Valorization of common ling (Molva-molva) roe by-products for the elaboration of a food seasoning: Effect of drying method

The fishing sector generates a large amount of discards and wastes that represent a problem for the industry, both economically and environmentally. For this reason, the valorization of a by-product of the salting fishing industry, common ling roe ( Molva-molva ) roe, was carried out by developing a fish seasoning for human consumption, subjecting the roe to two drying processes, freeze-drying [for 24 and 48 h (L24 and L48)] and air-drying in an oven [for 32 and 48 h (S32 and S48)]. Physicochemical, textural and sensory parameters of the roe seasoning were analyzed to compare both drying methods. The freeze-drying process produced technologically, nutritionally and sensorially more suitable seasonings, resulting in a product with lower moisture content and water activity, with less roasted coloration. In addition, the product had a saltier taste and a certain tendency to a greater umami and marine flavor, which are highly desirable in this type of product. Therefore, the valorization of ling roe as a fishery by-product is possible through the elaboration of a condiment of high nutritional and sensory value. • It is possible to produce a condiment from fish roe discarded by the fish industry. • The freeze-drying and oven-drying processes are effective for producing a seasoning. • The freeze-drying process provided products with lower water activity. • The freeze-drying gave saltier seasonings, tending towards a more umami flavor.