###### Abstract  
Fatty fish, such as mackerel (_Scomber scombrus_), are recommended as part of a healthy diet, providing essential fatty acids (FA). Fried fish is appreciated for its attributes, including a crispy texture, golden crust, and pleasant taste. However, frying increases the fat content and the caloric value of food. This study evaluated the use of pre-frying edible coatings on mackerel fillets aiming to: (i) reduce oil absorption, (ii) minimize water loss, preserving fish succulence, and (iii) prevent fat oxidation. For this purpose, alginate- and carrageenan-based coatings were supplemented with extracts of _Pelvetia canaliculata_ (Pc), a seaweed with high potential as a source of bioactive compounds. The fried fillets were analysed for colour, texture, moisture, ash, lipid content, and FA profile. No significant differences were observed for colour and textural parameters. Fillets coated with Pc-supplemented carrageenan showed the highest moisture (an increase of 3%) and the lowest fat content (a decrease of 7,5%) compared to the control (fried uncoated fillets). Coated fillets also exhibited reduced saturated FA and increased monounsaturated FA. In general, linoleic acid (C18:2) decreased markedly, while the values for docosahexaenoic acid (C22:6, n-3) remained stable (11-12% of total FA). Moreover, the n3/n6 ratio and atherogenic indices (AI) were improved in the coated fillets. 1  
. 2025  
. 28 12025  
. 1 July 2025  
than those of horse mackerel (15,826 tons) [7]. Nevertheless, despite its nutritional value, mackerel remains underestimated by consumers. It is, therefore, important to promote the valorization of this marine resource and to encourage its wider consumption. Mackerel, like many other fish species, can be cooked in a variety of ways, such as boiling, frying, roasting, steaming, and grilling. It can also be consumed raw as sashimi [8]. Frying is a widely used method for food preparation, preferred for its simplicity and appealing sensory properties [9]. Deep frying involves immersing food in oil (at 150-190 \({}^{\circ}\)C), which imparts unique characteristics to the final product, such as a crispy surface, a soft and jucity interior, and an appealing characteristic flavor [10]. During frying, various chemical reactions occur due to the presence of oxygen, moisture, and high oil temperatures [11; 12]. Oxidation is a major concern, as it significantly reduces the nutritional value of foods. In particular, the low thermal stability of PUFA, such as linoleic acid (C18:2), linoleic acid (C18:3), EPA, and DHA, can contribute to this nutritional loss [11]. Additionally, frying by immersion increases the fat content of food matrices, altering their fatty acid profile. This change can lead to harmful effects on consumer health, particularly due to the increased intake of saturated and trans-fatty acids [13]. In recent years, various strategies have been explored to reduce oxidation and oil absorption in foods during frying, with particular attention given to the development of edible coatings [14]. An edible coating is defined as a thin layer of edible material (typically composed of proteins, polysaccharides, or lipids) applied to the surface of food products, by spraying or immersion, to improve their quality, shelf life, and appearance. These coatings do not alter the visual appeal of the product while offering protection against deterioration processes such as oxidation, moisture loss, chemical reactions, and microbial growth [15]. Beyond their functional benefits, edible coatings must also maintain desirable sensory properties and be environmentally friendly and non-polluting [16; 17; 18]. Natural polysaccharides, such as alginate and carrageenan, are widely recognized as food additives and are commonly used in the formulation of edible coatings and films to prolong the shelf life of food products. These compounds are particularly valued for their neutral taste and odor, as well as for being non-allergenic [19].