Occurrence and Development of Off-Odor Compounds in Farmed Hybrid Catfish (Clarias macrocephalus × Clarias gariepinus) Muscle during Refrigerated Storage: Chemical and Volatilomic Analysis

Abstract

The goal of this study was to examine the changes in chemical parameters, major volatile compounds, and sensory aspects in farm-raised hybrid catfish (i.e., dorsal, lateral line and ventral muscles) during a 15-day period of refrigerated storage. Trichloroacetic acid-soluble peptides, free fatty acid, total volatile base-nitrogen (TVB-N), and non-heme iron levels in all muscles increased as storage time proceeded. The levels of trans-1,10-dimethyl-trans-9-decalol (geosmin) and 2-methylisoborneol (2-MIB) were higher than their thresholds, which was connected to a stronger earthy odor. The concentrations of geosmin and 2-MIB in all muscles increased, although there was a consistent trend of earthy odor throughout storage; this phenomenon could be attributed to the masking effect of other off-odors. During storage, the largest lipid oxidation was found in ventral muscle, as measured by peroxide value and thiobarbituric acid reactive substances. During storage, the formation of the most volatile products increased in the lateral line and ventral muscle, whereas the dorsal muscle had the lowest concentration. As storage time proceeded, the strength of spoiled, fishy, rancid, and overall off-odor intensity of all tested muscles tended to rise. Those alterations were linked to higher levels of TVB-N and trimethylamine, as well as all other volatile lipid oxidation products (e.g., hexanal, propanal, 2,4 heptadienal, 1-octen-3-ol, octanal, nonanal, trans-2-heptenal, and 1-hexanol).

Bioactive Compounds and Therapeutics from Fish: Revisiting Their Suitability in Functional Foods to Enhance Human Wellbeing

“…Nutrients in farmed fishes, especially fatty acids, are usually influenced by feed consumption. Farmed fish contains higher or similar total amounts of long-chain omega-3 PUFA and also higher fats than wild fish [ 117 , 118 ]. When raised under suitable conditions, nutrients and bioactive compounds in farmed fish are considered beneficial as those in wild fish, including for preventing diseases, such as cardiovascular diseases, with the advantages of being fresh and apparently not toxic.…”

Characterization of Antioxidant Peptides from Thai Traditional Semi-Dried Fermented Catfish

“…Pla Duk Ra, a semi-dried fermented catfish, is one of Thailand's most popular traditional fish products, especially in the south. It is created by salting and fermenting the farmed hybrid catfish (Clarias macrocephalus × Clarias gariepinus), which is Thailand's most intensively farmed freshwater fish [1,2]. According to the document of Thai Community Product Standard [3] and the observation from local producers in Southern Thailand, fresh fish was cleaned, headed, eviscerated, and drained for 3 h. The fish was then mixed with salt and sugar in a 10:0.4:0.4 (w/w/w) ratio and kept tightly sealed in earthen jar for 1 night at room temperature (27-29 • C) for fermentation.…”