STUDY ON CHEMICAL COMPOSITION OF JUTE LEAVES AND DEVELOPMENT AS HERBAL TEA

Abstract

This study investigated the effect of maturity on the nutrients of jute leaves (Corchorus spp). Jute seeds were sown at Jute Seed Production and Research Centre, Nashipur, Dinajpur, Bangladesh and the leaves were harvested on 3 days interval basis from 15th day to 33th day after seed sowing (DASS) when senescence has started setting in. The moisture, protein, fat, crude fibre, and ash were determined using AOAC standard methods. The study indicated that as the plant age or matures the nutritional quality increases and the optimum value for crude protein was observed at 24th DASS. Proximate composition results indicated that the 100 g dry matter contained 111KJ energy. The study also reveal that the processing and preparation methods such as solar drying and cooking reduced their final consumed amount, they should be dried in dry and dark place under low temperature and cooking should be done within a short time for maximum retention of nutrients. The experimental results of hot water extract indicated that Corchorus capsularis (CC) contained high concentration of (+) catechin hydrate, transferulic acid, (-) epicatechin, pyrogallol ( 159.77, 27.94, 24.83 and 13.97 mg/100 g of dry weight), respectively. Corchorus olitorius (CO) also contain same chemical (53.41, 17.39, 14.80 and 15.34 mg/100 g of dry weight), respectively . On the other side, galic acid was detected only CO at lower concentration ( 16.49 mg/100 g of dry weight). In water extract the caffeine was higher in CO (0.17 %) than CC (0.14%). The total antioxidant activity was higher in CC ( 214.32, 75.02 mg / 100 gm ) than CO ( 165.66 , 48.49 mg /100 gm ) ethanol and water extract respectively. The hot water extracts of both C. capsularis ( CC ) and C. olitorius (CO ) leaves were prepared by usual method and were their antidiabetic effect was studied in type 2 diabetic model rats. In this study, average food intake, average body weight, blood glucose, total cholesterol, triglycride, HDL and LDL were measured after 28th day. The rats were divided into five groups. Gliclazide (5mg/Kg body weight) and hot water extracts (1.25g/Kg body weight) were administered orally for 28 consecutive days with single feeding. Serum glucose and lipid profile were measured by enzymatic colorimetric method. Aqueous extract of CC and CO also reduced blood glucose levels. The acute toxicity test was investigated in 30 mice. After consuming five doses (1-5 gm/ kg body weight), the mice showed no abnormality for two weeks and no sign of toxicity and no severity. So, the potential of the jute leaf is of health or nutraceutical significance and should help encourage consumption. Thus it was safe to consume as herbal beverage as a functional food product. There is still much that begs for sustained research on jute leaves, and this study forms the basis for product development system, especially in regard to bio-prospecting and valorization (value addition) of the jute leaves biodiversity product of herbal tea. The formula was confirmed by the consumer acceptance test (n = 200). The hedonic ratings were moderately like (6.42 - 7.17). The McNemar test indicated that the health benefit information could change buying decision of consumers. The finished tea product qualities were correlated with the ISO 3720 and BSTI (808: 2008), black tea standard.