PHYSICAL AND FUNCTIONAL PROPERTIES OF SIX VARIETIES OF LENTIL (LENS CULINARIS MEDIK.)

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1 Asian J. Dairy & Food Res.., 33 (2) : , 2014 doi: / AGRICULTURAL RESEARCH COMMUNICATION CENTRE PHYSICAL AND FUNCTIONAL PROPERTIES OF SIX VARIETIES OF LENTIL (LENS CULINARIS MEDIK.) Varsha Rani* and R.B. Grewal Department of Foods and Nutrition, CCS Haryana Agricultural University, Hisar , India Received: Accepted: ABSTRACT Lentil is a valuable source of proteins, starch and non-starchy carbohydrates, minerals and micronutrients. The functional properties of flour that affect the sensory features of food are quite important to know the interaction and behaviour of different food ingredients during preparation, processing and storage of developed product. The aim of present research was to evaluate the physical and functional properties of lentil grains and flour. The bulk samples of six varieties of lentil LH-84-4, LH 89-48, L 9-12, LH 82-6, LH and L4076 were obtained and evaluated for various physical and functional properties i.e. moisture content, grain hardness, grain weight, grain colour, cooking time, seed density, hydration capacity, hydration index, swelling capacity, swelling index water absorption, oil absorption, gelation capacity, gel consistency, emulsification capacity, swelling power, gelatinization temperature, nitrogen solubility index (NSI) and flour solubility. Results showed that variety L 9054 had maximum grain weight (32.4g), seed density (1.31g/ml), water absorption (1.28g/g), swelling capacity (5.0%) and nitrogen solubility index (50.3%). Whereas, variety LH 8948 had lowest grain hardness (8.0 kg/grain) and cooking time (36.60 min.). It may be concluded that variety L 9054 and LH 8948 had comparatively better physical and functional qualities. Key words: Emulsification, Gel consistency, Lentil, Oil absorption, Physical, Water absorption. INTRODUCTION Legumes are inexpensive source of proteins with high nutritional profile and after cereals, important food source for humans (Doyle, 1994). Protein content in legume ranged from percent, contrasting with that of cereals 7-13% and comparable to meat 18-25% (Genovese and Lajolo, 2001). Being a cheap source of protein for low income group of population, legumes are commonly used as a substitute for meat and play a significant role in alleviating the protein-energy malnutrition. In addition they are also a good source of complex carbohydrates, dietary fiber and contain significant amounts of vitamins and minerals (Tharanathan and Mahadevamma, 2003). Lentil (Lens culinari s Medik.) is predominantly grown in South East Asia and commonly consumed dal made from whole grain or split pulse commonly referred to as dhal. Lentil grain can also be fried and seasoned for consumption; * Corresponding author s varshadangi@gmail.com flour is used to make soups, stews purees, and mixed with cereals to make bread and cakes, and as a food for infants (Williams and Singh, 1988). Lentil although called as a poor man s meat, is equally liked by all socioeconomic groups in South East Asia (Bhatty, 1988). Lentil is now considered as one of the most beneficial legumes for health (Combe et al., 2004). It is a valuable source of proteins, starch and non-starchy carbohydrates, minerals and micronutrients (Combe et al., 2004). Lentil is an important rabi pulse crop with a production of Mt in India, after gram. In the global context, India is the largest producer of lentil. In the year, 2005, about 27 per cent of 3.65 Mt world s lentil production was contributed by India (Reddy and Reddy, 2010). The functional properties of flour that affect the sensory features of food are quite important to know the interaction and behaviour of different food ingredients during preparation, processing and

2 storage of developed product. The factors that affect functional behaviour of grains in foods are their size, shape, protein content, amino acid composition and sequence, net charge, hydrophobicity, or interaction with other food constituents (Aluko and Yada, 1997). Legumes have gained immense importance in modern food design due to their nutritional value and favourable functional properties. Several food industries are in search for the desirable functional qualities of legume flours in order to meet their requirements. The use of edible legumes as a food deserves intensive study and promotion, it is necessary to investigate the functional properties of legume flours in view of optimal utilization and consumer acceptance. Therefore, present investigation was conducted to evaluate the physical and functional properties of lentil grains and flour. MATERIALS AND METHODS Procurement of material: The bulk samples of six varieties of lentil LH-84-4, LH 89-48, L 9-12, LH 82-6, LH and L4076 were obtained from the pulses section, Department of Plant Breeding, CCS Haryana Agricultural University, Hisar. Physical properties: Grains were evaluated for various physical characteristics i.e. grain hardness, grain weight, grain colour, cooking time, density, hydration capacity, hydration index, swelling capacity and swelling index. Moisture content was estimated using digital moisture meter, Indosaw (Osaw Industrial Products Pvt. Ltd.). Grain hardness was measured by pressing ten average sized well filled grains under the grain hardness tester, manufactured by Kiya Seisakusho Ltd., Japan. Grain weight was determined by AOAC (1995) method. One thousand seeds were counted thrice and were weighed in grams. Grains colour was observed visually. Lentils were boiled in water and cooking time was recorded in minutes after five seeds tested were found cooked. Seeds (50 g) were weighed accurately and transferred to a measuring cylinder. Then 50 ml distilled water was added to it. Seed volume was recorded by subtracting 50 ml from the total volume (ml). Density was recorded as g/ ml. Hydration capacity per seed was determined by using the following formula (weight of soaked seeds weight of seeds before soaking/ no. of seeds). Hydration index was calculated as hydration capacity per seed divided by the weight of one seed Vol. 33, No. 2, in gram. Swelling capacity per seed was determined by using the formula (volume of seeds after soaking volume of seeds before soaking/ no. of seeds). Swelling index was calculated as swelling capacity per seed divided by the volume of one seed in milli litre. Functional properties: Lentil grains were ground to get flour using an electric grinder (Cyclotec, M/s Tecator, Hoganas, Sweden) using 0.5mm sieve and were analysed for various functional properties i.e. water absorption, oil absorption, gelation capacity, gel consistency, emulsification capacity, swelling power, gelatinization temperature, nitrogen solubility index (NSI), flour solubility, swelling power and emulsification capacity. The water absorption and gelation capacity of lentil flour of different varieties was determined according to the method of Singh and Singh (1991). Oil absorption was determined by the method of Rosario and Flores (1981) with minor modifications by Iyer and Singh (1997). Emulsification capacity was determined by the method of Singh and Singh (1991) with minor modifications by Iyer and Singh (1997). Gel consistency was determined by the method of Iyer and Singh (1997). Gelatinization temperature was determined by the standard method (Singh, 2001) Swelling power and flour solubility of the flour was determined by the method of Subramanian et al. (1986). The nitrogen solubility index (NSI) was determined according to the AOAC approved method (AOAC, 1995) with minor modification by Iyer and Singh (1997). Data Analysis: The result of the three replicates were pooled and expressed as mean ± standard error a one way analysis of variance (ANOVA) and the Least Significance Difference (SLD) were carried out. Significance was accepted at P RESULTS AND DISCUSSION Physical properties: Moisture content of different lentil varieties ranged from per cent, 1000 grain weight of selected six varieties of lentil varied from g. Variety L 9054 had maximum grain weight followed by L 9-12, L 4076, L 84-8, LH 82-6 and LH A non significant difference in grain weight of L4076 and L9-12 varieties whereas significant difference in grain weight of other varieties was found (Table 1). Ereifej and Shibli (1995) observed a wide range ( g)

3 128 ASIAN JOURNAL OF DAIRY & FOOD RESEARCH TABLE 1: Physical properties of six promising lentil varieties Lentil Moisture(%) 1000 grain Grain hardness Cooking time Seed density Hydration Hydration Swelling capacity Swelling culti-vars weight (gm) (kg/grain) (min) (g/ml) capacity (g/seed) index (ml/seed) index L a ± b ± a ± b ± b ± a ± b ± a ± c ± 0.01 L a ± c ± c ± a ± c ± ab ± b ± b ± c ± 0.04 L b ± a ± c ± a ± a ± ab ± c ± b ± d ± 0.05 L b ± b ± c ± a ± b ± bc ± a ± c ± b ± 0.02 LH a ± d ± b ± b ± a ± bc ± b ± ab ± a ± 0.07 LH a ± e ± d ± b ± b ± c ± a ± c ± c ± 0.03 Overall mean 11.48± ± ± ± ± ± ± ± ± 0.18 CD (P< 0.05) Values are mean ± SD of three independent determinations Means with the same superscripts do not differ significantly (P< 0.05) for 1000 seed weight in four varieties of Jordan lentils. Grain hardness of lentil varieties varied from kg/grain, it was maximum in L 4076 and minimum in LH variety. A non significant difference in grain hardness of L 84-8, L 9054 and L 9-12 was found. Cooking time of selected lentil varieties ranged between minutes. L 4076, L and L 82-6 required less time to cooking than L 84-8, L 9054 and L The results of present study lend support by the study of Erskine et al. (1985) and Jood et al. (1998). Seed density of six varieties of lentil varied from g/ml. Seed density of L9054 and LH82-6 was found to be significantly higher than L4076, L9-12, LH89-48 and L84-8. Lowest seed density was recorded for L84-8. There was no significant difference in seed density of L 4076, L 9-12 and LH was found (Table 1). Hydration capacity and hydration index of six lentil varieties ranged from g/seed and , respectively. L 4076 had maximum hydration capacity, whereas hydration index was highest for L9-12. The variety named LH had minimum hydration capacity, whereas the variety named L 9054 had minimum hydration index. Ereifej and Shibli (1995) reported per cent of hydration capacity in four varieties of Jordan lentils. Jood et al. (1998) observed ml/ seed hydration capacity among three lentil varieties. Among selected varieties, L 4076 had maximum swelling capacity (4.2), whereas LH and L 9-12 had significantly lower swelling capacity than other varieties. No significant difference in swelling capacity LH 84-8, L 9054 and LH 82-6 was found, whereas, the swelling index of LH 82-6 was highest followed by L 9-12, LH 89-48, LH 84-8, L 4076 and L Significant difference in the swelling index of different varieties was found (Table 1). Swelling capacity ml/seed of three lentil varieties was reported by Jood et al. (1998). Colour of lentil varieties varied from pale reddish brown to greenish grey. Functional properties: The water and oil absorption of different lentil varieties ranged from g/g and g/g, respectively. Water absorption was highest for L 9054, whereas oil absorption was highest for L No significant difference in the water absorption of variety LH 89-48, L 9054 and

4 L 4076 was found. Similarly, no significant difference in oil absorption of variety L 4076, L 9054 and LH was found (Table 2). The difference in oil absorption capacity within different varieties of lentil may be due to the variation in the presence of non-polar side chai ns, which bi nd the hydrocarbon side chain of oil. Oil absorption capacity is desired in flavor retention, improvement of palatability, extension of shelf life of bakery products and soups. The emulsification value and gel consistency of vari ety L 4076 was maximum, whereas emulsification value and gel consistency of L 9054 was minimum. No significant difference in emulsification value of variety L 4076, L 84-8 and LH and gel consistency of variety L 84-8, L 9054, L 9-12 and LH was found. Gelation capacity for different lentil varieties ranged between per cent. LH 82-6 had highest and L 9054 had lowest gelation capacity. No significant difference in the gelation capacity of LH 89-48, L 9-12, L 84-8 and L 4076 was found, the gelation capacity of these varieties were significantly lower than LH 82-6 and significantly higher than L 9054 (Table 2). Swelling capacity of selected six varieties ranged from percent. It was highest for L 9054 and lowest for LH No significant difference in swelling capacity of L 9054 and LH and of L 4076 and L 9-12 was found. The swelling capacity of these varieties was significantly lower than L 9054 and LH but significantly higher than L 84-8 and LH Among different lentil varieties the flour solubility and NSI ranged from per cent and per cent, respectively. LH 82-6 had significantly higher flour solubility than others. However, the NSI of L 9054 was highest. Flour solubility and NSI of L 9-12 was lowest. At high acidic and alkaline ph the protein gets net positive and negative charge, respectively. Which favour the repulsion of molecules and thereby increasing the solubility of proteins (Adebowale and Lawal, 2004). The slight difference in solubility within the lentil varieti es might be due to physi cochemical characteri stics exhibi ted by these species. Gelatinization temperature among different lentil varieties ranged from 66 C-74 C (Table 2). The Vol. 33, No. 2, 2014 TABLE 2: Functional properties of flour of six promising lentil varieties Lentil varieties Water Oil absorption Emulsifi-cation Gel consistency Gelation capacity Swelling Flour Nitrogen Gelatini-zation absorption (g/g) (g/g) (g/g) (mm gel spread) (%) capacity (%) solubility (%) solubility tempera-ture index (%) L ab± a± a± a± ab± b± cd± b ± b ± 0.50 L bc± bc± a± c± ab± c± c± c ± c ± 0.50 L a± ab± c± c± c± a± b± a ± d ± 0.50 L bc± a± b± bc± ab± b± d± d ± a ± 0.50 LH c± c± b± ab± a± d± a± a ± e ± 0.50 LH a± ab± a± bc± b± a± c ± c ± c ± 0.50 Overall mean 1.23± ± ± ± ± ± ± ± ± 2.68 CD (P< 0.05) Values are mean ± SD of three independent determinations Means with the same superscripts do not differ significantly (P< 0.05) 129

5 130 ASIAN JOURNAL OF DAIRY & FOOD RESEARCH gelatinization temperature was highest for L 9-12 followed by L 4076, L 84-8, L 89-48, L 9054 and LH Except the gelatinization temperature of L and LH 89-48, the GT of other varieties was significantly different from each other. CONCLUSION As a result, variety named L 9054 had maximum grain weight, seed density, water absorption, swelling capacity and nitrogen solubility index. Whereas, variety named LH 8948 had lowest grain hardness and cooking time. On the basis of physical and functional properties of grain and flour it may not be said that this particular variety is best. It may be concluded however that variety L 9054 and LH 8948 had comparatively better physical and functional qualities. Therefore, these varieties may be used in developing various processed and value added products. REFERENCES Adebowale, K. O. and Lawal, O. S. (2004) Comparative study of the functional properties of bambara groundnut (Voandzeia subterranean), jack bean (Canavalia ensiformis) and mucuna bean (Mucuna pruriens) flours. J. Fd. Res. Int., 37: Aluko, R.E. and Yada, R.Y., (1997) Some physicochemical and functional properties of cowpea (Vigna Unguiculata) isoelectric protein isolate as a function of ph and salt concentration. Int. J. Fd. Sci.Nutr., 48: AOAC, (1995) Official Methods of Analysis. Association of Official Analytical Chemists, Washington, D.C. Bhatty, R.S. (1988). Composition and quality of lentil (Lens culinaris Medik): a review. J. Can. Inst. Food Sci. Technol. 21: Combe, E., Pirman, T., Stekar, J., Houlier, M.L., Mirand, P,P. (2004) Differential effect of lentil feeding on proteosynthesis rates in the large intestine, liver and muscle of rats. J Nutr Biochem.15:12 17 Doyle, J.J., (1994). Phylogeny of the legume family: An approach to understanding the origins of nodulation. Annu. Rev. Ecol. Syst., 25: Ereifej, K.I. and Shibli, R.A. (1995) Physical, chemical and cooking characteristics of a Landrace and three newly developed lentil cultivars grown in Jordon. J. Food sci. Technol. 32: Erskine, W., Williams, P.C. and Nakoul, H. (1985) Genetic and environmental variation in the seed size, protein, yield and cooking quality of lentils Field Crop Res. 12: Genovese, M.I. and Lajolo, F.M. (2001) Trypsin inhibitory activity of the bean (Phaseolus vulgaris L.): evaluation of critical method of the determinacy. J. Latin America nutrica. 51: Iyer, L. and Singh, U. (1997) Functional properties of wheat and chickpea composite flours. Food Australia 49(1) :27-31 Jood, S., Bishnoi, S. and Sharma, A. (1998) Chemical analysis and physical properties of chickpea and lentil cultivars. Nahrung 42: Reddy, A.A. and Reddy, G.P. (2010) Supply Side Constrains in Production of Pulses in India: A Case Study of Lentil. J.Agri. Eco. Res. Rev. 23: Singh, U. (2001) Functional properties of grain legume flours. J. Food Sci. Technol. 38(3): Singh, U. and Singh, B. (1991) Functional properties of sorghum-peanut composite flour. Cereal Chem. 68(5): Subramanian, V., Jambunathan, R. and Ramaiah, C.D. (1986) Physical and chemical characteristics of pearl millet grains and their relationship to roti quality. J. Food Sci. 51(4): Tharanathan, R.N. and Mahadevamma, S. (2003) Grain legumes a boon to human nutrition. Trends Food Sci.Technol., 14: Williams, P.C. and Singh U. (1988) Quality screening and evaluationin pulse breeding. In: World Crops: Cool Season FoodLegumes. R.J. Summerfield. Kluwer Academic Publishers, Dordrecht The Netherlands