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For the comparative purpose, all herbal teas were prepared in the same manner as follows: one full tablespoon of a dried herbal material was poured with 200 ml of boiling water, extracted for 10 or 45 min, and filtered before the taste evaluation. This method of preparation of the herbal teas is recommended by numerous popular books and Internet-resources and thus widely disseminated in households. The palatability scoring scale was adopted and rephrased for the herbal teas from the drinks analog scale (Macqueen et al., 2003) where originally each of the drinks tested was scored according to its taste and texture. The palatability of the herbal teas was evaluated using the 1 to 5 points subjective score scale according to the following criteria: 5 points: the tested herbal tea has an excellent taste; 4 points: the tested herbal tea “is not bad”; 3 points: the tested herbal tea is not palatable but has an acceptable taste for a herbal tea as such: 2 points: the tested herbal tea needs taste correction; 1 point: distasteful, the tested herbal tea is unsuitable for oral consumption. The method recommended in the European Pharmacopoeia (European Pharmacopoeia, 2010) for evaluation of bitterness value was used: each herbal tea was taken into mouth and passed it from side to side over the tongue for 30 s, then it spitted out and the mouth was rinsed with water. Estimation of palatability of herbal teas (experiment 1) 70 subjects (pharmacy students and graduates of both gender, 19 to 45 years) were involved in the open study, the experiment lasted for several days. Each of the subjects tasted all of the 43 teas (full list of herbs is given in the Table 1). Effect of extraction time on palatability of herbal teas (experiments 2 and 3) In the experiment 2, 31 pharmacy students of both genders were involved in the open study. The subjects evaluated the palatability of herbal teas of 2 different extraction times (10 and 45 min), respectively. The evaluation criteria were as in Experiment 1. This experiment was repeated a year later with another group of students (N=24; Experiment 3) while the list of herbs tested varied slightly depending on the actual availability of plant material. Effect of sweetening on palatability of herbal teas (experiment 4) The herbal teas were prepared as given above; the extraction time was 10 min. 1 teaspoon of sugar (saccharose, ca 5 g) per 200 ml tea was added for taste correction. 32 pharmacy students tasted the herbal teas before and after the sweetening and evaluated the taste using the 5 point scale as given above. RESULTS AND DISCUSSION Our study present unveiled that the palatability of the commonly used herbal teas varies quite much (Table 1). As a general trend, the “distasteful” herbal teas were considered unpalatable by all subjects while the favorable palatability of the teas was subjective and tended to differ among the experimenters to a great extent. Though not Raal and Matto 2515 specifically studied, indeed the bitterness and astringency are the major limiting factors for the consumption of the herbal teas. The most unpalatable herbal tea of the Experiment 1, the Bogbean leaves tea has a bitterness index 1:500 and it contains also about 7% tannins thereby being strongly astringent (Weiss and Fintelmann, 2001). Also, several other herbal teas tested are at least to some extent astringent. While the bitterness is a univocal criterion, the recent study by Childs and Drake (2010) reported that the degree of astringency considered by the subjects as desirable or undesirable attribute of a beverage is a person-specific feature. Notably, the Sage leaves and Wormwood herb, both with a low palatability score in our study, contain high levels of total polyphenols responsible for the astringency (Büyükbalci and El, 2008). Further, the same researchers concluded that the intensity of the astringency is not necessarily directly related to dislike. It is also well-known that the emotional and physical status of the subject contributes to the liking of any taste of the foods and beverages. This issue is widely studied in sport science, there are reports showing the role physical and mental exhaustion on perception and acceptance of fluid and sport drinks and vice versa (Passe et al., 2009; Passe et al., 2004). In our study, the experimenters were in sedentary laboratory conditions that may have impacted the decision of the palatability of herbal teas, too. In addition, the environmental and contextual conditions are known to bias the food or drink palatability (Roefs et al., 2006; Sakai et al., 2001) but it is not described for the herbal teas. Intuitively one might expect that the taste acceptance level of the medicinal herbal teas gains in the ailing condition of the subject. In future it is necessary to provide GC-MS or/and HPLC-MS analysis of the herbal teas investigated organoleptically determining the content of their biologically active substances which should be correlate with palatability points between 1 and 5. Also spectrophotometrical determination of total content of polyphenols, tannins or flavonoids in infusions could show interesting results if compared with points given by students. The mechanisms of perception of astringency as a general component that determines the palatability of teas is well described (Nayak and Carpenter, 2008). The prolongation of the extraction time of teas may augment the astringency due to increased solution of polyphenols but again, the psycho-emotional component plays also an important role in the perception of palatability (Sakai et al., 2001). This explains also the moderate discrepancy of results of the Experiments 2 and 3 (Tables 2 and 3, respectively). Thus, the amount of extraction of most of the active compounds groups such as the polyphenols, tannins, flavonols, coumarins, anthraquinones, saponins, etc. depends on the duration of the extraction time. The extraction of those constituents during the extraction process of 10 minutes is incomplete (Raal and Kuznetsova, 2007) and generally the extraction rate is
2516 J. Med. Plants Res. Table 1. Palatability score of herbal teas. Herb /plant material Average score* Score range Wild rose fruits (Rosae pseudo-fructus) 4.64 2-5 Peppermint leaves (Menthae piperitae folium) 4.63 3-5 Lime flowers (Tiliae flos) 4.63 3-5 Hawthorn fruits (Crataegi fructus) 4.50 2-5 Primula flowers (Primulae flos) 4.18 2-5 Mullein flowers (Verbasci flos) 4.10 2-5 Catmint leaves (Nepetae catariae folium) 4.07 2-5 Spearmint leaves (Menthae spicatae folium) 3.99 2-5 Raspberry leaves (Rubi idaei folium) 3.99 2-5 Juniper fruits (Juniperi fructus) 3.97 2-5 Creeping thyme herb (Serpylli herba) 3.93 3-5 Lemon balm leaves (Melissae folium) 3.85 2-5 Caraway fruits (Carvi fructus) 3.69 1-5 Liquorice roots (Glycyrrhizae radix) 3.66 1-5 St. John’s wort herb (Hyperici herba) 3.64 1-5 Common plantain leaves (Plantaginis majoris folium) 3.56 2-5 Pineapple weed flowers (Matricariae suaveolentis flos) 3.53 1-5 Cornflower flowers (Cyani flos) 3.51 2-5 Nettle leaves (Urticae folium) 3.50 2-5 German chamomile flowers (Chamomillae flos) 3.50 1-5 Hyssop leaves (Hyssopi folium) 3.47 1-5 Cottonweed herb (Gnaphalii uliginosi herba) 3.47 2-5 Lady’s mantle leaves (Alchemillae folium) 3.44 2-5 Common knotweed herb (Polygoni avicularis herba) 3.36 1-4 Birch leaves (Betulae folium) 3.33 1-5 Primula leaves (Primulae folium) 3.31 1-5 Flax seeds (Lini semen) 3.30 1-5 Pot marigold flowers (Calendulae flos) 3.30 1-5 Coltsfoot leaves (Farfarae folium) 3.18 1-5 Oak bark (Quercus cortex) 2.71 1-4 Hops (Lupuli strobilus) 2.61 2-5 Valerian root (Valerianae radix) 2.60 1-4 Rosemary herb (Ledi herba) 2.60 1-5 Yarrow herb (Millefolii herba) 2.54 1-5 Sage leaves (Salviae officinalis folium) 2.52 1-5 Cowberry herb (Vitis-idaeae herb) 2.36 1-4 Common motherwort herb (Leonuri herba) 2.34 1-4 Tormentil rhizome (Tormentillae rhizoma) 1.97 1-4 Bearberry leaves (Uvae ursi folium) 1.78 1-4 Frangula bark (Frangulae cortex) 1.67 1-3 Iceland moss (Lichen islandicus) 1.48 1-4 Wormwood herb (Absinthii herba) 1.19 1-2 Bogbean leaves (Menyanthidis folium) 1.03 1-2 70 subjects tasted all herbal teas. *5-point taste scale (1=distasteful, 5=excellent taste). increased if the extraction time is extended. Nevertheless, this phenomenon is medicinal plant specific and for an example, in our another study (Raal et al., 2012) it was found that prolongation of the extraction time of chamomile tea from 5 min to 12 h in a thermos bottle did not remarkably increased the content of the total polyphenols and flavonoids. Usually the German chamomile inflorescences cultivated in Estonia are rich of
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Journal of Medicinal Plants Researc
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Editors Prof. Akah Peter Achunike E
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Electronic submission of manuscript
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Fees and Charges: Authors are requi
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Table of Contents: Volume 6 Number
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Figure 1. Chuanxiong Rhizoma (http:
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Table 1. Identification of main pea
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Table 3. Pharmacokinetic parameters
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active component study, many invest
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and 1185 kg ha -1 in the first site
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Table 1. Recommendation for use fer
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Sadanandan AK, Hamza S (1996c). Stu
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and it has been traced to South Ame
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Table 3. Results of phytochemical a
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(a) (b) (c) Figure 1. (a) Normal ce
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emedies in the south of Brazil. J.
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known fatty acids and terpenoids we
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Table 1. Renal function tests of ra
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Al-Radahe et al. 2271 Figure 3.nnnn
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namely disruption of the vascular e
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Zayachkivska OS, Konturek SJ, Drozd
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β-carotene were purchased from Sig
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Figure 1. Effect of ethanol concent
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Table 3. Climatic and soil factors
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content of polysaccharides. Phospha
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Serge et al. 2285 Table 1. Relative
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Percentage inhibition % of inhibiti
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Table 1. Result of phytochemical sc
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Table 3. Result of thin layer chrom
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Table 2. MIC of a compound 1 from c
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Zirihi et al. 2301 Figure 2. Termin
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Figure 5. T. catappa Linn. (Combret
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Figure 8. A. fumigatus: Aspect of c
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Figure 12. Sensitivity of A. fumiga
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Noormi et al. 2311 Table 1. Callus
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Table 2. Contd. NoC=No callus. 4.0
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Figure 2. Contd. at 2.0 mg/L yellow
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Table 1. Biochemical parameters in
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Figure 3. Bcl-xL reactions in inter
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ACKNOWLEDGMENTS The authors would l
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Figure 1. The first page of the boo
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Figure 3. The most widely included
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Figure 4. Lithographic print “St.
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Table 1. List of plants included in
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Table 1. Contd. Nedelcheva 2333 Cin
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Table 1. Contd. Nedelcheva 2335 Rhe
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14 7 1 15 1 35 17 16 Imported plant
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Academy of Science Publishing House
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et al., 1996; van Wyk and Gericke,
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DPPH inhibition (%) DPPH % inhibiti
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% Mortality Concentration (µg/ml)
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information on plants used for the
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Table 1. Levels of independent vari
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Arbutin (mg/g) Co-solvent Figure 1.
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Arbutin (mg/g) Extraction pressure
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Table 3. Arbuitn content of Asian p
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Arbutin (mg/g) Extraction pressure
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Arbutin (mg/g) Extraction temperatu
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Table 1. Chemical composition of es
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Darjazi 2369 Table 2. Statistical a
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Table 3. Correlation matrix (number
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Table 1. Precision test. extraction
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Figure 2. Effect of different alcoh
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Table 6. Results of ANOVA. Nie et a
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Table 2. Plant data and MIC values
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exhibiting the polar extracts of P.
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Table 3. Contd. AcOEt ++ ++ ++ - Me
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Figure 1. Map of Ladakh region of I
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Warghat et al. 2391 Table 3. Summar
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Table 5. Inter-Population genetic i
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Excoffier L, Smouse PE, Quattro JM
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ice residue is an ideal raw materia
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DPPH• scavenging ratio(%) OD valu
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scavenging effect on free radical a
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our new CL system. Fenton reaction
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1 2 Time (s) Figure 2. Kinetic curv
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Wong et al., 2006). It can be seen
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Pan YM, Liang Y, Wang HS, Liang M (
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2422 J. Med. Plants Res. close cano
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2424 J. Med. Plants Res. Table 1. M
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2426 J. Med. Plants Res. Table 1. C
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2432 J. Med. Plants Res. Table 2. D
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2434 J. Med. Plants Res. Table 6. T
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2436 J. Med. Plants Res. budget dur
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2440 J. Med. Plants Res. Table 1. R
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2442 J. Med. Plants Res. Stability
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2444 J. Med. Plants Res. production
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2446 J. Med. Plants Res. Figure 2.
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2450 J. Med. Plants Res. Table 2. A
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2452 J. Med. Plants Res. Ghasemi Pi
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2454 J. Med. Plants Res. Table 1. I
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2456 J. Med. Plants Res. Table 3. M
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2460 J. Med. Plants Res. Department
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