## 2 Review Methodology
### Short Overview of Omic Technologies
#### 2.3.3 Lipidomics  
Lipidomics performed a significant impact in disclosing the lipid groups, abundance, cellular lipid metabolism, and 3-D dispersion, and the flavor metabolomics target volatile compounds and amino acids [56]. As a division of metabolomics, flavoromics and lipidomics implement the same platforms. It is remarkable that volatiles and lipids entail previous extraction, and considering that fish commodities are high in lipids, especially essential fatty acids like omega-3s, these products are predisposed to oxidation throughout production and storage [57].  
Communal lipid profile investigations utilize quantitative detectors like (i) flame ionization detectors (FID), diode array detectors (DAD), ultraviolet (UV), and electron light scattering detectors (ELSD), and charged aerosol detectors (CAD) [58]. To isolate and distinguish charged ionized elements in accordance with their \(m/z\) ratios, this omic approach applied separation methods such as TLC (thin layer chromatography), GC, and HPLC, which are joint with MS detectors.  
Revolutionary lipidomics investigations engaged the direct injection of the lipid mixture on the MS called direct infusion MS (DIMS) [59]. Targeted and untargeted lipidomics are two other approaches that usually include the chromatographic separation of the sample, which simplifies the isobaric molecule resolution. In a targeted study, the goal-mouth is the quantification and identification of a partial variety of lipids [53]. In a targeted study, the MS is arranged to explore a restricted number of transitions into SRM and MRM and, therefore, grow its sensitivity to the designated ions. The handling of lipidomics includes the application of numerous software implements. For example, the LipidSearch package was exploited to examine the lipid level. To identify the specific lipids included in the sample, lipidomic data found from MS analysis were likened to LipidSearch databases [57].  
Chemometrics investigation can be achieved by some software programs like Metabo-Analyst (version 6.0), Minitab (version 21), and Orange (version 3.32.0) for the application of PCA and PLS-DA.  
The most frequently utilized omics for the examination of the quality control of aquatic food products are represented in Figure 3.  
APCI, atmospheric pressure chemical ionization; APPI, atmospheric pressure photoionization; CE, capillary electrophoresis; COSY, correlation spectrometry; DIA-SWATH, data-independent acquisition-SWATH; DIGE, difference gel electrophoresis; EI, electronic impact; ESI, electrospray ionization; FTIR, Fourier transform ion cyclotron resonance; GC, gas chromatography; ICAT, isotope-codedaffinity tag; ITRAQ, isobaric tags for relative and absolute quantification; LC, liquid chromatography; LIT, linear ion trap; LTQ-Orbitrap, linear-quadrupoleion trap-Orbitrap; NMR, nuclear magnetic resonance; NOESY, nuclear Overhauser effect spectroscopy; PCR, polymerase chain reaction; Q, quadrupole; QIT, quadrupole ion trap; qPCR, quantitative PCR; QTrap, triple-quadrupole ion trap; Q-TOF, quadrupole-TOF; SILAC, stable isotope labelling of amino acids in cell culture; TOCSY, total correlation spectroscopy; TOF, time-of-flight;