15C-4 |
Amino acid composition of a carotenoprotein obtained from fermented and non-fermented shrimp wastes |
R. E. ARMENTA1, I. Guerrero-Legarreta1, and S. Lall2. (1) Departamento de Biotecnología, Universidad Autónoma Metropolitana, Iztapalapa, Apartado Postal 55-535, Mexico D.F., 09340, Mexico, (2) Institute for Marine Biosciences, National Research Council of Canada, 1411 Oxford St., Halifax, NS B3H 3Z1, Canada Large amounts of shrimp wastes are produced along the Mexican Pacific and Gulf seashores representing an important pollution source. Ensilation has been applied to these wastes to retard spoilage. The fermented material can be processed in order to obtain a protein-pigment complex, or carotenoprotein, able to further hydrolysis to obtain astaxanthin, a carotenoid pigment. The protein moiety has also potential applications. The objective of this work was to study the amino acid composition of the carotenoprotein obtained from fermented and non-fermented shrimp wastes. Shrimp wastes were subjected to lactic acid fermentation; the resulting liqueur was centrifuged and concentrated by lyophilization. Acid hydrolysis was performed for 24 h at 110ºC. Pre-hydrolysis oxidation with performic acid was carried out in order to analyze cysteine and methionine whereas basic hydrolysis was applied to determine tryptophan concentration. The hydrolyzed samples were analyzed using and automatic amino acid analyzer. Carotenoproteins from the two types of residues, fermented and non-fermented, were rich in aspartate, glutamate, and essential amino acids such as leucine and lysine (12.8, 14.2, 11.1 and 9.7 mg/g, respectively). Carotenoproteins extracted from fermented residues had higher essential amino acid concentrations (phenylalanine, histidine, threonine and tryptophan at 5.1, 3.2, 5.6 and 3.6 mg/g concentrations, respectively) than those found in non-fermented wastes. Conversely, valine and arginine were higher in non-fermented residues. Isoleucine and methionine concentrations were similar in both types of residues. Shrimp waste can be a good source of amino acids, improving the extraction yield by previously subjecting the residues to lactic fermentation. Carotenoproteins from fermented shrimp wastes represent an added value to the shrimp industry due to presence of a red-orange pigment, astaxanthin, and low ash and chitin content, undesirables in fish nutrition.
Session 15C, Food Chemistry: Food composition and analysis
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