Study on mechanism behind browning of Antarctic krill upon hot air drying and its control

Cooked Antarctic krill (AK) was sprayed with antioxidants, followed by hot air drying (HAD) to produce AK meal (AKM). The antioxidants could alleviate color darkening, reduce oxidation of lipids and proteins, among which tea polyphenol palmitate (TPP) + antioxidant of bamboo leaf (AOB) exhibited the best effect on improving overall quality of AKM. The color indicator (L*) was negatively correlated with hydrophilic pyrrole, hydrophobic pyrrole and lipid oxidation indexes, suggesting that Maillard-like reaction and lipid oxidation contributed to the color darkening. Furthermore, AK oil (AKO) extracted from the AKM treated with TPP + AOB showed lower initial oxidation level and better storage stability (peroxide value (POV): from 1.84 to 7.20 mg CHP/g, thiobarbituric acid reactive substances (TBARs): from 0.62 to 0.97 ppm) compared to that from the control AKM (POV: from 2.31 to 7.64 mg CHP/g, TBARs: from 0.68 to 1.04 ppm).