Applications of non-destructive spectroscopic techniques for fish quality and safety evaluation and inspection

Highlights

• We review spectroscopic techniques for fish quality evaluation and inspection.

• VIS spectroscopy is suitable for measuring fish freshness quality.

• IR spectroscopy is known as a complementary method for fish quality evaluation.

• Raman spectroscopy is valuable for protein structures and lipid oxidation detection.

• Spectral imaging has great potential for fish quality evaluation and inspection.

Fish quality and safety is a scientific discipline describing handling, preparation, processing, transportation and storage condition in ways that prevent food-borne illness and provide fish and fish products with premium quality for human health and the acceptance of consumers. However, it is well-known that fish is one of the most vulnerable and perishable aquatic products, and it serves as a growth medium for microorganisms that can be pathogenic or cause fish spoilage. Therefore, it is imperative to pay close attention to fish quality and safety. The traditional techniques and methods for evaluation and detection of fish quality and safety are tedious, laborious, expensive and time-consuming while spectroscopic techniques have successfully overcome some of these disadvantages and can supplement or replace them. There are growing interests in spectroscopic techniques due to high specificity, convenience, non-destructive, non-invasive, cost-effective and quick response. Spectroscopic techniques have shown great potentials for the detection of pathogens, foreign contamination, protein structure changes, and lipid oxidation, and for spoilage monitoring in fish in order to confirm whether it is safe for consumption and international trades or not. This review focuses on several valuable spectroscopic techniques including visible (VIS) spectroscopy, near-infrared (NIR) spectroscopy, mid-infrared (MIR) spectroscopy, Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and spectral imaging mainly related to hyperspectral imaging (HSI) and nuclear magnetic resonance imaging (NMRI). Moreover, the advantages and limitations of these techniques are noted and some perspectives about the current work are also presented.

Introduction

The market of fish and fish products is growing continuously as fish and fish products are commercially important for international trade as well as widely consumed muscle food. However, there are many problems and challenges associated with the evaluation of fish quality and safety at industrial level. It is widely known that fish and fish products are mainly composed of moisture, protein, fat and other compositions that contribute to fish quality and safety. Furthermore, fish quality and safety is also mainly influenced by diverse processes related to storage methods, time and temperature. In addition, changes in color, texture, juiciness, flavor and biochemical properties of fish are important factors that affect consumers' sensory evaluation of fish quality and their decisions in making a second purchase. On the other hand, fish is considered as the best sources of good fats, vitamins, and minerals to promote good human health (Forné, Abián, & Cerdà, 2010), thus it is a significant part of our daily diet, providing roughly 40% of the protein intake, and is consumed by nearly two-thirds of the world's population. Therefore, maintaining good quality and safety is of utmost importance in production and trade of fish and fishery products, hence it is necessary to develop fish quality evaluation and inspection techniques.

On one hand, there are many well established traditional analytical techniques and methods available, including sensory evaluation based on quality index method (Pons-Sanchez-Cascado, Vidal-Carou, Nunes, & Veciana-Nogues, 2006), microbial inspection based on total viable counts (Song, Luo, You, Shen, & Hu, 2011), biochemical methods related to high-performance liquid chromatography (Mendes, Cardoso, & Pestana, 2009), solid-phase micro-extraction gas chromatography–mass spectrometry (Iglesias et al., 2009), two-dimensional difference gel electrophoresis (Addis et al., 2012), and proteome analysis (Carrera, Cañas, & Gallardo, 2012). These techniques and methods play a pivotal role in current industrial fish quality and safety evaluation and inspection and some of them have been used as gold standards and regulation methods serving scientific researches due to their relative validity and accuracy. However these techniques and methods are normally expensive, time-consuming, laborious, tedious, and require highly skilled operators and are not suitable for on/in-line monitoring.

In order to surmount the aforementioned disadvantages, there is a need for complementary techniques to detect quality parameters and safety threats in the field of rapid screening. With recent technological progress in photonics and optics, many non-destructive, fast and cost-effective spectroscopic techniques have been developed for food quality and safety assessment and inspection and for online monitoring (van den Berg, Lyndgaard, Sørensen, & Engelsen, 2012). With regard to fish quality and safety, Uddin and Okazaki (2010) reviewed the applications of vibrational spectroscopy to the analysis of fish and other aquatic food products. In a recent study, another review published was intended to provide an overview of application of infrared technologies to determine and monitor composition and other quality characteristics in raw fish, fish products, and seafood (Cozzolino & Murray, 2012). However, no review is available to specifically address the application of several spectroscopic techniques including visible (VIS) spectroscopy (Abdel-Nour, Ngadi, Prasher, & Karimi, 2011; Antonucci et al., 2011; Zhu, Cheng, Wu, & He, 2011), near-infrared (NIR) spectroscopy (Alexandrakis, Downey, & Scannell, 2012; Magwaza et al., 2012; Pojić & Mastilović, 2013), mid-infrared (MIR) spectroscopy (Boubellouta & Dufour, 2012; Woodcock, Fagan, O'Donnell, & Downey, 2008; Wu, Nie, He, & Bao, 2012), Raman spectroscopy (Günaydın, Şir, Kavlak, Güner, & Mutlu, 2010; Liu, et al., 2013; Lu, Al-Qadiri, Lin, & Rasco, 2011; Sowoidnich, Schmidt, Maiwald, Sumpf, & Kronfeldt, 2010), nuclear magnetic resonance (NMR) spectroscopy (Ko, Cheng, Chen, & Hsieh, 2012; Rodríguez, Eim, Simal, Femenia, & Rosselló, 2013; Santagapita et al., 2012; Shao & Li, 2011; Sivam, Waterhouse, Zujovic, Perera, & Sun-Waterhouse, 2013), and spectral imaging (ElMasry, Sun, & Allen, 2011, 2012; Kamruzzaman, ElMasry, Sun, & Allen, 2011) for assessing, measuring and predicting the quality of fish and for quantitative and qualitative analysis of fish and related products. Therefore, the objective of this paper is to review applications of these spectroscopic techniques for fish quality and safety evaluation and inspection. Fig. 1 compares the spectral ranges used in these spectroscopic techniques.