Herbal teas are nutrient, antioxidant, and hydration-rich brews made from herbs and spices and taken for various purposes. The objective of this study was to formulate tea from clove (Syzygium aromaticum), leaves of lemongrass (Cymbopogon citratus), guava (Psidium guajava), and moringa (Moringa oleifera), as well as compared with Chinese and yellow Lipton Tea. The samples were analyzed for comparative sensory analysis using the 7 points hedonic scale. The sensory evaluation result demonstrated that the color of the clove tea sample (5.87) was most acceptable by participants, while the lemongrass tea (4.46) sample was least acceptable amongst all the tea samples. The clove remained the most accepted tea for aroma (6.07), taste (5.92), texture (5.76), general appearance (5.74), and general acceptability (5.93), in 7 points hedonic scale. However, all tea samples were had significant acceptable scores above average (p 0.05). Owing to the above results, these herbs can be successfully used to produce tea of relatively good quality to encourage herbs' local consumption and stay healthy.

Herbs have beengenerally used in history for various reasons1. These includeornaments and clothing but majorly processed in some crude forms as food andmedicine and for relaxation. This is because of their ability to cure diseases,maintain optimal health, simplicity, cheapness, availability, inexpensively,acceptable taste and smell. Herbal teas or 'tisanes' are nutrient-hydration-andbut straightforward-antioxidant-rich brews made from herbs and spices.Furthermore, herbal teas help stimulate internal organs, boost immunity,enhance relaxation (sleep time and rest), promote energy and soundness, as wellas general well-being2,3.

There has been moreresearch and interest on regular tea4. However, there ismore need to expand scientific investigations to other rich herbs like tea.This is even so, with the recent reoccurring outbreak of immune-compromisingdiseases of bacterial and viral sources to the extent of epidemics andpandemics that requires the need for not only immune boosters, anti-bioticactivities but as to sustain the entire well-being of humankind5.

The naturalcompositions of notable aromatic, antioxidant, antimicrobial, and crucialtherapeutic substances have placed herbs and teas as the lead for scientificinvestigations with the view of finding lasting solutions in the prevention,treatment, and management of various diseases like cancer, respiratorydiseases, and many more6,7. This is especiallybeneficial when consumed regularly as food and not necessarily as medicine. Thereason for selecting the herbs such as clove, lemongrass, guava, and moringa inthis study is the plethora of therapeutic benefits they possess from theliterature6-9 though commonlyunderutilized, whereas Chinese and Lipton's tea is consumed by people globally6. These are popularand preferred brands by consumers; thus, they were used as control. Therefore, the current research's main aimwas to evaluate the formulated tea samples' sensorial parameters and comparethem with the commercially available Chinese and Lipton tea. This studyrepresented the first evaluation of sensory properties and consumeracceptability of tea samples made from the clove.

Fresh leaf samples of lemongrass andguava were obtained from household gardens around Maikunkele and Bosso towns inBosso Local Government of Niger State, Nigeria, and determined at the FederalUniversity of Technology, Minna. Dry clove, commercial Chinese tea from Camelliasinensis Chinese tea plant, and the yellow Lipton tea were obtained fromBosso market, Minna, Nigeria.

Sample treatment

The fresh leaf samples were allowed to air dry atroom temperatures in the absence of sunlight for two weeks. All the dry sampleswere separately blended into a coarse chaffy powder. All the samples were keptin clean plastic bags and stored at room temperatures for use.

Tea formulation

Six tea diets were formulated fromeach sample (2 g) above. However, the sixth sample was a dry mixture of all theother five samples in the ratio of 1 : 1 : 1 : 1 : 1. Each dry sample was steeped in 10 mL ofboiled (100°C) distilled water and allowed to stay for three minutes, afterwhich the chaff was sieved out, and granulated sugar (2 g) was added to thefiltrate (4 mL). The mixture was stirred and served for sensory analysis underhygienic conditions, as illustrated in Figure 1.

Sensory analysis

A 7-point hedonic scale was used toshow the various samples' scoring using 150 scorers accustomed to tea drinking.The sensory evaluation was carried out among young adults (150 respondents)living around the Federal University of Technology and the University of Abuja,Nigeria. The various tea samples were scored for general appearance, taste,smell, color, texture, and general acceptability. Mean scores were calculatedfor each attribute.

Statistical analysis

The sensory scores include generalappearance, taste, aroma, color, texture, and general acceptability, wereanalyzed using two-way ANOVA with levels of significance determined at p<0.05. The means of the antioxidant and nutrient composition of the sampleswere also evaluated. The SPPS version 20 package was used for statistical analysis.

Ethical approval

Approved consent of the scorers was obtained from all respondents. Theassessment is carried out according to ethical standards approved by The E3REEResearch Committee under the Nigerian Regulatory Code for Human SubjectsResearch with Approval No. 0001.

Figure 1. General method of preparation of teasamples

Color

Participants’ responses on the colorof the prepared tea samples showed that the clove tea sample (5.87) was mostacceptable, while the lemongrass tea (4.46) sample was least acceptable amongstall the tea samples (Table I). There was a significantdifference in scores amongst the color of the tea samples. Score andacceptability for the aroma of the tea samples increased in order of lemongrass(4.46) < guava leaves (4.5) < Lipton (4.7) < moringa (4.79) < Chinesetea (4.84) < mixture (5) < clove (5.87). According to the literature,several amino acids in tea play an important role in imparting color to thetea. ‘Brightness’ and ‘briskness of tea were due to compounds like theaflavinand thearubigins, which affect sensory characteristics10,11.

Aroma

Results illustrated in Table I show that clove tea had the highest mean score(6.07) as compared to control Lipton (4.7) and Chinese tea (4.66), whereas thelowest mean score was assigned to the guava leaves tea sample (4.51) byconsumers. There was a significant difference in scores amongst the aroma ofthe tea samples. Score and acceptability for the aroma of the tea samplesincreased in order guava leaves (4.51) < lemongrass (4.65) < Chinese tea(4.66) < moringa (4.69) < Lipton (4.7) < mixture (4.93) < clove(6.07). As guava leaves tea samples were also the least preferred by consumersin terms of overall appearance (4.6), they remained the lowest in the aroma.

Taste

The result shows the variation intaste acceptability amongst tea samples (Table I). There was a significant difference in scoresamongst the general acceptability of the tea samples. The highest mean scorewas assigned to clove tea (5.92), whereas the lowest score was assigned toChinese tea (4.47). Compared to marketed tea formulations, Lipton and Chinesetea, the clove tea sample being the highest scored, was most preferred byparticipants. Score and acceptability for a taste of the tea samples increasedin order Chinese tea < Lipton < moringa < lemongrass < guava leaves< mixture < clove. Constituents such as tannins, catechins, amino acidscontribute to the flavor of the tea. Catechins were predominantly known tocontribute to 70-75% of bitterness and astringency, whereas caffeine andtannins were responsible for astringent or pungent taste. The brothy and thesweet taste was due to amino acids12-14.

Texture

The clove tea sample had the highestmean score (5.76) and remained the most preferred by consumers, while thelemongrass tea sample had received the lowest mean score (4.48). Lemongrass teasample was also least scored and preferred in general appearance (4.63) andcolor (4.46). There was a significant difference in scores amongst the textureof the tea samples (Table I). Score and acceptability for textureof the tea samples increased in order lemongrass (4.48) < guava leaves (4.5)< Lipton (4.64) < mixture (4.74) < moringa (4.76) < Chinese tea(4.78) < clove (5.76).

General appearance

Results show that the clove teasample was assigned the highest mean score in general appearance (5.74), whilethe guava tea sample had received the lowest score (4.6), as shown in Table I. There was a significant difference in scoresamongst the general appearance of the tea samples. Score and acceptability forthe general appearance of the tea samples increased in order guava leaves <lemongrass < moringa < Lipton < Chinese tea < mixture < clove.

General acceptability

As expected, the clove tea samplehad the highest mean score (5.93), whereas lemongrass was assigned the lowestscore (4.61). There was a significant difference in scores amongst the teasamples' general acceptability (Table I). Score and acceptability for thegeneral appearance of the tea samples increased in order lemongrass (4.61) <guava leaves (4.85) < Lipton (4.85) < moringa (4.88) < Chinese tea (4.96)< mixture (4.96) < clove (5.93). Interestingly, both Lipton (4.85) andguava leaves (4.85) tea samples were almost equally acceptable and preferred byparticipants. Similar results were obtained for Chinese tea (4.96) and mixture(4.96) sample tea.

Table I. Values of sensoryattributes of formulated tea samples with comparison to the commercial Liptonand Chinese tea sample

C: color; A: aroma; Ta: taste; Te: texture; Gap: general appearance;Gac: general acceptability. Alphabetical superscript signifies the meandifference significant at 0.05 level (95%). Values with different superscriptwithin a column were significantly different at p<0.05

The current study's primaryobjective was to formulate tea samples of various herbs and compare them withcommercially available Lipton and Chinese tea samples. According to theliterature, this study is the first to select some of the herbs used in previousstudies. The findings of this study suggest that among all the tea samples, theclove tea sample was the most accepted, preferred, and highest scored in termsof color (5.87), aroma (6.07), texture (5.76), taste (5.92), general appearance(5.74), and overall acceptability (5.93), whereas, lemongrass was least accepted,preferred, and lowest scored in color (4.46), texture (4.48), generalacceptability (4.61) by consumers (Figure 2). The guava leaves tea sample alsoremained the least preferred by participants in terms of general appearance(4.6) and aroma (4.51). The taste of Chinese tea was disliked and leastpreferred (4.47) by participants. Among all the lowest preferred samples, theincreasing order of dislike is as follows: guava leaves < Chinese tea <lemongrass. Surprisingly, the clove tea sample remained desirable, appealing,and most preferred by participants in all the sensory evaluation parameters (Figure 2).

Figure 2. Web diagram for mean sensory scores oftea samples. 1: strongly disliked; 2: moderately disliked; 3: slightly disliked;4: indifferent; 5: slightly liked; 6: moderately liked; 7: strongly liked15

No previous studies were found in the literature which used clove teafor sensory evaluation, thereby making this is the first study to incorporateit. A possible explanation for variation and the least preferred lemongrass teasample might be that aroma-producing compounds were volatile and may combinewith other constituents while preparing the sample16. Also, participants were probablynot familiar with lemongrass tea and would have expected sweet taste and anappealing black color17.

Furthermore, a previous study conducted by Ochanda et al.18 obtained similar results. They alsoreported that the panelist least preferred the lemongrass tea sample in termsof color, texture, and overall acceptability, consistent and in agreement withthe results obtained from our study. This study has shown that the clove teasample we formulated was most acceptable and preferred by the participantscompared to commercially available branded tea samples.

To our knowledge, this is the first study to demonstrate the consumeracceptability of tea prepared from the clove. Analysis of antioxidant andnutrient composition concludes that Clove tea samples had a higherconcentration of antioxidants and nutrient composition than other herbal tea,which suggests being responsible for sweet and high sensory attributes andflavor of the tea sample19. The high antioxidant composite ofthese tea samples produces tea of better quality to enhance health benefits.This will also encourage tea products and generate employment for many,culminating in economic development as tea import also reduces20.

Clove tea samples were the most preferred color, aroma,taste, texture, general appearance, and general acceptability. Lemongrass wasthe least accepted and preferred in terms of color and texture. The participantdid not prefer the aroma and general appearance of guava.

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