*2.5. Statistical Analysis*

One-way analysis of variance (ANOVA) was performed to evaluate statistical significance (*p* < 0.05) attributable to sample formulations (expressed in figures and tables with different superscript letters a, b, c, etc.) and two-way ANOVA was performed to evaluate statistical significance (*p* < 0.05) attributable to formulations and the effect of cooking (expressed in tables with different superscript numbers 1, 2) using the SPSS program (v.24, IBM SPSS Inc.; Chicago, IL, USA). Formulation and cooking were assigned as fixed effects and replication as a random effect. Results are given in terms of mean values and standard error of the mean. Least square differences (LSD) were used to compare mean values and formulations, while Tukey's HSD test was used to identify significant differences (*p* < 0.05) between formulations and cooking procedures.

#### **3. Results and Discussion**

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

Fresh meat products such as longanizas must be cooked and the electric grill is commonly used. Figure 1 shows the different appearances of raw and grilled samples.

**Figure 1.** Appearance of longanizas: raw (left) and grilled cooked (right) (for each type of sample). Longanizas formulated with normal (P-NF) and reduced (P-RF) fat content (both with all-animal fat), and reduced-fat content sausages replacing 90% of pork back-fat with chia (C-RF) or oat (O-RF) emulsion gels (EGs).

This culinary procedure involves weight loss which furnishes information on the ability of the products to retain water and fat during processing that could alter the composition of sausages. Weight loss in longanizas cooked on an electric grill ranging from 6.71% to 24.73% was affected (*p* < 0.05) by formulation (Table 1) and could be considered between low and normal (15% and 40%) using comparable fresh meat products as the standard [26,27]. Samples with normal fat content (P-NF) exhibited greater (*p* < 0.05) weight loss (Table 1) than the reduced-fat samples, regardless of the type of fat. According to the literature, weight loss from culinary treatments tends to decrease as fat content decreases [28]. A comparison of reduced-fat sausages showed that those formulated with EGs (C-RF and O-RF), regardless of whether they contained chia or oat, lost less weight (up to 33% less than those made only with animal fat) (Table 1). It is important to note that these weight loss values are much lower than the ones observed for other reduced-fat fresh meat products where different structured lipid systems were used as animal fat replacers [26,27]. Moreover, our weight loss results are in accordance with water and fat binding properties associated with the thermal process (70 ◦C for 30 min in a water bath) in raw longanizas as samples reformulated with chia or oat EGs as fat replacers lost less weight than samples elaborated with all-animal fat [20].


**Table 1.** Weight losses and proximate composition (%) of grilled cooked longanizas.

\* For samples denominations, see Figure 1. Means ± standard deviation. Different superscript letters (a,b,c) in the same row (for each parameter) indicate significant differences (*p* < 0.05) between different formulations (P-NF, P-RF, C-RF and O-RF).

These results show that EGs are suitable fat replacers if the aim is to maintain a high level of fat and water in the final product after standard preparation on an electric grill. This may result in greater juiciness in the samples containing EGs as it has been shown that juiciness and cooking loss are negatively correlated, implying that low cooking loss results in greater juiciness [29]. Moreover, the lower cooking loss found in C-RF and O-RF could imply higher nutrient and bioactive compound stability [21]. This means that the use of EGs would result in greater retention of chia and oat bioactive compounds (α-linolenic acid, β-glucans, insoluble fiber, minerals, etc.) [16,17].

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

Longanizas are fresh meat products and must be cooked before eating and this could alter the concentration of some of their components [21]. Therefore, we have evaluated modifications in their composition resulting from grilling on an electric pan.

### 3.2.1. Proximate Composition

Slight formulation-related differences were observed in the composition of raw samples. Raw normal fat samples (P-NF) had the lowest (*p*<0.05) moisture content (52%). However, a comparison among reduced-fat samples only (which ranged between 74 and 66%) showed that those prepared with EGs had the lowest (*p* < 0.05) values (approximately 66%). All raw longanizas had similar (*p* > 0.05) ash (~3%) and protein contents (13–14%). However, two different (*p* < 0.05) formulation-related fat levels were observed in raw samples: 30% in normal fat samples and approximately 13% in reduced-fat ones, regardless of whether they were made with animal fat or EG according to experimental design.

More differences were observed in the proximate composition of samples after grilling (Table 1). These significant differences could be mostly attributable to weight loss (Table 1) during the grilling process [21].

Regarding moisture content, cooked samples performed similarly to raw longanizas. In other words, reduced-fat samples exhibited higher (*p* < 0.05) values and, of these, samples with EG had the lowest (*p* < 0.05) moisture, regardless of whether they contained chia or oat (Table 1). These results coincide with observed weight losses (Table 1). Other authors have previously indicated that the moisture content of fresh grilled meat products such as patties, formulated in the same way as longanizas (by replacing animal fat with different types of emulsions), was lower than normal fat samples formulated with all-animal fat [26,27,30].

After cooking, normal fat samples (P-NF) exhibited the highest (*p* < 0.05) ash levels (related to mineral content) (Table 1). Among reduced-fat samples, those with EGs (C-RF and O-RF) had higher (*p* < 0.05) values than those with animal fat (P-RF) (Table 1). This could be because they lose less weight (Table 1) which implies lower mineral loss [31]. It must also be considered that these longanizas contain EGs made with chia and oat, ingredients with a high mineral content [16,17], which could account for the higher ash values observed in C-RF and O-RF (Table 1).

Cooked samples prepared with all-animal fat (P-NF and P-RF) had higher (*p* < 0.05) protein content than C-RF and O-RF, which had similar values regardless of whether they contained chia or oat (Table 1). This protein content in cooked longanizas could be related to the weight losses associated with each type of longaniza (Table 1) which, in turn, was possibly the result of moisture loss (drip and evaporation) and fat melting during cooking. In contrast to raw samples, three fat levels were observed in cooked samples (Table 1): normal fat samples (P-NF) with the highest (*p* < 0.05) fat content, and two significantly different reduced-fat levels, one higher level (*p* < 0.05) corresponding to C-RF and the other with similar values (*p* < 0.05) for P-RF and O-RF (Table 1).

Considering that the samples formulated with EGs (C-RF and O-RF) lost the same amount of weight (Table 1), it is worth noting that EG made with chia has a greater capacity to retain lipid content after grilling. A similar phenomenon has been described by other authors who observed a greater capacity to retain fat as a result of heat treatment in reduced-fat patties made with structured lipid materials as animal fat replacers when compared to samples made with animal fat only [26,27]. It is

also interesting to note that, as a result of cooking, lipid content decreased by 60% in normal fat sausages compared to a 16–30% reduction in the case of P-RF, O-RF and C-RF.

#### 3.2.2. Fatty Acid Profile

The fatty acid profile of longanizas, based on their saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) contents, is shown in Figure 2. Among raw samples, those with normal fat content exhibited the highest (*p* < 0.05) SFA and MUFA values (probably due to the higher lipid content). In reduced-fat samples, no significant differences were observed in MUFA content but SFA levels were higher in samples with all-animal fat (P-RF). Raw longanizas prepared with chia EG (C-RF) had similar (*p* > 0.05) PUFA content to samples with normal fat content (Figure 2), despite their lower (*p* < 0.05) lipid content (Table 1).

**Figure 2.** Saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) (g/100 g of product) of raw and grilled cooked longanizas. For samples denominations, see Figure 1. Different letters (a, b, c), for the same type of fatty acid (SFA, MUFA or PUFA) and treatment of samples (raw or cooked), indicate significant differences (*p* < 0.05) between different formulations (P-NF, P-RF, C-RF and O-RF).

Similarly, SFA and MUFA contents in cooked samples were higher (*p* < 0.05) in longanizas with normal fat content. However, among reduced-fat samples, those with chia or oat EGs exhibited higher MUFA values than longanizas with all-animal fat. Furthermore, samples with chia EG (C-RF) also showed the highest PUFA level: in most cases, double that of the others (Figure 2). It is worth highlighting their ALA content (1.09 g/100 g of product) even after cooking. Consequently, samples prepared with chia EG would be a good choice based on the daily dietary intake reference for ALA [32].

Use of these EGs in meat product development could be an interesting strategy for obtaining products with a healthy lipid profile, not only due to their vegetable oil content (such as olive oil) and other ingredients with high levels of healthy oil compounds (such as chia seed), but also due to their high capacity to retain that lipid content during cooking (Figure 2), a property not observed in all-animal fat samples (Table 1).

Evaluation of lipid composition is crucial in cooked products because meat fatty acids melt between about 25 and 50 ◦C, but SFAs melt at higher and PUFAs at lower temperatures. Moreover, changes in fatty acid concentration (mainly decreased PUFAs) can occur during cooking due to their low oxidative stability [21]. As a consequence of the culinary process applied, both SFA and MUFA content decreased in samples prepared with all-animal fat, ~54% in N-PF and ~30% in R-PF, while the decrease in PUFA was lower (49% and 22%, respectively, in these samples). This behavior was similar in longanizas made with oat EG, where SFA and MUFA contents decreased by approximately 19% for both, while PUFAs

decreased by 16%. However, longanizas made with chia EG exhibited di fferent reduction values for SFA, MUFA and PUFA (approximately 12%, 8% and 3%, respectively).
