Analysis and Evaluation of Sensory Properties and ... - UCSI University
Analysis and Evaluation of Sensory Properties and ... - UCSI University
Analysis and Evaluation of Sensory Properties and ... - UCSI University
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INTERNATIONAL JOURNAL FOR THE ADVANCEMENT OF SCIENCE AND ARTS, VOL. 2, NO. 2, 2011<br />
growing ornamental vine with heart-shaped leaves <strong>and</strong> pale purplish-blue flowers (Figure 1).<br />
Leaves <strong>of</strong> T. laurifolia are used as an antidote for poisons including drugs <strong>and</strong> cigarettes<br />
[7,8]. The plant has also been reported to have anti-inflammatory, anti-diabetic <strong>and</strong><br />
antipyretic properties [9,10]. The antioxidant properties <strong>of</strong> T. laurifolia are well studied<br />
[11,12]. In Malaysia, T. laurifolia has been planted as an ornamental climber <strong>and</strong> is not<br />
recognised to have any medicinal properties. The phytochemistry <strong>and</strong> pharmacological<br />
properties <strong>of</strong> T. laurifolia have recently been reviewed [13].<br />
Figure 1: Leaf (left) <strong>and</strong> plant (right) <strong>of</strong> Thunbergia laurifolia<br />
Much research has been conducted on the sensory properties <strong>of</strong> green, oolong <strong>and</strong> black teas<br />
<strong>of</strong> Camellia sinensis [14-18]. With the exception <strong>of</strong> teas <strong>of</strong> rooibos [19] <strong>and</strong> ginseng [20],<br />
hardly any work has been done for most <strong>of</strong> the herbal teas. In this study, the sensory<br />
properties <strong>and</strong> consumer acceptability <strong>of</strong> T. laurifolia teas produced from four different<br />
drying methods were assessed in comparison with the commercial T. laurifolia (Rang Chuet)<br />
tea from Thail<strong>and</strong>. <strong>Sensory</strong> characteristics were determined using quantitative descriptive<br />
analysis (QDA) by trained panellists. A hedonic survey was conducted to evaluate consumer<br />
acceptability <strong>of</strong> the five teas. This study represented the first evaluation <strong>of</strong> the sensory<br />
properties <strong>and</strong> consumer acceptability <strong>of</strong> T. laurifolia teas.<br />
2. MATERIALS AND METHODS<br />
2.1 Plant Materials<br />
The commercial T. laurifolia (Rang Chuet) tea was purchased from Bangkok, Thail<strong>and</strong>. Sold<br />
under the br<strong>and</strong> name <strong>of</strong> TriSiam New Life Tea, it consisted <strong>of</strong> 10 sachets per packet with<br />
each sachet containing 2 g <strong>of</strong> tea. Fresh leaves <strong>of</strong> T. laurifolia (Figure 1) were collected from<br />
B<strong>and</strong>ar Sri Menjalara, Kepong, Kuala Lumpur. Collected leaves (500 g) were cleaned,<br />
shredded into 0.2 cm strips with a pasta maker (GCH Retail, Malaysia) <strong>and</strong> dried.<br />
2.2 Drying Methods<br />
The drying methods used were microwave drying, oven drying, freeze drying <strong>and</strong> freeze<br />
withering. For each treatment, 600 g <strong>of</strong> leaves were dried in batches. The microwave-dried<br />
(MD) tea was produced by drying 12 g leaves in a microwave oven (Sharp, Malaysia, Model<br />
R-397JS, 230–240 V, 50 Hz) for 1.5 min. The oven-dried (OD) tea was produced by drying<br />
15 g leaves in a fan oven (Memmert UFB500, Germany) for 3 h at 50 o C. The freeze-dried<br />
17