Development of concentrated herbal tea based on three different tea grades incorporated with Pimenta dioica L. (Allspice), Mentha spicata L. (Mint), and Zingiber officinale Rosc. (Ginger)

Abstract

This study was aimed at the development of a concentrated herbal tea incorporating Allspice (Pimenta dioica L.), Mint (Mentha spicata L.), and Ginger (Zingiber officinale Rosc.) which cater not only to the multi-aroma and flavor but also to the therapeutic benefits for consumers. Refuse tea (T1), Broken Orange Pekoe Fanning’s (BOPF) (T2) and Dust (T3) grades were used as the tea bases for the concentrated herbal tea. The different concentrations of ingredients were optimized based on the results of the preliminary sensory evaluation. The aqueous extractions of tea grade, and herbal materials (Dried Allspice leaves (4-5%), fresh ginger (30-35%) and mint (20-25%)) were carried out using boiling hot water. Sugar was added and macerated until it reached a final concentration of 30-40 °Bx. Then the concentrated herbal tea was filtered and bottled following refrigeration at 4℃. The procedure was followed for each of the three grades separately and developed three concentrated herbal teas based on the tea grades (T1, T2, T3) and organoleptic, physicochemical characteristics and shelf life of three concentrated herbal teas were evaluated based on the tea grades by using Friedman test and one way ANOVA at 5 % significance level using Minitab software. The results revealed that sensory attributes such as mouth feel ( P ꞊ 0.002), overall taste ( P ꞊0.002), aftertaste ( P꞊0.002), and overall acceptability( P ꞊ 0.004) have significant differences among the three tea grades, while there is no any significant difference in appearance (P ꞊0.247) , color ( P ꞊ 0.165), or aroma (P ꞊0.368). The concentrated herbal tea based on BOPF grade was shown the best performance in sensory evaluation. Proximate parameters such as moisture (P ꞊0.000), carbohydrate content (P ꞊0.000), and energy (P ꞊0.000) were significantly differ among the three grades. The high carbohydrate (33.5%) and energy (135 kcal/100 mL) levels as well as high viscosity (16.7 centipoise), Total Flavonoid Content (TFC) values (1.81 ± 0.09 mg Quecertine equivalent/ mL serving per cup) and high caffeine content (2085 ppm/ 1 mL) were comprised of the concentered herbal tea based on BOPF grade. The Dust grade based on concentrated herbal tea indicated the highest color (L*/ Lightness: 15.8 ± 0.01, a* / Hue between Red and Green: 2.07 ± 0.01, b* / Hue between Yellow and Blue: 1.31 ± 0.01), Ferric Reducing Antioxidant Power (FRAP) (634 ± 30 mg trolox/ mL serving per cup), Total Polyphenol Content (TPC) (45.5 ± 17 mg/ mL serving per cup), Oxygen Radical Absorbance Capacity (ORAC) (0.22 ± 0.01 mg / mL serving per cup) values while BOPF based concentrated herbal ranking second highest. In conclusion, unique flavor combinations provided a pleasant sensorial experience to concentrated teas while the tea grade used directly impacted on the end quality of the product.