265
Protein and lipid contents of sea cucumber vary depending on season. Seasonal
variations in the proximate composition in body wall of A. japonicus have been
reported (Gao et al. 2011). In that study, it was determined that the moisture content
changed irregularly in all seasons, and the moisture content reached the lowest
value in September with a slow decrease from June to September, and the highest in
November. It was reported that the highest protein values were reached in September.
Minimum carbohydrate values were found in September and November. The highest lipid contents were found in March. On the other hand, ash content did not
change throughout the year (Gao et al. 2011). Ash content in sea cucumbers is
higher than in other sea foods due to the many calcareous ossicles found in body
wall tissues (Liu et al. 2015). The highest lipid content for Isostichopus sp. was
found in May and the highest percentage of protein was determined in July (Vergara
and Rodríguez 2016).
During the aestivation period, A. japonicus ceases to feed. Interestingly, crude
protein, carbohydrate, and lipid contents of fresh body wall tissues were comparatively high when the moisture content was at its minimum. As A. japonicus loses
30–50% of its body weight during aestivation, it can be suggested that the main
nutritional constituents of the body wall, including protein, carbohydrate, and lipid,
may all participate in the energy supply. The results may also show that there are no
special needs for lipid as a source of energy during the aestivation period (Liu
et al. 2015).
Sea cucumbers contain an interesting combination of valuable amino acids; glycine being the major component in almost all species identified. Glutamic acid,
aspartic acid, alanine, and arginine are prominent, among others. Another important
feature of sea cucumber’s amino acid composition is its low lysine/arginine ratio
together with high score of essential amino acids (EAAs) due to presence of considerable amount of threonine, tyrosine, and phenylalanine (Wen et al. 2010; Bordbar
et al. 2011). A total of 18 amino acids were identified in the dry body wall tissues,
digestive tract, and respiratory tree of A. japonicus. They were alanine, valine, leucine, isoleucine, proline, phenylalanine, tryptophan, methionine, glycine, serine,
threonine, cysteine, tyrosine, aspartic acid, glutamic acid, lysine, arginine, and histidine (Liu et al. 2015).
Moreover, sea cucumbers have Vitamin A, Vitamin B 1 (thiamine), Vitamin B 2
(riboflavin), Vitamin B 3 (niacin), and minerals, especially calcium, magnesium,
iron, and zinc (Chen 2003; Ridzwan 2007).
There are very few studies on sea cucumber mineral composition. Eleven sea
cucumber species were reported as excellent sources of macro-elements (Na, Cl,
Ca, and Mg). Calcium is present in sea cucumbers in large quantities (Chang-Lee
et al. 1989). It has been reported that Ca concentrations of sea cucumbers are significantly higher than that of other seafood products such as fish, shrimps, crabs.
The fact that sea cucumbers are embedded in a bendable body wall, isolated, have
the skeleton of microscopic ossicles consisting of CaCO 3 , is shown as the reason for
the high content of Ca (Wen and Hu 2010).
Some studies have shown that the body wall of the sea cucumber contains many
types of active polypeptides. The pentapeptides that consist of leucine, proline,
4.3 Sea Cucumbers
Protein and lipid contents of sea cucumber vary depending on season. Seasonal
variations in the proximate composition in body wall of A. japonicus have been
reported (Gao et al. 2011). In that study, it was determined that the moisture content
changed irregularly in all seasons, and the moisture content reached the lowest
value in September with a slow decrease from June to September, and the highest in
November. It was reported that the highest protein values were reached in September.
Minimum carbohydrate values were found in September and November. The highest lipid contents were found in March. On the other hand, ash content did not
change throughout the year (Gao et al. 2011). Ash content in sea cucumbers is
higher than in other sea foods due to the many calcareous ossicles found in body
wall tissues (Liu et al. 2015). The highest lipid content for Isostichopus sp. was
found in May and the highest percentage of protein was determined in July (Vergara
and Rodríguez 2016).
During the aestivation period, A. japonicus ceases to feed. Interestingly, crude
protein, carbohydrate, and lipid contents of fresh body wall tissues were comparatively high when the moisture content was at its minimum. As A. japonicus loses
30–50% of its body weight during aestivation, it can be suggested that the main
nutritional constituents of the body wall, including protein, carbohydrate, and lipid,
may all participate in the energy supply. The results may also show that there are no
special needs for lipid as a source of energy during the aestivation period (Liu
et al. 2015).
Sea cucumbers contain an interesting combination of valuable amino acids; glycine being the major component in almost all species identified. Glutamic acid,
aspartic acid, alanine, and arginine are prominent, among others. Another important
feature of sea cucumber’s amino acid composition is its low lysine/arginine ratio
together with high score of essential amino acids (EAAs) due to presence of considerable amount of threonine, tyrosine, and phenylalanine (Wen et al. 2010; Bordbar
et al. 2011). A total of 18 amino acids were identified in the dry body wall tissues,
digestive tract, and respiratory tree of A. japonicus. They were alanine, valine, leucine, isoleucine, proline, phenylalanine, tryptophan, methionine, glycine, serine,
threonine, cysteine, tyrosine, aspartic acid, glutamic acid, lysine, arginine, and histidine (Liu et al. 2015).
Moreover, sea cucumbers have Vitamin A, Vitamin B 1 (thiamine), Vitamin B 2
(riboflavin), Vitamin B 3 (niacin), and minerals, especially calcium, magnesium,
iron, and zinc (Chen 2003; Ridzwan 2007).
There are very few studies on sea cucumber mineral composition. Eleven sea
cucumber species were reported as excellent sources of macro-elements (Na, Cl,
Ca, and Mg). Calcium is present in sea cucumbers in large quantities (Chang-Lee
et al. 1989). It has been reported that Ca concentrations of sea cucumbers are significantly higher than that of other seafood products such as fish, shrimps, crabs.
The fact that sea cucumbers are embedded in a bendable body wall, isolated, have
the skeleton of microscopic ossicles consisting of CaCO 3 , is shown as the reason for
the high content of Ca (Wen and Hu 2010).
Some studies have shown that the body wall of the sea cucumber contains many
types of active polypeptides. The pentapeptides that consist of leucine, proline,
4.3 Sea Cucumbers