26
et al. 1994). In a study investigating the effect of organic acids on melanosis and
shelf life in shrimp (Penaeus japonicus), 1% lactic, citric, and acetic acids and 0.3%
sodium metabisulphite solutions and their combinations were used. Sodium metabisulphite combinations were found to be effective in delaying melanosis (Gokoglu
2004). In a study in which the effect of ferulic acid on the inhibition of polyphenoxidase and quality changes in pacific white shrimp (Litopenaeus vannamei) stored in
ice was investigated, different concentrations of ferulic acid (FA) and oxygenated
ferulic acid (OFA) were tried and inhibition of the concentration of polyphenoloxidase activity was observed (Nirmal and Benjakul 2009a). In another study, ascorbic
acid, citric acid, sodium benzoate, kojic acid and 4-Hexylresorcinol were tried separately and combinations to prevent melanosis and microbial degradation in shrimp
(Penaeus japonicus). It has been determined that sodium benzoate and kojic acid are
effective in the inhibition of melanosis in shrimps, and that 4-Hexylresorcinol is
effective with both alone and combination with ascorbic acid or citric (Montero
et al. 2001b).
7. Alternative methods
Today, consumers prefer natural ones instead of synthetic additives. Therefore,
researchers are studying on the use of natural additives to prevent melanosis.
Plant phenolics as potential natural additives have received more attention due to
their antioxidant and antimicrobial activities. These compounds are predominantly tocopherols, flavonoids, cinnamic acid derivatives and coumarins
(Banerjee 2006). They are present in fruits, vegetables, leaves, nuts, seeds, flowers, and barks. They are found naturally in plants such as grapes, green tea and
others and have antioxidant effect, which gives them inhibitory activity against
PPOs (Kim et al. 2000). The extract obtained from edible enokitake mushroom
tried as a preventive agent and was found to be successful (Jang et al. 2003).
Grape seed extract (Gokoglu and Yerlikaya 2008; Sun et al. 2014) and rosemary
extract were used in shrimps to prevent melanosis and were found to be effective
(Yatmaz and Gokoglu 2016). Gokoglu and Yerlikaya (2008) stored the shrimp
(Parapenaeus longirostris) at 4 °C after dipping into ethanol extracts of grape
seed which was prepared with distilled water, and they observed inhibition
effects of grape seed extract on melanosis. Sun et al. (2014) also immersed white
shrimp (Litopenaeus vannamei) into grape seed extracts in different concentrations (0, 7.5 and 15 g/L). They suggested that grape seed extract could be used
as an effective natural antimelanotic agent as alternative to synthetic ones. The
rosemary extract contains antioxidant compounds such as carnosol, carnosic
acid, rosmanol, epirosmanol isorosmanol, methyl carnosate and phenolic acids
(O’Grady et al. 2006). Certain components in rosemary extracts also show antimicrobial activity. In one study, it was determined that rosemary extract was
effective in preventing the darkening of Aristeus antennatus and its combination
with sodium metabisulphite was more effective. In the same study, green tea
extract showed similar effect (Yatmaz and Gokoglu 2016). Other researchers
have also reported similar results with green tea extract (Nirmal and Benjakul
2011a) Treatment of pacific white shrimp (Litopenaeus vannamei) with poly2 Crustacean Shellfish
et al. 1994). In a study investigating the effect of organic acids on melanosis and
shelf life in shrimp (Penaeus japonicus), 1% lactic, citric, and acetic acids and 0.3%
sodium metabisulphite solutions and their combinations were used. Sodium metabisulphite combinations were found to be effective in delaying melanosis (Gokoglu
2004). In a study in which the effect of ferulic acid on the inhibition of polyphenoxidase and quality changes in pacific white shrimp (Litopenaeus vannamei) stored in
ice was investigated, different concentrations of ferulic acid (FA) and oxygenated
ferulic acid (OFA) were tried and inhibition of the concentration of polyphenoloxidase activity was observed (Nirmal and Benjakul 2009a). In another study, ascorbic
acid, citric acid, sodium benzoate, kojic acid and 4-Hexylresorcinol were tried separately and combinations to prevent melanosis and microbial degradation in shrimp
(Penaeus japonicus). It has been determined that sodium benzoate and kojic acid are
effective in the inhibition of melanosis in shrimps, and that 4-Hexylresorcinol is
effective with both alone and combination with ascorbic acid or citric (Montero
et al. 2001b).
7. Alternative methods
Today, consumers prefer natural ones instead of synthetic additives. Therefore,
researchers are studying on the use of natural additives to prevent melanosis.
Plant phenolics as potential natural additives have received more attention due to
their antioxidant and antimicrobial activities. These compounds are predominantly tocopherols, flavonoids, cinnamic acid derivatives and coumarins
(Banerjee 2006). They are present in fruits, vegetables, leaves, nuts, seeds, flowers, and barks. They are found naturally in plants such as grapes, green tea and
others and have antioxidant effect, which gives them inhibitory activity against
PPOs (Kim et al. 2000). The extract obtained from edible enokitake mushroom
tried as a preventive agent and was found to be successful (Jang et al. 2003).
Grape seed extract (Gokoglu and Yerlikaya 2008; Sun et al. 2014) and rosemary
extract were used in shrimps to prevent melanosis and were found to be effective
(Yatmaz and Gokoglu 2016). Gokoglu and Yerlikaya (2008) stored the shrimp
(Parapenaeus longirostris) at 4 °C after dipping into ethanol extracts of grape
seed which was prepared with distilled water, and they observed inhibition
effects of grape seed extract on melanosis. Sun et al. (2014) also immersed white
shrimp (Litopenaeus vannamei) into grape seed extracts in different concentrations (0, 7.5 and 15 g/L). They suggested that grape seed extract could be used
as an effective natural antimelanotic agent as alternative to synthetic ones. The
rosemary extract contains antioxidant compounds such as carnosol, carnosic
acid, rosmanol, epirosmanol isorosmanol, methyl carnosate and phenolic acids
(O’Grady et al. 2006). Certain components in rosemary extracts also show antimicrobial activity. In one study, it was determined that rosemary extract was
effective in preventing the darkening of Aristeus antennatus and its combination
with sodium metabisulphite was more effective. In the same study, green tea
extract showed similar effect (Yatmaz and Gokoglu 2016). Other researchers
have also reported similar results with green tea extract (Nirmal and Benjakul
2011a) Treatment of pacific white shrimp (Litopenaeus vannamei) with poly2 Crustacean Shellfish