Functional Properties and Biological Potentials of the Tunisian Green Seaweed Ulva lactuca

  • Imen Zaghbib aHigh Graduate School of Food Industry of Tunisia, Research Unit “Biopreservation and Valorisation of Agro-Food Products”, 58 Avenue Alain Savary, Tunis El Khadra 1003, Tunisia
  • Soumaya arafa aHigh Graduate School of Food Industry of Tunisia, Research Unit “Biopreservation and Valorisation of Agro-Food Products”, 58 Avenue Alain Savary, Tunis El Khadra 1003, Tunisia
  • Mnasser Hassouna aHigh Graduate School of Food Industry of Tunisia, Research Unit “Biopreservation and Valorisation of Agro-Food Products”, 58 Avenue Alain Savary, Tunis El Khadra 1003, Tunisia
Keywords: Ulva lactuca, functional properties, antioxidant activity, antimicrobial avtivity


Recently, seaweeds are getting importance because of their numerous bioactive compounds and their utilisation as functional ingredients in various fields ranging from food to medical. In this respect, the green macro algae Ulva lactuca, known as « sea lettuce », has been studied. Hence, physico-chemical properties and biological potentials of Ulva lactuca, obtained from Cap Zebib collecting station (North of Tunisia) on July 2021, were investigated. It was found that the green seaweed species contained high level of moisture (12.75 ± 0.05 % dry weight (DW)), protein (10.63 ± 0.2 % DW), lipid (5.64 ± 0.11 % DW) and ash (17.25 ± 0.31 % DW). The study of the functional properties showed that WHC and OHC of this alga were 9.32 ± 0.42 g water/g DW and 1.67 ± 0.59 g oil/g, respectively. Antioxidant activity of the methanolic extract was determined using DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay. Ulva lactuca exhibited a relatively high DPPH radical scavenging activity (54.46 ± 0.39 % of inhibition) with low IC50 896.77 ± 0.31 µg/mL. Seaweed U. lactuca was screened for the potential bioactive natural substance against human pathogenic microorganisms. The methanolic extract showed the highest zone of inhibition against L. monocytogenes (17.04 ± 0.05 mm), followed by G. candicum (15.07 ± 0.09 mm),  A. niger (14.02 ± 0.02 mm), S. aureus (13.01 ± 0.01 mm), E. coli (11.01 ± 0.01 mm) and S. typhimurium (10.06 ± 0.08 mm). The present study suggested that local seaweed Ulva lactuca could be potentially used as raw materials or additives to improve the nutritive value and functional properties of foods.


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