218
combination of dry ice (20%) and water ice (50%) has been tried since dry ice is
expensive to use alone and sometimes causes freezing. Despite the fact that this
combination has a similar effect with 100% water ice on the shelf life of squid, the
combined use of dry ice and wet ice in the short-term transport of squid was recommended to the seafood industry (Jeyasekaran et al. 2010). In a similar study, both
dry ice (at the ratio of 1:1) and a combination of dry ice and wet ice (in the ratio of
1:0.2:0.5) improved the quality and increased the shelf life of cuttlefish (Sepia pharaonis) fillets by about 33%, when compared to wet ice alone (in the ratio of 1:1)
(Jeyasekaran et al. 2011).
In some studies, icing has been applied by direct and indirect contact method to
protect them from the melted ice and to avoid leaching. Melting ice in contact with
the fish permits water to penetrate the skin, thereby reducing muscle translucency
(Lougovois et al. 2008). Lapa-Guimaraes et al. (2002) reported that non-contact ice
storage method presented no advantages when compared with the contact ice storage method with respect to the quality preservation of squid (Loligo plei) under
laboratory conditions on the other hand. Whereas Prafulla et al. (2000) indicated
that indirect icing preserves most of the nutrients in squid and cuttlefish, but with
shorter shelf life. On the other hand, it has been reported that contact icing is not
suitable because it causes colour, texture, and aroma changes in squid (Illex illecebrosus) (Ke et al. 1991). Manimaran et al. (2016b) did not advice the storage in
non-contact with ice due to the rapid multiplication of spoilage bacteria as reflected
by the reduction in NPN as well as accumulation of water soluble ammoniacal
nitrogen, TVB-N and FFA.
Different packaging methods have been used to increase the shelf life of cephalopods in addition to chilling. In a study, cuttlefish were packed in three different
atmospheres (MAP1: 20% CO 2 -80% N 2 ; MAP2: 50% CO 2 -50% N 2 ; MAP3: 70%
CO 2 -30% N 2 ) and under vacuum and stored at 2 °C. As a result of the study, it was
determined that packaging in a modified atmosphere is effective in increasing the
shelf life. Especially MAP2 and MAP3 samples with high CO 2 concentration had a
longer shelf life (8 days) compared to MAP1 and vacuum-packed samples. Vacuum
packed samples did not differ from control samples (Bouletis et al. 2015). Longer
shelf lives have been reported for squid (Illex coindetii) packed with the same gas
ratios. Again, in this study, the best results were obtained with A2 and A3 atmospheres, and the shelf life of 8 and 10 days was determined respectively (Bouletis
et al. 2014). While a shelf life of 9 days was reported for cuttlefish packed under
modified atmospheres (A1: 50% CO 2 -50% N 2 ; A2: 80 CO 2 %-20% N 2 ; A3: 65%
CO 2 -35%), control samples were rejected on day 5 (Caglak et al. 2014). In a study
examining the effect of modified atmosphere and active packaging on the shelf life
of Cuttlefish (Sepia officinalis), a group of cuttlefish was packed in a modified atmosphere (20% CO 2 /80% N 2 ), while the other group was packaged in the same modified atmosphere but with the addition of an adsorbent with high water retention in
the package. The total number of psychrotrophic microorganisms and TVB-N and
TMA-N values of the samples in the adsorbent-added packages were lower than
that of the MAP and control samples (Albanese et al. 2005).
3 Molluscan Shellfish
combination of dry ice (20%) and water ice (50%) has been tried since dry ice is
expensive to use alone and sometimes causes freezing. Despite the fact that this
combination has a similar effect with 100% water ice on the shelf life of squid, the
combined use of dry ice and wet ice in the short-term transport of squid was recommended to the seafood industry (Jeyasekaran et al. 2010). In a similar study, both
dry ice (at the ratio of 1:1) and a combination of dry ice and wet ice (in the ratio of
1:0.2:0.5) improved the quality and increased the shelf life of cuttlefish (Sepia pharaonis) fillets by about 33%, when compared to wet ice alone (in the ratio of 1:1)
(Jeyasekaran et al. 2011).
In some studies, icing has been applied by direct and indirect contact method to
protect them from the melted ice and to avoid leaching. Melting ice in contact with
the fish permits water to penetrate the skin, thereby reducing muscle translucency
(Lougovois et al. 2008). Lapa-Guimaraes et al. (2002) reported that non-contact ice
storage method presented no advantages when compared with the contact ice storage method with respect to the quality preservation of squid (Loligo plei) under
laboratory conditions on the other hand. Whereas Prafulla et al. (2000) indicated
that indirect icing preserves most of the nutrients in squid and cuttlefish, but with
shorter shelf life. On the other hand, it has been reported that contact icing is not
suitable because it causes colour, texture, and aroma changes in squid (Illex illecebrosus) (Ke et al. 1991). Manimaran et al. (2016b) did not advice the storage in
non-contact with ice due to the rapid multiplication of spoilage bacteria as reflected
by the reduction in NPN as well as accumulation of water soluble ammoniacal
nitrogen, TVB-N and FFA.
Different packaging methods have been used to increase the shelf life of cephalopods in addition to chilling. In a study, cuttlefish were packed in three different
atmospheres (MAP1: 20% CO 2 -80% N 2 ; MAP2: 50% CO 2 -50% N 2 ; MAP3: 70%
CO 2 -30% N 2 ) and under vacuum and stored at 2 °C. As a result of the study, it was
determined that packaging in a modified atmosphere is effective in increasing the
shelf life. Especially MAP2 and MAP3 samples with high CO 2 concentration had a
longer shelf life (8 days) compared to MAP1 and vacuum-packed samples. Vacuum
packed samples did not differ from control samples (Bouletis et al. 2015). Longer
shelf lives have been reported for squid (Illex coindetii) packed with the same gas
ratios. Again, in this study, the best results were obtained with A2 and A3 atmospheres, and the shelf life of 8 and 10 days was determined respectively (Bouletis
et al. 2014). While a shelf life of 9 days was reported for cuttlefish packed under
modified atmospheres (A1: 50% CO 2 -50% N 2 ; A2: 80 CO 2 %-20% N 2 ; A3: 65%
CO 2 -35%), control samples were rejected on day 5 (Caglak et al. 2014). In a study
examining the effect of modified atmosphere and active packaging on the shelf life
of Cuttlefish (Sepia officinalis), a group of cuttlefish was packed in a modified atmosphere (20% CO 2 /80% N 2 ), while the other group was packaged in the same modified atmosphere but with the addition of an adsorbent with high water retention in
the package. The total number of psychrotrophic microorganisms and TVB-N and
TMA-N values of the samples in the adsorbent-added packages were lower than
that of the MAP and control samples (Albanese et al. 2005).
3 Molluscan Shellfish