Undesirable discoloration in edible fish muscle: Impact of indigenous pigments, chemical reactions, processing, and its prevention

Abstract

Fish is rich in proteins and lipids, especially those containing polyunsaturated fatty acids, which made them vulnerable to chemical or microbial changes associated with quality loss. Meat color is one of vital criteria indicating the freshness, quality, and acceptability of the meat. Color of meat is governed by the presence of various pigments such as hemoglobin, myoglobin (Mb), and so on. Mb, particularly oxy‐form, is responsible for the bright red color of fish muscle, especially tuna, and dark fleshed fish, while astaxanthin (AXT) directly determines the color of salmonids muscle. Microbial spoilage and chemical changes such as oxidation of lipid/proteins result in the autoxidation of Mb or fading of AXT, leading to undesirable color with lower acceptability. The discoloration has been affected by chemical composition, post‐harvesting handling or storage, processing, cooking, and so on . To tackle discoloration of fish meat, vacuum or modified atmospheric packaging, low‐ or ultralow‐temperature storage, uses of artificial and natural additives have been employed. This review article provides information regarding the factors affecting color and other quality aspects of fish muscle. Moreover, promising methodologies used to control discoloration are also focused.

Quality changes and experimental accelerated shelf‐life determination of ready‐to‐eat burgers made from striped catfish and salmon mince blend by thermal processing in retort pouches

“…The effect of fish meat ratios on color parameters was observed with increasing L*, a*, and b* values when salmon meat content increased. The orange color of salmon is due to carotenoids such as astaxanthin and canthaxanthin (Singh et al 2022), which are not found in white-fleshed fish, so the carotenoids content in salmon meat was possibly responsible for variation in color parameters. 22.2 ab ± 0.9 22.1 ± 0.7 23.7 ab ± 1.9 3 16.6 d ± 1.0 20.8 b ± 0.7 22.5 a ± 0.8 22.3 ± 0.7 23.9 ab ± 1.6 1 35°C 17.9 ab ± 0.8 20.4 c ± 0.9 22.3 a ± 0.5 22.3 ± 0.9 24.1 a ± 2.1 2 18.0 ab ± 0.8 21.2 b ± 1.0 22.4 a ± 1.0 22.4 ± 0.9 24.2 a ± 1.9 3 18.1 ab ± 0.8 21.7 a ± 0.8 22.8 a ± 0.9 22.4 ± 0.9 24.4 a ± 1.9 Hardness and chewiness decreased, whereas cohesiveness increased after retort processing.…”

“…The effect of fish meat type ratios on color parameters was observed with increasing L *, a *, and b * values when salmon meat content increased. The orange color of salmon is due to carotenoids such as astaxanthin and canthaxanthin (Singh et al 2022), which are not found in white‐fleshed fish, so the carotenoids content in salmon meat was possibly responsible for variation in color parameters.…”

“…Changes in the color of reformulated fish products were reported to be attributed to fat, moisture, and fish pigment contents (Pietrasik, 1999). During the preparation of fish burgers, discoloration of the orange color of salmon may occur as a result of enzymatic conversion of glucose or glycogen to glucose‐6‐phosphate and fructose‐6‐phosphate during thawing (Singh et al 2022). Retort processing also contributed to the changes in color parameters.…”

Conventional and Non-conventional Smoking on Microbial Quality and Histamine of Ikan Fufu (Smoked Fish)

“…Fish smoked by conventional smoking is carried out in a closed manner so that it does not come into contact with the open air, while non-conventional smoking techniques are carried out openly so that it is potentially contaminated with sources of histamine-producing bacteria. Handling is the main key in inhibiting the formation of histamine, discoloration, protein solubility, and microbial growth in skipjack tuna (Singh, Mittal, & Benjakul, 2021). Smoking fish is intended to maintain freshness, in the sense that it still meets the requirements for human consumption by preventing the occurrence of fish spoilage.…”

The greening reaction of skipjack tuna (Katsuwonus pelamis) metmyoglobin promoted by free cysteine during thermal treatment

“…In the canning tuna industry, the greening of tuna muscle has been reported as an anomaly of discoloration by thermal treatment. However, although there is no data available related to the economic impact, considering that tuna greening is an unwanted muscle pigmentation, this results in financial loss for this industry ( Singh, Mittal & Benjakul, 2022 ).…”