The essential and non essential amino acid has been estimated to determine the quality of protein of ediable fishes from trash fish collected from Karachi fish harbor. The crude protein was analyzed by standard method. The amino acid contents from protein hydrolyze were analyzed by high speed amino acid analyzer model 835. The results were discussed in order to evaluate the protein value of the ediable species present in trash and its utilization as a food of poultry, supplement of cereal food because of nutritional point of view, man cannot survive on a bread diet alone. It was suggested that the variations in values of protein contents of edible fishes of trash may be due to difference in species, size, age, physiological state, time and region of catch.
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As food, fishes are highly nutritious. They are particularly valuable for providing proteins of high quality compare to meat, milk or eggs. This has been shown by biological experiments as well as by amino acid analysis (Ghu, 1992). Fishes are also a good supplement of cereal food because form nutritional point of view man cannot survive on bread diet alone; more over all cereal grains are low in protein quantity and quality (Scrimshow and Bressani, 1960). They are particularly low in lysine and methionine which are essential amino-acids while the fish protein is relatively rich in these amino acids and it also contain all the other essential amino acids which are required for a balanced diet (Haris, 1964). Pakistan has large fishery resources but they are not fully exploited. In Pakistan malnutrition and protein deficiencies are prevalent and by proper civilization of our protein resource we can solve our problems of malnutrition.
So many scientists worked on the nutritive value of ediable fishes Bransted (1963) estimate the amino acid composition of fresh fish and influence of storage and processing. Ekern et al. (1962) studies the fish and fishery products in ruminant nutrion. Mesck (1962) described the importance of fisheries production and utilization in the food economy fish in nutrition. The biochemical and nutritional studies on East Pakistan fish part V. influence of age of fish on the distribution of protein in their body; part Vii chemical composition and quality of the traditionally processes fish (Qudrat -i- Khuda and Khan, 1962; Qudrat -i- Khuda et al., 1962). Stansby (1962) observe the proximate composition of fish. Brody (Yousif and Hindik, 1965) worked on fishery by-products. Haq et al. (1974) studied the fish hydrolyzates and fish extracts form teleostean fishes of the Arabian sea. Gras et al. (1978) estimated free amino acids and ninhydrin positive. substance in fish 1. Muscle and skin of rainbow trout (Salmo gaitdneric).
Medford and Mackey (1978) studied the protein and lipid content of gonads liver and muscle of northern Pike (Esoxlucius) in relative to gonade growth. Nakagawa and Kayama (1978) have done the biochemical studies on crap plasma protein 2. Amino acid composition of an albumin. Afolobi and Oke (1981) studied the seasonal variability of nutritive values of fish blue whiting (Micromesistius poutassou). lvor (1997) have studied the option for utilization of bycatch and discard from marine. Lall (2000) estimated the rate of nutrition in fish health. Jacobsen and Hansin (2000) studied the feeding habit of atlantic salmon. Nwanna (2003) estemated the nutritive value and digestibility of fermented shrimp head waste meal by Africal cat fish Calrias gariepinus. Hung et al. (2004) made the comparison of dietary protein and energy utilization in three Asian cat fishes (Panagasius bocouti, P. hypothalmus and P. djambal).
So it is important to point out that for the proper use of trash it is desirable to conduct studies on its biochemical composition and nutritive value. Keeping in view this objective the present research work was to estimate the crude protein and further analyzed into their component i.e., essential amino acid from the protein hydrolysate. Trash fish has great economic importance, it is widely used in many developed and under developed countries for industrial purposes mainly for the production of several different by products, such as fish protein concentrate, fish fertilizer and fish meal. Fish protein concentrate is one of the most important by-product which could be an important food item of the future human diet. It is very rich in protein essential mineral and vitamins. The fish fertilizer increases the quantity of crops. The present study was undertaken to evaluate the food value of edible fishes which are caught as trash on our coast. By proper utilization of protein resources we can solve our problems of malnutrition.
MATERIALS AND METHODS
The crude protein of twenty three edible species form trash were determined by microkjeldahl distillation method (Hawk et al., 1954). In the pre-treatment for protein hydrolyzed analsysis by the reagents like HCl, NaOH and NH4OH were used of A.R. grade (Merck and BDH) and amino acid contents form protein hydrolyzate were analyzed on high speed amino acid analyzer model 835.
RESULTS AND DISCUSSION
A marked variation has been found in protein content of these fishes. It ranged from 42.18 to 65.62%. Among the twenty-three species studies, half of them have protein percentage 40 to 50%.
C. malbaricus (44.06), A. dispar (43.75) J. axillaries (43.7), G. setifer (42.18), R. sarba (42.96), C. indicus (45.62), L. brevirostris (46.87), Pomasays sp. (48.43), G. microlepis (46.87), C. dorab (49.53), L. strongylocephalus (48.43). In six species it varied form 50 to 60% C. sexfaciatus (59.375), J.sina (55.4), A. latus (52.34), C. forskalii (58.59), I. Filigra (52.65) and N. nasus (55.46), while in the rest five species more than 60% protein have been found, O. argenteus (64.06), P. filamentosa (62.5), L. lactarius (65.62), E. hamiltoni (61.25) and S. acutipinnis (61.25) (Table 1).
These results showed that in all these fishes a good quantity of protein is present just like the commercial fishes so they can be safely used in food to supplement protein. The variation in crude protein content have been reported by Qudrat-i-Khuda et al. (1962), Stansby (1962) and Haq et al. (1974) reported the protein of some commercial fishes and trash, they estimated protein value by four different methods i.e by proteolytic the method (78.65%), by alkaline extraction method (79.81%), by aqueous extraction method (84.432%) and by drying method (42.10%). (The variation may be due to difference in species, age, time and region of catch).
|Table 1:||Crude protein of edible fishes of trash (expressed as mg g-1 of dry wt.)|
All amino acids which are shown in Table 2 are detected in T. jarbua, L. brevirostris, Pomadasys sp., L. lactaris, C. dorab, L. strongylocephalus, S. acutipinnis and A. disper. In J. axillaries sp. arginine was not detected, in J. sina and O. argenteus sp. histidine in not detected. In C. forskalii sp. three amino acid, isoleucine, leucine and arginine were not detected. In C. malbaricus sp. methionene tyrosine, histidne and arginine are absent. In C. sexfaciatus sp. the absence of proline, methionine, tyrosine, phenylalanine, histidine and arginine are noted. In P. filamentosa threonine, alanine, valine, isoleucine, histidine and agrinine were not found. In A. latus sp. the absence of glutamic acid, proline, methionine, isoleucine, tyrosine, phenylalanine, histidine and arginine were noted. In R. sarba sp. only five amino acids were detected, aspartic acid, serince gultamic acid, glycine and lysine. Only in one species C. indicus not a single amino acid detected, this may be due to complete spoilage.
Present results indicated that some of the species show low quantity of amino acid. It is due to spoilage of fishes because there is improper handling of trash fish resulting in the absence of some essential amino acid. Due to spoilage the amino acid content decompose into NH3. Those fishes which were not spoiled before procuring have all the essential amino acid and we can place them in high grade protein fishes. If fisherman would have handled and carried the trash fishes properly then all the fishes must have shown a high rate protein and we can use these edible fishes as good sources of protein.
The length of sample fishes (fresh) with their commercial size (Munro, 1955 and Qureshi, 1955) is in Table 3. This comparison showed that all these species of trash were caught and have not attained their normal size fishes. It is a great economic loss to the nation because if these would have been spared form catching, they would have attained marketable size within a small period of time and have been used as human food. In the form to trash avoid these fishes get spoiled due to mishandling and loose their nutritive values.
|Table 2:||Amino acid composition (protein hydrolyzate) of edible fishes of trash (expressed in mg g-1 of dry wt.)|
|Table 3:||A comparison between size of ediable fishes found in (A) trash and (B) found in commercial catch) (Munro, 1995; Qureshi, 1955)|
- Hawk, P.B., B.L. Oser and W.H. Summerson, 1954. Practical Physiological Chemistry. 13th Edn., McGraw Hill Book Co. Inc., New York, USA., pp: 573-575.
- Nwanna, L.C., 2003. Nutritive value and digestibility of fermented shrimp head waste meal by African cat fish Clarias gariepinus. Pak. J. Nutr., 2: 329-334.