Evaluation of Biochemical Properties of Burnt and Normal Meat in Pacific Bluefin Tuna (&amp;lt;i&amp;gt;Thunnus orientalis&amp;lt;/i&amp;gt;)

Ming-Chih Huang

doi:10.11648/j.ijnfs.20170605.14

Abstract

Burnt meat is one of the unusual meats often occurring in tuna species. In order to reveal the biochemical properties of burnt meat in tuna, burnt meat and normal meat samples were collected to examine the quality parameter including pH, color parameters, lactic acid content, the activities of antioxidant enzymes, and the levels of thiobarbituric acid reactive substances (TBARS) and scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. The results showed pH was significantly lower in burnt meat than in normal meat, and the lactic acid content was generally higher in burnt meat. In color parameters, the L* and b* values were higher in burnt meat. Besides, the activities of antioxidant enzymes, namely, superoxide dismutase (SOD), glutathione reductase (GR) and catalase (CAT) in normal meat were higher than those in burnt meat. TBARS levels were significantly higher in burnt meat than in normal meat. It is thus likely that strong struggle of fish throughout catch and high water temperature induce partial inactivation of these antioxidant enzymes, resulting in free radical formation which triggers the occurrence of burnt meat. This fact could be beneficial for aquaculture and livestock industry of tunas to prevent burnt meat.

Highlights

Burnt meat is one of the unusual meats often taking place in yellowfin (Thunnus albacores), bigeye (T. obesus) and bluefin tunas (T. thynnus)
Results pH values of both burnt and normal portions in the same specimens from 15 individuals are shown in Figure 1 and Table 1
Our results showed that pH of normal meat was generally higher than that of burnt meat and the lactic acid content was generally higher in burnt than normal meat

Summary

Introduction

Burnt meat is one of the unusual meats often taking place in yellowfin (Thunnus albacores), bigeye (T. obesus) and bluefin tunas (T. thynnus). It has been reported in other species like yellowtail (Seriola quinqueradiata) [1, 2]. The meat color is obviously pale and the elasticity is low [3, 4]. It tastes a little more sour and rancid than normal meat. The "Sik-Bah" is a Taiwanese word for unusual tuna meat. We have previously reported that "Sik-Bah" is burnt meat [5]. The problem of burnt meat has been existing in Taiwan from a long time ago, the mechanisms involved are still not clear

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Discussion

Conclusion