## 3 Results
### Evaluation of Microbial Growth in Atlantic Mackerel Muscle under Different Packaging Systems  
The evolution of microbial development in fish corresponding to the AF-treated (AF-1 and AF-2 for low and high concentrations of AF) and CTR batches is depicted in Table 1.  
In terms of _Enterobacteriaceae_, the two batches containing algal extracts presented lower average values than did the gelatin CTR batch. Thus, the presence of the algal extract in the packaging films led to lower average values at all the sampling times. Remarkably, the AF-1 batch presented lower average values than its counterpart, the AF-2 batch. These results indicate that the incorporation of algal extracts into the gelatin films resulted in _Enterobacteriaceae_ numbers nearly ten times lower in the AF-1 batch than in the pure gelatin CTR batch. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Microbial Group**} & **Packaging** & \multicolumn{3}{c}{**Refrigeration Time (Days)**} \\  & **Condition** & & **2** & **6** & **9** \\ \hline \multirow{4}{*}{_Enterobacteriaceae_} & CTR & 1.00 \(\pm\) 0.00 a & 1.86 \(\pm\) 0.52 Ab & 2.33 \(\pm\) 0.35 Ab & 4.21 \(\pm\) 0.65 Ac \\ \cline{2-6}  & AF-1 & 1.00 \(\pm\) 0.00 a & 1.53 \(\pm\) 0.20 Ab & 1.73 \(\pm\) 0.88 Ab & 3.23 \(\pm\) 0.35 Ac \\ \cline{2-6}  & AF-2 & 1.00 \(\pm\) 0.00 a & 1.75 \(\pm\) 0.64 Ab & 2.28 \(\pm\) 0.87 Ab & 3.73 \(\pm\) 0.41 Ac \\ \hline \multirow{4}{*}{Psychrotrophs} & CTR & 2.82 \(\pm\) 0.24 a & 4.68 \(\pm\) 0.79 Bb & 6.32 \(\pm\) 0.32 Bc & 8.78 \(\pm\) 0.15 Bd \\ \cline{2-6}  & AF-1 & 2.82 \(\pm\) 0.24 a & 2.93 \(\pm\) 0.35 Aa & 5.16 \(\pm\) 0.32 Ab & 7.83 \(\pm\) 0.30 Ac \\ \cline{2-6}  & AF-2 & 2.82 \(\pm\) 0.24 a & 4.68 \(\pm\) 0.39 Bb & 6.44 \(\pm\) 0.15 Bc & 7.54 \(\pm\) 0.55 Ad \\ \hline \multirow{4}{*}{Lipolytic bacteria} & CTR & 2.00 \(\pm\) 0.00 a & 2.26 \(\pm\) 0.24 Aa & 3.13 \(\pm\) 0.41 Ab & 4.95 \(\pm\) 1.09 Ac \\ \cline{2-6}  & AF-1 & 2.00 \(\pm\) 0.00 a & 2.66 \(\pm\) 0.58 Ab & 2.43 \(\pm\) 0.51 Aab & 3.64 \(\pm\) 1.05 Ab \\ \cline{2-6}  & AF-2 & 2.00 \(\pm\) 0.00 a & 2.16 \(\pm\) 0.28 Aab & 3.00 \(\pm\) 0.89 Abc & 3.63 \(\pm\) 0.46 Ac \\ \hline \multirow{4}{*}{Lipolytic bacteria} & \multicolumn{3}{c}{*Average values \(\pm\) standard deviations (\(n\) = 3). In each row, different lowercase letters denote significant differences (\(p\) < 0.05) with refrigeration time; in each column, different capital letters denote significant differences (\(p\) < 0.05) as a result of the packaging conditions. **Packaging conditions: CTR (Control; gelatin films prepared without alga flour extract); AF-1 and AF-2 correspond to low and high concentrations of alga flour extracts, respectively, in gelatin films.} \\ \cline{2-6}  & AF-2 & 2.00 \(\pm\) 0.00 a & 2.16 \(\pm\) 0.28 Aab & 3.00 \(\pm\) 0.89 Abc & 3.63 \(\pm\) 0.46 Ac \\ \hline \hline \end{tabular}  
* Average values \(\pm\) standard deviations (\(n\) = 3). In each row, different lowercase letters denote significant differences (\(p\) < 0.05) with refrigeration time; in each column, different capital letters denote significant differences (\(p\) < 0.05) as a result of the packaging conditions. **Packaging conditions: CTR (Control; gelatin films prepared without alga flour extract); AF-1 and AF-2 correspond to low and high concentrations of alga flour extracts, respectively, in gelatin films.  
\end{table} 
Table 1: Determination of _Enterobacteriaceae_, psychrotrophs, and lipolytic bacterial counts (log CFU-g\({}^{-1}\) muscle) * in refrigerated mackerel subjected to different packaging conditions **. Table 1 shows the evolution of psychotroph counts in all three batches during refrigerated storage. Similar to the results observed for _Enterobacteriaceae_, the AF-1 batch, which included a lower concentration of alga extract, provided better microbial control than the other two batches did. Thus, the AF-1 batch presented significantly (\(p<0.05\)) lower psychotroph counts than did the two other batches at intermediate storage times (days 2 and 6).