Sensory attribute preservation in roasted sunflower seeds with addition of oregano and Lippia essential oils as natural antioxidants

QUIROGA, P. R.; RIVEROS, C.; GAYOL MF; NEPOTE V; GROSSO NR

Las Vegas, USA

Congreso; IFT Anual Meeting and Food Expo 2012; 2012

Institute of Food Technologists

Oxidation products and rancid flavors decrease sensory quality of food products making them unacceptable for consumers. Synthetic antioxidants such as BHA and BHT are used in many foods to prevent rancidity. However, their health safety is questioned. Natural antioxidants are an alternative. Essential oils are natural compounds and many of them have shown antioxidant activity. The objective of this study was to evaluate the preservation effect on sensory properties of roasted sunflower seeds for the addition of oregano and Lippia essential oils acting as antioxidant additives. Roasted sunflower (RS), roasted sunflower with addition of BHT (RS-BHT), and oregano (RS-O) and Lippia (RS-L) essential oils were prepared. Samples were stored during 35 days at room temperature. Intensity ratings of attributes were measured by descriptive analysis every 7 days. Peroxide value (PV) and p-anisidine value (AV) were also measured. Statistical analysis was performed on the data (ANOVA, LSD test and regression analysis). Oxidized and cardboard flavor intensity ratings increased during storage in all treatments being higher in RS. The intensity ratings of roasted flavor decreased much more in RS during storage. Oxidized flavor slopes in RS-BHT (0.3890) and RS-O (0.4379) were lower than in other treatments. These results indicate that the addition of EOs showed protection in the product inhibiting the formation of undesirable flavor that comes from secondary lipid oxidation process. To confirm this effect, lipid oxidation indicators were also measured during storage. PV and AV increased in all treatments during storage. These indicators were higher in RS. In regression analysis, RS-BHT had the lowest AV slope (0.0937) followed by RS-O slope (0.2923). Oregano EO with respect to Lippia EO showed better antioxidant activity in roasted sunflower seeds preserving its sensory properties and increasing its shelf-life. Industry Relevant Information: The addition of natural additives instead of synthetic ones covers the present trend in food technology. The shelf-life of food product could be prolonged by the addition of natural preservatives as essential oils from aromatic plants. This research showed that the addition of essential oil preserved the intensity ratings of positive attributes in roasted sunflower seeds during storage. The addition of essential oil should be considered for the food industry as a natural source of antioxidant additives for preserving quality properties in food products with high lipid content.