Gelatin production from turkey (Meleagris gallopavo) skin as a new source: from waste to a sustainable food gelling agent.

BACKGROUND: Turkey skin, a byproduct of poultry processing, contains a significant amount of collagen that might be used to make non-mammal gelatin. However, gelatin production from turkey skin has not yet been investigated. The present study aimed to determine the optimum gelatin extraction conditions from turkey employing the central composite design and response surface methodologies. The independent factors such as temperature (50, 60, and 70 °C) and time (5, 7, and 9 h) were optimized for three response variables: yield, gel strength, and foam expansion (FE). RESULTS: With R2 values of 0.8576 for yield, 0.8386 for gel strength, and 0.9283 for foam expansion, linear, quadratic, and respective models were used. The yield, gel strength, and FE actual values were found to be 15.36%, 396.61 g, and 40%, respectively. The optimum extraction conditions were found to be 62.90 °C for 6.84 h. The foam stability, L, and b values were significantly impacted by temperature and extraction time (P < 0.05). CONCLUSION: The gel strength value of the gelatin extracted under optimal conditions was higher than that of commercial bovine. The findings of the present study showed that turkey skin is a suitable raw material for the manufacturing of gelatin. © 2023 Society of Chemical Industry.

Textural, rheological, and structural properties of turkey and chicken gelatins from mechanical deboning residues.

Large amounts of collagen-rich by-products are generated in poultry processing. In particular, gelatin from the by-products of turkey processing is limited. Gelatin extraction from turkey and chicken MDRs (mechanically deboning residue) was the purpose of this study. Both materials were modified at the highest swelling pH for chemical denaturation of collagen and hot water extraction of gelatin was performed at the optimum temperature-time, which was determined to be pH 1.0 and 80°C-6 h, respectively. In these conditions, yields of 9.90% turkey gelatin (TG) and 13.85% chicken gelatin (CG) were produced. They demonstrated similar viscosity, gel strength, and lightness values of 72-73 g, 2.5-2.7 mPas, and 31, respectively. These results are close to those of bovine gelatin (BG). TG with 239.78 g Bloom exhibited higher strength than CG (225.27 g) and BG (220.00 g). The melting and gelation temperatures of CG and BG were 21 and 30°C, respectively, while those of TG were 19 and 28°C. Imino acids (proline + hydroxyproline) of TG (22.82%) were higher than those of CG (20.73%). Fourier transform infrared spectroscopy (FTIR) analysis revealed secondary structure and functional groups of CG and TG similar to those of BG. CG displayed a higher thermal transition temperature than BG, while TG exhibited the highest temperature sensitivity, according to the differential scanning calorimetry (DSC) analysis. In conclusion, TG showed higher potential for effective utilization with higher bloom and imino acids. Overall, turkey and chicken MDRs are a promising and potential alternative source to produce gelatin with comparable properties to bovine gelatin for intended food applications as well as for pharmaceutical and cosmetic fields.