Investigation of antioxidants to extend foodservice oil fry life

Abstract: The desire for improved frying oil performance has been intensified due to global high oleic oil shortages. Some companies sell oil containing antioxidants claiming a longer fry life. Antifoam, such as dimethylpolysiloxane or (DMPS), is typically added to foodservice frying oils. Prior Cargill testing and expertise suggests antioxidants may not improve oil life beyond DMPS addition. The objective of this research was to identify commercially available non-synthetic antioxidant systems which can further extend foodservice frying oil life beyond DMPS alone.

A frying study was conducted over 11 days comparing 7 commercial antioxidant systems added to soybean oil containing 2 ppm DMPS against a control (DMPS only, no antioxidant). All variables were tested in duplicate. Fresh potato fries were fried with a daily load of food/oil ratio ~1. Fryers were topped off (~6.5%) daily with fresh oil. Measurements of Total Polar Materials (TPM), Gardner Red color, free fatty acids (FFA), OSI (110 °C), and p-anisidine value were evaluated.

The addition of antioxidants did not extend the oil fry life beyond DMPS alone. Antioxidants did not meaningfully improve TPM formation, color, FFA, or oxidation measurements. Antioxidant treatments did not show lower TPM (key indicator of oil degradation) than the Control and all exhibited TPM >25 after 11 days of frying. Minimal difference observed in OSI values after 1 day of frying which then was similar (3-6.5 hours OSI at 110 °C) throughout the remainder of the study. Viable options to substantially improve oil life in foodservice frying applications are still needed.