Application of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging for Evaluating the Quality of Fish Fillets

Abstract

Consumption of fish is rapidly increasing worldwide. It is important to evaluate fish fillet quality because fish undergoes physical and chemical changes during frozen storage. Fish fillets exhibit formaldehyde (FA) accumulation from the decomposition of trimethylamine N-oxide. FA is a powerful protein denaturant; thus, it is important to avoid FA buildup during fish processing to preserve fish quality, especially texture. To determine where FA accumulates, in order to maintain the quality of fish fillets, we performed matrix-assisted laser desorption/ionization mass spectrometry imaging, aiming to identify muscle-derived peptides, which reflect conditions such as denaturation and/or aggregation. We used frozen sections from which lipophilic molecules were washed out and detected various peptide peaks. Furthermore, we tried to identify indices to represent fish fillet softening by protease treatment. We could detect characteristic peaks owing to FA and protease treatment; the findings were consistent with the results of texture profiles showing fish fillet’s real solidity. These molecules might thus serve as effective markers to evaluate fish fillet quality.

Effect of Artificial Formalin Treatment on Fish Muscles Textural Quality and Different Formalin Lessening Techniques from Muscles

“…A signi cantly reduced to 82.54%, 75.93 % 69.33% with increasing formalin concentration. The reduction in the protein solubility can be due to the protein denaturation causing the aggregation as effected by the formalin treatment (Morisasa et al, 2020). The marked reduction in the pH value also found to be concurrent with the protein solubility and this might be due to shifting of isoelectric pH of the muscle protein.…”

“…The reason for the increase in the hardness could be due to reduced water holding capacity and dehydration of muscles. In addition, the protein aggregation stimulated by formalin treatment is also one of the important factors for muscle stiffening (Morisasa et al, 2020). Formaldehyde accumulates during improper storage of sh reacts with protein and this result in protein denaturation and toughness in the muscle (Sotelo et al, 1995).…”

Seafood Processing, Preservation, and Analytical Techniques in the Age of Industry 4.0

“…Therefore, the work highlights the importance of the chromatographic and spectrometric techniques on quality and safety food parameters, opening the door for the development of a targeted method providing robust species-independent tests to be applied in the seafood chain by producers and competent authorities. In another study, MALDI-MSI was used with success to identify two biochemical indices (formaldehyde derived from the decomposition of trimethylamine N-oxide and protease-induced softening) that could be used to evaluate the quality of Macruronus novaezelandiae fillets [148]. Recently, Shen and co-authors [149] authenticated successfully cod (most valuable fish species) and oil fish (less expensive fish species) using rapid evaporative ionization MS coupled to intelligent surgical knife.…”