## 3 Examples of Chemometrics and Vibrational Spectroscopy Applications in Seafood  
### Authentication, Provenance and Traceability  
Seafood processing often removes morphological properties of seafood species that enable the consumer to distinguish one type from another [63; 64; 65; 66]. Consequently, species substitution is an extremely common form of economic adulteration within the seafood industry [63; 64; 65; 66]. Both visible (VIS) and NIR spectroscopy were evaluated to detect and quantify species authenticity and adulteration in crabmeat samples by [PERSON] and collaborators [67; 68; 69]. In one study, these authors have reported the adulteration of Atlantic blue (_Callinectes sapidus_) crabmeat with blue swimmer (_Portunus armatus_) crab. The authors observed that water absorption bands dominated the main features in the crabmeat spectra, with a decrease in sample absorbance observed with increasing adulteration percentage [67; 68; 69]. These authors also reported the use of several data pre-treatments to the NIR spectra such as moving average, a combination of first and second derivatives, as well as the use of multiplicative scatter correction in addition to the raw data, prior to developing PLS regression models [67; 68; 69]. [PERSON] and team determined that VIS and NIR spectroscopy combined with chemometric tools were useful for detecting and quantifying species authenticity and adulteration in crabmeat [67; 68; 69]. In a similar study, the same authors utilised both VIS and NIR spectroscopy to detect, monitor and define the economic adulteration of crab meat [67; 68; 69]. In this study, Atlantic blue (_Callinectes sapidus_) and blue swimmer (_Portunus armatus_) crab meat samples were adulterated with surimi-based imitation crab meat. Here, the authors determined that both PLS and principal component (PCR) regression methods after pre-processing the spectra using the first derivative provided the best means of detecting adulteration in crab meat samples adulterated with surimi [67; 68; 69]. [PERSON] and [PERSON] [70] utilised NIR spectroscopy combined with PCA to differentiate between shrimp (_Pandalus borealis_) from a commercial freezer trawler. The shrimp was processed in several ways including, iced, stored in fresh water and brine of various salt concentrations before being steam-cooked and peeled [70]. The authors demonstrated that chemometrics combined with NIR spectra obtained from samples of whole shrimp and of minced fresh from the various treatments could differentiate between frozen and thawed material, between salt content, pH in the flesh, cooking period (temperature) as well as the whole or minced shrimp [70]. [PERSON] and co-workers [71] demonstrated the potential of VIS-NIR spectroscopy combined with a hyperspectral imaging system to discriminate fresh, cold-stored and frozen-thawer shelled shrimp (_Metapeneusensis_). Results derived from this study indicated that the combination of both chemometrics and spectroscopy were useful to detect illegally substituted and mislabelled products [71]. The authors confirmed the usefulness of VIS-NIR spectroscopy to classify between fresh shrimps and those from either cold storage or freezing with classification rates higher than 91% and 88%, respectively [71]. [PERSON] and co-workers also exploited hyperspectral imaging combined with chemometric methods to assess the reliability and accuracy of the technique to detect gelatine adulteration in prawns [72]. [PERSON] and co-workers investigated the potential of NIR spectroscopy as a means of authentication of wild European sea bass (_Dicentrarchus labrax_) [73]. The authors explored three different chemometric techniques to process the NIR spectra, and their ability to discriminate between wild and farmed sea bass samples was evaluated [73].