Rosemary as antioxidant in pressure processed chicken during subsequent cooking as evaluated by electron spin resonance spectroscopy Neura Bragagnolo a , Bente Danielsen b , Leif H. Skibsted b, ⁎ a Department of Food Science, State University of Campinas, P.O. Box 6121, 13083-970, Campinas, SP, Brazil b Food Chemistry, Department of Food Science, The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958, Frederiksberg C, Denmark Received 8 August 2005; accepted 30 April 2006 Abstract The potential of rosemary (Rosmarinus officinalis L.) to inhibiting lipid oxidation in minced chicken breast and thigh muscle processed at 600 MPa for 10 min during subsequent heat treatment was investigated using electron spin resonance (ESR) spectroscopy and electrochemical detection of oxygen consumption. Chicken breast cooked at 95 °C was found to have significantly higher rate of formation of free radicals and oxygen consumption rate than the samples cooked at 70 °C and 120 °C and this intermediate cooking temperature was used to evaluate the effect of pressure on oxidation during subsequent cooking. Rosemary was found effective in retarding lipid oxidation since the pressurized, minced chicken breast and thigh with rosemary added showed lower rate of oxygen consumption and lower tendency of free radical formation following heat treatment than the samples without rosemary. Pressurized chicken thigh showed a higher susceptibility to oxidation than chicken breast upon subsequent heat treatment. Oxidation in pressurized and subsequently heat-treated chicken breast was from a higher tendency of radical formation concluded to be in an earlier phase of oxidation compared to thigh subjected to the same treatment. © 2006 Elsevier Ltd. All rights reserved. Keywords: Chicken breast and thigh; Rosemary; High-pressure processing; ESR; Oxygen consumption; Lipid oxidation Industrial relevance: High-pressure processing has a great potential for microbial control of raw chicken meat as a “fresh” chill-stored, convenience product for wok cooking. While raw chicken meat is oxidatively stable, high-pressure treatment at 600 MPa and above induces lipid oxidation resulting in off-flavors during subsequent cooking. Addition of 0.1% dried rosemary to minced chicken thighs or breasts prior to high- pressure processing inhibit lipid oxidation during subsequent cooking and could form the basis for product development. 1. Introduction Pre-cooked and refrigerated ready-to-eat meat products are getting a larger marked share as an increasing number of con- sumers purchase convenience foods that do not require extensive home preparation. Chilled raw meat is usually oxidatively stable, but mincing, cooking and other processing prior to refrigerated storage disrupt muscle cell membranes facilitating the interaction of unsaturated lipids with prooxidant substances such as non- heme iron, accelerating lipid oxidation leading to rapid quality deterioration and development of rancidy (Tichivangana & Morrissey, 1985). Poultry develop very easily rancidity and warmed-over-flavour as poultry fat is highly unsaturated and often has low content of tocopherols. Extensive investigations in the last decade have revealed the potential of high-pressure processing for the preservation of meat since the microbial load is reduced prolonging the storage life during subsequent chilled storage (Cheftel & Culioli, 1997). On the other hand, high-pressure treatment of meat and meat products are initiating oxidative processes, and 500 MPa was found to be critical as working pressure for processing of chicken breast, as higher pressure results in development of rancidity (Orlien, Hansen, & Skibsted, 2000). Beltran, Pla, Yuste and Mor-Mur (2004) likewise found that oxidation was not enhanced in minced chicken breast treated at 500 MPa. In contrast, a significant increase in secondary lipid oxidation products was observed in chicken breast upon subsequent cooking for high-pressure treatment at 600 MPa (Wiggers, Kröger-Ohlsen, & Skibsted, 2004). Innovative Food Science and Emerging Technologies 8 (2007) 24 – 29 www.elsevier.com/locate/ifset ⁎ Corresponding author. Tel.: +45 3528 3221; fax: +45 3528 3344. E-mail address: ls@kvl.dk (L.H. Skibsted). 1466-8564/$ - see front matter © 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.ifset.2006.04.005