## 3 Results and Discussion
### Consumer Preference and Freshness Evaluation of Raw Samples
For both species, with respect to the liquid in the packaging, the chi-square test analysis showed that, regardless of the freshness stage, MAP-PAD conditions exhibited less liquid (\(p\) < 0.05) than the respective MAP samples (Supplementary Table S4). This result was expected since the liquid that leaks from the fish tissue is absorbed by the pad. Mucus presence did not differ significantly between groups at any of the two freshness stages (Supplementary Table S5). With regard to fillets (Supplementary Table S2), gilthead seabream did not exhibit any significant difference between MAP-PAD and MAP samples at either time point. Nevertheless, seabass fillets with a pad (MAP-PAD) were perceived as fresher in odor (\(p\) = 0.030) and overall (\(p\) = 0.028), while consumers were more willing to buy them (\(p\) = 0.045) and perceived them as closer to the ideal product of packaged fish (\(p\) = 0.010) at the end of high-quality shelf-life compared to their counterparts without a pad (MAP). Similarly to the whole-gutted fish, the presence of liquid was significantly higher (\(p\) < 0.05) in MAP fillets than in MAP-PAD ones (Supplementary Table S4), regardless of the species or freshness stage; this indicates a significant impact of the pad in absorbing sample-excreted liquid, besides its main role as gas releaser. A significantly (\(p\) < 0.05) higher rated fresh odor, overall freshness perception, purchase intention and proximity to the ideal product for the MAP-PAD samples in whole seabream and filleted seabass indicated that, besides the self-explained relation between freshness perception and purchase intention, perceived freshness seems mainly to be attributed to the perception of fresh odor, more than the other sensory attributes that did not differ significantly between different packaging. Previous research has pointed out the complexity \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Fish Processing**} & \multirow{2}{*}{**Species**} & \multicolumn{2}{c}{**Shelf-Life**} & \multirow{2}{*}{**MAP-PAD**} & \multirow{2}{*}{**MAP**} & \multirow{2}{*}{\(p\)**-Value**} \\  & & & **Time Point** & & & \\ \hline \multirow{4}{*}{Whole fish} & Seabream & HQ & 42 & 28 & 0.120 \\  & & End & 54 & 12 & \textless{}0.001 \\  & Seabass & HQ & 41 & 30 & 0.235 \\  & & End & 40 & 27 & 0.142 \\ \hline \multirow{4}{*}{Fish fillets} & Seabream & HQ & 38 & 24 & 0.098 \\  & & End & 44 & 20 & 0.004 \\ \cline{1-1}  & Seabass & HQ & 40 & 23 & 0.043 \\ \cline{1-1}  & & End & 48 & 14 & \textless{}0.001 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Consumer preference results presented as frequencies (\(n\)). \(p\)-values were calculated by applying a binomial test at a = 0.05.  
of freshness and quality evaluation of fish by consumers [13], while elsewhere it has been reported that consumers feel uncertain or find it difficult to evaluate freshness [30]. Apart from fresh odor, the flesh tended to be perceived as brighter white and firmer in MAP-PAD gilthead seabream (\(p\) = 0.091) and seabass (\(p\) = 0.071) fillets at the end of high quality comparing to their MAP counterparts. Appearance affects perceived quality, and in turn consumer decision on the point of purchase [31; 32; 33]. Thus, liquid in all tested samples, and to some extent flesh color in the fillets, may have been easier for the consumers of this study to evaluate. Consumers may be more familiar with these appearance attributes given that they are more distinctive in the packed fish and fillets during purchase. On the other hand, skin in the fillet, or eyes and skin in the whole fish, may be more difficult for the consumer to evaluate before opening the package. The use of consumers in the evaluation of fish fillet freshness was applied in a recent study [31], in which consumer acceptance or rejection at different time points of storage was investigated, in order to define the sensory acceptability limit on fish stored in refrigeration for days.