Nutrient composition and sensory evaluation of drumstick (Moringa oleifera Lam.) leaf products

Drumstick (Moringa oleifera Lam.), an indigenous underexploited tree, is now valued for health care. It provides pods and leaves for vegetables, and has various nutraceutical values. Nutrient composition of pods and leaves of drumstick KDM-01 (Bhagya, a recently released variety from University of Horticultural Sciences, Bagalkot during 2012) and S-6/4 (Dhanraj) and sensory evaluation of products that contained dehydrated drumstick leaf powder at different levels was carried out at College of Horticulture, University of Horticultural Sciences, Bagalkot, Karnataka, India. There was no significant difference observed between the varieties with respect to proximate composition of pods and leaves. In micronutrient composition, pods showed significant difference between the varieties in ascorbic acid, phosphorus, potassium and magnesium contents. The pods of variety KDM-01 were significantly higher in ascorbic acid (138.54 mg/100 g), phosphorus (109.70 mg/100 g) and magnesium (24.50 mg/100 g) content. Whereas, the pods of the variety S-6/4 was significantly higher in potassium (265.28 mg/100 g) content. In leaf micronutrient composition, KDM-01 variety showed significantly higher ascorbic acid (17.48 mg/100 g), calcium (2399.11 mg/100 g) and copper (0.081 mg) contents than variety S-6/4 (15.82 mg/100 g, 2081.77 mg/100 g and 0.073 mg/100 g, respectively). Whereas, the leaf of S-6/4 was significantly higher in iron (28.56 mg/100 g) than KDM-01 (27.36 mg/100 g). With regard to sensory evaluation studies, the acceptability of Thalipattu incorporated with 5% fresh leaves was accepted highly, followed by 5% dehydrated leaf powder. Rice Kichadi prepared by incorporation of 7.5% dehydrated drumstick was accepted most, followed by control (without incorporation of drumstick leaves). Products incorporated with drumstick leaves at different levels showed corresponding elevation in micronutrient composition. Drumstick leaves are an outstanding indigenous source of highly digestible protein, calcium, iron, ascorbic acid and vitamin A, and can be exploited either in fresh or in dehydrated form in traditional food items. This would help in alleviating micronutrient deficiencies in a cheaper and most affordable way. INTRODUCTION Micronutrient deficiencies are more common in developing countries and the cause for their high prevalence is low dietary intake by populations and poor availability of micronutrients. Iron deficiency is the most common nutritional problem worldwide and contributes to maternal deaths in pregnancy and parturition. In India 79% of 290 SEAVEG2014: Families, Farms, Food children between 6 to 35 months and women between 15 to 49 years of age are anaemic (Krishnaswamy 2009). Vitamin A deficiencies are estimated to cause 600,000 deaths whereas zinc deficiencies cause 400,000 deaths annually. The most sustainable approaches to increasing the micronutrient status of populations are foodbased strategies, which include food production, dietary diversification and food fortification. Food-based intervention focus on natural, processed, or fortified foods alone or in combination as the primary tool for improving the quality of diets and for overcoming and preventing malnutrition and nutritional deficiencies. Green leafy vegetables are rich sources of iron and other essential micronutrients, but they are discarded and are not used for human consumption. Drumstick leaf (Moringa oleifera L.) is one of them, which is available at no cost. The leaves are micronutrient-dense and provide more vitamins per mouthful than any other leaves. It is commonly said that drumstick leaves contain more vitamin A than carrots, more calcium than milk, more iron than spinach, more vitamin C than oranges and more potassium than bananas and that the protein quality rivals that of milk and eggs. Drumstick leaves can be utilized in multiple ways by incorporating them into existing products and formulations of health foods using techniques of dehydration. Devising several simple and acceptable micronutrient-rich recipes containing drumstick leaves would not only bring variety to the diet but also help in combating micronutrient deficiencies. Therefore, we studied nutrient composition and sensory evaluation by utilizing the dehydrated drumstick leaf powder to enhance the nutritional quality of traditional products. METHOD Two varieties of drumstick (kdm-01 and s-6/4) pods and leaves were procured from the Research Field Unit, Department of Vegetable Science, College of Horticulture, University of Horticultural Sciences, Bagalkot. The other ingredients used for the preparation of formulations were procured from the local market. Proximate composition (protein, fat, crude fibre, carbohydrate and moisture), vitamin A and ascorbic acid content of pods leaves and incorporated products were analyzed by using the standard procedure of AOAC (2004). Mineral estimation of the samples was carried out by the method of Ranganna (1986). Preparation of drumstick leaves for drying Fresh, green, undamaged, non-insect infested leaves were sorted out and the stalks of the leaves were cut from the main branches. Leaves were washed thoroughly three to four times under running water to remove the adhering dust and dirt particles. Washed leaves were spread on cotton cloths on the working table for shade drying in a wellventilated room until the leaves were dried completely and became crisp and brittle to touch. The dried leaves were powdered, stored in airtight containers in a refrigerator and used for incorporation in traditional products Thalipattu and Kichadi. Product formulation Two products, Thalipattu and Kichadi, were selected for incorporating dehydrated drumstick leaves powder. Thalipattu is a mixed cereal and legume pancake-like product consumed for breakfast. Bengal gram flour (25 g), rice flour (25 g), fine semolina (25 g) and whole wheat flour (25g) were mixed together. Onion (40 g), tomatoes (20 g), half green chili (finely chopped), ajwain (1 g), cumin seed powder (1 g) and salt (3 g) were added to flour mixture and made into a stiff dough with water. The dough was rolled with roller and pin to have a diameter of about 5 inches and Sustaining Small-Scale Vegetable Production and Marketing Systems for Food and Nutrition Security 291 roasted by using oil (5 ml) on a nonstick tawa. Then it was turned upside down so that it was roasted on both sides. The dehydrated drumstick leaf powder at 2, 5, 7.5, 10% levels and 5% fresh drumstick leaves were incorporated into the flour mixture. The dough without addition of drumstick leaves served as control. Kichadi is a pressure-cooked product prepared by using rice (70 g) and a legume, green gram dhal (30 g). Onion, chili, salt, mustard seeds, cumin seeds, oil and curry leaves were added for the product preparation. Rice and green gram dhal were washed thoroughly and cooked in a pressure cooker until soft. Seasoning was given with a little oil, mustard, cumin, chopped onion, chilli and curry leaves and mixed together with the cooked rice and green gram dhal mixture. During cooking the Kichadi was prepared by incorporating dehydrated drumstick lead powder at 2, 5, 7.5 and 10% levels and 5% fresh drumstick leaves. The Kichadi without incorporation of drumstick leaf served as control. Sensory evaluation The formulated products were subjected to sensory evaluation with the help of panel of 20 members using 9-point hedonic ranking scale for appearance, colour, texture, taste and overall acceptability (Swaminathan 1987). The product without dehydrated drumstick leaf powder and fresh leaves served as control. The data was compiled and analyzed statistically. Statistical analysis Statistical analysis for nutrient and micronutrient composition of drumstick pods and leaves was carried out by Student’s ‘t’ test. The sensory evaluation data was subjected to ANOVA (Panse and Sukathme 1967) and ‘F’ test was carried out to know the significant difference among the products that were developed. RESULTS AND DISCUSSION Proximate composition of drumstick pods and leaves Proximate composition of drumstick pods and leaves are presented in Figures 1 and 2. The moisture content of the pods of Dhanraj and Bhagya was 87.95 and 87.41%, respectively, whereas, leaves contain 76.22 and 75.83%, respectively and there was no significant difference between the varieties. Protein content was slightly higher in the pods (3.50%) and leaves (6.11%) of Bhagya than Dhanraj (3.43% and 5.87%, respectively) though there was no significant difference between the varieties. Fat content was higher in Dhanraj pods (0.12%) and leaves (1.83%) than Bhagya (0.10 % and 1.71%, respectively). Crude fibre content was more (4.93%) in Bhagya pods than Dhanraj (4.66%) whereas, leaves of Dhanraj (2.50%) was higher amount than Bhagya (2.46%). The pods and leaves of Bhagya (4.06% and 13.89%) variety was higher carbohydrate than Dhanraj (3.84% and 13.58 %, respectively). The difference between the pods and leaves of two varieties with regard to proximate composition were found to be statistically insignificant. Vitamin and mineral composition of drumstick pods and leaves Vitamin and mineral composition of drumstick pods and leaves are depicted in Table 1 and Table2. In pods of Bhagya the ascorbic acid content was 138.54 mg/100 g and it was significantly different than the pods of Dhanraj (121.43 mg/100 g). The same trend was also observed in ascorbic acid content of leaves, where in the leaves of 292 SEAVEG2014: Families, Farms, Food variety Bhagya was higher (17.48 mg/100 g) ascorbic acid than the variety Dhanraj (15.82 mg/100 g). Vitamin A content of both varieties was on par with each other in both the pods and leaves. However, the leaves of Bhagya (18.12 mg/100 g) was higher in Vitamin A than Dhanraj (16.46 mg/100 g). In mineral composition there was significant difference between the pods of two varieties with respect to phosphorus, potassium and magnesium content. Phosp