Valuation of Goat and Sheep By-Products: Challenges and Opportunities for Their Use

SIMPLE SUMMARY: Goat and sheep by-products are the source of many healthy and biologically active compounds that have significant potential to provide new and valuable food ingredients. However, the lack of data on these small ruminants and their undervaluation challenges the community to determine the best way to use this resource. This review highlights challenges and opportunities regarding the use of goat and sheep by-products in many different food applications. Although these by-products undoubtedly present themselves as a rich source of nutrition and allow the elaboration of many dishes, and the development of several technological applications, it is still necessary to investigate their potential use for the extraction of bioactive components, through obtaining peptides from the hydrolysis of proteins that have different biological and technological properties, in addition to the hydrolyzed use of these by-products as precursors for the production of flavorings. ABSTRACT: Goat and sheep meat production is a challenge for the meat industry as well as for environmental management. Yet within cultures, certain by-products, such as liver, the lungs, heart, brain, spleen, blood, tail and ears, are traditionally used in the production of typical dishes for regional or local cuisine. These by-products are a rich source of lipids, proteins, essential amino acids, B-complex vitamins, and minerals. They can be effectively exploited for higher (value-added) applications, including functional foods or feed ingredients, food supplements, enzymes and other chemical products such as hydrolyzed proteins and flavorings. This review article gathers data on: (i) the production of by-products obtained from slaughter and available for processing, and (ii) potential strategies for using and applying these by-products in obtaining new value-added ingredients. Other than proteins, the review discusses other macromolecules and possible uses of these by-products in culinary dishes, as hydrolyzed enzymes, and as food additives. Even though these by-products undoubtedly present themselves as rich in nutrients, there remains an unfortunate lack of documented information on the potential use of these by-products for their bioactive components, peptides that have various biological and technological properties, and the use of hydrolyzed versions of these by-products as precursors for the production of flavorings.