Application of temperature-controlled attenuated total reflectance-mid-infrared (ATR-MIR) spectroscopy for rapid estimation of butter adulteration

There is a continual need for development of rapid methods that meet or exceed the detection levels of currently available analytical methods for authentication of food products. The objective of this study was to evaluate temperature-controlled attenuated total reflectance-mid-infrared (ATR-MIR) spectroscopy combined with multivariate analysis as a simple and rapid method for the determination of butter adulteration as a dairy food system. Commercial samples of butter fat were adulterated with margarine fat at levels ranging from 0% to 100% (v/v). Partial least square regression (PLSR) models gave standard error of cross-validation (SECV) of <1.2% (v/v) and correlation coefficients (r) > 0.99. Excellent predicting capabilities were obtained using an external validation set consisting of butter adulterated with margarines at ratios of 2.5%, 13%, and 45%. We have demonstrated the feasibility of a temperature-controlled ATR-MIR spectroscopy technique that would allow for rapid analysis of dairy products.     

Analysis of lard in meatball broth using Fourier transform infrared spectroscopy and chemometrics

Meatball is one of the favorite foods in Indonesia. For the economic reason (due to the price difference), the substitution of beef meat with pork can occur. In this study, FTIR spectroscopy in combination with chemometrics of partial least square (PLS) and principal component analysis (PCA) was used for analysis of pork fat (lard) in meatball broth. Lard in meatball broth was quantitatively determined at wavenumber region of 1018–1284 cm^− 1. The coefficient of determination (R²) and root mean square error of calibration (RMSEC) values obtained were 0.9975 and 1.34% (v/v), respectively. Furthermore, the classification of lard and beef fat in meatball broth as well as in commercial samples was performed at wavenumber region of 1200–1000 cm^− 1. The results showed that FTIR spectroscopy coupled with chemometrics can be used for quantitative analysis and classification of lard in meatball broth for Halal verification studies. The developed method is simple in operation, rapid and not involving extensive sample preparation.     

The use of cooling and heating thermograms for monitoring of tallow, lard and chicken fat adulterations in canola oil

The use of cooling and heating thermograms from differential scanning calorimetry (DSC) for monitoring the presence of genuine lard (GLD), beef tallow (BT), chicken fat (CF) as adulterants in canola oil has been investigated. Mixing of animal fats especially lard and tallow in any form in food products is a cause of concern for certain religions. Canola oil samples spiked separately with BT, GLD and CF in levels ranging from 1 to 20% (w/w) were analysed by DSC to obtain their cooling and heating profiles. The heating measurements showed that detection of GLD and BT adulterations could be possible based on characteristic differences of GLD and BT adulteration peaks appearing in the higher temperature region of heating thermograms while cooling measurements showed that BT adulteration could be determined by a distinct exothermic peak appearing in the higher temperature region of the cooling thermograms. The determination of GLD by cooling measurements could not be possible since the changes due to GLD and CF adulterations were very similar.     

A Fourier Transform Infrared Spectroscopy Method for Analysis of Palm Oil Adulterated with Lard in Pre-Fried French fries

Fourier transform infrared spectroscopy with attenuated total reflectance accessory was used to detect the presence of lard in French fries pre-fried in palm oil adulterated with lard. A Fourier transform infrared calibration model was obtained using partial least squares for prediction of lard in a blend mixture of lard and palm oil. The coefficient of determination (R²) of 0.9791 was obtained with 0.5% of detection limit. The error in calibration expressed with root mean square error of calibration was 0.979%. In addition, the error obtained during cross validation was 2.45%. A discriminant analysis test was able to distinguish between fries samples adulterated with lard and samples, which were pre-fried with palm oils. Fourier transform infrared spectroscopy is a fast and powerful technique for quantification of lard present in French fries.      

微胶囊西藏酥油茶粉的技术研究

酥油茶是我国藏族地区相传千年的特有饮品,是利用青藏高原地区牦牛鲜奶,用传统工艺分离出的乳脂。酥油茶味道鲜美,营养成分极为丰富,有18种氨基酸,脂肪中不饱和脂肪高于40%,人体必需的不饱和脂肪酸占总脂肪的1/3以上,尤其是亚麻酸高达5.2%。目前西藏酥油茶的加工依然停留在原始阶段的水平上,含水量高达10%～15%,容易变质,即影响风味,也大大缩短了保质期,食用也很不方便。本研究采用食品微胶囊技术进行酥油茶工业化生产实验,分析酥油茶的营养成分及其生理功能,摸索酥油茶的工业生产路线及工艺条件,为中试提供依据。     

基于傅里叶变换红外光谱的大豆原油掺伪定量 分析模型研究

目的应用傅里叶变换红外光谱(FTIR)结合最小偏二乘法(PLS)建立大豆原油-棕榈油二元掺伪体系的定量分析模型。方法以42个大豆原油、21个精炼油、88个掺伪油的FIIR谱图为模型样本,预处理方法选用标准正态变量(SNV),在此基础上应用主成分分析(PCA)提取特征变量,随机选取60个掺伪油样组成校正集,28个掺伪油样组成验证集,以PLS方法建立大豆原油的掺伪定量模型。结果 PCA可将大豆原油及精炼油分成独立的2类。经PCA分析,大豆原油中掺入棕榈油的掺伪检测限为5%。PLS校正模型的判定系数R2为0.9926,校正误差均方根RMSEC为1.8121。预测模型的R2为0.9823,交叉验证误差均方根RMSECV为2.8189。同时得到的预测结果的偏差在1.3909%~3.1019%之间,差异不显著,说明此模型可行。结论 FTIR-PLS模型能够实现大豆原油的掺伪定量分析,分析速度快,能够满足大豆原油入库要求,是一种可行的大豆原油掺伪分析方法。     

Analysis of pork adulteration in beef meatball using Fourier transform infrared (FTIR) spectroscopy

Meatball is one of the favorite foods in Indonesia. The adulteration of pork in beef meatball is frequently occurring. This study was aimed to develop a fast and non destructive technique for the detection and quantification of pork in beef meatball using Fourier transform infrared (FTIR) spectroscopy and partial least square (PLS) calibration. The spectral bands associated with pork fat (PF), beef fat (BF), and their mixtures in meatball formulation were scanned, interpreted, and identified by relating them to those spectroscopically representative to pure PF and BF. For quantitative analysis, PLS regression was used to develop a calibration model at the selected fingerprint regions of 1200-1000 cm(-1). The equation obtained for the relationship between actual PF value and FTIR predicted values in PLS calibration model was y = 0.999x + 0.004, with coefficient of determination (R(2)) and root mean square error of calibration are 0.999 and 0.442, respectively. The PLS calibration model was subsequently used for the prediction of independent samples using laboratory made meatball samples containing the mixtures of BF and PF. Using 4 principal components, root mean square error of prediction is 0.742. The results showed that FTIR spectroscopy can be used for the detection and quantification of pork in beef meatball formulation for Halal verification purposes.     

Persistent organochlorine pesticides in Mexican butter

Organochlorine pesticides have been used in Mexico in malaria control programmes against ectoparasites and as seed dresser. Owing to their chemical stability, they tend to accumulate in the lipid part of the organisms. The stored pesticides are excreted with the endogenous fat during milk production. The aim was to monitor the organochlorine pesticide levels in butter manufactured in Mexico. From the pesticides, only HCB, β-HCH, pp '-DDT, op '-DDT and pp '-DDE with major frequency and levels were detected. The HCB mean level was low at 0.008 mg kg -1 on a fat basis. From the HCH isomer, only the β-HCH at 0.065 mg kg^-1 on a fat basis was determined, remaining as the main contaminant of the monitored butters. Among DDTs, pp '-DDE was the major constituent (0.043 mg kg^-1 on a fat basis) followed by pp '-DDT (0.036 mg kg^-1) and op '-DDT (0.009 mg kg^-1). Comparing the previous study (1994) and this one (2001), all organochlorine pesticides had a descendent tendency; β-HCH decreased from 0.095 to 0.065 mg kg^-1 on a fat basis, whereas the total DDT decreased from 0.056 to 0.047 mg kg^-1, pp '-DDT from 0.050 to 0.036 mg kg^-1, op '-DDT from 0.018 to 0.009 mg kg^-1, while pp '-DDE increased from 0.032 to 0.043 mg kg^-1. The decreased DDT levels in Mexican butters is caused by the substitution of organochlorine insecticides with pyrethroids used by the Mexican Ministry of Health since 1999 in sanitary programmes.     

Use of Fourier Transform Infrared (FTIR) Spectroscopy and Chemometrics for Analysis of Lard Adulteration in “Rambak” Crackers

“Rambak” crackers are one of the traditional foods consumed among Indonesian people made from various kinds of animal skin. The present study highlights the analysis of lard obtained from extraction of “rambak” crackers using Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics of partial least square and principle component analysis. FTIR spectroscopy at wavenumber regions of 1200–1000 cm^–1 was successfully used for quantification and classification of lard in “rambak” crackers. The relationship between actual value of lard and Fourier transform infrared predicted value has R² value of 0.946 with low errors in calibration and validation models. Furthermore, the chemometrics principle component analysis can be successfully used for determination of pig skin through analysis of lard in commercial “rambak” crackers. The developed method (FTIR spectroscopy coupled with chemometrics) is rapid and reliable for quantification and classification of lard in “rambak” crackers.     

Butter and butter oil classification by PTR-MS

The potential of proton transfer reaction mass spectrometry (PTR-MS) as a tool for classification of milk fats was evaluated in relation to quality and authentication issues. Butters and butter oils were subjected to heat and off-flavouring treatments in order to create sensorially defective samples. The effect of the treatments was evaluated by means of PTR-MS analysis, sensory analysis and classical chemical analysis. Subsequently, partial least square-discriminant analysis models (PLS-DA) were fitted to predict the matrix (butter/butter oil) and the sensory grades of the samples from their PTR-MS data. Using a 10-fold cross-validation scheme, 84% of the samples were successfully classified into butter and butter oil classes. Regarding sensory quality, 89% of the samples were correctly classified. As the milk fats were fairly successfully classified by the combination of PTR-MS and PLS-DA, this combination seems a promising approach with potential applications in quality control and control of regulations.     

硫酸化变质油的制备

通过猪油硫酸化，变质油脂交换、硫酸化，再和多种有效成分复配，制得皮革加脂剂。     

Detection of fresh palm oil adulteration with recycled cooking oil using fatty acid composition and FTIR spectral analysis

There is a growing concern over the food safety issue related to increased incidence of cooking oil adulteration with recycled cooking oil (RCO). The objective of this study was to detect fresh palm olein (FPO) adulteration with RCO using fatty acid composition (FAC) and Fourier-transform infrared spectroscopy (FTIR) spectral analyses combined with chemometrics. RCO prepared in the laboratory was mixed with FPO in the proportion ranged from 1% to 50% (v/v) to obtain the adulterated oil samples (AO). FACs for FPO, RCO, and AO were determined using gas chromatography equipped with a flame ionization detector (GC-FID). The compositions of most fatty acids in RCO lied within the normal ranges of Codex standard, except for C8:0, C10:0, C11:0, C15:0, trans C18:1, and polyunsaturated fatty acids (PUFAs), C20:5. PUFAs showed a consistent decreasing trend with increasing magnitude of change with respect to increasing adulteration level and thus might be a good indicator for detecting FPO adulteration with RCO. The evaluation parameters (coefficient of determination, root mean standard error) of the FTIR-partial least square (PLS) model of palm oil adulteration with recycled oil are R² = 0.995 and 3.25, respectively. For FTIR spectral analysis, the distinct variations in spectral regions and aberrations in characteristic bands between FPO and RCO were observed. The optimized PLS calibration model developed from normal spectral of the combined region at 3602–3398, 3016–2642, and 1845–650 cm^?1 overpredict the adulteration level. On the other hand, the discriminant analysis classification model was able to classify the FPO and AO into two distinct groups. Improvement of the principles of combined techniques in authenticating AO from fresh oil is beneficial as a guideline to detect adulteration in cooking oil.     

脂肪和猪油的食用价值

在现代的生活中经常存在这样一些现象--谈\"肥\"色变和断绝食用猪油,因为在一般观念中,肥肉和猪油总是和油腻、肥胖、胆固醇高紧密相连,许多中年人更是把它们列为\"禁品\".其实他们殊不知适量食用一些肥肉和猪油对身体是很有益的.本文主要对肥肉和猪油的营养价值及人们所担心的健康问题阐述,同时探讨如何防止食用过程中肥肉和猪油对人体健康所造成的不良影响的方法.     

猪油资源的深加工

介绍了以猪油可再生资源为原料进行化学深加工综合利用及所得产品。这些产品包括硬化油、甘油、脂肪酸、脂肪酸盐、脂肪酸单甘酯、醇酸树脂涂料、脂肪酸甲酯、高碳醇等。     

Direct determination of the total fat content of butter and edible oil emulsions — an international collaborative study

A standard operating procedure for the direct determination of fat in butter and edible oil products involved the extraction of the fat from the sample, separation of the solvent–fat phase from the serum phase and transfer of the solvent–fat phase to a fat-collecting vessel. The solvent was removed by distillation or evaporation and the mass of extracted matter was determined gravimetrically. This method was studied collaboratively involving 13 laboratories and eight samples to determine precision estimates. Estimates of repeatability and reproducibility were 0.23 g per 100 g and 0.45 g per 100 g, respectively. The method is recommended for adoption as an international reference method.     

猪油酯交换产物性质测定与分析

本实验对酯交换前后样品进行SF1和DSC测定分析,确定了本实验进行的酯交换过程是脂肪酸排布随机化的过程,并且随机化后产品物理性质得到改良,更适合用作起酥油.