Elaboração e caracterização de gelatina de bexiga natatória de robalo (Centropomus undecimalis)

• Ano de defesa: 2021
• Autor(a) principal: Pinheiro, Leina Maria Herculano Maia
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Pescado; Colágeno; Proteína; Hidrocolóide; Parâmetros de qualidade; Aplicações em alimentos
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/66211

The development of fish gelatine is an alternative to reduce the waste generated by the fishing industry, thus minimizing environmental impacts. In addition, it presents a quality similar to those of bovine origin (most used in the industry), as well as pork and poultry. However, few studies have evaluated the influence of the gelatine production process on its final properties (gel strength, melting point, gelling point and viscosity). The gelatins were extracted from sea bass swim bladder using 0.5 M acetic acid at five time and temperature combinations: 4 °C for 24 h (T1), 24 °C for 48 h (T2), 4 °C for 24 h (T3), 24 °C for 48 h (T4) and 14 °C for 36 h (T5). The gelatins were lyophilized and characterized by yield, proximate composition, energy value, particle size, pH, turbidity, color, rheological properties (gel strength, viscosity, gelling point and melting point), thermogravimetric analysis, differential scanning calorimetry, spectroscopy in infrared by Fourier transform, scanning electron microscopy, amino acid profile and listed for use in various types of food applications. Yields ranged from 11.63% to 31.23%. The proximate composition indicated great potential for collagen extraction, with protein contents above 84%. The energy value ranged from 3.52 to 3.81 Kcal/g. Sea bass gelatins had a particle size of 8 mesh, while the commercial bovine gelatine had 10 mesh. The color parameters L*, a* and b* indicated that the gelatins tended to light yellow and were lighter than the control (commercial bovine gelatin). The pH ranged from 4.24 to 4.91. Turbidity ranged from 38.00 %T to 85.07 %T while gel strength was rated as high bloom for all gelatins. The viscosity ranged from 5.11 cP to 35.61 cP. The melting and gelling point temperatures of gelatins solubilized in distilled water (6.67%) were 25.83 °C to 28.67 °C and 17.80 °C to 24.67 °C, respectively, where it was observed that T5 gelatin had the highest values. For the Dunnett test, the control used was commercial bovine gelatin. The FTIR spectra of the gelatins obtained revealed the presence of all bands (Amide A, B, I, II and III). The morphologies of the gelatins showed a lamellar shape. The DSC thermograms showed that the melting points of freeze-dried gelatins occurred at temperatures from 23.6 °C and the TGA/DTG thermograms showed the presence of three endothermic events, all of which showed good thermal stability. Principal component analysis showed that extraction using 36 h at 14 °C (T5) was crucial for obtaining the best rheological characteristics (viscosity, melting points and gelling). The amino acid composition for gelatin with better rheological characteristics (T5) ranged from 0.21 g/100 g to 23.84 g/100 g, with a predominance of glycine. Sea bass swim bladder gelatins showed their potential for industrial production and for using in various food applications, such as desserts in general, chocolates, yogurts and others