Assessment of Quality Changes in Mackerel Scomber japonicus During Refrigerated Storage: Development of a Freshness Indicator

Abstract

No freshness indicator for fish has yet been established. Thus, we investigated changes over time in mackerel quality in an effort to development useful indicators. Fresh whole mackerel Scomber japonicus were stored at 4°C immediately after capture and quality changes were evaluated every 3 days for a total of 15 days. Whole fish were divided into ventral parts (VPs) and dorsal parts (DPs); we measured the trimethylamine (TMA) and volatile basic nitrogen (VBN) levels, pH values, and color values in/of these parts. The TMA and VBN levels tended to increase during storage and the TMA changes in VPs were higher than those in DPs. In particular, the VP TMA content attained a maximum of 3.68 mg/100 g at 6 days, and the VBN content attained a maximum of 20.88 mg/100 g at 9 days, suggestive of initial fish spoilage. The pH ranged from 5.99-6.17 over the first 3 days and from 6.17-6.38 from days 6-15. Surface color changes on VPs and DPs were explored. Significant decreases in both VP lightness and yellowness were evident after 3 days. The data suggest that both TMA level and lightness of the color are valuable indicators of freshness in the initial stage of mackerel retail.

Shelf Life Prediction of Vacuum-Packaged Grilled Mackerel

“…The TMA content of grilled mackerel before storage was 5.55 mg/100 g but increased significantly to 6.77 mg/100 g on the 3rd day of storage at 5°C, to 6.30 mg/100 g on the 6th day at −5°C, and to 6.41 mg/100 g on the 27th day of storage at −20°C ( P <0.05). Park et al (2016) reported that the TMA value of fresh mackerel stored at 4°C increased rapidly between 3 and 6 days of storage. Jo et al (1988) also found that the TMA content increased rapidly after 4 days of storing vacuum-packaged mackerel at 5°C, indicating a difference in the TMA content compared to control.…”

“…Considering that current HMR-related research has mainly focused on meat, research on seafood products have been scarce. Some studies assessing the changes in the quality of fresh mackerel during refrigerated storage have been conducted to develop a freshness indicator ( Park et al, 2016 ) and determine the effects of freezing storage temperature on the shelf life of mackerel fish ( Joo et al, 2016 ). For cooked mackerel, several studies have mainly observed quality changes in the packaging state as determined by the quality of baked mackerel muscle during partially frozen storage ( Lee et al, 1983 ) and by the effects of salt and soy sauce on lipid oxidation in broiled mackerel ( Ryu et al, 2002 ).…”

Supercooling with stepwise algorithm preserves the freshness of salmon and olive flounder during extended storage

“…Trimethylamine oxide (TMAO) is a natural and nontoxic substance found in aquatic species, such as sh and shell sh (Tee and Siow, 2015). The TMAO contained in defunct sh is converted to TMA by bacteria or enzymes, and a shy smell is generated, which determines the degree of spoilage of sh (Park et al, 2016). During sh spoilage, there is not only an increase in TMA level, but also in total volatile basic nitrogen (TVBN) (Shin, 2008).…”

“…The TMAO value of the samples stored in the refrigerated treatment increased rapidly from 3 to 6 days, which is consistent with Shin (2008). A large increase in TMA probably occurs as the activity of enzymes or bacteria increases (Park et al, 2016). Consequently, supercooling storage is more effective in slowing the spoilage of sh than refrigeration storage.…”