Major Non-essential Amino Acids Research Articles

Amino Acid Profile and Vitamin C Content of Selected Condiments Used as Thickeners in Soup Preparation

Aim: This study aimed to analyze the amino acid profile and determine the vitamin C content of the condiments named Detarium microcarpum (DM), Cissus populnea (CP), Grewia mollis (GW) and Parkia biglobosa (PB).
 Study Design: The condiments obtained from Gwagwa market, Federal Capital Territory (FCT), Abuja were used for this study to analyze and determine the amino acid profile and vitamin C content.
 Place and Duration of the Study: The study was conducted in Abuja, Nigeria at the Department of Medicinal Chemistry and Quality Control, National Institute for Pharmaceutical Research and Development [NIPRD], from February 2020 to September 2020.
 Methodology: The amino acid profile of the condiments was analyzed using methods described by (Maria et al., 2004). The samples were dried to constant weight, defatted, hydrolyzed, evaporated in a rotary evaporator and loaded into the Applied Biosystems PTH Amino Acid Analyzer while the Ascorbic acid content of the condiments was determined by titration method.
 Result: The result indicated that non- essential amino acids are higher in concentration in all the samples (PB - 33.77, DM - 27.51, GM - 18.21 and CO - 25.86) compared to the essential amino acids (PB -27.16, DM - 19.46, GM - 1 6.47 and CO - 22.38) and semi-essential amino acid (PB - 22.22, DM - 16.59, GM - 9.64, CO - 14.01). Among the essential amino acids, leucine is the predominant acid, while glutamic, aspartic acids were found to be the major non-essential amino acids in the samples. High concentrations of aspartic acid, glutamic acid valine, alanine and leucine predominate in all the samples analyzed. The sample Parkia biglobosa has the highest concentration of vitamin C with 0.3 mg/L followed by Detarium Microcarpum 0.18 mg/L, Grewia Mollis 0.12 mg/L and Cissus populnea 0.11 mg/L.
 Conclusion: Results indicate that these condiments contained amino acids in appropriate quantities that can serve as supplementary potential sources of essential amino acids to man and appreciable amount of vitamin C.

Effects of the lactation period, breed and feed on amino acids profile of mare’s milk

The effects of the lactation period, breed, and feed on amino acids profile of mare’s milk were investigated. The feed contained two major essential amino acids (EAAs) leucine (7.31 – 10.3 g.kg-1) and arginine (6.37 – 9.59 g.kg-1); it also included minor EAAs methionine (2.11 – 3.05 g.kg-1) and histidine (2.48 – 3.60 g.kg-1). Glu+Gln, Asp+Asn, and proline, major nonessential amino acids (NEAAs), constituted approximately 60% of total NEAAs (TNEAAs). The ratio of total EAAs to NEAAs ranged from 1:1.2 to 1:1.4. Amino acids (AA) content throughout all milk samples varied due to mare’s different conditions and lactation days. Except for the 1P milk sample, total AA content in the 2 – 8Ps specimens caused by differences in breed oscillated from the 2nd to 28th day of lactation within the following limits: 21.9 – 54.6 g.kg-1, 33.6 – 70.7 g.kg-1, 38.1 – 71.2 g.kg-1, 29.46 – 74.2 g.kg-1, 52.2 – 87.1 g.kg-1, 37.9 – 70.3 g.kg-1 and 26.4 – 64.5 g.kg-1, respectively. In relation to TEAAs in milk, the highest EAAs levels were reached in arginine, leucine and lysine ranging between 2.41 – 4.35 g.kg-1, 3.36 – 5.59 g.kg-1 and 2.72 – 4.80 g.kg-1, respectively, while the lowest AAs amounts were indicated in histidine and methionine, 0.91 – 1.58 g.kg-1 and 1.23 – 2.04 g.kg-1 respectively. Total NEAAs content was slightly higher than that of EAAs; the TNEAAs to TEAAs ratio was 1:0.9 proximately. Glu+Gln, Asp+Asn and proline were determined as major NEAAs of milk ranging between, 6.77 – 11.0 g.kg-1, 3.21 – 5.60 g.kg-1 and 1.25 – 2.18 g.kg-1, respectively; levels of NEAAs such as cysteine and glycine oscillated between 0.89 – 1.52 g.kg-1 and 0.64 – 1.15 g.kg-1, respectively. The average TAAs contents caused by breed differences were 62.8 g.kg-1, 42.8 g.kg-1, 44.7 g.kg-1 and 44.8 g.kg-1, respectively, on the 2nd, 5th, 10th, and 28th lactation days.

Effect of Addition Watermelon Rind Powder on Quality Criteria and Microbial Aspects of Beef Burger Patties during Frozen Storage Periods

The Watermelon rind powder (WMRP) as a natural source of fiber, minerals, amino acids and natural antioxidant compounds. This research was performed to evaluate the influence of addition of WMRP at different level (3, 6, 9 and 12%) from total formula of beef burger patties on chemical, physiochemical, microbiological and sensory characteristics of beef burger patties during frozen storage period at – 18 ±2°C up to 90 days. The obtained results showed that the percentage of the WMR about 37.84 % from the total weight of watermelon fruit which can be considered as by-product for processing. However, the WMRP contained crude fiber (15.98%), total ash (12.55%), Na (515.44 mg/100g), Ca (311.22 mg/100g), Mg (298.61mg/100g), P (288.28 mg/100g), and K (130.04 mg/100g), while Fe (12.98mg/100g) and Zn (3.12 mg/100g) as macro and micro elements. Lysine, leucine, valine and isoleucine were the major essential amino acids (4.97, 4.71, 3.75 and 3.14 gm/100gm protein, respectively). Meanwhile, glutamic, arginine, Aspartic, Alanine and Glycine were the major non-essential amino acids (9.94, 8.91, 6.63, 6.11 and 5.76 gm/100gm protein, respectively). Moreover, the incorporation of WMRP into the beef burger patties as texturized soy substitute, caused to improvement of gross chemical composition as that increased both of fiber, total ash, total soluble carbohydrates content and decreased crude fat of beef burger patties, as well as the improvement of physiochemical quality criteria (pH value, WHC, shrinkage, TVN and TBA values) throughout frozen storage in comparison with control sample. In addition, WMRP inhibited the growth and activity of microbial, as well as reduction of lipid oxidation in tested prepared product. Also, beef burger patties containing the WMRP exhibited a good sensory properties and better acceptability, especially those contained 6 and 9 % WMRP, even after stored for 90 days under frozen condition. The present results are useful of used WMRP in fortification of meat products to improve the nutritionally and healthy safe.

Nutritive value of cultured white leg shrimp Litopenaeus vannamei

Biochemical assays play a major role in recent years. The biochemical composition is the yardstick to measure and assess the nutritional quality of food sources. In the present study, protein, carbohydrate, lipid, moisture and ash in Litopenaeus vannamei was 35.69, 3.20, 19, 76.2 and 1.2% respectively. Calcium content was maximum (154.5 mg) followed by sodium (67.7 mg) and potassium (56.7 mg). Manganese was reported to be minimum (0.898 mg). Copper and chromium were observed in trace. Totally 18 amino acids were detected, among these, argentine, histamine, isoleucine ,leucine, methionine, phenylalanine, tryptophan, lysine and valine are essential amino acids and alanine, asparagine, aspartic acid, cysteine, glutamic acid, glycine, proline, serine and tyrosine are non-essential amino acids. In individual essential amino acids, valine (23.72%) was maximum, followed by lysine (13.42%) and methionine (13.06%). Histidine was minimum (1.08%). Glycine (9.8%), cystine (5.56%) and proline (4.26%) contributed as major non-essential amino acids. Ten individual fatty acids were identified, which includes both unsaturated and saturated fatty acids. Three saturated fatty acids (SFA) were recorded (Palmitic acid, Margaric acid and Stearic acid). The polyunsaturated fatty acids (PUFA) were the most dominant common fatty acids (38.5%) with the higher levels of linoleic acid (16.3%) and alpha-linolenic acid (11.2%). Oleic acid is the only monounsaturated fatty acid (MUFA) contributed 12.48% of total fatty acids. At the same time the Omega – 6 and omega - 3 fatty acids accounted for 16.3 and 35.4% of the total PUFA (51.7%). the present study confirming that based on the results, L.vannamei species can be considered as a good source of fatty acid as well as protein. Key words: Litopenaeus vannamei, proximate composition, fatty acids, amino acids, minerals, shrimp nutrition.

Changes in Biochemical Composition and Digestive Enzyme Activity During the Embryonic Development of the Marine Crab,Charybdis japonica(Crustadea: Decapoda)

In this study, we investigated the biochemical composition and digestive enzyme activity during embryonic development in the marine crab, Charybdis japonica. Water, protein, and ash content increased, while levels of lipids and carbohydrates decreased significantly during embryonic development, and a marked correlation between water content and egg volume (r = 0.97; P < 0.01) was recorded. The utilization percentages of lipids and carbohydrates were 32.72% and 91.56%, respectively. The predominant essential amino acids (EAA) were lysine, leucine, arginine and valine, and the major nonessential amino acids (NEAA) were glutamic acid and aspartic acid. From the fertilized egg stage to the protozoea stage, total amino acid (TAA) concentration increased from 52.18% to 55.11% on a dry weight basis, but the ratio of EAA/TAA decreased from 52.57% to 48.90%. The quantitatively more important fatty acids were C16:0, C18:1n-9c, C16:1, C22:6n-3 (docosahexaenoic acid, DHA), and C22:2. Polyunsaturates (PUFA) and monounsaturated (MUFA) were consumed at similar rates (34.20% and 36.70%, respectively); both were consumed at higher rates than saturates (SFA) (26.56%). In particuler, n-3 fatty acids decreased significantly, with a high consumption rate of 43.74%. Activities of trypsin and pepsin increased during both the early and later embryonic stages, but decreased during the middle stages. Lipase activity increased gradually during embryonic development, except in the protozoea stage with a significant decrease, while activities of amylase and cellulase showed an ascending trend after an initial decline. The activity of all digestive enzymes increased, except for that of lipase, from the heartbeat stage to the protozoea stage.

Biochemical and Bacteriological properties of fresh and frozen sold cephalopods in the Egyptian market.

arious cephalopods are available for seafood consumers in the Suez Canal area either caught from the Suez Canal and stored in ice during transporting and marketing or imported and sold frozen in retail market. The lower price of imported cephalopods compared with the fresh ones makes it more demanded by consumers, restaurants and hotels. The objective of this study is to evaluate the quality and safety of fresh/chilled squid (Uroteuthis duvauceli) and cuttlefish (Sepia pharaonis) compared to frozen imported squid in the Egyptian market through chemical, biochemical and bacteriological analyses. The chemical analysis revealed that the mantle tissue pH, volatile base nitrogen (VBN) and trimethylamine (TMA) in frozen squid were significantly higher (P < 0.05) than that in fresh/chilled samples. The biochemical analysis showed that the crude protein content (% dry weight) was significantly lower (P < 0.05) (14.2±0.73%) in frozen samples than that in fresh squid and cuttlefish (17.25±0.41% & 19.95±0.55% respectively). The total lipid content was generally low, ranging from 0.39 – 1.77% in all samples. Most of saturated fatty acid content of the three samples was presented as C16:0, monounsaturated fatty acid content as C18:1 and polyunsaturated fatty acid (PUFA) content as eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic (DHA, C22:6n-3). EPA and DHA contents were significantly lower (P < 0.05) in frozen squid than in fresh samples. The major essential amino acids (EAA) in the three samples were lysine, arginine, and leucine. The major non-essential amino acids (NEAA) were glutamic acid, aspartic acid and glycine. EAA and NEAA values were significantly lower (P < 0.05) in frozen squid than in fresh cuttlefish. Bacteriological results suggest that hydrogen sulphide producing bacteria constituted a significant proportion of the total spoilage flora in frozen samples, while Pseudomonas sp. constituted a major part of the spoilage flora of fresh samples. An overall look into the data obtained showed that there might be significant health hazards to humans from consuming imported frozen squid besides its much lower nutritional value than fresh samples.

Assessment of protein fractions of three cultivars of Pisum sativum L.: effect of germination

Protein composition, nitrogen and amino acid content of Osborne fractions in different cultivars of Pisum sativum L. (cv. ucero, cv. ramrod and cv. agra) seeds were investigated and the effect of germination on these parameters was also analysed. Albumins comprised the main protein fraction in raw seeds, globulins were constituted mainly by vicilin, with a smaller proportion of the glutelin and prolamine fractions. Regarding the amino acid profile of pea protein fractions, although differences among pea cultivars were found, in general albumin, glutelin and prolamine fractions presented Asp, Glu and Gly as the major non-essential amino acids (NEAA) and Lys as the main essential amino acid (EAA). The globulin fraction, however, presented Asp, Glu, Gly and Arg as the major NEAA and Leu, Phe, Lys, and Thr as the main EAA. In general, the albumin fraction accounted for more sulphur amino acids and Lys, followed by the glutelin + prolamine fraction. Germination caused an increase in the total protein content of P. sativum cv. ucero and P. sativum cv. ramrod. In the albumin fraction a wide number of proteins underwent degradation and convicilin disappeared from the globulin fraction of pea sprouts whilst vicilin and legumin decreased slightly. In general, all the Osborne fractions of pea sprouts presented higher EAA contents than raw seeds. The estimated essential amino acid indexes of protein fractions for P. sativum cv. ucero (EAAIadult and EAAIegg) improved with the germination process whilst for P. sativum cv. ramrod and P. sativum cv. agra depended on the Osborne fraction.

Distribution, abundance, biology and biochemistry of the stout bobtail squid Rossia macrosoma from the Portuguese coast1 and

A study of Rossia macrosoma in Portuguese waters with emphasis on its biogeographical, biological and biochemical characteristics is presented. Approximately 1000 specimens collected in 32 cruises between 1990 and 2003 were used to determine the distribution and abundance of the species and some population biology parameters (weight, length, sex and maturation). The first biochemical characterization of the species at different stages of gonad development was made. The species was found at depths up to 860 m along the whole Portuguese coast. The sex ratio was approximately 1:1 and did not vary with depth or position along the coast (P≫0.05). Females grew larger (84:67 mm mantle length) and heavier (161:100 g total body weight) than males. Mature specimens of both sexes constituted <1% of all records. Immature and maturing specimens were found year round, without significant differences between female monthly distributions (P > 0.05). No significant difference between sexes in the distribution of maturity stages with depth or position along the coast was noted (P≫0.05). During sexual maturation there was a significant increase (P < 0.05) in total amino acid, protein, lipid and fatty acid contents in the gonad, but the allocation of these organic compounds from digestive gland and muscle was not evident. In the three tissues analysed, the major fatty acids were 16:0, 18:0, 18:1, 20:1, 20:4n-6, 20:5n-3 and 22:6n-3, the major essential amino acids were lysine, leucine and arginine and the major non-essential amino acids were glutamic acid, aspartic acid and serine.

The presence of high concentrations of free d-amino acids in human saliva

Free neutral d-amino acids have previously been detected in human plasma, usually accounting for less than 2% of the total free amino acid concentration ( d-amino acid ratio) [Nagata, Y., Masui, R., Akino, T., 1992a. The presence of free d-serine, d-alanine and d-proline in human plasma. Experientia 48, 986–988. Nagata, Y., Yamamoto, K., Shimojo, T., 1992b. Determination of d- and l-amino acids in mouse kidney by high-performance liquid chromatography. Journal of Chromatography 575, 147–152. Nagata, Y., Yamamoto, K., Shimojo, T., Konno, R., Yasumura, Y., Akino, T., 1992c. The presence of free d-alanine, d-proline and d-serine in mice. Biochimca et Biiophysica Acta 1115, 208–211]. In the present study to search for the source of free d-amino acids, d- and l-enantiomers of the major non-essential amino acids, i.e., the free form of serine, alanine, proline, aspartate and glutamate were analyzed by HPLC in human saliva, submandibular glands and oral epithelial cells. The d-enantiomer ratios to total of free alanine or proline were 35% and 20%, respectively, in saliva. The ratios of the other d-amino acids were less than 11%. The effect of ingested food and oral bacteria on the saliva amino acid levels was suggested to be insignificant. d-Alanine and d-aspartate were also detected in the submandibular gland in ratios up to 5%, and d-alanine and d-proline were found in oral epithelial cells in ratios of 18% and 5%, respectively. The submandibular gland and oral epithelial cells are suggested to be possible sources of the saliva d-alanine and d-aspartate.

Amino and fatty acid dynamics of Lysmata seticaudata (Decapoda: Hippolytidae) embryos during early and late reproductive season

The present study investigates amino and fatty acid dynamics of embryos of different-sized simultaneous hermaphrodite shrimp (SH) (Lysmata seticaudata) during early (ERS) and late reproductive seasons (LRS). A significant relative decrease in total amino acids and essential amino acids (EAA) was recorded (P<0.05) during the development of embryos produced by shrimp collected during ERS and LRS. The content of non-essential amino acids (NEAA) showed a smaller variation, without a marked decrease. During the last embryonic stage, the major EAAs of embryos were, in decreasing magnitude, lysine and arginine, while the major NEAAs were glutamic acid and valine. A substantial decrease in lipid content (P<0.05) was observed, and the quantitatively more important fatty acids were the saturates 16:0 and 18:0, the monounsaturates 18:1n-9 and 18:1n-7 and the polyunsaturates 20:4n-6 (arachidonic acid, ARA), 20:5n-3 (eicosapentaenoic acid, EPA) and 22:6n-3 (docosahexaenoic acid, DHA). Monounsaturates were used at a higher rate, and embryos produced by SH shrimp displayed similar consumption rates of saturated and polyunsaturated fatty acids. Considering individual fatty acids, no clear utilization pattern between different-sized SH shrimp in ERS and LRS was recorded. The inexistence of consistent differences between amino and fatty acid utilization during embryogenesis among different-sized SH shrimp in ERS and LRS emphasizes the variability affecting offspring in decapod crustaceans.

Changes in amino acids and lipids during embryogenesis of European lobster, Homarus gammarus (Crustacea: Decapoda)

We studied the amino acid and lipid dynamics during embryogenesis of Homarus gammarus. Major essential amino acids (EAA) in the last stage of embryonic development were arginine, lysine and leucine; major nonessential amino acids (NEAA) were glutamic acid, aspartic acid, valine and glycine. The highest percent of utilization occurred in respect to EAA (27.8%), mainly due to a significant decrease ( p<0.05) of methionine (38.3%) and threonine (36.0%). NEAA also decreased significantly ( p<0.05, 11.4%), namely serine (38.1%), tyrosine (26.4%) and glutamic acid (25.7%). In contrast, the free amino acid content increased significantly ( p<0.05) during embryonic development, especially the free nonessential amino acids (FNEAA). In the last stage, the most abundant FNEAA were glycine, proline, alanine and taurine, and the major free essential amino acids (FEAA) were arginine, lysine and leucine. Lipid content decreased significantly ( p<0.05) during embryonic development. A substantial decrease in all neutral lipid classes was observed (>80% of utilization). Major fatty acids were 16:0, 18:0, 18:1n-9, 18:2n-6, 18:3n-3, 20:5n-3 and 22:6n-3. Unsaturated (UFA) and saturated fatty acids (SFA) were used up at similar rates (76.5% and 76.3%, respectively). Within UFA, monounsaturates (MUFA) were consumed more than polyunsaturates (PUFA) (82.9% and 67.5%, respectively).

Biochemical composition of cephalopods with different life strategies, with special reference to a giant squid, Architeuthis sp.

The present study is a comprehensive comparison of the biochemical composition (protein, lipid, glycogen and cholesterol contents, and amino acid and fatty acid profiles) of 14 species of cephalopods with different life strategies (benthic, nektobenthic, benthopelagic and pelagic) in distinct habitats (neritic, demersal, oceanic and deep sea), with special emphasis placed on a male Architeuthis sp. The giant squid showed a significantly lower protein and total amino acid content in the gonad and digestive gland. The major essential amino acids were leucine, lysine and arginine. The major non-essential amino acids were glutamic acid, aspartic acid and proline. The benthopelagic cirrate octopus Opisthoteuthis sp. showed a lower content of these nitrogen compounds in the muscle. In respect to lipid and fatty acid contents, the giant squid showed the highest values in the gonad and digestive gland and the lowest in the muscle. Most of saturated fatty acid content was presented as 16:0; monounsaturated fatty acid content, as 18:1 and 20:1; and polyunsaturated fatty acid content, as 20:4n-6, 20:5n-3 and 22:6n-3. The highest cholesterol content in the gonad was detected in Opisthoteuthis sp. and Architeuthis sp.; in the digestive gland. in Todarodes sagittatus; and in the muscle, in Sepia elegans. The highest glycogen value in the gonad was detected in Octopus vulgaris; in the digestive gland and muscle, the highest values were attained in Opisthoteuthis sp. The relationships between life strategies and biochemical composition were investigated and principal component analysis (PCA) was performed. The different cephalopod life strategies could be well separated on the basis of the first two principal components. The nektobenthic and pelagic strategies were clearly separated from the benthic, suggesting that these groups of species are characterized by lower lipid content and higher protein content in the gonad. A rather similar life-strategy distinction was obtained for the digestive gland. The benthopelagic strategy was also well separated from benthic and pelagic strategies and from Architeuthis sp. In the muscle, the results indicated lower nitrogen and carbon compound contents in Architeuthis sp. and Opisthoteuthis sp. The environmental conditions that possibly explain the Architeuthis sp. stranding, the relationships between biochemical compositions and the life strategies of the different cephalopod species studied are discussed.

Biochemical dynamics of spermatogenesis and oogenesis in Eledone cirrhosa and Eledone moschata (Cephalopoda: Octopoda)

The effect of spermatogenesis and oogenesis on protein, lipid, glycogen, cholesterol and energy contents, total amino acid and fatty acid profiles of Eledone cirrhosa and Eledone moschata tissues (gonad, digestive gland and muscle) was investigated. A significant ( p<0.05) increase in the amino acids and protein content of the gonad throughout sexual maturation (namely in oogenesis) was observed, but the allocation of these nitrogen compounds from the digestive gland and muscle was not evident. The major essential amino acids (EAA) in the three tissues were leucine, lysine and arginine. The major nonessential amino acids (NEAA) were glutamic acid, aspartic acid and alanine. A significant increase in lipid and fatty acid contents of gonad and digestive gland was observed. There was also little evidence of accumulated lipid storage reserves being used for egg production. It seems that for egg production Eledone species use energy directly from food, rather than from stored products. Most of saturated fatty acid (SFA) content of the three tissues was presented as 16:0 and 18:0, monounsaturated fatty acid (MUFA) content as 18:1 and 20:1 and polyunsaturated fatty acid (PUFA) content as 20:4 n-6, 20:5 n-3 and 22:6 n-3. Cholesterol and glycogen contents significantly increased in gonad and digestive gland throughout maturation while the muscle revealed no obvious pattern. If Eledone's component sterols are of a dietary origin, a considerable variation in the cholesterol content between species might be expected on the basis of the sterol composition of their prey. Although spermatogenesis and oogenesis had a significant effect ( p<0.05) in gonad and digestive gland energy content, the biochemical composition of digestive gland and muscle may not be primarily influenced by sexual maturation, but rather by other biotic factors such as feeding activity, food availability, spawning and brooding.

Effect of sexual maturation on the tissue biochemical composition of Octopus vulgaris and O. defilippi (Mollusca: Cephalopoda)

Changes in the protein, lipid, glycogen, cholesterol and energy contents, total amino acid and fatty acid profiles of Octopus vulgaris and O. defilippi tissues (gonad, digestive gland and muscle) during sexual maturation (spermatogenesis and oogenesis) were investigated. Both species showed an increase of amino acids and protein content in the gonad throughout sexual maturation (namely in oogenesis), but allocation of these nitrogen compounds from the digestive gland and muscle was not evident. The major essential amino acids in the three tissues were leucine, lysine and arginine. The major non-essential amino acids were glutamic acid, aspartic acid and alanine. With respect to carbon compounds, a significant increasing trend (P 0.05) in the digestive gland and muscle revealed no evidence that storage reserves are transferred from tissue to tissue. The biochemical composition of digestive gland and muscle may not be influenced by sexual maturation, but rather by other biotic factors, such as feeding activity, food availability, spawning and brooding.

4P-0942 Effects of medical nutrition therapy on the blood lipid levels in hyperlipidemic patients according to genetic polymorphism of Apo E

We studied the amino acid and lipid dynamics during embryogenesis of Homarus gammarus. Major essential amino acids (EAA) in the last stage of embryonic development were arginine, lysine and leucine; major nonessential amino acids (NEAA) were glutamic acid, aspartic acid, valine and glycine. The highest percent of utilization occurred in respect to EAA (27.8%), mainly due to a significant decrease (p<0.05) of methionine (38.3%) and threonine (36.0%). NEAA also decreased significantly (p<0.05, 11.4%), namely serine (38.1%), tyrosine (26.4%) and glutamic acid (25.7%). In contrast, the free amino acid content increased significantly (p<0.05) during embryonic development, especially the free nonessential amino acids (FNEAA). In the last stage, the most abundant FNEAA were glycine, proline, alanine and taurine, and the major free essential amino acids (FEAA) were arginine, lysine and leucine. Lipid content decreased significantly (p<0.05) during embryonic development. A substantial decrease in all neutral lipid classes was observed (>80% of utilization). Major fatty acids were 16:0, 18:0, 18:1n-9, 18:2n-6, 18:3n-3, 20:5n-3 and 22:6n-3. Unsaturated (UFA) and saturated fatty acids (SFA) were used up at similar rates (76.5% and 76.3%, respectively). Within UFA, monounsaturates (MUFA) were consumed more than polyunsaturates (PUFA) (82.9% and 67.5%, respectively).

Free amino acid and protein content in the planktonic copepod Temora longicornis compared to Artemia franciscana

Previous studies have indicated that natural zooplankton, the natural prey organisms of marine fish larvae, is superior to enriched Artemia spp. nauplii in supporting survival, growth and normal development of pigmentation and eye migration in Atlantic halibut larvae. The present study was designed to compare the amino acid dynamics in copepods harvested from a natural lagoon with that of enriched Artemia franciscana nauplii. The natural zooplankton in the present study was dominated by Temora longicornis, but varied in its developmental stage composition, apparent nutritional quality, amount and availability. The protein content in natural zooplankton varied from 31% to 54% of dry mass (DM) compared to 31% in enriched Artemia nauplii. The amount of free amino acids (FAA) in relation to protein was 14% in enriched Artemia nauplii and varied between 16% and 27% in zooplankton in two consecutive seasons. The FAA composition of zooplankton in 1996 was unaffected by stage and season, and showed a species-specific pattern. In response to starvation, two patterns in the amino acid dynamics of copepods were found. The first, exhibited by the major nonessential amino acids (NEAA), showed a continuous reduction in individual amount, while the second pattern, exhibited by the minor nonessential amino acids and all the essential FAA, had an initial increase followed by a reduction. It is suggested that the protein amount in DHA Selco™ (INVE)-enriched Artemia nauplii is too low in order to maximise the growth potential of some marine fish larvae as cod and halibut.