This book discuss the utilization of olive mill wastes (olive pomace) and tomato processing wastes (tomato pomace) and was conducted to investigate the following aspects: The possibility of extracting of some functional compounds (e.g. phenolics, carotenoids and flavonoids) from olive and tomato pomace. Identification of these functional compounds and determination by different methods. Effect of gamma irradiation on efficiency of extraction process of functional compounds. Studying the antimicrobial activity of extracts against some microbial strains. Evaluation of antioxidant activity of extracts comparing to some synthetic antioxidant. Application of these extracts in some plant oils and meat product.