Aquaculture of Pacu (Piaractus mesopotamicus) and a Comparison of its Quality: Microbiological, Sensory, and Proximate Composition
Sharma V. S. Pullela
Master's Thesis submitted to the Faculty of the Virginia Tech
in partial fulfillment of the requirements for
the degree of
Food Science and Technology
Dr. George J. Flick, Jr., Chair
Dr. Custodio F. Fernandes
Dr. George S. Libey
Dr. Stephen A. Smith
Dr. Charles W. Coale, Jr.
February 3, 1997
(Piaractus mesopotamicus) initially weighing 72.0 g were fed three diets - a) 0.5% vegetable (zucchini), b) commercial 32% (P32) and c) commercial 36% (P36) protein diets for 24 weeks and their growth performance compared. Processing yields and proximate composition were determined following dressing of pacu. The microbiological quality of pond cultured pacu was compared to aquacultured hybrid striped bass, tilapia, and rainbow trout grown in pond and recirculating aquaculture systems. Sensorial analyses for differences in flavor, preference, and color were also determined. Protein concentration significantly influenced the weights, lengths, specific growth rate, feed conversion ratio, and protein efficiency ratio (p < 0.05). Diet insignificantly influenced the processing yields (p > 0.05). The moisture, protein and total lipid contents were significantly affected (p < 0.05) by the dietary protein. The indicative bacterial quality differed significantly for pacu as well as the water used for culturing pacu (p < 0.05) among dietary treatments. Aquaculture production systems significantly influenced the indicative and pathogenic bacterial quality. Listeria monocytogenes, Salmonella spp., Yersinia enterocolitica, and Escherichia coli O157:H7 were not isolated from any of the sampled fish. The qualitative and quantitative results of Clostridium botulinum were influenced by the production system (p < 0.05). Flavor of pacu was comparable to that of hybrid striped bass, tilapia, and rainbow trout, but superior to catfish. Cooking significantly improved the color of the ground fish fillets.