The aimed of the study was to evaluate the caloric value as a function of the proximal composition and correlate the selling price with the nutritional values ​​of commercial cuts of tambaqui (Colossoma macropomum) and pirarucu (Arapaima gigas) in different weight classes. The sample collections were performed in two processing units located in the state of Rondônia, Brazil. Were 200 tambaquis in five weight classes were studied. And, were 77 pirarucus were studied in seven weight classes. The design was completely randomized, with processing carried out in triplicate. The Kruskal-Wallis test (α=0.05) was used to compare the averages and the Spearman correlation (ρ) between price and nutrients. The commercial cuts with the highest caloric value were the tambaqui filet (145.70 kcal/100g) and the pirarucu filet mignon (119.11 kcal/100g) (p<0.05). And the less caloric commercial cuts were steak of tambaqui (100.47 kcal/100g) and pirarucu loin 102.01 kcal/100g) (p<0.05). It was also observed that the variables caloric value and protein content did not correlate with the price of the kilo of fish for the different commercial cuts, which leads to infer that, possibly, the sensorial, market and cultural factors were responsible for the price variations. Regarding the caloric value according to the composition of the tambaqui, the Class 4 was the most efficient category for production and commercialization. And in the composition of the pirarucu, the Class 4 presented satisfactory values of proteins and lipids and a good percentage of mineral matter.

The aimed of this study was to evaluate the mineral composition in commercial cuts of tambaqui (Colossoma macropomum) and pirarucu (Arapaima gigas). Were compared to the minimum values of daily consumption of minerals recommended by the World Health Organization (WHO). The experimental design was completely randomized, with processing performed in triplicate. Data were submitted to ANOVA. If ANOVA appeared statistically significant (α=0.05), the means were compared by Tukey's Test. There was a difference (p<0.05) between commercial cuts of the tambaqui for different minerals. Tambaqui ribs and band presented the highest values of total iron 1.08 ± 0.12 mg/100g compared to other commercial cuts. The mineral elements Na+, K+, Ca2+ and Mg2+ expressed the highest values for the tambaqui steak, 301.00 ± 80.58, 457.00 ± 129.33, 36.00 ± 4.36 and 46.90 ± 4.68 mg/100g, respectively. There was a difference (p<0.05) between commercial cuts of the pirarucu for different minerals. The mineral elements Total Iron, Na+, K+ and Ca2+ expressed the highest values for pirarucu loin, 0.80 ± 0.07, 406.00 ± 117.50, 529.30 ± 130.58 and 32.00 ± 5.12 mg/100g, respectively. However, Mg2+ expressed a higher value for pirarucu tail fillet 37.10 ± 4.99 mg/100g. The tambaqui steak and pirarucu loin were the cuts that best met the minimum needs for mineral supply.

The study aimed to determine the fatty acid profile, omegas and lipid quality indeces in commercial cuts of pirarucu (Arapaima gigas) of the slaughter class 11.1 to 14.0 kg. Sample collections were carried out in two fish processing industries located in Rondônia state, Brazil. The experimental design was completely randomized, with processing performed in triplicate. Data were submitted to ANOVA to assess differences between commercial cuts in chemical compositions. If ANOVA appeared statistically significant (α=0.05), the averages were compared by Tukey's test. In the composition of fatty acids, there was a difference (p <0.05) between cuts. Commercial cuts that expressed the highest percentages of SFAs tail fillet 51.2%, of MUFAs fillet mignon 39.8% and of PUFAs deboned cut 20.7%. The indeces prescribed for lipid quality, ∑PUFAs/∑SFAs, ∑PUFAs (n-6/∑n-3), AI, TI and HH, indicate that commercial cuts have lipid quality. Deboned is the cut with the highest PUFA fatty acid content, with the highest values of Omega 3, 6, 7 and n-9 being also expressed. Nutritional information is important for the processes of conservation and processing, development of new products on the market, as well as guiding the form of preparation, thus providing commercial security for different market niches.

The aim of this study was to evaluate the influence of different stunning methods on the meat quality of Arapaima gigas fillets from fish farming. A total of 48 specimens of A. gigas in the weight class 11.1 to 14.0 kg were investigated; these fish were subjected to different stunning methods for slaughter: ice asphyxia (IA), air asphyxia (AA), electronarcosis (EE) and hypothermia followed by bleeding (HB). Then, data were obtained from the analysis of pH, rigor mortis index (RI), water activity (Aw), instrumental texture (compression strength, firmness and adhesiveness) and blood glucose and via instrumental colourimetry. During the study, for up to 15 days of refrigerated storage, the methods provided pH values below 6.0. A. gigas submitted to EE and HB remained longer in the pre-rigor status. In addition, they expressed lower percentages of Aw. The EE method resulted in better texture assignments in the fillets. The blood glucose values indicated that the fish subjected to EE were less stressed. Concerning instrumental colourimetry, the fillets submitted to EE and HB showed greater luminosity; the fillets subjected to AA showed greater red-green colour intensity, while the fillets subjected to EE showed greater yellow-blue colour intensity. Therefore, the fish did not suffer stress with electronarcosis, and the fillets showed better preservation, juiciness, and tenderness.

The study aimed to determine the fatty acids profile, omegas, and lipid quality in loin in different weight classes of pirarucu (Arapaima gigas). A total of six pirarucu loin samples were used and sent to the laboratory by weight class, 1 (< 8 kg), 2 (8.1 to 11 kg), 3 (11.1 to 14 kg), 4 (14.1 to 18 kg), 5 (18.1 to 23 kg), 6 (23.1 to 32 kg), and 7 (> 32 kg). The experimental design was completely randomized, with processing conducted out in triplicate. Data were submitted to analysis of variance (ANOVA) to assess differences in pirarucu loin between weight classes. When ANOVA was statistically significant (α = 0.05), the averages were compared using Tukey’s test. Weight class 7 showed higher values of mineral matter = 1.43, crude protein = 28.93, and energy = 526.35 KJ∙100g-1. However, weight class 2 showed a higher value of total lipids, 2.60, and moisture, 78.19. The pirarucu loin showed essential fatty acids, EPA, DHA, AA, and ALA, while weight classes 4 and 5 had the highest percentages of PUFAs. However, all weight classes expressed high values in omegas 3, 6, 7, and 9. There is no need to market heavier fish, as pirarucu loin in lighter weight classes 3 and 4 already meet the nutritional demand of the market.

The tropical fish are a food source rich in nutrients, including proteins of high biological value. The fish is present in society's eating habits due to its numerous benefits. Therefore, it is important to know the nutritional components present in the musculature of the fish, this will promote its commercialization and reach more demanding markets, in addition to promoting public health and well-being through its regular consumption. The aimed of this study was to evaluate the chemical composition of commercial cuts of pirarucu (Arapaima gigas) processed in different weight classes. The sample collections were carried out in fish processing units in the state of Rondônia, Brazil. The data were obtained from 77 fish in five weight classes and their commercial cuts evaluated for chemical composition. The Kruskal-Wallis test (α=0.05) was used to compare the averages. The crude protein content of filet mignon increased (p0.05) between the weight classes for mineral content and total lipids. The total lipid levels did not vary between weight classes (p>0.05). The moisture content decreased with increasing body weight. Among the weight ranges with good commercialization, class 4 stands out (14.1 to 18 kg). Among the weight ranges with good commercialization, class 4 (14.1 to 18 kg) stands out, since it presented satisfactory values ​​of proteins and lipids and a good percentage of mineral matter. In other words, it was the most efficient category for production and marketing.