Stability and Antioxidant Activity of Annatto (Bixa orellana L.) Tocotrienols During Frying and in Fried Tortilla Chips

Abstract

Annatto tocotrienols (AnT3), which contain approximately 90% δ‐tocotrienol (δ‐T3), were added to mid‐oleic sunflower oil used for frying tortilla chips over 3 d. The objectives were to evaluate their stability during frying, absorption by the fried food, and activity as antioxidants in frying oil and in tortilla chips during storage. AnT3 did not significantly affect the stability of the oil during frying or the sensory profiles of freshly fried chips. The naturally present α‐tocopherol (α‐T) in the oil degraded at a lower rate in the presence of AnT3, resulting in significantly higher α‐T by the end of the frying study. Levels of tocopherols and tocotrienols in the chips mirrored oil levels. AnT3 did not affect the sensory profile of the chips after 1 wk of storage at 50 °C, but after 3 wk of storage, the control chips had higher levels of painty and rancid flavors compared to chips with AnT3. Headspace hexanal was also significantly higher in the control chips compared to the chips with AnT3 after 3 wk of storage.

Annatto tocotrienols, containing primarily delta‐ and gamma‐tocotrienols, were added to mid‐oleic sunflower oil used for frying tortilla chips. The tocotrienols were absorbed by the chips along with the oil. They slowed the degradation of α tocopherol during frying, and reduced levels of painty and rancid flavor scores as well as headspace hexanal in chips that were stored for 3 wk at elevated temperatures. The results indicated that fried snack foods such as tortilla chips may be a suitable and convenient vehicle for enriching tocotrienols in the diet, and that tocotrienols may also enhance the shelf‐life of fried foods.