35
for 15–120 s was reported to have excellent results in peeling of shrimps (Jabbour
and Hognason 2011).
Although there are studies about enzyme, microwave, and ultrasound applications for peeling of plant-based foods, there is not enough study about the use these
methods for shrimps. These are the issues that need to be considered and studied.
We have found a very recent study on this subject. In this research, individual and
combined ultrasound and enzyme methods have been used to facilitate the shrimp
peeling by loosening the shell from the meat. The ultrasound pre-treatments
increased peelability of shrimp with increasing ultrasonic amplitude and time. The
parallel ultrasound-enzyme combination substantially improved the peelability of
shrimp due to erosion and diffusion effects. Cavitation bubbles generated from
sound waves pitted the surface of shrimp shell, generating pathways for enzyme
diffusion into the muscle-shell attachment. The ultrasound either alone or in parallel
combination with enzyme modified the shrimp shell not only the morphology but
also the structural and functional properties (Dang et al. 2018b).
In another study in which protease solutions were used to promote the relaxation
of shrimp shells prior to peeling, enzymatic maturation was found to effectively
increase the peelability of shrimps. It has been reported that this enzymatic maturing process offers a better shrimp product in terms of texture and colour compared
to an industrially used brine matured reference (Dang et al. 2018c).
Deveining
The vein is the dark line which appears in the upper dorsal region of prawns or
shrimps’ flesh. It can be a source of contamination with sand and bacteria for
shrimps. Deveining is the removal of the vein by cutting longitudinally along the
dorsal region of the prawns or shrimps and pulling the vein.
2.1.3.3 Chilling of Shrimps/Prawns
Shrimps have limited shelf life. For this reason, they should be stored immediately
after harvest or catching. The most common preservation method used for this purpose is chilling. Chilling is the process of lowering the temperature of the fish to a
temperature just above the freezing point. Chemical and biochemical reactions
responsible for quality deterioration during storage will slow down with decrease in
storage temperature, and the storage life will be prolonged at lower temperatures
(Riaz and Qadri 1990).
The main purpose of chilling is to reduce or stop the activities of microorganisms
by reducing the temperature and to prevent the physical, chemical, and biochemical
phenomena occurring under normal conditions. Chilling cannot stop the spoilage
completely, but it can delay a certain period. The first measures to preserve the
freshness of the shrimp start on the fishing boat. Since the degradation is largely
dependent on the temperature, the temperature of the caught fish should be reduced
to 0 to −1 °C as soon as possible (Gokoglu 2002).
2.1 Shrimps/Prawns
for 15–120 s was reported to have excellent results in peeling of shrimps (Jabbour
and Hognason 2011).
Although there are studies about enzyme, microwave, and ultrasound applications for peeling of plant-based foods, there is not enough study about the use these
methods for shrimps. These are the issues that need to be considered and studied.
We have found a very recent study on this subject. In this research, individual and
combined ultrasound and enzyme methods have been used to facilitate the shrimp
peeling by loosening the shell from the meat. The ultrasound pre-treatments
increased peelability of shrimp with increasing ultrasonic amplitude and time. The
parallel ultrasound-enzyme combination substantially improved the peelability of
shrimp due to erosion and diffusion effects. Cavitation bubbles generated from
sound waves pitted the surface of shrimp shell, generating pathways for enzyme
diffusion into the muscle-shell attachment. The ultrasound either alone or in parallel
combination with enzyme modified the shrimp shell not only the morphology but
also the structural and functional properties (Dang et al. 2018b).
In another study in which protease solutions were used to promote the relaxation
of shrimp shells prior to peeling, enzymatic maturation was found to effectively
increase the peelability of shrimps. It has been reported that this enzymatic maturing process offers a better shrimp product in terms of texture and colour compared
to an industrially used brine matured reference (Dang et al. 2018c).
Deveining
The vein is the dark line which appears in the upper dorsal region of prawns or
shrimps’ flesh. It can be a source of contamination with sand and bacteria for
shrimps. Deveining is the removal of the vein by cutting longitudinally along the
dorsal region of the prawns or shrimps and pulling the vein.
2.1.3.3 Chilling of Shrimps/Prawns
Shrimps have limited shelf life. For this reason, they should be stored immediately
after harvest or catching. The most common preservation method used for this purpose is chilling. Chilling is the process of lowering the temperature of the fish to a
temperature just above the freezing point. Chemical and biochemical reactions
responsible for quality deterioration during storage will slow down with decrease in
storage temperature, and the storage life will be prolonged at lower temperatures
(Riaz and Qadri 1990).
The main purpose of chilling is to reduce or stop the activities of microorganisms
by reducing the temperature and to prevent the physical, chemical, and biochemical
phenomena occurring under normal conditions. Chilling cannot stop the spoilage
completely, but it can delay a certain period. The first measures to preserve the
freshness of the shrimp start on the fishing boat. Since the degradation is largely
dependent on the temperature, the temperature of the caught fish should be reduced
to 0 to −1 °C as soon as possible (Gokoglu 2002).
2.1 Shrimps/Prawns