Effects of various blanching methods on fucoxanthin degradation kinetics, antioxidant activity, pigment composition, and sensory quality of Sargassum fusiforme

Abstract

This paper aims to study the effects of hot water blanching, salt water blanching, microwave blanching, and steam blanching on the quality of Sargassum fusiforme using different detection indicators, such as fucoxanthin content, pigment composition, antioxidant activity (2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging ability), and sensory quality. Results revealed that the blanching treatment exhibits dual effects of promoting dissolution and degradation of fucoxanthin. Besides hot-water blanching with 98.3 °C, the other three methods were not conducive to the retention of fucoxanthin. The Weibull model provides a good description of the degradation kinetics of fucoxanthin during blanching. For the radical scavenging assay, the extract obtained by microwave blanching had the strongest activity, followed by steam blanching. However, the other two kinds of blanching with water were not conducive to retaining activity. Sensory analysis revealed that the sensory quality could be better restored by blanching for a shorter time. Finally, the following three essential blanching conditions were selected from all the tests: the best pretreatment condition for fucoxanthin extraction: hot water blanching at 60 °C for 12 min; the best antioxidant activity: microwave blanching for 8 min; the best sensory quality: microwave blanching for 2 min.