Valorization of waste chicken skin for conjugated linoleic acid (CLA) production: optimization using response surface methodology

The valorization of waste chicken skin fat (WCSF) for conjugated linoleic acid (CLA) production was performed by photoisomerization and optimized the process conditions for high CLA production by response surface methodology. The fat extraction yield from waste chicken skin was approximately 52%. The linoleic acid content of the fat obtained from waste chicken skin was increased by the fractionation process approximately 2 times, up to 52%. Optimum iodine amount and processing time for predicted maximum total CLA amount were determined as 0.87% and 116.36 h, respectively. The maximum total CLA amount was predicted and produced experimentally as 32.14% and 29.01%, respectively. Additionally, iodine amount, processing time, and their interaction significantly affected the amount and variety of produced CLA isomers. The results indicated that dominant isomers produced by photoisomerization of WCSF were trans , trans isomers. However, the amount of cis 9, trans 11 and trans 10, cis 12 CLA isomers could be more increased by optimizing the production parameters. The present study indicated that waste chicken skin could be valorized in CLA production by photoisomerization and obtained high value–added product, and also a more economical and faster CLA production could be realized.