Resistance of Nile tilapia leather subjected to pickling with different salt concentrations and exposure times of skins in salt-free water Marcos Antonio Matiucci, Stefane Santos Corrêa, Maria Luiza Rodrigues de Souza Acta Veterinaria Brasilica, 2025 The skins discarded during the filleting process, when subjected to an appropriate tanning process, can be transformed into high-quality leather. Thus, the objective of this study was to analyze the effect of salt concentration and acid swelling as a function of the exposure time of Nile tilapia skins acidified in salt-free water. To this end, three tests were conducted: Test I – Evaluation of pickled skins; Test II – Evaluation of the effect of salt concentration in the pickling stage; and Test III – Evaluation of the effect of pickled skins at different exposure times in salt-free water. The removal of acidified skins to salt-free water promotes acid swelling, which can significantly reduce the leather’s resistance, tear strength, elongation, and tensile strength. A salt concentration below the recommended level leads to acid swelling, while an excessive concentration prevents proper tanning, resulting in collagen fiber densification. Regarding the exposure time of skins in salt-free water, significant losses in their properties were already observed after ten minutes. It is concluded that salt is essential in the pickling stage, requiring a Baumé degree of 7. Skins should not be exposed to a salt-free solution to prevent acid swelling, which compromises their resistance quality. Exposure to salt-free water can reduce elasticity, tensile strength, and progressive tearing, regardless of the exposure duration.
Characterization of fillets and skins from two varieties of genetically improved farmed Nile tilapia (Oreochromis niloticus) Vinicius José Campos, Eliane Gasparino, José Wellington Rodrigues Lima Júnior, Angélica de Souza Khatlab, Marisa Silva Bastos, et al. Plos One, 2025 Genetically improved farmed tilapia (GIFT) is a strain of Nile tilapia (Oreochromis niloticus) developed for improved production and commercial parameters. Skin color, one of the characteristics distinguishing tilapia varieties, is an important phenotypic trait associated with qualitative and productive performance. This study aimed to assess fillet and skin characteristics in GIFT Nile tilapia with black and red skin phenotypes. For this, 24 GIFT Nile tilapia from the same spawning stock were divided into two groups based on skin color, namely a black variety (dark skin) and a red variety (reddish skin). There were no significant differences in biometric parameters between varieties. Fish of the red variety had higher 2 h post-slaughter pH and muscle antioxidant capacity and lower yellow-blue axis value (b*), luminosity (L*), thawing loss, cooking loss, and conjugated diene content (P < 0.05). The skin of black tilapia exhibited higher force in the progressive tear test tear, and higher strength, tensile strength, deformation, and elongation in the traction and stretching test than that of red tilapia. Black tilapia skin had higher collagen and hydroxyproline contents. The skin of the red variety exhibited higher expression levels of alpha 1, 2, and 3 type I collagen genes, lower expression levels of the vimentin gene, and higher antioxidant capacity. The results suggest that skin color phenotype may be linked to important metabolic pathways influencing fish fillet and skin traits. These findings can support future research aimed at identifying optimal varieties of Nile tilapia for specific purposes and optimizing the utilization of filleting waste.
Preparation of Nile tilapia (Oreochromis niloticus) waste meal for human consumption Maria Luiza Rodrigues de Souza, Ana Paula Sartorio Chambo, Bruna Albino Bronharo, Ricardo Souza Vasconcellos, Angélica de Souza Khatlab, et al. Ciencia Rural, 2024 This study aimed to prepare and characterize Nile tilapia (Oreochromis niloticus) waste meal. The experimental design consisted of three treatments (carcass meal, mechanically separated meat meal - MSM, and head meal) and five replications of each treatment. Yield, microbiological quality, pH, water activity, proximate composition, energy value, mineral composition, fatty acid profile, amino acid composition, color, and particle size fractions and the geometric mean particle diameter (GMD) analyses were performed. Data were subjected to ANOVA, and means were compared by Tukey’s test at P < 0.05. Carcass, mechanically separated meat, and head meals had a protein content of 56.45%, 78.60%, and 50.33%, respectively, a lipid content of 7.16%, 13.15%, and 4.58%, respectively, and an ash content of 32.61%, 4.26%, and 38.41%, respectively. The mean yield of fish waste meals was 13%. Oleic, palmitic, and linoleic acids were the major fatty acids in the three fish waste meals, and glutamic acid, leucine, lysine, and glycine were the major amino acids. Color analysis showed that lightness (L*) ranged from 55.32 to 77.19, redness (a*) from 4.44 to 4.88, and yellowness (b*) from 4.13 to 9.51. The GMD ranged from 0.37 to 0.99 mm. The results indicate that Nile tilapia waste meals have high nutritional value and adequate pH, water activity, and microbiological quality for use in human nutrition.
Use of Nile tilapia (Oreocromis niloticus) processing residues in the production of pâtés with the addition of oregano (Origanum vulgare) essential oil Marcos Antonio Matiucci, Iza Catarini dos Santos, Natallya Marques da Silva, Patricia Daniele Silva dos Santos, Gislaine Gonçalves Oliveira, et al. Plos One, 2023 The effect of the use of Nilo tilapia filleting residues in the production of pâtés with the addition of oregano essential oil stored for 90 days at 4 °C was evaluated. For that, 5 treatments were performed as follows: TSA—control treatment; TES with the addition of sodium erythorbate; and formulation TOE1 with 600 ppm oregano essential oil; TOE2 with 1000 ppm essential oil; and TOE3 with 1400 ppm essential oil. The pâtés showed adequate technological and physicochemical characteristics and microbiological counts within the legislation standards. No significant differences were observed in the luminosity of the pâté formulations during storage, and the addition of oil contributed to the increase in a* values and stability of b* values. Regarding the lipid and protein oxidation, TOE3 showed lower values at the end of the shelf-life. The addition of essential oil did not affect the hardness and cohesiveness of the products. The fatty acids in greater amounts in the samples were linoleic, oleic, palmitic, and stearic acids. The analysis of biogenic amines indicated that only the treatments with the highest amounts of sodium erythorbate (TES and TOE1) showed losses of spermidine. It was observed that decreasing the inclusion of sodium erythorbate and increasing the inclusion of oregano essential oil resulted in a drop in cadaverine values. A total of 46 volatile compounds were detected in the samples with the highest amount of free fatty acids and all the formulations were well accepted sensorially.
Proximate composition, energy value, and lipid quality in loin in different weight classes of pirarucu (Arapaima gigas) from fish farming Ana Sabrina Coutinho Marques Rocha, Sheyla Cristina Vargas Baldi, Maria Luiza Rodrigues de Souza, Bruna Laurindo Rosa, Emerson Carlos Soares e Silva, et al. Boletim do Instituto De Pesca, 2023 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.
Quality of Oreochromis niloticus and Cynoscion virescens fillets and their by-products in flours make for inclusion in instant food products Stefane Santos Corrêa, Gislaine Gonçalves Oliveira, Melina Coradini Franco, Eliane Gasparino, Andresa Carla Feihrmann, et al. Plos One, 2023 The production of fish flour is an alternative for better use of the raw material, although it is rarely used in instant food. Thus, the aimed of this study was to evaluate Oreochromis niloticus (Nile tilapia) and Cynoscion virescens (croaker) fillets and the elaboration of flour with filleting by-products for inclusion in food products. Carcasses and heads of the two fish species were cooked, pressed, ground, subjected to drying and re-grinding to obtain standardized flours. These carcass flours were seasoned (sweet and salted). This study was organized into two experimental tests: Test 1: Yield, physicochemical and microbiological analyzes of fillets and flours made from carcass and head of Nile tilapia and croaker; Test 2: Seasoned flours made from Nile tilapia carcasses. There was a difference in fillets yield, where the croaker demonstrated 46.56% and the Nile tilapia 32.60%. Nile tilapia fillets had higher protein content (17.08%) and lower lipid content (0.89%) compared to croaker fillets (14.21 and 4.45%). Nile tilapia backbone flour had the highest protein content (55.41%) and the croaker the highest ash (45.55%) and the lowest Nile tilapia (28.38%). The head flours had lower protein contents (39.86%). Flours produced with croaker backbone had higher levels of calcium and phosphorus (9.34 and 9.27%). However, Nile tilapia backbone flour showed higher contents of essential amino acids. These flours demonstrated a fine granulometry (0.23 to 0.56 mm). Seasoned flours demonstrated interaction between fish species and flavors for moisture, ash, carbohydrates, calcium and phosphorus. The highest protein content (29.70%) was for Nile tilapia flour sweet flours (31.28%) had higher protein content, while salted lipids (8.06%). Nile tilapia has a lower fillet yield, although with a high protein content and low lipid content. Comparing the flours made from filleting by-products, the backbone flour has better nutritional quality, with Nile tilapia being superior to that of croaker, especially in terms of protein and amino acids.
Temperature, pH and sarcomere length of Caiman yacare in different body weight categories at slaughter Melina Franco CORADINI, Gislaine Gonçalves OLIVEIRA, Sabrina Campos SBARAINI, Fernanda Losi Alvez de ALMEIDA, Maria Luiza Rodrigues de SOUZA Revista Brasileira De Saude E Producao Animal, 2023 The objective of this work was to characterize the internal temperature of the carcass, pH and sarcomere length in four categories of body weight at a slaughter. The categories were: category 1, animals up to 1.5 kg, category 2, animals from 1.501 to 2.5 kg, category 3, animals from 2.501 to 3.5 kg and category 4, animals over 3.501 kg. The time intervals evaluated were 0.5, 2, 4, 6, 8, 10, 12, 14, 16, 18, 24 and 36 hours after bleeding, therefore, a factorial scheme (4 x 12) was used, in which where four categories of pre-slaughter weight and the behavior of the carcasses during the post-slaughter time were evaluated. There was no interaction effect between the weight categories and the time for the variation of the carcass internal temperature, pH and sarcomere length, but when only the time of rigor was evaluated, there were significant differences for the analyzed parameters. The internal temperature of the initial average carcass (0.5 hours) was 16.02°C, reaching 3.80°C at 36 hours post-slaughter. In addition, the lowest average pH found was at 24 hours, with a value of 5.39. Regarding the sarcomere length, the smallest mean length observed was 1.41 µm at 16 hours post-slaughter and the final mean length (36 hours) was 1.89 µm. It was concluded that the analyzed margin of the categories of body weight at slaughter did not interfere in the variation of temperature, pH and sarcomere length during the post-mortem of the Pantanal caiman.
Elaboration of pâté using fish residues Marcos Antonio Matiucci, Ana Paula Sartório Chambo, Jane Martha Graton Mikcha, Suzana Maria da Silva Réia, Kelly Cristina Vitorino, et al. Acta Veterinaria Brasilica, 2021
Preparation of lasagnas with dried mix of tuna and tilapia Katia Setsuko KIMURA, Maria Luiza Rodrigues de SOUZA, Eliane GASPARINO, Jane Martha Graton MIKCHA, Ana Paula Sartorio CHAMBÓ, et al. Food Science and Technology Brazil, 2017
Addition of different tuna meal levels to pizza dough Daniel Abreu Vasconcelos Campelo, Universidade Estadual de Maringá, Brazil, Maria Luiza Rodrigues de Souza, Lorena Batista de Moura, Tadeu Orlandi Xavier, et al. Brazilian Journal of Food Technology, 2017
Extruded snacks with the addition of different fish meals Elenice Souza dos Reis GOES, Maria Luiza Rodrigues de SOUZA, Daniel Abreu Vasconcelos CAMPELO, Grazyella Massako YOSHIDA, Tadeu Orlandi XAVIER, et al. Food Science and Technology Brazil, 2015
Sensorial analysis of soups and broths made by smoked fish carcasses meal: Its utilization to supplement school meals Ciencia E Tecnologia De Alimentos, 2010
Influence of Processing Method and Weight Categories on Carcass, Fillet and Skin Yield of Nile Tilapia (Oreochromis niloticus) Revista Brasileira De Zootecnia, 1999
