**1. Introduction**

Plant-based ingredients are used to enhance health-promoting bioactive components in meat products [1,2]. Oat bran (*Avena sativa* L.) is an example that has been widely used in the preparation of a number of meat products, mainly providing them with soluble fiber (β-glucans), minerals (Mg, Fe, Cu, etc.), vitamins and phenolic compounds [3–5]. Chia (*Salvia hispanica* L.) is a plant-based ingredient that is gaining in popularity due to its interesting nutritional properties deriving from higher α-linolenic acid levels, insoluble dietary content and minerals (Ca, Fe, Mg, Mn, etc.) and vitamins [6]. Hence, chia has been added to different meat products to provide them with various bioactive compounds [7–13] and attractive technological properties (water and fat binding capacity, emulsifying and gelling properties, etc.) [14,15]. Due to their emulsifying and gelification potential, both chia and oat have been used in oil structuring processes to obtain new lipid materials which, thanks to their characteristics, can be used as animal fat substitutes. With this aim in mind, it is worth noting the use of EGs to reformulate fresh and cooked meat products due to their technological properties (texture, color, etc.) and their capacity to deliver bioactive compounds [16,17]. Especially in certain fresh meat products such as longanizas, chia and oat EGs have been deemed as suitable animal fat replacers and vehicles of bioactive compounds, allowing them to make different nutritional and health claims [18,19] and also feature optimal sensorial, technological and microbiological properties [20]. However, marketing these fresh sausages as healthier alternatives based on their composition may not be entirely accurate given the variety of processes that must be carried out prior to consumption (storage, thawing, cooking, etc.) [21]. Longanizas, for example, like other fresh meat products, need to be cooked prior to consumption. Cooking methods (roasting, grilling, frying, etc.) and conditions (time, temperature, heating rate, etc.) have a noticeable impact on the balance of (healthy/unhealthy) compounds and energy value [21]. Furthermore, lipid oxidation or other technological variations occur as a consequence of high temperatures [21,22].

It therefore makes sense that in the case of fresh meat products designed and produced to be healthier, we need information on their real nutritional and technological properties after having been subjected to di fferent cooking procedures. Hence, the first aim was to produce a healthier fresh meat product (longanizas) by adding chia or oat EGs as animal fat replacers and delivery systems of certain bioactive compounds to evaluate the impact of grilling (selected because it is one of the most common ways to cook this type of product) on the composition and technological properties of longanizas. The second aim of the study was to determine how nutritional and health claims were a ffected by this cooking process. Longanizas elaborated with only animal fat (pork back-fat) (normal and reduced fat content) were used as reference.

#### **2. Materials and Methods**

#### *2.1. Oil-in-Water Emulsion Gels and Longanizas Preparation*

Oil-in-water (O/W) emulsion gels (EGs) and longanizas (fresh sausages) were prepared as reported by Pintado et al. [20]. Briefly, two di fferent EGs, one containing chia (*Salvia hispanica* L.) flour and the other oat (*Avena sativa* L.) bran, were used as animal fat replacers in the preparation of longanizas. These EGs were formulated with 20% olive oil, 58% water, 2% gelling agen<sup>t</sup> based on alginate (0.73% sodium alginate, 0.73% CaSO4 and 0.54% sodium pyrophosphate) and 20% chia flour or oat bran depending on the desired formulation [16,17].

Four di fferent longanizas were prepared with the same quantity of pork meat (60 g/100 g product). Two were formulated with only animal fat (pork back-fat) and used as the reference (all-animal fat): one with normal fat content (29 g pork back-fat/100 g product) called P-NF and the other with reduced fat content (7.25 g pork back-fat/100 g product) called P-RF. Additionally, two di fferent reduced-fat longanizas were formulated replacing 90% of pork back-fat with 27 g/100 g of chia or oat EGs, with the final products denominated C-RF and O-RF, respectively. All the samples contained 4% of commercial seasoning for fresh sausages.

#### *2.2. Cooking Method for the Longanizas and Weight Loss*

Longanizas were cooked on an electric grill. Four samples were used for each formulation. This cooking method was chosen because it is the one that is most used for this kind of product. Preliminary cooking trials were performed to establish the cooking conditions required to achieve a meat core temperature of 70 ◦C. Sausages were weighed and cooked for 2 min at 210 ± 4 ◦C on an electric grill (Princess classic multigrill type 2321, Tilburg, The Netherlands). All sausages were then cooled at room temperature (20–22 ◦C) for 30 min, dabbed with a paper towel to remove visible exudate and then weighed to calculate weight loss determined by weight di fference (four determinations). Results were expressed as a percentage of the initial weight. Samples were stored under chilled conditions (3 ± 2 ◦C) until analysis.

#### *2.3. Composition and Energy Content of Longanizas*
