39
that microbial growth and total volatile nitrogen values were slowed down in fresh
shrimps (Penaeus aztecus) packaged under modified atmosphere compared to
shrimps stored in normal air atmosphere. Shrimps pre-treated with bisulphite wash
solution and packed under modified atmosphere had shelf life up to 10 days compared to shrimp packed in air with or without sulphite wash (Kalleda et al. 2013).
Before chilling, treatment of shrimps with various antimicrobials may influence
shelf life. Organic acids were used as antimicrobial preservative to protect the quality of shrimps. It was determined that total psychrotrophic bacteria, hypoxantine
and trimethylamine levels were lower compared to the control group of the shrimp
(Panaeus aztecus) dipped in ascorbic acid, citric acid, potassium sorbate and 4-hexyl
resorcinol solutions and stored at −1 °C (Pardio et al. 2011). Nirmal and Benjakul
(2009b) reported that in the shrimps treated with ferulic acid (1 and 2%), the increase
in the number of mesophilic and psychophilic bacteria was prevented as well as the
prevention of melanosis during storage for 10 days. Organic acid treatments
improved the sensory quality and extended the shelf life of shrimp samples stored at
0 °C (Attala 2012).
Natural plant extracts are also used as preservative for protecting quality and
extend the shelf life of shrimps before chilling. It was reported that the increase in
psychrophilic bacteria and Enterobacteriaceae numbers was delayed during the cold
storage of shrimps treated with green tea extract (0.1%) and ascorbic acid (0.005
and 0.01%) (Nirmal and Benjakul 2010). Grape seed extract treatment before storage in iced and refrigerated storage was found effective on keeping quality of
Litopenaeus vannamei (Sun et al. 2014) and Parapenaeus longirostris (Gokoglu
and Yerlikaya 2008). Orange peel extract having antioxidant and antimicrobial
activity improved quality of shrimps during refrigerated storage (Vakili and
Ardakani 2018). Application of turmeric in peeled shrimp (Penaeus semisulcatus)
stored in ice extended its shelf-life up to 8 days (Prabhu et al. 2016).
Chitosan, a derivative of chitin, is obtained from waste shells of the crab, shrimp,
and crawfish industries. It has superior characteristics. It is biodegradable, nontoxic,
biocompatible, broadly antimicrobial, nutritional, and antioxidative. There are several studies on use of chitosan in chilled and refrigerated shrimps. TVB-N and
TMA-N formation reduced in deep water pink shrimps (Parapenaeus longirostris)
immersed into solutions containing chitosan (Bingol et al. 2015). Shrimp coated
with a chitosan coating, shrimp coated in a chitosan-protein-lipid concentrate coating, shrimp dipped in a lactic acid solution and shrimp un-coated used as control
were stored 5 °C for 17 days. Shrimp coated in a chitosan-protein-lipid concentrate
inhibited the growth of microorganisms (Arancibia et al. 2015). Whole and headless
shrimp (Pandalus borealis) were dipped in various concentrations of chitosan solution and stored at 4–7 °C for 20 days. The microbial growth, total volatile bases,
nucleotide breakdown, and melanosis were monitored during the storage. At the
concentrations between 0.0075 and 0.01% chitosan inhibited several microorganisms due to its strong antimicrobial properties (Simpson et al. 1997). The pretreatment of shrimp (Litopenaeus vannamei) with carboxymethyl chitosan and
chitosan solution (1.0 or 1.5%) retarded growth of psychrophilic bacteria compared
to control during the storage at 0 °C (Huang et al. 2012).
2.1 Shrimps/Prawns
that microbial growth and total volatile nitrogen values were slowed down in fresh
shrimps (Penaeus aztecus) packaged under modified atmosphere compared to
shrimps stored in normal air atmosphere. Shrimps pre-treated with bisulphite wash
solution and packed under modified atmosphere had shelf life up to 10 days compared to shrimp packed in air with or without sulphite wash (Kalleda et al. 2013).
Before chilling, treatment of shrimps with various antimicrobials may influence
shelf life. Organic acids were used as antimicrobial preservative to protect the quality of shrimps. It was determined that total psychrotrophic bacteria, hypoxantine
and trimethylamine levels were lower compared to the control group of the shrimp
(Panaeus aztecus) dipped in ascorbic acid, citric acid, potassium sorbate and 4-hexyl
resorcinol solutions and stored at −1 °C (Pardio et al. 2011). Nirmal and Benjakul
(2009b) reported that in the shrimps treated with ferulic acid (1 and 2%), the increase
in the number of mesophilic and psychophilic bacteria was prevented as well as the
prevention of melanosis during storage for 10 days. Organic acid treatments
improved the sensory quality and extended the shelf life of shrimp samples stored at
0 °C (Attala 2012).
Natural plant extracts are also used as preservative for protecting quality and
extend the shelf life of shrimps before chilling. It was reported that the increase in
psychrophilic bacteria and Enterobacteriaceae numbers was delayed during the cold
storage of shrimps treated with green tea extract (0.1%) and ascorbic acid (0.005
and 0.01%) (Nirmal and Benjakul 2010). Grape seed extract treatment before storage in iced and refrigerated storage was found effective on keeping quality of
Litopenaeus vannamei (Sun et al. 2014) and Parapenaeus longirostris (Gokoglu
and Yerlikaya 2008). Orange peel extract having antioxidant and antimicrobial
activity improved quality of shrimps during refrigerated storage (Vakili and
Ardakani 2018). Application of turmeric in peeled shrimp (Penaeus semisulcatus)
stored in ice extended its shelf-life up to 8 days (Prabhu et al. 2016).
Chitosan, a derivative of chitin, is obtained from waste shells of the crab, shrimp,
and crawfish industries. It has superior characteristics. It is biodegradable, nontoxic,
biocompatible, broadly antimicrobial, nutritional, and antioxidative. There are several studies on use of chitosan in chilled and refrigerated shrimps. TVB-N and
TMA-N formation reduced in deep water pink shrimps (Parapenaeus longirostris)
immersed into solutions containing chitosan (Bingol et al. 2015). Shrimp coated
with a chitosan coating, shrimp coated in a chitosan-protein-lipid concentrate coating, shrimp dipped in a lactic acid solution and shrimp un-coated used as control
were stored 5 °C for 17 days. Shrimp coated in a chitosan-protein-lipid concentrate
inhibited the growth of microorganisms (Arancibia et al. 2015). Whole and headless
shrimp (Pandalus borealis) were dipped in various concentrations of chitosan solution and stored at 4–7 °C for 20 days. The microbial growth, total volatile bases,
nucleotide breakdown, and melanosis were monitored during the storage. At the
concentrations between 0.0075 and 0.01% chitosan inhibited several microorganisms due to its strong antimicrobial properties (Simpson et al. 1997). The pretreatment of shrimp (Litopenaeus vannamei) with carboxymethyl chitosan and
chitosan solution (1.0 or 1.5%) retarded growth of psychrophilic bacteria compared
to control during the storage at 0 °C (Huang et al. 2012).
2.1 Shrimps/Prawns