*2.2. Production of Fucus Vesiculosus Extracts*

The brown seaweed *Fucus vesiculosus* was strategically collected in the Hvassahraun coastal area, southwestern Iceland, during peaks in bioactive content: in particular, the raw materials of batches for this study were collected in two di fferent periods, in July 2013 and July 2014, and the batches were named B200314 and B290814, respectively. They were used as feedstocks for a pilot-scale extraction. The seaweeds were stored at −18 ◦C until cleaned and shredded in preparation for extract production. The preparation of seaweed extract was performed according to Wang *et al.* [22]. Briefly, the extracts were produced as follows: the seaweeds were soaked and rinsed in cold water to remove sand and other debris, wet-milled, mixed with water, extracted, filtered (refined), and the extracted liquid collected and frozen at −20 ◦C until further processing. Finally, the defrosted liquid extract was spray dried. During the process, unprocessed seaweed/water mixtures, liquid extracts, and lyophilized extracts were analyzed for microorganisms, to exclude contamination. Two aqueous seaweed extracts were produced.

## *2.3. Production of Extruded Rye Snacks*

Development of prototypes of extruded rye snacks enriched with seaweed extracts was performed by Ruislandia, a small and medium enterprises (SME) involved in the European EnRichMar project (606023) and VTT (Finland). Several rye snack samples enriched with various amounts of seaweed extracts and three di fferent flavorings (garlic or basil + tomato or rosemary), have been produced by an optimized extrusion and roasting processes. An overview of the parameters (time and temperature) of di fferent production phases is reported in Table S1.
