The effect of carnosol, carnosic acid and rosmarinic acid on the oxidative stability of fat‐filled milk powders throughout accelerated oxidation storage

Abstract

The in vitro antioxidant effects of the most potent antioxidants of rosemary, namely car-nosol, carnosic acid and rosmarinic acid (c: ca: ra) were assessed in fat‐filled milk powders (FFMPs) under accelerated conditions (40 °C and relative humidity (RH) 23%) over 90 days. Lipid oxidation was assessed in FFMPs by measuring peroxide values (PVs), thiobarbituric acid reactive substances (TBARS) and aroma volatiles using headspace (HS) solid‐phase microextraction (SPME) coupled to gas‐chromatography‐mass spectrometry (GC‐MS). The antioxidant potency of c: ca: ra exhibited a concentration‐related effect (308 ppm > 200 ppm > 77 ppm), with the highest concentration being the most effective at controlling the formation of TBARS and PVs. At a concentration of 308 ppm c: ca: ra were particularly effective (p < 0.05) in inhibiting all the evaluated oxidation indices (primary and secondary) compared to the control samples, but in some cases less effectively (p < 0.05) than butylated hydroxyanisole: butylated hydroxytoluene (BHA: BHT) (200 ppm).