Effect of different processing conditions on antioxidant activity of Gracilaria edulis(Rhodophyseae) in Sri Lanka
Keywords:Antioxidant, scavenging, absorbance, processed, Inhibition
Gracilaria edulis is red marine algae currently cultivated in Sri Lanka but relatively low than other country such as China and Japan. This species are used to produce drugs and healthy delicious low calorie foods because of they are primary source of secondary metabolite and to be used as natural antioxidants and antimicrobials. The Purpose of this research investigates effect of different processing conditions on antioxidant activity of G.edulis (Rhodophyseae) by hydrogen peroxide scavenging activity assay. Absorbance at 230 nm, hydrogen peroxide scavenging assays were done. Different processed G.edulis such as fresh, steamed, boiled, dried and microwaved were extracted with methanol. Their antioxidant properties were compared to the L-ascorbic acid which used as positive control. The methanolic extracts of this red algae was prepared keeping methanol as a standard. Methanol was used as control. In minitab-15 statistical software package, Paired T-Test was clearly shown the absorbance, inhibition or hydrogen peroxide scavenging activity depend on the processing conditions of the G.edulis methanol extract. This statistical test did tell about the difference between the different processing conditions of the methanol extract of the G.edulis (p<0.05) and antioxidant activity and these were not independent factors such are depend on each other. Hence antioxidant activity or H2O2 scavenging activity was highly in boiled G.edulis, followed by fresh, microwaved, dried and steamed respectively. L-ascorbic acid was used as Positive control and its antioxidant activity was higher than dried and steamed but relatively lowers than microwaved, fresh and boiled G.edulis. Finally Boiled G.edulis sample was recorded prominent antioxidant activity due to leaching of less antioxidant compounds. In future this study is used to functional product development incorporation of dried followed by boiled G. edulis into bakery Products.
(1) Acker S. A. van, van den Berg D. J., Tromp M. N., Griffioen D. H., Bennekom W. P. van, Vijgh W. J. van der and Bast A., (1996). Structural aspects of antioxidant activity of flavonoids. Free Radical Biol. Med, 20, 331–342.
(2) Akoh, C. C. and Min, B. D. (1997). Food Lipid Chemistry. In: NutritionBiotechnology Marcel Dekker Inc., New York.
(3) Al-Azzawie, H. F. and Mohamed-Saiel, S. A. (2006). Hypoglycemic and antioxidant effect of oleuropein in alloxan-diabetic rabbits. Life Science, 78, 1371-1377.
(4) Albertus J. Smit. (2004). Medicinal and pharmaceutical uses of seaweed natural products: A review. Authors; Authors and affiliations. Journal of Applied Phycology. 16, 245–262.
(5) Amic, D., Davidovic-Amic, D. and Beslo, N. (2003). Trinajstic, Structure-radical scavenging activity relationship of flavonoids. Croatia Chemica Acta, 76, (1), 55-61.
(6) Amin Ismail & Tan Siew Hong.,(2002). Antioxidant Activity of Selected Commercial Seaweeds. Department of Nutrition and Health. Mal J Nutr 8(2): 167-177.
(7) Amin Ismail & Tan Siew Hong.,(2002). Antioxidant activity of selectedcommercial seaweeds, Mal J Nutr 8(2), pp.167 -177.
(8) Armida, T., Maurizio, T., Andrea T. and Sergio, B., (2005). Copper(II)-Quercetin complexes in aqueous solutions: Spectroscopic and kinetic properties. J. Mol.Struct. 44, 759–766.
(9) Arnold, T M. and Targett, N. M., (1998). Predicting the effects of brown algal phlorotannins on marine herbivores in tropical and temperate oceans. Journal of Phycology, 34, 195-205.
(10) Arthur C. Mathieson, Judith R. Pederson, Christopher D. Neefus, Clinton J. Dawes, and Troy L. Bray. Mathieson., (2000). Atlantic. Multiple assessments of introduced seaweeds in the Northwest Atlantic. Journal of Marine Science, 65: 730–741.
(11) Aruoma, I. O., (1999). Antioxidant action of plant foods. Use of oxidative DNA damage, as a tool for studying antioxidant efficacy. Free Radical Research, 30, 419-427.
(12) Bandoniene, D. and Murkovic, M., (2002). On-line HPLC-DPPH screening method for evaluation of radical scavenging phenols extracted from apples (Malus domestica L.). Journal of Agricultural and Food Chemistry, 50, 2482-2487.
(13) Bansemir, A., Blume, M., Schroder, S. and Lindequist, U., (2006). Screening of cultivated seaweeds for antibacterial activity against fish pathogenic bacteria. Aquaculture, 252, 79-84.
(14) Bodamyali, T., Stevens, C. R., Blake, D. R. and Winyard, P. G. (2000). Reactive oxygen/nitrogen species and acute inflammation: a physiological process. In: Winyard, P. G. Blake, D. R. and Evans, C. H., Eds. Free radicals and inflammation.Basel, Switzerland: Birkhauser pp. 11-19.
(15) Bouhlal, R.-Haslin, C-Chermann, J.C.-Colliec-Jouault, S.-Sinquin, C-Simon, G. -Cerantola, S.-Riadi, and H-Bourgougnon, N. (2011). Antiviral activities of sulfated Polysaccharides isolated from Sphaerococcuscoronopifolius (Rhodophyta, Gigartinales) andBoergeseniellathuyoides (Rhodophyta,
Ceramiales). In Marine Drugs, vol. 9: p. 1187-1209.
(16) Chanda, S.,(2010), Seaweeds : A novel ,untapped source of drug from sea to combat infectious diseases, Current Research, Technology and Education Topics in Applied Microbiology & Microbial Biotechnology,Vol 1,pp.473-480.
(17) Chandini, S. K., Ganesan, P. and Bhaskar N., (2008). In vitro antioxidant activities of three selected brown seaweeds of India, Food Chemistry. 107, 707-713.
(18) Chengkui, Z., Tseng, C.K., Junfu, Z., and Chang, C.F., (1984).Chinese seaweeds in herbal medicine. Hydrobiologia , 116-117:152-154.
(19) Cheung L.M., Cheung P.C.K. and Ooi V.E.C., (2003). Antioxidant activity and total phenolics of edible mushroom extracts, FoodChem. 81, 249–255.
(20) Chew, Y. L., Lim, Y. Y., Omar, M. and Khoo, K. S., (2008). Antioxidant activity of three edible seaweeds from two areas in South East Asia. LWT, 41, 1067-1072.
(21) Chiewchan, N., Praphraiphetch, C. and Devahastin, S., (2010). Effect of pretreatment on surface topographical features of vegetables during drying. Journal of Food Engineering, 101, 41-48.
(22) Cox, S., Abu-Ghannam, N. and Gupta, S., (2010). An assessment of the antioxidant and antimicrobial activity of six species of edible Irish seaweeds. International Food Research Journal, 17, 205-220.
(23) Duan, X. J., Zhang, W. W., Li, X. M. and Wang, B. G., (2006). Evaluation of antioxidant property of extract and fractions obtained from a red alga, Polysiphonia urceolata. Food Chemistry, 95, 37-43.
(24) Erhardt J. G., Meisner C., Bode J. C. and Bode C., (2003). Lycopene, β-carotene, and colorectal adenomas. Am. J. Clin.Nutr. 78, 1219–1224.
(25) Fisch, K. M., Bӧhm, V., Wright, A. D. and Kӧnig, G. M. (2003). Antioxidative meroterpenoids from the brown alga Cystoseira crinite. Journal of Natural products.66, 968-975.
(26) Fujiwara-Arasaki, T., N. Mino, and M. Kuroda., (1984). The protein value in human nutrition of edible marine algae. Journal of Applied Phycology. 11:231–239.
(27) Gahler, S., Otto K. and Bohm, V., (2003). Alterations of vitamin C, total phenolics, and antioxidant capacity as affected by processing tomatoes to different products. Journal of Agriculture and Food Chemistry, 51, 7962-7968.
(28) Ganesan, P., Kumar, C. S. and Bhaskar, N., (2008). Antioxidant properties of methanol extract and its solvent factions obtained from selected Indian red seaweeds. Bioresource Technology, 99, 2717-2723.
(29) Gonzalez del Val, A., Platas, G., Basilo, A., Cabello, A., Gorrochategui, J., Suay, I., Vicente, F., Portillo, E., Jimenez del Rico, M., Garcia Reina, G. and Pelez, F., (2001). Screening of antimicrobial activities in red, green and brown macroalgae from Gran Canaria (Canary Islands, Spain). International Journal of Microbiology, 4, 35-40.
(30) Gough D.R and Cotter, T. G., (2011). Hydrogen peroxide: a Jekyll and Hyde signaling molecule.Cell Death Dis, 2, 213.
(31) Halliwell, B. and Gutteridge, J. M., (1990). Role of free radicals and catalytic metal ions in human diseases: an overview. Methods in Enzymology, 186, 25-30.
(32) Harbourne, J. B., (1994). The Flavonoids: Advances in Research Since 1986. London, UK: Chapman and Hall.
(33) Haslam, E., (1989). Plant Polyphenols: Vegetable Tannins Revisited. Cambridge University Press, Cambridge, UK.
(34) Herrmann, K., (1989). Occurrence and content of hydroxycinnamic and hydroxybenzoic acid compounds in food. CRC Critical Reviews in Food Science and Nutrition, 28, 315-347.
(35) Hwang Pai-An, Wu Chwen-Herng, Gau Shu-Yun, Chien Shih-Yung and Hwang Deng-Fwu., (2010). Antioxidant and immune-stimulating activities of hot-water extract from seaweed Sargassum hemiphyllum, Journal of
Marine Science and Technology, 18(1): pp. 41-46.
(36) Ismail, A., Marjan, Z. M. and Foong, C. W., (2004). Total antioxidant activity and phenolic content in selected vegetables. Food Chemistry, 87, 581-586.
(37) Ito K and Hori K., (1989). Seaweed: Chemical composition and potential food uses. Food Rev Int 5:101–144.
(38) Jadhav, S.J. Nimbalkar, S.S. Kulkarni, A.D. & Madhavi, D.L., (1995). Lipid Oxidation In Biological and Food Systems. In: Food Antioxidants. Madhavi DL, Deshpande SS & Salunkhe DK (eds). New York.
(39) Jun, T., Liancai Z. and Bochu, W., (2007). Free radicals, natural antioxidants and their mechanisms. Int. J. Pharmacol., 3, 19–26.
(40) Kahkonen, M. P., Hopia, A. I., Vuorela, H. J., Rauha, J. P., Pihlaja, K., Kujala, T. S., (1999). Antioxidant activity of plant extracts containing phenolic compounds. Journal of Agricultural and Food Chemistry, 47, 3954-3962.
(41) Kasi Pandima Devi, Natarajan Suganthy, Periyanaina Kesika and Shanmugaiahthevar Karutha Pandian., (2008). Bioprotective properties of seaweeds: In vitro evaluation of antioxidant activity and antimicrobial activity against food borne bacteria in relation to polyphenolic content”, 8th Ed., BMC Complementary and Alternative
(42) Kawanishi, S., Hiraku, Y., Murata, M. and Oikawa, S., (2002). The role of metals in site-specific DNA damage with reference to carcinogenesis. Free Radical Biology and Medicine, 32, 822-832.
(43) Kolanjinathan, K. and Saranraj, P., (2014). Pharmacological efficacy of marine seaweed Gracilaria edulis extracts against clinical pathogens. Global Journal of Pharmacology. 8(2):268-274.
(44) Koruk M, Taysi S, Savas MC, Yilmaz O, Akcay F and Karakok M., ( 2004). Oxidative stress and enzymatic antioxidant status in patients with nonalcoholic steatohepatitis. Annals of clinical and laboratory science, 34:57–
(45) Kuda, T., Kunii, T., Goto, H., Suzuki, T. and Yano, T., (2007). Varieties of antioxidant and antibacterial properties of Ecklonia stolonifera and Ecklonia kurome products harvested and processed in the Noto peninsula, Japan. Food Chemistry, 103, 900-905.
(46) Laguerre, M., Lecomte, J. and Villeneuve, P., (2007). Evaluation of the ability of antioxidants to counteract lipid oxidation: Existing methods, new trends and challenges. Progress in Lipid Research, 46, 244-282.
(47) Layse C F. de Almeida, Heloina de S. Falcao and Leonia M. and Batista (2011). Bioactivities from Marine Algae of the Genus Gracilaria. Int J Mol Sci. 12(7): 4550–4573.
(48) Lim, S. N., Cheung, P. C. K., Ooi, V. E. C. and Ang, P. O., (2002). Evaluation of antioxidative activity of extracts from a brown seaweed, Sargassum siliquastrum. Journal of Agricultural and Food Chemistry, 50, 3862-3866.
(49) Lim, Y. Y. and Murtijaya, J., (2007). Antioxidant properties of Phyllanthus amarus extracts as affected by different drying methods. LWT Food Science and Technology, 40, 1664-1669.
(50) Lu, F. and Foo, L. Y., (1995). Phenolic antioxidant components of evening primrose.
(51) Madhusudan, C., S. Manoj, K. Rahul and C.M. Rishi., (2011). Seaweeds: A diet with nutritional, medicinal and industrial value. Journal of Medicinal plant 52, 153-157.
(52) Manach, C., Scalbert, A., Morand, C., Rémés, C. and Jiménez, L., (2004). Polyphenols: food sources and bioavailability. American Journal of Clinical Nutrition, 79, 727-747.
(53) Mat´es J. M., (2000). Toxicology, Effects of antioxidant enzymes in the molecular control of reactive oxygen species toxicology. 153, 83–104.
(54) Matsukawa, R., Dubinsky, Z., Kishimoto, E., Masak, K., Masuda, Y., Takeuchi, T., Chihara, M., Yamamoto, Y., Niki, E. and Karube, I., (1997). A comparison of screening methods for antioxidant activity in seaweeds. Journal of Applied Phycology, 9, 29-35.
(55) Meenakshi, S. D. and Manicka Gnanambigai., (2009).Total flavonoid and invitro antioxidant activity of two seaweeds of Rameshwarem coast. Global journal of pharmacology. 3(2), 59-62.
(56) Micheline Cristiane Rocha de Souza, Cybelle Teixeira Marques and Celina Maria Guerra., (2007). Antioxidant activities of sulfated polysaccharides from brown and red seaweeds. J Appl Phycol. 19(2): 153–160.
(57) Miguel M. G., ( 2011). Anthocyanins: Antioxidant and/or anti-inflammatory activities. J. Appl. Pharm. Sci, 01, 07–15.
(58) Miller HE, Rigelhof F, Marquart L, Prakash A. and Kanter M., (2000). Antioxidant content of whole grain breakfast cereals, fruits and vegetables. J Am Coll Nutr,19:312S–319S.
(59) Miller, H.E., Rigelhof, F., Marquart, L., Prakash, A., and Kanter, M., (2000). Cereal Foods World, 45(2), 59-63.
(60) Monaghan B. R. and Schmitt F. O., (1932). The effects of carotene and of vitamin A on the oxidation of linoleic acid. J. Biol. Chem. 96,387–395.
(61) Morli`ere P., Patterson L. K., Santos C. M. M., Silva A. M. S., Mazi`ere J., Filipe P., Gomes A., Fernandes E., Garciah M. B. Q. and Santusc R., (2012). The dependence of α-tocopheroxyl radical reduction by hydroxy-2,3-diarylxanthones on structure and micro-environment.Org. Biomol. Chem.10, 2068–2076.
(62) Moure, A., Cruz, J. M., Franco, D., Dominguez, J. M., Sineiro, J., Dominguez, H., Nunez, M. J. and Parajo, J. C., (2001). Natural antioxidants from residual sources. Food Chemistry, 72, 145-171.
(63) Mueller L. and Boehm V., (2011). Antioxidant Activity of β-Carotene Compounds in Different in Vitro Assays.Molecules, 16, 1055–1069.
(64) Naczk, M. and Shahidi, F., (2004). Extraction and Analysis of Phenolics in Food. Journal of Chromatography, 1054, 95-111.
(65) Nakamura, Y., Watanabe, S., Miyake, N., Kohno, H. and Osawa, T., (2003). Dihydrochalcones: evaluation as novel radical scavenging antioxidants. Journal of Agricultural and Food Chemistry, 51, 3309-3312.
(66) Nijveldt RJ, van Nood E, van Hoorn DEC, Boelens PG, van Norren K. and van Leeuwen PAM.,( 2001). Flavonoids: a review of probable mechanisms of action and potential applications. J Clin Nutr. 74(4): 418-425.
(67) Oh C., Kim M. Li, E., Park J. S., Lee J., Ham S. W. and Bull., (2010). Antioxidant and radical scavenging activities of ascorbic acid derivatives conjugated with organogermanium.Korean Chem. Soc. 31, 3513–3514.
(68) Ong In A. S. H., Niki E. and Packer L. (Eds), Nutrition, Lipids, Health, and Disease Champaign, American Oil Chemists Society.(pp. 86-95).
(69) Pisani, P. Bray, F. and Parkin, D.M. Estimates of the world-wide prevalence of cancer for 25 sites in the adult population. Int J Cancer 97:71–81.
(70) Plaza, M., Santoyo, S. Jaime, L., García-Blairsy Reina, G., Herrero, M., Senoráns, F.J. and Ibánez, E., (2009). Screening for bioactive compounds from algae. Journal of Pharmaceutical and Biomedical Analysis, 51 (2), 450-
(71) Ragan, M. A. and Glombitza, K. W., (1986). Phlorotannins, brown algal polyphenols. In: Hellebustad, JA, Craigie, JS (Eds), Handbook of Phycological Methods, Vol II. Cambridge University Press, Cambridge, (pp. 129-241).
(72) Reaven, P. D. and Witzum, J. L., (1996). Oxidised LDL in atherogenesis. Role of dietary modification. Annual Review of Nutrition, 16, 51-71.
(73) Rungapamestry, V., Duncan, A. J., Fuller, Z. and Ratcliffe, B., (2007). Effect of cooking Brassica vegetables on the subsequent hydrolysis and metabolic fate of glucosinolates. Proceedings of the Nutrition Society, 66, 69-81.
(74) Russo, N., Toscano, M. and Uccella, N., (2000). Semiempirical molecular modeling into quercetin reactive site: structural, conformation, and electronic features. J. Agric. Food Chem. 48 (8), 3232–3237.
(75) Sachidanandame, K., Fagan, S. C. and Ergul, A. (2005). Oxidative stress and cardiovascular disease: antioxidants and unresolved issues. Cardiovascular drug reviews, 23, 115-132.
(76) Schwarz K, Bertelsen G, Nissen LR, Gardner PT, Heinonen MI, Hopia A, Huynh-Ba T, Lambelet P, McPhail D, Skibsted LH and Tijburg L., (2001).Investigation of plant extracts for the protection of processed foods against
lipid oxidation. Comparison of antioxidant assays based on radical scavenging, lipid oxidation and analysis of the
principal antioxidant compounds. Eur Food Res Technol., 212:319–328.
(77) Shahidi, F. (2009). Nutraceuticals and functional foods: Whole versus processed foods. Trends in Food Science and Technology, 20 (9), 376-387.
(78) Shahidi, F. and Zhong, Y., (2008). Bioactive Peptides. Journal of AOAC International, 91, 914-931.
(79) Shahidi, P. K. J. and Wanasundara, P. D., (1992). Phenolic antioxidants. Critical Reviews in Food Science and Nutrition, 32 (1), 67-103.
(80) Shan, B., Cai, Y. Z., Brooks, J. D. and Corke, H., (2007). The in vitro antibacterial activity of dietary spice and
medicinal herb extracts. International Journal of Food Microbiology, 117, 112-119.
(81) Shon, M. Y., Kim, T. H. and Sung, N. J., (2003). Antioxidants and free radical scavenging activity of Phellinus baumii (Phellinus of Hymenochaetaceae) extracts. Food Chemistry, 82, 593-597.
(82) Shukla, V. K., Wanasundara, P. K. and F. Shahidi., (1997). Natural antioxidants from oilseeds. In: (Shahidi, F. eds), Natural antioxidants: Chemistry, health effects, and applications. AOCS Press, Champaign, IL. pp. 97-132.
(83) Skibola, C., (2004).The effect of Fucus vesiculosus, an edible brown seaweed, upon menstrual cycle length and hormonal status in three pre-menopausal women: a case report. BMC Complementary and Alternative
Medicine 4, 10–17.
(84) Stone J. R. and Yang S., (2006). Hydrogen Peroxide: A Signaling Messenger.Antioxid. Redox Signaling, 8, 243–270.
(85) Takamatsu, S., Hodges, T. W., Rajbhandari, I., Gerwick, W. H., Hamann, M. T. and Nagle, D. G., (2003). Marine natural products as novel antioxidant prototypes. Journal of Natural Products, 66, 605-608.
(86) Tesoriere L, Fazzari M, Angileri F, Gentile C. and Livrea M. A., ( 2008). In vitro digestion of betalianic foods. Stability and bioaccessibility of betaxanthins and betacyanins and antioxidative potential of food digesta. J Agric Food Chem. 56(22): 10487-92.
(87) Turkmen, N., Sari, F. and Velioglu, Y. S., (2005). The effect of cooking methods on total phenolics and antioxidant activity of selected green vegetables. Foodchemistry.93,713-718.
(88) Umakanthan, G., Vinobaba, P., Radampola, K., (2016). Phytochemical constitution of cultured G.edulis from the east coast of Batticaloa District, in Sri Lanka. Proceedings of 1st International conference at Trinco campus, Eastern University, Sri Lanka Konesapuri, Nilaveli Sri Lanka.
(89) Valentão, P., Fernandes, E., Carvalho, F., Andrade, P. B., Seabra, R. M. and Bastos, M. L., (2002). Antioxidative properties of Cardoon (Cynara cardunculus L.) infusion against superoxide radical, hydroxyl radical and hypochlorous acid. Journal of Agricultural and Food Chemistry, 50, 4989-4993.
(90) Valko M, Leibfritz D, Moncol J, Cronin MT, and Mazur M., (2007). Free radicals and antioxidants in normal physiological functions and human disease. Int J Biochem Cell Biol 1: 44-84.
(91) Valko M., Rhodes C. J., Moncol J., Izakovic M. and Mazur M., (2006). Free radicals, metals and antioxidants in oxidative stress-induced cancer. Chem.–Biol. Interact.160, 1–40.
(92) Varahalarao vadlapudi and K. Chandrashekar Naidu., (2010). In vitrobioevaluationofantioxidant activities of selected marine algae, Journal Of Pharmacy Research 3(2), 2010, pp.329-331.
(93) Vimala, S., Norhanom, A. W. and Yadav, M., (1999). Anti-tumour promoter activity in Malaysian ginger rhizobia used in traditional medicine. British Journal of Cancer, 80,110-116.
(94) Volden, J., Borge, G. I. A., Hansen, M., Wicklund, T. and Bengtsson, G. B., (2009). Processing (blanching, boiling and steaming) effects on the content of glucosinolates and antioxidant-related parameters in cauliflower
(Brassica oleracea L. ssp. botrytis). LWT Food Science and Technology, 42, 63-73.
(95) Volden, J., Borge, G. I. A., Hansen, M., Wicklund, T. and Bengtsson, G. B., (2009). Processing (blanching, boiling and steaming) effects on the content of glucosinolates and antioxidant-related parameters in cauliflower (Brassica oleracea L. ssp. botrytis). LWT Food Science and Technology, 42, 63-73.
(96) Wallace, G. and Fry, S. C., (1994). Phenolic components of the plant cell wall. International Review of Cytology, 151, 229-267.
(97) Watchtel-Galor, S., Wong, K. W. and Benzie, I. F. F., (2008). The effect of cooking on Brassica vegetables. Food Chemistry, 110, 706-710.
(98) Waterman, P. G. and Mole, S., (1994). Analysis of Phenolic Plant Metabolites. In: Methods in Ecology. Blackwell Scientific Publications, Oxford, UK.
(99) Witting P. K., Upston J. M. and Stocker R., (1997). Role of α-Tocopheroxyl Radical in the Initiation of Lipid
Peroxidation in Human Low-Density Lipoprotein Exposed to Horse Radish Peroxidase. Biochemistry, 36, 1251–1258.
(100) Wright, J.S., Johnson, E.R. and Di Labio, G.A., (2001). Predicting the activity of phenolic antioxidants: theoretical method, analysis of substituent effects, and application to major families of antioxidants. J. Am. Chem. Soc. 123 (6), 1173–1183.
(101) Yamaguchi, T. Takamura, H. Matoba, T. & Terao, J., (1998). HPLC method for evaluation of the free radicalscavenging activity of foods by using 1, 1-diphenyl-2-picrylhydrazyl. Biosci Biotechnol Biochem 62:1201-
(102) Yu, L., Halet, S., Perret, J. and Harris, M. (2002). Antioxidant properties of hard winter wheat extracts. Food Chemistry, 78, 457-461.
(103) Yuan, Y. V., Carrington, M. F. and Walsh, N. A. (2005). Extracts from dulse (Palmaria palmata) are effective antioxidants and inhibitors of cell proliferation in vitro. Food and Chemical Toxicology, 43, 1073-1081.
(104) Zhang, D. and Hamauzu, Y. (2004). Phenolics, ascorbic acid, carotenoids and antioxidant activity of broccoli and their changes during conventional and microwave cooking. Food Chemistry, 88, 503-509.