Preparation and functional properties of beverages made
from sea algae
Takeshi Nagai*, Takakiyo Yukimoto
Department of Food Science and Technology, National Fisheries University, Shimonoseki, Yamaguchi 7596595, Japan
Received 8 April 2002; received in revised form 18 September 2002; accepted 18 September 2002
Beverages were successfully prepared from four sea algae. The antioxidant properties of these beverages were investigated using
four diﬀerent methods: autoxidation test, superoxide anion radical, DPPH radical, and hydroxyl radical scavenging tests. Among
them, sea trumpet showed strong eﬀects against autoxidation and the scavenging of superoxide anion radical. The antioxidant
activities of these beverages correlated with their contents of polyphenols. This shows that these beverages have a potential as
health drinks with functional properties and for patients suﬀering cancer, cardiovascular diseases, and diabetes.
# 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Preparation of beverage; Functional property; Sea algae
Tea is one of the most popular beverages in the world
because of its attractive ﬂavour, aroma, and taste. Over
three hundred diﬀerent kinds of tea are now produced.
The composition of tea varies with species, season, the
age of the leaf, climate, and horticultural practices.
Green tea contains polyphenols, including ﬂavonols,
ﬂavandiols, ﬂavonoids (Hertog, Hollmann, & van de
Putte, 1993), and phenolic acids. These compounds may
account for up to 30% of the dry weight. The poly-
phenols are the most signiﬁcant group of tea compo-
nents. The major tea catechins are (À)-epigallocatechin
3-gallate (EGCG), (À)-epigallocatechin (EGC), (À)-
epicatechin 3-gallate (ECG), (À)-epicatechin (EC), (+)-
gallocatechin, and (+)-catechin (C).
Many functions of tea polyphenols have been studied
(Yang and Wang, 1993): antioxidative activity (Ho,
Chen, Shi, Zhang, & Rosen, 1992; Katiyar, Agarwal, &
Mukhtar, 1994; Yen and Chen, 1995; Lin, Juan, Chen,
Liang, & Lin, 1996), anti-inﬂammation (Lin & Lin,
1997), antimutagenic (Shiraki et al., 1994), and antic-
arcinogenic eﬀects (Wang et al., 1992; Katiyar, Agarwal,
Zaim, & Mukhtar, 1993). Several ﬂavonoids have been
shown to autoxidize and generate reactive oxygen spe-
cies, such as hydrogen peroxide. It has been reported
that several phenolic antioxidants can accelerate oxida-
tive damage of DNA, protein, and carbohydrates
(Aruoma, Halliwell, Aeschbach, & Loliger, 1992;
Aruoma, Murcia, Butler, & Halliwell, 1993).
Sea algae constitute one of the common foods of
Japan and the Japanese consume a wide range of sea
algae, such as wakame and hizikia. Particularly wakame
is consumed as a food in sweetened vinegar, cooked
food and ingredients. Hizikia is consumed as fried food,
sea lettuce as food in sweetened vinegar, ingredients,
and green laver (JAPAN association of training colleges
for cooks, 1996). It is well known that sea algae contain
much dietary ﬁbre and minerals to protect life-style-
related disease. Moreover, sea algae are now being
recognized for their contents of some vitamins, such as
, and C. Until now, there are few reports of the
preparation and functional properties of beverages
made from sea algae. In the present study, we report
properties of these beverages by four diﬀerent methods,
namely autoxidation test, superoxide anion radical gen-
erated from the xanthine/xanthine oxidase system,
DPPH free radical, and hydroxyl radical scavenging
tests. The data should be useful with regard to prevent-
ing various diseases.
0308-8146/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
Food Chemistry 81 (2003) 327–332
* Corresponding author. Tel.: +81-832-86-5111x407; fax: +81-
E-mail address: machin@ﬁsh-u.ac.jp (T. Nagai).