Quality Index Method (QIM) for the hybrid tambacu (Colossoma macropomum × Piaractus mesopotamicus) and the correlation among its quality parameters

Aquaculture in Brazil is favoring the native species with zootechnical potential that are well accepted by consumers and potentially and economically viable for aquaculture. The tambacu hybrid is widely cultivated in Brazilian aquaculture. The objective of this study was to estimate the shelf life of the freshwater species tambacu (Colossoma macropomum × Piaractus mesopotamicus), gutted and ice-stored, by correlating physical, chemical, sensory and bacteriological analyses, and to develop a Quality Index Method (QIM) scheme to assess the freshness of this species. Bacteriological analysis (mesophilic and psychrotrophic counts), physical and chemical analyzes (pH, total volatile base nitrogen (TVB-N) index acidity, peroxide index, thiobarbituric acid-reactive substances (TBARS), instrumental color and texture) and the development of the Quality Index Method the tambacu gutted and stored on ice were performed. Principal component analysis (PCA) was used for interpreting physical, chemical and bacteriological quality parameters and partial least squares (PLS) regression was used for correlating the QIM attributes. The resultant QIM scheme has a total of 26 demerit points, where 0 indicates total freshness. This study suggests that gutted tambacu is fit for human consumption during the first 11 days of ice storage.