Differentiation of Beef and Kangaroo Meat by Visible/Near-Infrared Reflectance Spectroscopy

A visible/near-infrared (NIR) spectroscopic method was developed with canonical discriminant analysis and stepwise multiple linear regression to differentiate beef from kangaroo meat. Results showed that beef and kangaroo meat could be separated when samples were analyzed by spectrophotometry as minced meat or cut meat. For minced meat, scatter correction and derivative treatment of reflectance spectra improved classification. For cut meat, original reflectance spectra produced better classification. Overall classification accuracy was 83% to 100%, and no kangaroo meat was misclassified. NIR spectroscopy might be an efficient test method for species identification.     

Near-Infrared Spectroscopy Determination of Physical and Chemical Characteristics in Beef Cuts

The qualities of beef cuts were compared with near-infrared (NIR) spectroscopy readings using reflectance, transmittance and a fiber optic probe. Multiple linear regression analyses were used to select the optimum wavelengths for estimating beef properties. High multiple correlation coefficients (R) were obtained for Warner-Bratzler shear value (R = 0.798?0.826), protein (R = 0.822?0.904), moisture (R = 0.895?0.941), fat (R = 0.890?0.965) and energy content (R = 0.899?0.961) with each reflectance, transmittance and using the fiber optic probe. Total pigment content also highly correlated with optical densities using transmittance (R = 0.946) and the fiber optic probe (R = 0.893). NIR with a fiber optic probe is a useful tool for determining physical and chemical characteristics of beef.     

High Hydrostatic Pressure Effects on Rapid Thawing of Frozen Beef

High hydrostatic pressure (HHP) during thawing of frozen beef was investigated by measuring temperature changes in frozen beef and the pressurization fluid. Frozen ground beef sample variables were pressure levels (140, 210, 280, and 350 MPa), times (5, 15, and 30 min), sample diameters (55, 65, and 80 mm), and initial temperatures (7, 11, 18 and 22°C). Properties of cooked patties were compared between beef thawed using HHP and using conventional thawing (atmospheric pressure at 3°C). Pressures of 210 to 280 MPa provided a critical processing range that effectively thawed the beef. Sample size and initial temperature did not affect thawing rate. The lowest temperature at which the beef was efficiently thawed was-24+2°C. HHP treated beef thawed much faster than controls. HHP thawing resulted in similar color and texture to controls.     

Classification of Fresh and Frozen‐thawed Fish by Near‐infrared Spectroscopy

ABSTRACT: Frozen fish usually have a much lower market price than fresh fish; therefore, adulteration could occur. This article focuses on the use of near infrared (NIR) spectroscopy to detect whether fish has been frozen‐thawed because NIR spectroscopy has demonstrated the potential for addressing some authenticity issue in foods and is known to be a nondestructive rapid technique. Horse mackerel (n = 162) were evaluated as fresh and frozen‐thawed fish sample. Dry extract spectroscopy by infrared reflection (DESIR) of fresh and frozen‐thawed fish samples was performed on the meat juices then discriminated by principal component analysis (PCA) and multiple linear regressions (MLR). In DESIR spectra, the overall absorbance level was found to decrease in frozen‐thawed samples, indicating the different chemical composition of juice, amount of dry matter, particle size, and their scattering properties. The spectral changes that take place between fresh and frozen‐thawed samples are clearly seen in the 1920‐ to 2350‐nm region. The spectra are dominated by peaks attributed to proteins, in particular, peaks at 1510, 1700, 1738, 2056, 2176, 2298, and 2346 nm. It was found that fresh and frozen‐thawed fish could be separated 100% correctly by DESIR technique.     

近红外技术在牛肉质量分级体系中的应用研究进展

牛肉等级评价体系旨在使市场形成以质论价、优质优价的优良市场机制,并引导肉牛产业的健康发展.世界主要发达国家都有较完善的牛肉等级评价体系,我国牛肉等级评价体系起步较晚,牛肉自动分级技术处于探索和研究阶段.近红外技术作为一种快速、在线的检测技术,在牛肉质量检测方面得到了广泛的研究.本文对国内外主要的牛肉质量分级标准体系进行了概述,指出了目前国内外的牛肉质量分级技术体系存在的问题,综述了国内外的近红外技术在牛肉质量分级体系中应用现状和研究进展,总之近红外技术在牛肉质量分级技术体系中具有很大的潜力.     

不同冻结温度下牛肉的肌原纤维蛋白变性与肌肉持水性

为明确冷冻温度对牛肉肌原纤维蛋白变性和肌肉持水性（water-holding capacity,WHC）的影响、探讨肌 原纤维蛋白变性与WHC的相关性。以牛背最长肌作实验材料,探究－9、－18、－23、－38 ℃下冻结后肌原纤维 蛋白理化特性和牛肉WHC。通过测定巯基含量、蛋白质溶解度、Ca2＋-三磷酸腺苷酶（adenosine triphosphatase, ATPase）活力及蛋白质热稳定性考察牛肉冻结后肌原纤维蛋白变性情况,利用解冻汁液流失与加压失水率指标衡 量牛肉WHC,采用低场核磁共振（low field-nuclear magnetic resonance,LF-NMR）波谱和磁共振成像（magnetic resonance imaging,MRI）技术对比分析了肌肉水分分布情况,并于4 ℃解冻后测定了色差与剪切力。结果表明： －23 ℃与－38 ℃下冻结试样较－9 ℃与－18 ℃肌原纤维蛋白变性程度小：－23 ℃与－38 ℃下冻结试样蛋白质溶解 度、Ca2＋-ATPase活力、巯基含量和总变性焓相比－9 ℃与－18 ℃实验组较高（P＜0.05）。－23 ℃与－38 ℃下冻 结牛肉解冻后L*值、b*值、剪切力、解冻汁液流失和加压失水率显著低于－9 ℃与－18 ℃（P＜0.05）。LF-NMR 及MRI结果相互佐证了肉样在－23 ℃与－38 ℃冻结下肌肉WHC高于－9 ℃与－18 ℃的实验结果。肌原纤维蛋白理 化特性（蛋白质溶解度、Ca2＋-ATPase活力、巯基含量、总变性焓）与WHC（解冻汁液流失率、加压失水率）均呈 极显著相关（P＜0.01）,L*、b*值及剪切力亦与WHC存在极显著相关（P＜0.01）。相关性分析结果验证了牛肉冻结 过程中肌原纤维蛋白变性对肌肉持水性存在显著影响,进而导致牛肉解冻后出现肉色劣变、嫩度下降及汁液流失。     

Identification of Repeatedly Frozen Meat Based on Near-Infrared Spectroscopy Combined with Self-Organizing Competitive Neural Networks

A rapid, effective method of identifying repeatedly frozen meat by near-infrared spectroscopy (NIRS) combined with a self-organizing competitive neural network (SCNN) model was established. A total of 180 samples were adopted, including hot, cold, frozen, and repeatedly frozen meats. We compared the treatment effects of four pretreatment methods on the spectrogram samples, namely, multiplicative scatter correction (MSC), standard normal variables (SNV), first-order differential and second-order differential. The second differential pretreatment exerted the optimum effect. A total of 120 pork samples were randomly selected and used to establish a calibration model, and the remaining 60 samples were used for prediction. SCNN analysis revealed that classification performance was the highest when the learning number was 250. The recognition ratio of the 60 prediction collection was 93.3%, in which the recognition ratio of the repeatedly frozen meat was 100%. Thus, combined NIRS and SCNN can rapidly and accurately detect repeatedly frozen meat without destruction.     

Quantitation of Lamb Content in Mixtures with Raw Minced Beef Using Visible, Near and Mid-Infrared Spectroscopy

Samples of beef (32), lamb (33) and 5%, 10% and 20% (w/w) lamb-in-beef mixtures (33 each) were minced and reflectance scanned in the visible, near and mid-infrared spectral regions. Partial least squares (PLS) regression models were developed to predict percentage lamb content using each spectral region alone and combinations of all three. The most accurate models combined mid-IR (800-2000 cm^-1) and near IR (1100-2498 nm) spectral data following 2^nd derivatization; standard errors of prediction of 0.91% (0–20% range in lamb content) and 4.1% (0–100% range in lamb) were obtained. This technique may be useful for screening such meat mixtures.     

近红外光谱技术分析草鱼的质构特性

采用化学计量学方法,测定211个草鱼样品鱼肉的质构参数和持水性,并采集各样品的近红外光谱,以建立基于近红外光谱技术的草鱼质构特性的快速检测方法。结果表明,样品数据范围较大,可满足建模要求,比较多种光谱预处理方法,确定正交信号校正(OSC)适宜分析鱼肉持水性、硬度、回复性、弹性和剪切力的大小,而鱼肉咀嚼性的近红外光谱的最佳预处理方法是数据标准化(S)。采用偏最小二乘法分别建立草鱼各质构指标的近红外定量分析模型。所建立的鱼肉持水性、硬度、回复性、弹性、咀嚼性和剪切力指标的近红外光谱模型的相关系数分别为0.9194、0.9812、0.9830、0.9871、0.7860和0.9896,说明除了咀嚼性模型外,草鱼质构指标各数学模型的预测值和实测值之间具有较高的相关性,采用该方法能较为准确、快速地测出草鱼鱼肉持水性、硬度、回复性、弹性和剪切力的值。     

近红外光谱技术在生鲜禽肉质量检测中应用的研究进展

近红外光谱（near-infrared spectroscopy,NIRS）技术作为一种快速、无损、绿色的检测技术正在被广泛用于禽肉品质研究,通过将肉样光谱信息和品质指标参考值相关联,构建高精度、高稳定性的数学模型预测未知肉品品质。相比传统检测方式,NIRS技术具有无需预处理、更加丰富的信息量、数据计算更快等优势,在肉制品检测应用方面潜力巨大。本文主要综述了NIRS技术在生鲜禽肉（鸡肉、鸭肉、鹅肉）物理属性、化学指标以及微生物腐败等方面检测的研究进展,归纳总结了NIRS技术结合不同化学计量学算法构建模型检测禽肉各品质指标的效果,同时提出了NIRS技术在检测禽肉方面存在的缺点及未来发展趋势,可为改善NIRS技术检测应用、研发便携式NIRS检测设备提供数据支撑和理论参考。     

解冻和加工过程中冷冻猪肉保水性的研究

以冷冻猪4号肉为原料,研究解冻和加工过程中肉的来源、解冻方法、肉本身所含磷酸盐及加工过程中添加的磷酸盐对肉的保水性等指标的影响。结果表明:解冻过程中,解冻方法对猪肉的解冻汁液损失影响较大,肉流水解冻时汁液损失最小,保水性最好。当肉的来源不同时,汁液损失也不相同。肉本身所含磷酸盐对肉的解冻汁液损失影响较小。加工过程中添加不同浓度磷酸盐,对肉的保水性等指标影响显著(P<0.05)。当磷酸盐添加量≥0.4%时,肉的离心损失会显著下降(P<0.05)。在对肉保水性的影响方面,加工时添加的磷酸盐与解冻后肉本身所含磷酸盐及解冻方法之间存在交互作用。     

Predictive Analysis of Cocoa Procyanidins Using Near-Infrared Spectroscopy Techniques

ABSTRACT A near-infrared reflectance (NIR) spectroscopy technique for the prediction of procyanidins in cocoa beans ( Theobroma cacao ) has been developed. A select group of cocoa liquors from different origins used for the manufacture of chocolate were analyzed to determine quantitative levels of procyanidin oligomers (monomer to decamer) using normal-phase high-performance liquid chromatography. The calibration set included seasonal, environmental, and fermentation variations to cover the concentration range of procyanidins found at naturally occurring levels. The sample set was analyzed on FOSS NIR System II 6500 spectrophotometers and partial least-squares algorithms developed. Very good calibration statistics were obtained for the prediction of the total procyanidin oligomers ( r 2 = 0.983) with standard deviation/standard error of cross validation ratio (SD/SECV) of 5.68. A global version of this calibration, involving 20 Foss instruments produced a calibration r 2 = 0.98 with a SD/ SECV = 6.20. Procyanidins have attracted increasing attention because of the rapidly growing body of evidence associating these compounds with a wide range of potential health benefits. A rapid method for the analysis of procyanidins in cocoa liquors would be beneficial in quality-control environments and would provide cost benefits to manufacturing operations.     

近红外光谱技术的发展及其在制浆造纸中的应用

介绍近红外光谱分析技术的原理、特点以及研究进展,对近红外光谱分析技术在制浆造纸领域中的应用进行了综述。     

近红外光谱技术在造纸工业中的应用

本文就近红外光谱(NIR)的发展概况及其测定工作原理、技术特点，特别是在造纸工业中的应用如：近红外光谱技术对废纸脱墨效率的评价，蒸煮过程中纸浆卡伯值的NIR法在线测量，近红外漫反射光谱法测定纸浆卡伯值，测定纸浆中木素含量的方法，检测纸页涂料中的水分含量等作了较为详细的论述。     

基于拉曼光谱技术的掺鸡肉牛肉馅快速判别方法

利用拉曼光谱技术结合化学计量学方法对掺入鸡肉的掺假牛肉馅进行快速判别。选取89 个样本,采集样 本的拉曼光谱,对原始光谱进行卷积平滑预处理,采用主成分分析法进行聚类分析,并利用支持向量回归建立模 型。结果表明：掺假牛肉馅样本校正模型的决定系数R2 c为0.999 4,均方根误差（root mean sruare error,RMSE）为 0.230 0;交互验证决定系数R2 cv为0.999 3,RMSE为0.298 0;预测模型的决定系数R2 p为0.971 6,RMSE为0.236 0。因 此,利用拉曼光谱技术结合化学计量学方法对掺鸡肉的牛肉馅进行快速判别是可行的。     

Gel Attributes of Beef Heart When Treated by Acid Solubilization Isoelectric Precipitation

ABSTRACT: Beef heart (BH), a low water binding meat, was treated by acid-solubilization isoelectric-precipita-tion (SIP), and functional and textural properties were compared with untreated BH and BH treated by a surimi-type process. The effect of salt, 0% or 2% NaCl, on gel attributes was also evaluated. Acid-SIP BH without salt exhibited higher gel attributes (water-holding capacity, cook yield, texture profile analysis) than untreated BH or surimi BH without salt. In addition, acid-SIP BH without salt had gel attributes that were superior to untreated BH with salt and comparable to surimi BH with salt. Acid-SIP produced a protein with enhanced gel-forming ability without the aid of salt.     

基于近红外透射光谱与机器视觉的蜜柚 汁胞粒化分级检测

汁胞粒化是一种柑橘类水果中汁液囊的生理失调现象,表现为汁液囊变硬、干燥等,对水果内部品质产生消极影响.蜜柚是一种厚皮的柑橘类水果,很难通过外部果皮及果形,鉴定果实内部的汁胞粒化程度.采用近红外透射光谱结合机器视觉技术的快速无损检测方法,对蜜柚汁胞粒化程度进行分级检测.采集600个不同生长期的蜜柚样本在900～1700 ...     

骨架蛋白肌联蛋白、伴肌动蛋白、纽蛋白的降解对冷却猪肉持水性的影响

肉的持水性可用许多指标衡量,而汁液流失率(drip loss)是其中一个重要指标.持水性受很多因素影响,但目前对形成汁液流失的机理的认识还很有限.本文综述了近几年来国内外学者对持水性的研究,主要分析了宰后骨架蛋白(肌联蛋白、伴肌动蛋白、纽蛋白)的降解及钙激活蛋白酶系统降解骨架蛋白对持水性的影响,以期为宰后猪肉持水性提高和肉品质改善提供参考.