Development of New HS–SPME–GC–MS Technique to the Measurement of Volatile Terpenoid Profile of MilkFood Analytical Methods - Tập 14 Số 12 - Trang 2585-2596 - 2021
Rita Székelyhidi, Erika Lakatos, Beatrix Sik, Zsolt Ajtony
AbstractThis study presented the development of such a HS–SPME–GC–MS technique, with the use of which, directly from the raw milk sample matrix, both qualitatively and quantitatively; the volatile terpenoids (α-pinene, sabinene, β-pinene, p-cymene, limonene, linalool, α-thujene, camphor, menthol, methyl chavicol, caryophyllene E, α-humulene) can be determined, derived from herbs eaten by the dairy animals by different feeding methods. Repeatability was less than 10% in the case of milk fat samples. The estimated limits of quantitation were between 2 and 16 ng/g. The lowest values were 2 ng/g for p-cymene and methyl chavicol; the highest value was 16 ng/g for caryophyllene. In the case of goat milk, the repeatability was better than 8% except for α-thujene. The estimated limits of quantitation were between 1 and 8 ng/g. The lowest values were 1 ng/g for β-pinene, p-cymene and limonene, and the highest value was 8 ng/g for linalool. In milk fat, the highest concentration was identified in caryophyllene E (470 ng/g) and α-humulene (430 ng/g), while the lowest concentration was in p-cymene (2 ng/g) and camphor (2 ng/g). In goat milk, limonene was present in all samples, but its amount varied depending on the type of consumed herb. Methyl chavicol and caryophyllene E were detected in goat’s milk only in one case. The former was detected in sage milk at 2.09 ng/g and the latter in tarragon milk at 2.28 ng/g. We have also successfully demonstrated that the feed consumed by dairy animals also affects the quality of dairy products.
A Rapid Routine Methodology Based on Chemometrics to Evaluate the Toxicity of Commercial Infant Milks Due to Hazardous ElementsFood Analytical Methods - - 2022
Ainara Gredilla, Silvia Fdez‐Ortiz de Vallejuelo, Gorka Arana, Alberto de Diego, Marcos L.S. Oliveira, Kátia da Boit, Juan Manuel Madariaga, Luis Silva
AbstractThe toxicity and the health risk assessment associated to the presence of some hazardous elements (HEs) in dried (infant formula and powdered) milks due to manufacturing and packaging process, raw materials used, environmental conditions, etc. need to be determined. With this aim, a new methodology based on the combination of health risk quotients and non-supervised (as cluster analysis (CA) and principal component analysis (PCA)) chemometric techniques is proposed in this study. The methodology was exemplified using the concentration of 27 elements, some of them HEs, measured in 12 powdered milk samples produced for children and adults in Brazil and Colombia. The concentration values were obtained by inductively coupled plasma-mass spectrometry (ICP-MS) after acid microwave digestion. Elemental concentrations vary depending upon the type of milk (initiation, growing-up, follow-on milks and adult milks). However, hazard quotients (HQ) and carcinogenic risk (CR) values showed no risk associated to the presence of HEs on milks. The methodology designed made possible to conclude that adults’ milks are more characteristic of elements naturally present in milk. Children milks present major presence of trace and minor elements. Between infant milks, sample H, designed for babies between 12 and 36 months, was identified as of poor quality. Moreover, it was possible to deduce that while the fortification process applied to children powdered milks is a probable metal and metalloid source, together with the manufacturing, the skimming process is not a contamination source for milks.
Graphical abstract
Non-Destructive Assessment of Microbial Spoilage of Broiler Breast Meat Using Structured Illumination Reflectance Imaging with Machine LearningFood Analytical Methods - - 2024
Ebenezer O. Olaniyi, Yuzhen Lu, Xin Zhang, Anuraj T. Sukumaran, Hudson T. Thames, Diksha Pokhrel
Meat quality has gained ample attention owing to increased consumer awareness and competition among poultry processors to deliver premium quality products. Nevertheless, chicken breast meat is susceptible to microbial spoilage resulting in economic and product losses. Conventional approaches such as organoleptic, aerobic plate count (APC), and molecular methods have been employed for assessing the microbiological quality of meat products but suffer various shortcomings. This study was a proof-of-concept evaluation of emerging structured illumination reflectance imaging (SIRI) as a non-destructive, objective means to evaluate microbial spoilage in chicken breast meat. The experimental chicken breast samples were kept on a retail tray for 1–13 days at 3-day intervals and subjected to image acquisition by broadband SIRI at varied spatial frequencies of sinusoidally-modulated structured illumination (0.05–0.40 cycles mm−1). The chicken samples were categorized into fresh and spoiled classes using the APC threshold of 5 log10 CFU g−1. Acquired pattern images were demodulated into amplitude component (AC) and direct component (DC) images (corresponding to uniform illumination). Three pre-trained deep learning models, including VGG16, EfficientNetB6, and ResNeXt101, were employed to extract the features from the demodulated images, followed by principal component analysis (PCA) to reduce feature redundancy. The selected PCs were used to build classification models using linear discriminant analysis (LDA) and support vector machine (SVM) separately to distinguish between fresh and spoiled samples. AC images consistently outperformed DC images in the resultant classification performance. When the LDA classifier was used, AC images yielded maximum accuracy improvements of 3.6%–6%, depending on feature type and spatial frequency; with the SVM classifier, AC images achieved maximum improvements of 4.4% to 6.4%. The SVM model with the features extracted by ResNeXt101 from AC images at 0.25 cycles mm−1 achieved the best overall classification accuracy of 76% in differentiating fresh and spoiled samples. This study shows that the SIRI technique is effective for enhanced assessment of microbial spoilage in broiler breast meat, but more dedicated efforts are needed to improve both hardware and software for practical application.
Determination of Organochlorine Pesticides in Tea Beverage by Directly Suspended Droplet Microextraction Combined with GC-ECDFood Analytical Methods - Tập 8 - Trang 147-153 - 2014
Lijun Wu, Chunman Song, Yong Zhao, Zhijun He, Guiyuan Zhou, Wei Lu, Baoxing Wang
In this paper, a simple and efficient directly suspended droplet microextraction (DSDME) method has been developed and optimized, which can be applied on extracting organochlorine pesticides (OCPs) in beverage for gas chromatography–electron capture detector (GC-ECD) analysis. The optimal DSDME was adding 100 μL of isooctane into 5 mL of the beverage sample and stirred for 10 min at 1,000 rpm. The relative recoveries of the DSDME method were ranged from 81 to 117 % (relative standard deviations were 2–20 %, n = 5). The limits of detections were 0.8–5.0 ng/L. Furthermore, DSDME was applied to rapidly determine the OCPs in tea beverage and the results suggested that the method can be used as rapid determination of OCPs in the tea beverage.
Protein Extraction and Identification by Gel Electrophoresis and Mass Spectrometry from Edible bird’s Nest SamplesFood Analytical Methods - Tập 10 - Trang 387-398 - 2016
Siti Najihah Zukefli, Lee Suan Chua, Zaidah Rahmat
Edible bird’s nest (EBN) is a delicacy rich in protein and carbohydrate from the salivary secretion of swiftlets. There are limited studies on the protein profile of EBN, mainly due to its complexity in chemical composition and diversity of species, as well as the capacity of analytical techniques. The protein extraction methods, namely, ultrasonic and detergent (Triton X-100 and SDS)-assisted methods, as well as Tris–HCl buffer solubilization were used to compare the protein profiles of EBNs harvested from two locations (Batu Pahat and Kota Tinggi) in Malaysia. Ultrasonic assisted extraction produced the highest protein content because EBN contains mostly water-soluble protein. The electrophoretic gels revealed that EBNs from Batu Pahat (17–150 kDa) exhibited more protein bands than those samples from Kota Tinggi (25–154 kDa). The difference could be explained by the variance in the geographical origin of EBNs. Additional protein bands (25, 27, and 92 kDa) were detected for the detergent-assisted methods. These could be poorly water-soluble membrane proteins that were released after cell lysis by detergents. The mass spectra revealed that acidic mammalian chitinase precursor is the most abundant protein. The other proteins include trypsinogen, inter-alpha-trypsin inhibitor heavy chain H2 precursor, tumor necrosis factor receptor superfamily member 5 precursor, and phospholipase A2-like. There are also collagen and co-enzyme Q-binding proteins which are important for skin complexion in line with the traditional belief of Chinese community. The protein extraction methods could produce good quality of proteins for affirmative confirmation using gel electrophoresis and mass spectrometric identification.
Characterization of Volatile Organic Compounds of Vinegars with Novel Electronic Nose System Combined with Multivariate AnalysisFood Analytical Methods - Tập 7 - Trang 1073-1082 - 2013
Binbin Guan, Jiewen Zhao, Hao Lin, Xiaobo Zou
A novel electronic nose system (also called artificial olfaction system) based on colorimetric sensor array was developed for characterization and identification of the volatile organic compounds (VOCs) of vinegars fermented from different raw materials. Fifteen chemo-responsive dyes including nine metalloporphyrins and six pH indicators were selected according to their sensitivity to volatile compounds from vinegar samples. The colorimetric sensor array was made by printing selected chemo-responsive dyes on a silica gel plate. A color change profile for each sample was obtained by differentiating the images of the colorimetric sensor array before and after exposure to the odorant of vinegar sample. The digital data (i.e., red, green, and blue components of the image) representing the color change profiles for the vinegar samples were analyzed. Genetic algorithm partial least squares was employed to select sensitive image digital variable to build a calibration model. Several methods (i.e., linear discrimination analysis, LDA; partial least square discrimination analysis; artificial neural network) were also used comparatively for classification, the result was evaluated by the % correct identification of samples. The optimal model was achieved by LDA model with 14 image digital variables used, and all the vinegar samples were correctly identified both in training and testing sets. This research suggests that the system shows significant potential in vinegar VOCs characterization and discrimination.
Xác định Spectinomycin trong các sản phẩm chế biến thức ăn và dạng thuốc bằng phương pháp HPLC sử dụng sự chuyển hóa 1-Naphthyl Isocyanate và phát hiện UV Dịch bởi AI Food Analytical Methods - Tập 9 - Trang 2444-2451 - 2016
F. Belal, Sawsan A. Abd El-Razeq, Manal M. Fouad, S. Zayed, Fatma A. Fouad
Một phương pháp HPLC mới, đơn giản và nhạy cảm đã được phát triển để xác định spectinomycin hydrochloride trong các dạng bào chế và hỗn hợp thức ăn thông qua sự chuyển hóa với 1-naphthyl isocyanate. Việc tách biệt được thực hiện trên cột C18 với pha động bao gồm acetonitril/nước (50:50 v/v, pH 3.2) với tốc độ dòng 1 mL/phút và phát hiện UV tại 230 nm. Các yếu tố ảnh hưởng đến hiệu suất phản ứng chuyển hóa được nghiên cứu và tối ưu hóa một cách cẩn thận. Phương pháp có độ tuyến tính trong khoảng nồng độ từ 10–100 μg/mL với giới hạn phát hiện là 0.25 μg/mL và giới hạn định lượng là 1.75 μg/mL. Phương pháp phát triển đã được áp dụng thành công để phân tích thuốc trong các dạng bào chế thương mại và mẫu hỗn hợp thức ăn có thêm; tỷ lệ thu hồi trung bình lần lượt là 99.79 và 99.56. Hiệu suất phân tích của phương pháp đã được xác thực hoàn toàn và kết quả đạt yêu cầu. Một đề xuất về đường đi của phản ứng đã được trình bày.
#HPLC #spectinomycin #1-Naphthyl isocyanate #phát hiện UV #bào chế thuốc #hỗn hợp thức ăn
Fluorescent Detection of 2,4-Dichlorophenoxyacetic Acid in Food Samples Based on Covalent Organic Frameworks and MnO2 NanosheetsFood Analytical Methods - Tập 13 - Trang 1842-1851 - 2020
Fei Qu, Yang Sun, Shuxian Guo, Hang Yan, Jinmao You
2,4-Dichlorophenoxyacetic acid (2,4-D) is a typical chlorinated aromatic herbicide which is widely used because of its low cost. Herein, a new fluorescent assay for 2,4-D is developed based on covalent organic frameworks (COFs) and MnO2 nanosheets. The fluorescence of COFs is quenched effectively by MnO2 nanosheets. Ascorbic acid 2-phosphate (AAP) is hydrolyzed by alkaline phosphatase (ALP) to produce ascorbic acid (AA), which reduces MnO2 nanosheets into Mn2+, so the quenched fluorescence recovers. Additionally, 2,4-D can inhibit the catalytic activity of ALP. Therefore, the addition of 2,4-D quenches the fluorescence of COF-MnO2 system again. Under the optimum conditions, this assay displays a wide linear range of 2,4-D from 1 to 150,000 ng/mL with a limit of detection of 0.36 ng/mL. Then, this method is successfully used to measure 2,4-D in rice, millet, and cucumber samples with satisfactory recoveries. Compared with other probes for 2,4-D detection, both of COFs and MnO2 nanosheets are stable, cost-effective, and easily prepared. The sensitivity and linear range of 2,4-D in this strategy are superior to most reported works. This is the first time that a novel sensing platform using fluorescent COFs and MnO2 nanosheets is developed for 2,4-D.
A Review of Current Methods for the Determination of Acrylamide in Food ProductsFood Analytical Methods - Tập 5 - Trang 29-39 - 2011
Serife Evrim Kepekci Tekkeli, Cem Önal, Armağan Önal
Acrylamide (AA) is a potentially carcinogenic substance which is formed during heating of food products containing carbohydrates and asparagine. It was first detected in food products in 2002. Since that time, several analytical methods have been made available for the quantification of AA in various foods. Starting from the announcement in 2002, occurrence, formation, chemistry, toxicology, and potential health risk in the human diet have been investigated and methods of analysis have been reviewed in many articles. In this paper, current information and analytical methods for the determination of AA have been reviewed.
Validation of the Methods for the Non-Milk Fat Detection in Artificially Adulterated Milk with Palm OilFood Analytical Methods - - 2023
Marwa El-Nabawy, Sameh Awad, Amel Ibrahim
AbstractDairy products are among the most adulterated food products. Due to the current high price of milk fat, it has been replaced by low-cost oils, especially those oils that have the same fatty acid profile as milk fat. This study intends to confirm the lowest level of palm oil added to milk and validate various methods for detecting palm oil in milk, including gas chromatography, reverse-phase high performance liquid chromatography, and Fourier transform infrared. Different amounts of palm oil were prepared in the final liquid milk using five treatments of fresh milk cream and an emulsion of palm oil. The results of this study showed that the values of the saponification number decreased with the increase in the percentages of added palm oil. There was no decrease under the limits of the Egyptian standards until the addition of 50% palm oil. The iodine number is less sensitive than the saponification number in the detection of palm oil. Butyro refractometer reading is unable to detect the palm oil in milk. The fatty acid profile in milk determined by gas chromatography correlated well with the addition of palm oil. Furthermore, there is a positive relationship between the level of added palm oil and the β-sitosterol content as measured by reverse-phase high-performance liquid chromatography. There was no relationship between the behavior of the spectra resulting from Fourier transform infrared spectroscopy and the presence of palm oil.
