###### Abstract
They also help to overcome the issue of seasonality for certain foods, allowing for their consumption throughout the year, as well as maintaining a more diverse diet [12]. Marine macroalgae are perishable ingredients that undergo many physicochemical changes as soon as they are removed from their environment. Moreover, according to the conservation methods applied, the changes can be even more noticeable due to the action of physical (e.g., heat or solar UV radiation), chemical (e.g., pH change or addition of salt) and/or biological (e.g., enzymatic reactions or action of microorganisms) factors [14]. Preservation techniques applied so far in the processing of seaweeds (such as drying, salting or freezing) do not allow for keeping their organoleptic and nutritional properties unchanged [15; 16]. Drying can lead to a loss of volatile organic compounds (VOCs) and the emergence of off-flavors due to the auto-oxidation and enzymatic reactions [17; 18]. Furthermore, during the entire process, the product is subjected to temperatures higher than the glass transition temperature (Tg), which results in shrinkage of the tissues [19]. Salting has less pronounced effects on VOCs due to its ability to inhibit oxidation reactions by applying low processing temperatures and promoting osmotic dehydration. However, the \"salting out\" effect can also lead to a loss of volatiles and the alteration of sensory properties such as firmness [20; 21; 22]. Both drying and salting techniques are based on water activity (\(\mathrm{a_{w}}\)) reduction. The major drawback of freezing stems is the loss of texture (decreased hardness), due to ice crystal formation that damages seaweed tissues [23; 24]. The type and content of hydrocolloids present in the seaweeds will also affect water loss--and consequently phytochemical composition--during long-term frozen storage [25]. A study also revealed that frozen marine macroalgae tend to develop green aromas, probably as a consequence of the auto-oxidation and enzymatic conversion of aldehydes from polyunsaturated fatty acids via the action of lipoxygenases (LOX) [22; 26; 27]. In addition, the loss of nutritional value, water-holding capacity alteration, and significant color modification are also reported as being the main changes promoted by using conventional conservation techniques such as drying, salting or freezing [15; 28]. Freeze-drying processing can overcome some of the aforementioned problems, but it has the disadvantages of high costs and long processing times, being used only for products with high added value [29; 30; 31]. Modern techniques such as high-pressure processing (HPP) still exhibit high operating costs, being applied to seaweeds only in scientific trials. In the tests performed, HPP showed to be a valid processing technology for extending the shelf-life of edible seaweeds under refrigerated storage; although, microbiological, physicochemical, color, and texture attributes along with enzymatic activity, varied significantly between treatments and storage time [32; 33]. Modified atmosphere packaging (MAP) is a technique used to increase the shelf-life of fresh or minimally processed foods. In this conservation method, the air that surrounds the food in the package is suppressed and substituted for a gas (or mixture of gases) with another composition. This new atmosphere mainly acts by modulating the respiration of fresh products, and by inhibiting microbial activity and oxidation. The gas mixture in the package depends on the type of product, packaging materials and storage temperature. MAP allows the original characteristics of the products to be extended [34]. Despite its widespread use in vegetables, meat, and other foods, there is currently no known article discussing the utilization of MAP for preserving seaweed. [PERSON] & [PERSON] [35], however, studied the use of vacuum-packing as a preservation method for _Gracilaria salicornia_ (Rhodophyta).