1
|
Ferreira MM, Marins-Gonçalves L, De Souza D. An integrative review of analytical techniques used in food authentication: A detailed description for milk and dairy products. Food Chem 2024; 457:140206. [PMID: 38936134 DOI: 10.1016/j.foodchem.2024.140206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/04/2024] [Accepted: 06/22/2024] [Indexed: 06/29/2024]
Abstract
The use of suitable analytical techniques for the detection of adulteration, falsification, deliberate substitution, and mislabeling of foods has great importance in the industrial, scientific, legislative, and public health contexts. This way, this work reports an integrative review with a current analytical approach for food authentication, indicating the main analytical techniques to identify adulteration and perform the traceability of chemical components in processed and non-processed foods, evaluating the authenticity and geographic origin. This work presents results from a systematic search in Science Direct® and Scopus® databases using the keywords "authentication" AND "food", "authentication," AND "beverage", from published papers from 2013 to, 2024. All research and reviews published were employed in the bibliometric analysis, evaluating the advantages and disadvantages of analytical techniques, indicating the perspectives for direct, quick, and simple analysis, guaranteeing the application of quality standards, and ensuring food safety for consumers. Furthermore, this work reports the analysis of natural foods to evaluate the origin (traceability), and industrialized foods to detect adulterations and fraud. A focus on research to detect adulteration in milk and dairy products is presented due to the importance of these products in the nutrition of the world population. All analytical tools discussed have advantages and drawbacks, including sample preparation steps, the need for reference materials, and mathematical treatments. So, the main advances in modern analytical techniques for the identification and quantification of food adulterations, mainly milk and dairy products, were discussed, indicating trends and perspectives on food authentication.
Collapse
Affiliation(s)
- Mariana Martins Ferreira
- Laboratory of Electroanalytical Applied to Biotechnology and Food Engineering (LEABE), Chemistry Institute, Uberlândia Federal University, Major Jerônimo Street, 566, Patos de Minas, MG, 38700-002, Brazil
| | - Lorranne Marins-Gonçalves
- Laboratory of Electroanalytical of Food and Environmental Contaminants (LECAA), Chemistry Institute, Uberlândia Federal University, João Naves de Ávila Street, 2121, 1D block, Santa Mônica, Uberlândia, MG, 38400-902, Brazil
| | - Djenaine De Souza
- Laboratory of Electroanalytical of Food and Environmental Contaminants (LECAA), Chemistry Institute, Uberlândia Federal University, João Naves de Ávila Street, 2121, 1D block, Santa Mônica, Uberlândia, MG, 38400-902, Brazil..
| |
Collapse
|
2
|
Zhou C, Liu L, Chen J, Fu Q, Chen Z, Wang J, Sun X, Ai L, Xu X, Wang J. Rapid authentication of characteristic milk powders by recombinase polymerase amplification assays. Food Chem 2024; 443:138540. [PMID: 38277935 DOI: 10.1016/j.foodchem.2024.138540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/30/2023] [Accepted: 01/21/2024] [Indexed: 01/28/2024]
Abstract
The authentication of dairy species has great significance for food safety. This study focused on a more rapid method for identifying major dairy species, and specific recombinase polymerase amplification (RPA)-based assays for cattle, goat, sheep, camel and donkey were developed. Through the developed RPA-based assays, goats and sheep could be simultaneously identified and bovine families could be differentiated. The performances of the RPA assays were validated using 37 milk powder samples, of which 16.2% (6/37) were suspected of being adulterated and 24.3% (9/37) were potentially at risk of being wrongly identified as adulteration. The effectiveness of the developed assays for crude DNA detection was also validated by a rapid nucleic acid extraction kit, and results showed that the presence of large amounts of protein and fat did not affect the qualitative results. Therefore, these assays could combine with the rapid nucleic acids extraction methods for being used in field detection.
Collapse
Affiliation(s)
- Cang Zhou
- School of Public Health, Hebei Medical University, Shijiazhuang 050017, China; Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang 050051, China; Hebei Key Laboratory of Environment and Human Health, Shijiazhuang 050017, China
| | - Libing Liu
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang 050051, China
| | - Jia Chen
- College of Chemical Technology, Shijiazhuang University, Shijiazhuang 050035, China
| | - Qi Fu
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang 050051, China
| | - Zhimin Chen
- Shijiazhuang Food and Drug Inspection Center, Shijiazhuang 050020, China
| | - Jinfeng Wang
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang 050051, China
| | - Xiaoxia Sun
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang 050051, China
| | - Lianfeng Ai
- Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang 050051, China
| | - Xiangdong Xu
- School of Public Health, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Environment and Human Health, Shijiazhuang 050017, China.
| | - Jianchang Wang
- School of Public Health, Hebei Medical University, Shijiazhuang 050017, China; Food Microbiology and Animal Quarantine Laboratory, Technology Center of Shijiazhuang Customs, Shijiazhuang 050051, China; Hebei Key Laboratory of Environment and Human Health, Shijiazhuang 050017, China.
| |
Collapse
|
3
|
Ma X, Xia H, Pan Y, Huang Y, Xu T, Guan F. Double-Tube Multiplex TaqMan Real-Time PCR for the Detection of Eight Animal-Derived Dairy Ingredients. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:11640-11651. [PMID: 38725129 PMCID: PMC11117397 DOI: 10.1021/acs.jafc.4c01294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/09/2024] [Accepted: 04/30/2024] [Indexed: 05/23/2024]
Abstract
Milk and dairy products represent important sources of nutrition in our daily lives. The identification of species within dairy products holds importance for monitoring food adulteration and ensuring traceability. This study presented a method that integrated double-tube and duplex real-time polymerase chain reaction (PCR) with multiplex TaqMan probes to enable the high-throughput detection of animal-derived ingredients in milk and dairy products. The detection system utilized one pair of universal primers, two pairs of specific primers, and eight animal-derived specific probes for cow, buffalo, goat, sheep, camel, yak, horse, and donkey. These components were optimized within a double-tube and four-probe PCR multiplex system. The developed double-tube detection system could simultaneously identify the above eight targets with a detection limit of 10-0.1 pg/μL. Validation using simulated adulterated milk samples demonstrated a detection limit of 0.1%. The primary advantage of this method lies in the simplification of the multiplex quantitative real-time PCR (qPCR) system through the use of universal primers. This method provides an efficient approach for detecting ingredients in dairy products, providing powerful technical support for market supervision.
Collapse
Affiliation(s)
- Xinyu Ma
- College
of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Huili Xia
- Taizhou
Food and Drug Inspection and Research Institute, Taizhou 318000, China
| | - Yingqiu Pan
- Taizhou
Food and Drug Inspection and Research Institute, Taizhou 318000, China
| | - Yafang Huang
- College
of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Ting Xu
- College
of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Feng Guan
- College
of Life Sciences, China Jiliang University, Hangzhou 310018, China
| |
Collapse
|
4
|
Kourkouli A, Thomaidis N, Dasenaki M, Markou A. Novel and Sensitive Touchdown Polymerase Chain Reaction Assays for the Detection of Goat and Sheep Milk Adulteration with Cow Milk. Molecules 2024; 29:1820. [PMID: 38675639 PMCID: PMC11052330 DOI: 10.3390/molecules29081820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/04/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Milk is the most consumed liquid food in the world due to its high nutritional value and relatively low cost, characteristics that make it vulnerable to adulteration. One of the most common types of milk adulteration involves the undeclared addition of cow's milk to milk from other mammalian species, such as goats, sheep, buffalo or donkeys. The incidence of such adulteration not only causes a crisis in terms of commercial market and consumer uncertainty but also poses a risk to public health, as allergies can be triggered by proteins in undeclared cow's milk. In this study, a specific qualitative touchdown (TD) PCR method was developed to detect the undeclared addition of cow's milk in goat and sheep milk based on the discrimination of the peak areas of the melting curves after the modification of bovine-specific primers. The developed methodology has high specificity for the DNA templates of other species, such as buffalos and donkeys, and is able to identify the presence of cow's milk down to 1%. Repeatability was tested at low bovine concentrations of 5% and 1% and resulted in %RSD values of 1.53-2.04 for the goat-cow assay and 2.49-7.16 for the sheep-cow assay, respectively. The application of this method to commercial goat milk samples indicated a high percentage of noncompliance in terms of labeling (50%), while a comparison of the results to rapid immunochromatographic and ELISA kits validated the excellent sensitivity and applicability of the proposed PCR methodology that was able to trace more adulterated samples. The developed assays offer the advantage of multiple detection in a single run, resulting in a cost- and time-efficient method. Future studies will focus on the applicability of these assays in dairy products such as cheese and yogurt.
Collapse
Affiliation(s)
- Ariadni Kourkouli
- Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece; (A.K.); (N.T.)
| | - Nikolaos Thomaidis
- Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece; (A.K.); (N.T.)
| | - Marilena Dasenaki
- Laboratory of Food Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Athina Markou
- Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece; (A.K.); (N.T.)
| |
Collapse
|
5
|
Usman I, Sana S, Afzaal M, Imran A, Saeed F, Ahmed A, Shah YA, Munir M, Ateeq H, Afzal A, Azam I, Ejaz A, Nayik GA, Khan MR. Advances and challenges in conventional and modern techniques for halal food authentication: A review. Food Sci Nutr 2024; 12:1430-1443. [PMID: 38455157 PMCID: PMC10916607 DOI: 10.1002/fsn3.3870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 11/05/2023] [Accepted: 11/13/2023] [Indexed: 03/09/2024] Open
Abstract
Food is one of the most necessary needs since human civilization. For Muslims, it is mandatory to consume halal food. From a halal authentication perspective, adulteration of food products is an emerging challenge worldwide. The demand for halal food consumption has resulted in an ever-increasing need for halal product validity. In the market, there are several food products in which actual ingredients and their source are not mentioned on the label and cannot be observed by the naked eye. Commonly nonhalal items include pig derivatives like lard, pork, and gelatin derivatives, dead meats, alcohol, blood, and prohibited animals. Purposely, various conventional and modern methods offer precise approaches to ensure the halalness and wholesomeness of food products. Conventional methods are physiochemical (dielectric) and electrophoresis. At the same time, modern techniques include high-pressure liquid chromatography (HPLC), gas chromatography (GC), electronic nose (E-Nose), polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), near-infrared (NIR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. This review intends to give an extensive and updated overview of conventional and modern analytical methods for ensuring food halal authenticity.
Collapse
Affiliation(s)
- Ifrah Usman
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
- University Institute of Food Science and Technology, The University of LahoreLahorePakistan
| | - Saima Sana
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Muhammad Afzaal
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Ali Imran
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Farhan Saeed
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Aftab Ahmed
- Department of Nutritional SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Yasir Abbas Shah
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Muniba Munir
- National Institute for Biotechnology & Genetic Engineering FaisalabadFaisalabadPakistan
| | - Huda Ateeq
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Atka Afzal
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Iqra Azam
- Department of Food SciencesGovernment College Women University FaisalabadFaisalabadPakistan
| | - Afaf Ejaz
- Department of Food SciencesGovernment College University FaisalabadFaisalabadPakistan
| | - Gulzar Ahmad Nayik
- Department of Food Science and TechnologyGovernment Degree College ShopianShopianJammu and KashmirIndia
| | - Mahbubar Rahman Khan
- Department of Food Processing and PreservationHajee Mohammad Danesh Science & Technology UniversityBangladesh
| |
Collapse
|
6
|
Rullo R, Caira S, Nicolae I, Marino F, Addeo F, Scaloni A. A Genotyping Method for Detecting Foreign Buffalo Material in Mozzarella di Bufala Campana Cheese Using Allele-Specific- and Single-Tube Heminested-Polymerase Chain Reaction. Foods 2023; 12:2399. [PMID: 37372609 DOI: 10.3390/foods12122399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 05/31/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
Mozzarella di Bufala Campana (MdBC) cheese is a Protected Designation of Origin (PDO) product that is important for the economy and cultural heritage of the Campania region. Food fraud can undermine consumers' trust in this dairy product and harm the livelihood of local producers. The current methods for detecting adulteration in MdBC cheese due to the use of buffalo material from foreign countries could exhibit limitations associated with the required use of expensive equipment, time-consuming procedures, and specialized personnel. To address these limits here, we propose a rapid, reliable, and cost-effective genotyping method that can detect foreign buffalo milk in a counterpart from the PDO area and in MdBC cheese, ensuring the quality and authenticity of the latter dairy product. This method is based on dedicated allele-specific and single-tube heminested polymerase chain reaction procedures. By using allele-specific primers that are designed to detect the nucleotide g.472G>C mutation of the CSN1S1Bbt allele, we distinguished an amplicon of 330 bp in the amplification product of DNA when extracted from milk and cheese, which is specific to the material originating from foreign countries. By spiking foreign milk samples with known amounts of the counterpart from the PDO area, the sensitivity of this assay was determined to be 0.01% v/v foreign to PDO milk. Based on a rough estimate of its simplicity, reliability, and cost, this method could be a valuable tool for identifying adulterated buffalo PDO dairy products.
Collapse
Affiliation(s)
- Rosario Rullo
- Institute for the Animal Production System in the Mediterranean Environment, National Research Council, 80055 Portici, Italy
| | - Simonetta Caira
- Institute for the Animal Production System in the Mediterranean Environment, National Research Council, 80055 Portici, Italy
| | - Ioana Nicolae
- Research and Development Institute for Bovine, 077015 Balotesti, Romania
| | - Francesca Marino
- Department of Clinical Medicine and Surgery, Endocrinology Unit, University Federico II, 80131 Naples, Italy
| | - Francesco Addeo
- Dipartimento di Agraria, Università degli Studi di Napoli "Federico II", 80055 Portici, Italy
| | - Andrea Scaloni
- Institute for the Animal Production System in the Mediterranean Environment, National Research Council, 80055 Portici, Italy
| |
Collapse
|
7
|
Xiao F, Gu M, Zhang Y, Xian Y, Zheng Y, Zhang Y, Sun J, Ding C, Zhang G, Wang D. Detection of Soybean-Derived Components in Dairy Products Using Proofreading Enzyme-Mediated Probe Cleavage Coupled with Ladder-Shape Melting Temperature Isothermal Amplification (Proofman-LMTIA). Molecules 2023; 28:molecules28041685. [PMID: 36838673 PMCID: PMC9964665 DOI: 10.3390/molecules28041685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/28/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
Food adulteration is a serious problem all over the world. Establishing an accurate, sensitive and fast detection method is an important part of identifying food adulteration. Herein, a sequence-specific ladder-shape melting temperature isothermal amplification (LMTIA) assay was reported to detect soybean-derived components using proofreading enzyme-mediated probe cleavage (named Proofman), which could realize real-time and visual detection without uncapping. The results showed that, under the optimal temperature of 57 °C, the established Proofman-LMTIA method for the detection of soybean-derived components in dairy products was sensitive to 1 pg/μL, with strong specificity, and could distinguish soybean genes from those of beef, mutton, sunflower, corn, walnut, etc. The established Proofman-LMTIA detection method was applied to the detection of actual samples of cow milk and goat milk. The results showed that the method was accurate, stable and reliable, and the detection results were not affected by a complex matrix without false positives or false negatives. It was proved that the method could be used for the detection and identification of soybean-derived components in actual dairy products samples.
Collapse
Affiliation(s)
- Fugang Xiao
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
- Correspondence: (F.X.); (D.W.); Tel.: +86-374-2968805 (F.X.); +86-374-2968907 (D.W.)
| | - Menglin Gu
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
- College of Grain and Food, Henan University of Technology, Zhengzhou 450001, China
| | - Yaoxuan Zhang
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
- College of Grain and Food, Henan University of Technology, Zhengzhou 450001, China
| | - Yaodong Xian
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
| | - Yaotian Zheng
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
| | - Yongqing Zhang
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
| | - Juntao Sun
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
| | - Changhe Ding
- College of Grain and Food, Henan University of Technology, Zhengzhou 450001, China
| | - Guozhi Zhang
- College of Grain and Food, Henan University of Technology, Zhengzhou 450001, China
| | - Deguo Wang
- Henan Key Laboratory of Biomarker Based Rapid-Detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, China
- Correspondence: (F.X.); (D.W.); Tel.: +86-374-2968805 (F.X.); +86-374-2968907 (D.W.)
| |
Collapse
|
8
|
Chaudhary V, Kajla P, Dewan A, Pandiselvam R, Socol CT, Maerescu CM. Spectroscopic techniques for authentication of animal origin foods. Front Nutr 2022; 9:979205. [PMID: 36204380 PMCID: PMC9531581 DOI: 10.3389/fnut.2022.979205] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Milk and milk products, meat, fish and poultry as well as other animal derived foods occupy a pronounced position in human nutrition. Unfortunately, fraud in the food industry is common, resulting in negative economic consequences for customers as well as significant threats to human health and the external environment. As a result, it is critical to develop analytical tools that can quickly detect fraud and validate the authenticity of such products. Authentication of a food product is the process of ensuring that the product matches the assertions on the label and complies with rules. Conventionally, various comprehensive and targeted approaches like molecular, chemical, protein based, and chromatographic techniques are being utilized for identifying the species, origin, peculiar ingredients and the kind of processing method used to produce the particular product. Despite being very accurate and unimpeachable, these techniques ruin the structure of food, are labor intensive, complicated, and can be employed on laboratory scale. Hence the need of hour is to identify alternative, modern instrumentation techniques which can help in overcoming the majority of the limitations offered by traditional methods. Spectroscopy is a quick, low cost, rapid, non-destructive, and emerging approach for verifying authenticity of animal origin foods. In this review authors will envisage the latest spectroscopic techniques being used for detection of fraud or adulteration in meat, fish, poultry, egg, and dairy products. Latest literature pertaining to emerging techniques including their advantages and limitations in comparison to different other commonly used analytical tools will be comprehensively reviewed. Challenges and future prospects of evolving advanced spectroscopic techniques will also be descanted.
Collapse
Affiliation(s)
- Vandana Chaudhary
- College of Dairy Science and Technology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, India
| | - Priyanka Kajla
- Department of Food Technology, Guru Jambheshwar University of Science and Technology, Hisar, India
| | - Aastha Dewan
- Department of Food Technology, Guru Jambheshwar University of Science and Technology, Hisar, India
| | - R. Pandiselvam
- Division of Physiology, Biochemistry and Post-Harvest Technology, ICAR–Central Plantation Crops Research Institute, Kasaragod, India
| | | | | |
Collapse
|
9
|
QU Q, JIN L. Application of nuclear magnetic resonance in food analysis. FOOD SCIENCE AND TECHNOLOGY 2022. [DOI: 10.1590/fst.43622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|