The influence and mechanism of the color of Antarctic krill meal on the color of extracted Antarctic krill oil

Abstract

The quality of Antarctic krill meal (AKM) influences the nutritional value and sensory attributes of Antarctic krill oil (AKO), especially color, which is critical for market acceptance. The impact of color deterioration of the stored AKM on the color of the extracted AKO was investigated. After 60 d-storage at room temperature, AKM shifted from reddish-orange to yellowish-brown due to lipid oxidation and Maillard/Maillard-like reaction. AKO extracted from the stored AKM showed lower redness value (a∗, red-green chromaticity index) than directly stored AKO. This indicated drastic astaxanthin (ASTA) degradation in stored AKM, with only 2.91 % of initial ASTA extracted into AKO after 15 d and none after 30 d. A₄₂₀ value in AKO extracted from stored AKM increased by 11.31 % (vs. 548.96 % in stored AKM), suggesting minimal brown substance transfer to AKO during extraction. These implied that the color deterioration of the stored AKM negatively influenced AKO color. In addition, after 60 d, L∗ (light-dark chromaticity index) in two tea polyphenol palmitate (TPP) + antioxidants of bamboo leaf (AOB)-treated AKM decreased by 7.36 %/3.92 % (vs. 7.75 % in con group). The a∗ and ASTA content in the AKO extracted from two TPP + AOB-treated AKM decreased by 59.43 %/46.20 % and 100 %/99.89 % (vs. 87.21 % and 100 % in con group). Obviously, spraying TPP + AOB before/after drying inhibited the yellowish-brown of stored AKM, and improved the redness value and ASTA content of AKO extracted from the stored AKM.