Accepted Article Hydroxytyrosol extracts, olive oil and walnuts as functional components in chicken sausages Gema Nieto*, Lorena Martínez, Gaspar Ros (1)Department of Food Technology, Nutrition and Food Science, Veterinary Faculty, University of Murcia, Campus de Espinardo, 30100 Espinardo, Murcia, Spain. *Corresponding author: Gema Nieto, Tel.: +34-868884798. Fax: +34-868884147 E-mail address: gnieto@um.es Abstract BACKGROUND: Olive oil, hydroxytyrosol and walnut can be considered ideal Mediterranean ingredients for their high polyphenolic content and healthy properties. Three extracts of hydroxytyrosol obtained using different extraction process (HXT 1, 2, 3) (50 ppm) were evaluated for use as antioxidants in eight different chicken sausage formulas enriched in polyunsaturated fatty acids (2.5 g/100 g walnut) or using extra virgin olive oil (20 g/100 g) as fat replacer. Lipid and protein oxidation, colour, emulsion stability, and the microstructure of the resulting chicken sausages were investigated and a sensory analysis was carried out. RESULTS: The sausages with HXT extracts were found to decrease lipid oxidation and to lead to the loss of thiol groups compared with control sausages. Emulsion stability (capacity to hold water and fat) was greater in the sausages containing olive oil and walnut than in control sausages. In contrast, the HXT extracts produced high emulsion instability (increasing cooking losses). Sensory analysis suggested that two of the HXT extracts studied (HXT 2 and HXT 3 ) were unacceptable, while the acceptability of the other was similar to that of the control products. Sausages incorporating HXT showed different structures than control samples or sausages with olive oil, related to the composition of the emulsion. CONCLUSION: These results suggest the possibility of replacing animal fat by olive oil and This article is protected by copyright. All rights reserved. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/jsfa.8240