In recent years, the frequent economically motivated adulteration (EMA) caused by component displacement, illegal addition, and other problems makes the food authenticity become a global issue, which requires appropriate identification methods. Raman spectroscopy combination with chemometrics becomes a rapid, non-destructive method to verify the nature or origin of food. This review assembles and comprehensively summarizes the principle, workflow, advantages, challenges and applications of Raman spectroscopy in food authenticity. Besides, existing problems and outlooking on Raman spectroscopy are also discussed.

Raman spectroscopy coupled with chemometrics for food authentication: A review

Animal origin food products, including fish and seafood, meat and poultry, milk and dairy foods, and other related products play significant roles in human nutrition. However, fraud in this food sector frequently occurs, leading to negative economic impacts on consumers and potential risks to public health and the environment. Therefore, the development of analytical techniques that can rapidly detect fraud and verify the authenticity of such products is of paramount importance. Traditionally, a wide variety of targeted approaches, such as chemical, chromatographic, molecular, and protein-based techniques, among others, have been frequently used to identify animal species, production methods, provenance, and processing of food products. Although these conventional methods are accurate and reliable, they are destructive, time-consuming, and can only be employed at the laboratory scale. On the contrary, alternative methods based mainly on spectroscopy have emerged in recent years as invaluable tools to overcome most of the limitations associated with traditional measurements. The number of scientific studies reporting on various authenticity issues investigated by vibrational spectroscopy, nuclear magnetic resonance, and fluorescence spectroscopy has increased substantially over the past few years, indicating the tremendous potential of these techniques in the fight against food fraud. It is the aim of the present manuscript to review the state-of-the-art research advances since 2015 regarding the use of analytical methods applied to detect fraud in food products of animal origin, with particular attention paid to spectroscopic measurements coupled with chemometric analysis. The opportunities and challenges surrounding the use of spectroscopic techniques and possible future directions will also be discussed.

https://www.mdpi.com/2304-8158/9/8/1069/pdf

Fraud in animal origin food products: advances in emerging spectroscopic detection methods over the past five years

Adulteration of extra virgin olive oil (EVOO) with cheaper edible oils is of considerable concern in the olive oil industry. The potential of Raman spectroscopy combined with multivariate statistics has been investigated for evaluating the authenticity (or purity) and concentration of EVOO irrespective of it being adulterated with one or more adulterants. The adulterated oil samples were prepared by blending different concentrations of EVOO (10–100% v/v) randomly with cheaper edible oils such as corn, soybean and rapeseed oil. As a result, a Raman spectral database of oil samples (n = 214 spectra) was obtained from 11 binary mixtures (EVOO and rapeseed oil), 16 ternary mixtures (EVOO, rapeseed and corn oil) and 44 quaternary mixtures (EVOO, rapeseed, corn and soybean oil). Partial least squares (PLS) calibration models with 10-fold cross validation were constructed for binary, ternary and quaternary oil mixtures to determine the purity of spiked EVOO. The PLS model on the complex dataset (binary + ternary + quaternary) where the spectra obtained with different measurement parameters and sample conditions can able to determine the purity of spiked EVOO inspite of being blended with one or more cheaper oils. As a proof of concept, in this study, we used single batch of commercial oil bottles for estimating the purity of EVOO. The developed method is not only limited to EVOO, but can be applied to clean EVOO obtained from the production site and other types of food.

Authenticity and Concentration Analysis of Extra Virgin Olive Oil Using Spontaneous Raman Spectroscopy and Multivariate Data Analysis

Determination of milk fat authenticity in ultra-filtered white cheese by using Raman spectroscopy with multivariate data analysis.

With the dramatic development of source and detector components, terahertz (THz) spectroscopy technology has recently shown a renaissance in various fields such as medical, material, biosensing and pharmaceutical industry As a rapid and noninvasive technology, it has been extensively exploited to evaluate food quality and ensure food safety In this review, the principles and processes of THz spectroscopy are first discussed The current state-of-the-art applications of THz and imaging technologies focused on foodstuffs are then discussed The advantages and challenges are also covered This review offers detailed information for recent efforts dedicated to THz for monitoring the quality and safety of various food commodities and the feasibility of its widespread application THz technology, as an emerging and unique method, is potentially applied for detecting food processing and maintaining quality and safety

Terahertz spectroscopy technology as an innovative technique for food: Current state-of-the-Art research advances.

Raman spectroscopy coupled with chemometric methods for the discrimination of foreign fats and oils in cream and yogurt.

Antibiotics are one of the most widely used types of drugs in pharmaceutics. However, efficiency of these drugs has decreased recently owing to the threat of antibiotic resistance. One of the important factors causing antibiotic resistance is the excessive use of antibacterials in animals. Therefore, detection of antibiotics in foods of animal origin is crucial. The aim of this study was to develop a novel whole-cell based bioassay to be used for detection of some antibiotics. Green fluorescent protein (GFP)-expressing Escherichia coli cells were used as a recognition agent, and antibiotic detection was carried out by pursuing the inhibition rate of fluorescence intensity as a result of the inhibition of viable cells by the time of progress. The performance of bioassay was tested for different antibiotics, and the obtained results showed that the developed method can be used successfully for detection of ampicillin, benzylpenicillin, gentamicin, neomycin, and tetracycline with the limit of detection (LOD) values of 3.33, 0.29, 28.00, 618.36, and 33.17 µg/L, respectively. The assay was also tested with antibiotic spiked milk samples (skimmed UHT, full-fat UHT, and whole raw milk). According to obtained recovery values, developed method was successful for all samples. The precision and bias values of the method were found between the range of 1.30% to 7.54% and -8.00% to 0.64%, respectively. The developed method, which is inexpensive and simple with detection limits in line with the regulatory limits, is promising for use in milk quality monitoring. Method has potential to be used as a screening method after comprehensive validation. PRACTICAL APPLICATION: This method could be used in animal husbandry to check whether the antibiotic prescribed for the treatment of sick animals is still present in their milk as residual. For dairy industry, detection of residual antibiotics in milk is crucial because of their inhibition effects on the fermentation processes. Therefore, the proposed method can be used for routine analysis of raw milk reception in dairy industries. In addition, it is considered to have a wide range of applications for all foods.

Nazife Nur Yazgan Karacaglar

Papers

Raman spectroscopy coupled with chemometric methods for the discrimination of foreign fats and oils in cream and yogurt.

Development of a green fluorescence protein (GFP)-based bioassay for detection of antibiotics and its application in milk