Praveen K Sappati1,3, Ingrid Undeland2, Jens J. Sloth3, Susan L. Holdt3
1Indian Institute of Technology, Kharagpur, West Bengal, India, 2Biology and Biological Engineering, Food and Nutrition Science, Chalmer’s University of Technology, Gothenburg, Sweden, 3DTU Food, The National Food Institute, Technical University of Denmark, Kgs. Lyngby, Copenhagen, Denmark
Fresh sugar kelp was harvested from five geographical locations Denmark, Sweden, Norway, Faroe Island, and Greenland in the summer (Early May – Mid July) 2020 and freeze-dried, vacuum dried, sun-dried, hot-air dried at 40 °C and 70 °C, blanched for 120 s and 20 s at 80 °C and fermented using various strains of lactobacillus. The tough structure of the cell wall allows seaweed to grow in the marine environment, but such complex polysaccharides present in the cell wall are hard to digest, and also this layer acts as a sponge for the trace metals.
Concentrations of potentially toxic elements (PTE) comply with regulations after processing in the US and Scandinavia, and therefore this study should remove the fear of contaminants as market barriers. The initial concentration of iodine I in kelp collected from Norway and Sweden (in excess of 6,000 mg/kg dry weight) is a matter of concern due to due to French recommendations. However, blanching is seen to be most effective for reducing the concentration of iAs and I. The final concentration of I in all the blanched samples irrespective of their geographical origin is less than 1,000 mg/kg of dry weight, whereas it seems ineffective against Hg and Cd ions.
Further investigations on the digestion models (INFOGEST) as well as/or a repeated study are needed, to make any concluding remarks related to the bioaccessibility of the compound of interest.