Seaweed aquaculture makes up a significant portion of organisms cultured worldwide, ~28 million metric tons, with a value ~U.S. $10 billion. In addition to other uses (i.e. hydrocolloids and feed) for cultivated seaweed, Undaria , Porphyra and Laminaria are extensively used as food for direct human consumption. Seaweed is different from the land-based fruits or vegetables in many senses considering its complex physiology and composition . While the scientific has community already confirmed the positive effects of bioactive compounds in various types of seaweed in both raw and fresh form, the fate of the compounds in processed products and value-added products is yet to be established. So far, the focus of post-harvest processing and preservation has been on the drying or blanching and frozen products. There is limited study on the behavior, availability and release of bioactive compounds and heavy metals in the seaweed as it pass through various processing conditions.
Primarily, t he existing processing conditions include drying of seaweed with hot-air medium. Different drying methods have been found to greatly affect the nutritional composition of the brown seaweed, Sargassum hemiphyllum (Chan, Cheung, & Ang, 1997). For example, Wong and Cheung (2001) reported that oven-drying was better than freeze-drying for the extractability and quality of proteins isolated from three subtropical brown seaweeds. The most commonly applied drying conditions, mainly in Asia, have longer drying time with higher throughputs. The target moisture content of the dried products varies from 8-15% wet basis. The educated consumers of today like to purchase a product with minimal proce ssing and high quality. The existing processing and storage conditions don't provide any information on the fate and availability of bioactive compounds in the final products.
Besides, seaweed has not been tested to a number of advanced food processing technologies that are used for land-based food products. In addition to hot-air, these advanced technologies use microwave, pressure, vacuum etc. to develop high quality solid and liquid food products as well as ingredients . In this presentation, I will discuss on the available advance of food processing and preservation technologies that can be utilized for developing a number of food products and high value-added products from seaweed, mainly focusing on kelp (Sachharina latissima) .