Impact of processing treatments on color and the level of heavy metal reduction of the green alga Ulva sp.: A Preliminary Study
CD Poeloengasih1, A Windarsih1, Y Khasanah1, R Suryani1, B Kumayanjati1, DJ Prasetyo1, Hernawan1, P Yulianto1

1Research Center for Food Technology and Processing, National Research and Innovation Agency (PRTPP BRIN)

Abstract

Abstract. Ulva sp. is an abundant green alga in Gunungkidul water, Indonesia, considered a source of nourishing food, sought after by food industries. This green alga could be served as a dish, a seasoning, or an ingredient- hence, assessment of its safety is important. The present study was conducted to reduce heavy metal residues in Ulva sp. collected from Sepanjang beach, Gunungkidul, Indonesia by using three different processing treatments, i.e., washing with salt solution, washing with citric acid, and blanching in various times and seaweed-to-solution ratios. The amount of heavy metal residues (As, Cd, Pb and Hg) was determined by Inductive Coupled Plasma Mass Spectrometry (ICP-MS) and visual green color loss was measured by a color spectrophotometer. The result showed that the concentration of As and Cd in the unprocessed sample was higher compared to SNI 2690:2015 for raw seaweed and National Food and Drug Agency of the Government of Indonesia (BPOM Indonesia) permissible limits in food. Washing Ulva sp. with citric acid 0.5% for 10 min in a seaweed-to-solution ratio of 1:20 could reduce the level of As up to 42.53%, whereas washing Ulva sp. with citric acid 0.5% for 15 min in a seaweed-to-solution of 1:10 could reduce the level of Cd up to 96.12%. All processing treatments affect the appearance of Ulva sp. which is indicated by the increase in color differences (&#916-E) > 2.

Keywords: Ulva sp., washing, citric acid, blanching, heavy metal reduction, discoloration

Topic: Fisheries Product Technology and Food Safety (International)