Effect of different drying methods on the physicochemical properties and phycobiliprotein structure of <i>Porphyra haitanensis</i>
Dalun Xu, Nan Sun, Shifen Xuan, Chen Wang, Tao Huang, Chao Li, Jinjie Zhang, Wenge Yang
Abstract
Abstract This study explored the effects of four drying methods, namely vacuum freeze-drying (VFD), hot-air drying (HD), microwave drying (MD) and shade drying (SD) on the sensory quality, amino acids composition, phycobiliproteins structure and rehydration rate of Porphyra haitanensis . It showed that VFD dried P. haitanensis had the highest protein (35.44 ± 0.87%), polysaccharide (18.91 ± 0.64%), umami amino acids (484.67 ± 5.03 mg/100 g, dry weight) and essential amino acids (9.89 ± 0.27 g/100 g, dry weight) than another three dried products. Drying affected secondary structure of phycobiliproteins, and the phycobiliproteins from VFD laver contained the most α -helix structure and the least random coil. In addition, VFD processed laver was rich in water-soluble polysaccharides and hydrophilic amino acids, which resulted in its quick rehydration and high-water absorption capacity. The results showed that VFD was suitable for producing high-quality P. haitanensis with excellent flavor and high contents of nutritional compounds.