要求。     

不同装样称重顺序对成品烟丝含水率检测结果影响的研究

本文主要通过试验方法探究使用同时装样同步称重、同时装样统一称重和红外测量后称重三种不同装样称重顺序,对成品烟丝含水率检测结果的影响。通过使用烘箱法和实验室红外水分仪快速检测两种实验室常用成品烟丝含水率检测方法,利用方差分析法确定不同装样称重顺序之间存在的差异。结果表明:三种装样称重顺序对烘箱法检测含水率无明显影响,同时装样统一称重检测含水率略低于同时装样同步称重和红外测量后称重;三种装样称重顺序对对实验室红外水分仪检测结果有显著影响,红外测量后称重的装样方式对检测结果的影响最小。     

微波谐振腔微扰技术快速检测烟丝含水率

为快速准确地测定烟丝的含水率.采用基于微渡谐振腔微扰技术扫描和最小二乘法建立了不同微波测量参数(输出电压、谐振频率、输出信号带宽、输出电压/带宽)与烟丝的含水率数学校正模型,并将检测结果与烘箱法的测定结果进行了比较.结果表明:[1]微波谐振腔微扰技术测定烟丝含水率时的检测精度与所选用的微波测量参数校准模型有关;[2]当采用信号带宽、输出电压/信号带宽-含水率校正模型时,烟丝含水率的测定误差均小于0.3%,符合烘箱法的精度要求.该法检测响应速度快(ms级),可用于烟丝及其它烟草制品含水率的快速检测.     

谷物水分测量方法的比较研究

水分是粮食贮藏、收购、加工、运输过程中必须测量的重要质量指标.本文用国家标准中的两种标准方法和一种水分快测法对湖南隆回的紫晶特种稻米的含水率进行测量,并对试验结果作了分析研究.结果表明,用金子公司便携式水分快测仪测得的稻谷含水率值与实际水分（国家标准测水分法测得的水分）,可以用下面公式转化：ω3=1.0149ω1＋0.0837.国家标准中的105℃恒温法与高温烘干法测得的谷物含水率值,有以下关系：ω3=0.9523ω2＋0.382.（上两式中ω1为快测法测得的含水率值,ω2为105℃恒温法测得的含水率值,ω3为高温烘干法测得的含水率值.）     

烟丝组织结构与平衡含水率的关系

为了解烟丝组织结构与保润性能的关系,应用扫描电子显微镜(SEM)观察了烤烟、白肋烟、香料烟3种烟丝表面和切面结构,光学显微镜观察烟丝下表皮气孔,比表面积测试仪测定烟丝毛细管比表面积大小。结果表明:①香料烟结构最为紧密,切面含有很多空隙结构,国产烤烟和津巴布韦烤烟的切面较疏松。②白肋烟气孔数目在烤烟与香料烟之间,同一品种烤烟不同部位烟丝样品比表面积大小:中部 >下部 >上部。③低湿度(RH=30%)环境条件下烟丝组织结构与平衡含水率正相关;高湿度(RH=60%)环境条件下,烟丝组织结构与平衡含水率负相关,随着相对湿度的增加,烟丝表面化学成分对含水率的影响程度逐渐加强。      

凉感强度参比标度的建立及其时间-强度动态变化

采用15 cm线性标度法在确定了凉感强度描述语并通过凉感评价小组对系列质量浓度的L-薄荷醇参比样进行标度的基础上,建立了符合费希纳定律的凉感强度参比标度,即：L-薄荷醇质量浓度为：4.00、7.60、12.00、15.00、20.00 g/L,对应凉感标记值为：2.50 cm（微凉）、5.00 cm（有点凉）、7.50 cm（中凉）、11.00 cm（很凉）及13.00 cm（特凉）。同时,还利用时间-强度法对强度参比标度的动态变化进行了研究,通过相关性分析发现时间-强度参数（Imax为最大强度/cm、Ttot为凉感持续时间/min、AUC为曲线下面积）与强度参比系质量浓度间成正相关关系;通过分析凉感整体强度值（Ioverall,cm）与时间-强度参数的相关性发现,Ioverall与Ttot及AUC的相关系数均在0.90以上,其中与Imax的相关系数高达0.99,表明在凉感强度标度时,Imax对整体强度标度值的影响最大。     

Image J色度分析在烟丝纤维素漂白过程中的应用

为了研究漂白条件对烟丝纤维素漂白效果的影响,并定量分析烟丝中纤维素的质量分数,利用Image J色度分析软件,同时结合烟丝纤维素的质量分数和提取率,研究确定了烟丝纤维素漂白的最佳制备工艺。考察了加热温度、加热时间、漂白溶液的pH和漂白次数对漂白效果的影响。结果表明：采用60 mL pH=3的3%（质量百分数）亚氯酸钠漂白溶液,在75℃水浴中加热30 min,重复漂白2次,达到最佳漂白效果,烟丝纤维素漂白提取率为65.32%,质量分数为93.25%,烟丝纤维素压片照片的色度比仅是对照组（Con）的11.67%。利用Image J色度分析软件对烟丝纤维素压片照片的色度比定量分析结果有效。     

用综合评价模型建立烟丝质量评价指标

目前对烟丝的质量一般用单一指标来分别评价,而缺乏一个科学的综合性指标来反映烟丝的整体质量状况。综合评价模型兼有主观赋权法和客观赋权法的优点,用该方法对烟丝的含水率、填充值、纯净度、整丝率、掺配精度、加香精度六项指标分别赋予权重,得到归一化后的权向量为(0.58,0.3,0.048,0.04,0.024,0.01)。该向量结合每一项的质量检验得分可得到综合性的烟丝质量指标V值。将该算法整合到MES系统中,系统能够自动完成对烟丝质量评价,提升烟丝分级的效率和准确性。     

滚筒式薄板烘丝机基于排潮风风量的烟丝含水率控制方法

为解决滚筒式薄板烘丝机烟丝加工过程中筒内环境温度波动对烟丝香气的影响等问题,通过分析滚筒式薄板烘丝机工作过程中影响烟丝含水率的相关变量,在薄板温度和热风温度均恒定的条件下,提出了一种基于排潮风风量的烟丝含水率控制方法。基于排潮风风量建立了控制模型,研究了入口烟丝含水率和入口烟丝流量对排潮风含水量的影响,以及排潮风门开度与风量的关系。利用排潮风门自适应PID专家控制策略实现了控制过程,通过PID值整定,防止烟丝含水率超调和波动。结果表明:改变排潮风风量可以控制薄板烘丝机的烟丝含水率,排潮风门响应时间比蒸汽加热时间短,调控速度比调节薄板温度或热风温度更快,实现了烟丝含水率的快速可调可控;保证了烟丝干燥时香气的稳定,避免同批次烟丝在同质化加工中产生差异,有效提高了卷烟品质。     

谷物水分测量方法的比较研究

水分是粮食贮藏、收购、加工、运输过程中必须测量的重要质量指标。本文用国家标准中的两种标准方法和一种水分快测法对湖南隆回的紫晶特种稻米的含水率进行测量,并对试验结果作了分析研究。结果表明,用金子公司便携式水分快测仪测得的稻谷含水率值与实际水分(国家标准测水分法测得的水分),可以用下面公式转化:ω3=1.0149ω1+0.0837。国家标准中的105℃恒温法与高温烘干法测得的谷物含水率值,有以下关系:ω3=0.9523ω2+0.382。(上两式中ω1为快测法测得的含水率值,ω2为105℃恒温法测得的含水率值,ω3为高温烘干法测得的含水率值。)     

主要谷物水分测定方法比较研究

对大米、小麦和玉米水分测定方法进行了比较研究.水分测定方法包括:(Ⅰ)GB/T 5497 105℃恒重法(烘箱干燥105℃,3 h)、(Ⅱ)GB/T 5497定温定时烘干法(烘箱干燥130℃,40 min)、(Ⅲ)ISO712粉状物测定(烘箱干燥130℃,90 min)、(Ⅳ)ISO712常规法(烘箱干燥130℃,2 h)、(Ⅴ)GB/T 10362粉碎玉米水分测定(烘箱干燥130℃,4 h)、(Ⅵ)GB/T 10362整粒玉米水分测定(烘箱干燥130℃,38 h)和(Ⅶ)M105/72(烘箱干燥105℃,72 h).在小麦和大米水分测定及同一类型的粮食水分测定中,方法(Ⅳ)测定值要大于方法(Ⅰ)、(Ⅱ)、(Ⅲ);其标准偏差要小于这三种方法,精确度较高,方法(Ⅰ)、(Ⅱ)、(Ⅲ)测定值与方法(Ⅳ)测定值的相关系数较高.玉米水分测定中,方法(Ⅴ)测定值和精确度大于方法(Ⅰ)、(Ⅱ),这两种方法的测定结果与方法(Ⅴ)的相关系数较高.     

Comparison of various methods for determination of water in white yoghurts

Water content was determined in 11 samples of white yoghurts. Several techniques, namely Karl Fischer (KF) volumetric titration, near and middle infrared spectroscopy (MIR), oven drying and moisture analyser were used. Optimisations of solvent, titration temperature and extraction time were carried out for the KF titration. Methanol at room temperature with 5 min extraction period was used as final conditions. For the infrared spectroscopy (FTIR) the suitable solvent and the appropriate wavenumbers for water analysis were chosen. The measurement in the near infrared (NIR) region at the wavenumber 10270 cm⁻¹ using acetonitrile as solvent and transmission method was evaluated as the best of the FTIR methods. Based on the comparison of individual methods the oven drying at 105 °C seems to be the most suitable, but it is the most time consuming. However, KF volumetric titration and especially FTIR methods appear to be good alternatives to the drying methods.     

食品中水分含量测定装置的研究现状

食品中水分含量是食品质量控制的一个重要指标,对其测定的装置可分为直接测定装置和间接测定装置,如直接测定装置中的干燥器、干燥箱、蒸馏装置、卡尔费休水分测定仪、卤素水分测定仪、红外水分测定仪、微波水分测定仪;间接测定装置中的阿贝折射仪、阻容法水分测定仪、近红外成分分析仪、核磁共振仪、高光谱成像系统。本文对食品中水分含量测定装置的基本结构,测定原理,应用和优缺点等方面进行了综述,为食品中水分含量测定装置的选择和使用提供参考。     

A comparative evaluation of methodologies for water content determination in green coffee

The main objective of this study was to compare methods for mass loss evaluation in green coffee to water content determination by Karl Fischer titration (KFT). The following methodologies were tested: (i) ISO 6673 (oven drying at 105 °C for 16 h); (ii) the reference method employed by the Brazilian Agriculture Ministry (oven drying at 105 °C for 24 h)—BRAMw, employing whole beans and BRAMg, employing ground beans; and (iii) infrared drying (IRD). Reference oven drying methodologies ISO 6673 and BRAMw presented results statistically equivalent (p>0.05) to those from KFT in the moisture content range that is of interest for green coffee commercialization (8-13 g/100 g), whereas IRD results were lower than those for KFT. ISO 6673 and BRAMw also presented the highest values of correlation coefficients to KFT. Differences in moisture content determination became more significant for lower moisture content values (4-7 g/100 g), probably due to loss of organic volatile substances during drying and occurrence of moisture loss during sample grinding.     

ASSESSMENT of NEAR INFRARED (NIR) DIFFUSE REFLECTANCE ANALYSIS FOR MEASURING MOISTURE and WATER ACTIVITY IN RAISINS

Near Infrared (NIR) Analysis was applied to assess its potential for measuring water activity (a_w) and moisture in California Seedless Raisins in moisture equilibrium and nonequilibrium conditions. Samples covered a wide range of anticipated moisture contents. an NIR calibration for a_w was made for whole raisins that were fully equilibrated. For ground raisins, NIR calibrations were made both a_w and vacuum oven moisture, covering a large range of moisture contents and equilibrium conditions. Direct measurement of a_w by a dewpoint device gave highly repeatable results, especially for ground raisins. Vacuum oven analysis of moisture was less precise than a_w measurements. Full spectrum NIR calibrations indicated that NIR could predict a_w of raisins in ground form, irrespective of their state of hydration beyond three hours following processing. A much larger sample population will be needed to establish precise calibrations for vacuum oven moisture.     

快速检测木质活性炭碘吸附值方法研究

碘吸附值是衡量活性炭质量优劣的重要指标,该实验以GB/T 12496.8—2015中（150±5） ℃烘箱法为参考,用卤素水分测定仪HX204确定木质活性炭快速检测方法主参数为温度130 ℃,加热模式标准,关机模式1 mg/32 s。用卤素水分测定仪测定的水分计算干基碘吸附值,与烘箱法测定的碘吸附值相对标准偏差为1.36%,在误差允许范围,两种方法碘吸附值无显著差异。     

Impact of Infrared Broiling on the Thiamin and Riboflavin Retention and Sensory Quality of Salmon Steaks for Foodservice Use

Salmon steaks were broiled using infrared radiation and compared to convection oven baking. Total percent cooking losses of moisture and fat content were not significantly different. Samples broiled by infrared oven retained 87.2% and 92.6% of thiamin and riboflavin content, respectively. There were no significant differences for vitamin retention by both methods. Appearance and color of salmon steaks baked in the convection oven were rated significantly higher than infrared broiled samples. Tenderness and juiciness scores for infrared broiled steaks were significantly higher than those for convection oven baked steaks. There were no significant differences in panel scores for odor, flakiness, flavor and overall acceptability of steaks prepared by both methods.     

Effects of ultrasound and infrared assisted conductive hydro-drying,freeze-drying and oven drying on physicochemical properties of okra slices

Okra (Abelmoschus esculentus) is a nutritious vegetable but it is highly perishable and drying is one of the best methods for its preservation. Ultrasound and infrared assisted conductive hydro-drying (UIACHD) is a new patented drying method that can dry food materials with high quality and high energy efficiency. In this study, okra slices were dried using UIACHD with different settings and also by freeze-drying and oven drying. The UIACHD drying curves, moisture content, color, vitamin C content, hydrocolloids rheology and microstructure of the dried okra sample as affected by drying method were investigated. Drying curves showed that the application of ultrasound and infrared could increase the drying rate. In terms of quality parameters, UIACHD performed significantly better than oven drying and the quality of the products was comparable to freeze-drying. Flow and oscillation rheology tests showed that UIACHD drying could result in okra hydrocolloids with higher apparent viscosity and the application of ultrasound and infrared has preserved the rheological properties of the okra hydrocolloids. The microstructure of the dried okra slices was also well preserved by UIACHD. This study showed that UIACHD is a suitable drying method for maintaining the physicochemical quality of dried okra.Industrial relevanceDried okra can be used as a nutritious and functional ingredient in the formulation of different products such as soups, sauces and other culinary products. This study shows that ultrasound and infrared assisted conductive hydro-drying can be a suitable method for the production of high quality dried okra with well-retained color, nutritional value and rheological properties.     

A Study on Staling Characteristics of Gluten-Free Breads Prepared with Chestnut and Rice Flours

The effects of chestnut flour and a xanthan–guar gum blend–DATEM mixture on staling of gluten-free rice breads baked in conventional and infrared–microwave combination ovens were studied. Staling properties of the bread were assessed using mechanical compression (TA), differential scanning calorimetry, X-ray diffraction, and fourier transform infrared spectroscopy (FT-IR). Hardness, moisture loss, and retrogradation enthalpy values for all bread samples increased significantly during storage. FT-IR spectra showed that the integrated area of peaks around 1,041 and 1,150 cm^?1 wave lengths, which are related to the structure of starch retrogradation, increased with storage time. The X-ray diffractograms of aged breads indicated a B-type structure with the appearance of peaks at around 17°, 19.5°, and 22°. An additional peak at 24° was observed in breads stored for longer periods. Higher values of hardness and lower moisture contents were obtained for breads baked in an infrared–microwave combination oven, but the use of infrared–microwave combination oven did not result in excessive hardness after storage. Retrogradation enthalpies and total crystallinity values of breads did not show significant differences with baking type.The replacement of rice flour with chestnut flour and addition of xanthan–guar gum blend–DATEM mixture in formulations significantly delayed staling of gluten-free breads by decreasing moisture loss, hardness, retrogradation enthalpy, and total mass crystallinity.     

烘箱内湿度与纺织材料回潮率测试分析的GM(1,2)模型

针对利用测试烘箱内空气湿度来了解待测纺织材料干燥状态的测试方法,及其所建立的纤维材料前后2次质量差与测试频率差的非线性回归方程模型进行了分析,指出这一模型存在较大误差。提出运用灰色系统建模方法建立烘箱内空气湿度与正在烘燥的纺织材料回潮率之间的灰微分方程GM(1,2)模型。经分析证实,该模型对试验结果的拟合误差低于回归方程模型,可满足工程计算的要求,为用检测烘箱内空气湿度的方法确定待测纺织材料的烘燥状态这一测试理论提供一种计算工具。