Evaluation of physiochemical properties of Lime (Citrus aurantifolia) leaves tea

Abstract

This study was conducted to make caffeine- free tea from lime (citrus aurantifolia) leaves (LLT). Leaves were obtained from the farm of university of Khartoum faculty of agriculture. Then thy washed by water and divided into four samples (250 gm.) for each sample , then three samples were exposed to withering process for fourteen hours to reduce moisture content of leaves , because withering enhance color and teats of the tea. Then leaves exposed to fermentation process in closed plastic containers, because fermentation of tea very important for color, test and quality of tea .the fermentation were done to three samples for (four, six and eight hr.) . Fermentation of tea is very important process in tea manufacture for color and quality of tea .and the rest sample was crushed and dried without fermentation. Results of proximate analysis of lime leaf tea (LLT) showed that (LLT) non-fermented(15.1%) and ( LLT) fermented for six hours(16.24%) and ( LLT) fermented for eight hours (14.78%)are better in ratio of carbohydrates and there were no significant between them .While (LLT) fermented for four hours(11.27%) occupied the second place. And there are no significant differences between ash (3.7% , 3.6% , 3.5%, 3.8%) , moisture (1.5% , 1.4% , 1.6% 1.5%) , protein (6.3%, 6.7% 5.4%, 6.4%) , fat (0.3%, 6.6% , 6.2% , 6.5%) and fiber(6.3%, 6.6% , 6.2% , 6.5%)respectively. The results of minerals content showed that that non-fermented (LLT)(169.8 mg/100g) and (LLT) fermented for six hours(167.6 mg/100g) had high calcium content compared to the rest of samples , while the (LLT) fermented for eight hours(154.3 mg/100g) occupy the second class and the lowest percentage in calcium was in (LLT) fermented for four hours(135.6 mg/100g) and there is no significant between it and the (LLT)fermented for eight hour((154.3 mg/100g). Also the results shows there were no significances differences between (Fe, Mg, k, p) in (non-fermented (LLT) , (LLT) fermented for four hr. , (LLT) fermented for six hr. , (LLT) fermented for eight hr. ) (1.2 mg/100g, 0.8 mg/100g, 1.3 mg/100g, 0.7 mg/100g) (66.9 mg/100g, 55.7 mg/100g, 61.17 mg/100g, 54.58 mg/100g) (11.8 mg/100g, 108.9mg/100g, 113.1 mg/100g , 111.6 mg/100g) respectively. The results of sensory evaluation showed that the red tea was better in color, while there were no significant different between non-fermented (LLT) , (LLT) fermented for four hours , (LLT) Fermented for six Hours , (LLT) fermented for eight hours (3.4 B) , (3.7B) , (3.7 B) , (3.7 B) . red tea(4.4A) and (LLT) fermented for four hours(4.1 A) was better in flavor compared the rest of the samples, while the (LLT) fermented for eight hours (3.4 AB) ranked middle the samples however (LLT) fermented for six(3.0 B , ) hours and (LLT) non-fermented (3.0 B) measured on late order. ) that the red tea(4.3 A) was significantly higher in taste but not significantly different from the (LLT) fermented for four hours(4.0 AB) , while the non-fermented (LLT)(3.2 BC) and (LLT) fermented for eight hours(3.7 ABC) ranked second and the (LLT) fermented for six hours(2.8 C) was last. Overall acceptability of (LLT) red tea(4.5 A) was better but not significantly different from the (LLT) fermented for four hours(3.4 AB) , while the (LLT) fermented for eight hours(3.2 BC) and non-fermented (LLT)(3.3 BC) ranked second .and (LLT) fermented for six hours(2.7 C) ranked last. The results of this study revealed that It possible to produce caffeine-free tea from lime (citrus aurantifolia )leaves -(LLT) fermented for four hours can be alternative for red tea and it is good drink for people who suffering from high level of calcium due to its lowest calcium content.