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India contributes about one-third of the world acreage under rice. Rice is available in over 5000 varieties, of which Basmati rice occupies a prime position on account of its extra long superfine slender grains, pleasant, exquisite aroma, fine cooking quality, sweet taste, soft texture, length-wise elongation with least breadth-wise swelling on cooking and tenderness of cooked rice. The present work was undertaken to compare the effect of an organic and inorganic method of cultivation on the quality of Rice. The results revealed higher hardness, true density and percent porosity in inorganic grains of rice. Inorganic rice had better milling quality but cooking quality was found better of organic rice as evident from higher elongation ratio and swelling rate. Organically grown foods were found to be tastier in comparison to inorganic foods as organic samples scored higher for all the parameters of sensory. Moisture was found higher in inorganic Rice. The quantity of protein was less, but the quality was definitely better in organic crops as measured by in-vitro protein digestibility.
No definite trend was seen for effect of inorganic and organic mode of cultivation on total ash, crude fiber and carbohydrate content on rice crops. Iron was found to be significantly higher in organic rice (1.32 mg/100 g), Phosphorus was significantly higher in inorganic rice (112.80 mg/100 g), No significant difference was observed in manganese, cobalt, zink and copper content of the produced from an organic and inorganic mode of cultivation. Keywords: Organic, Inorganic, Rice, Food quality INTRODUCTION Rice, Oryza sativa, the staple food of nearly one-half of world’s population, contributes over 20% of the total calorie intake of man. But in Asia, where 95% of the world’s rice is produced and consumed, it contributes 40±80% of the calories of the Asian diet. India is one of the largest rice growing countries of the world, second only to China, cultivating 43 million hectares annually, which is about a third of the world acreage under rice (Muthu, 1993). Oryza sativa Linn is the major cereal crop of India, being available in over 5000 varieties differing with respect to size, texture, glutinous nature, aroma and cooking quality (Vachhani et al., 1962).
Indian agriculture is facing the strenuous task to provide food security as well as nutritional security for all. According to UNDP, safeguarding national food security means improving the quality of life of the farming community by ensuring no further depletion of the natural resource base. The most desirable way to meet the food grain requirements is the maintenance of good soil health and stability in production through the use of organic and biological resources. Organic agriculture is one of the most widely practiced, diversified conventional farming systems to make agriculture sustainable. In many respects, organic farming is profitable because of the low cost of production, though with somewhat lower yields than modern farming. Its success depends on the efficient agronomic management to stimulate the productivity of the soil resource. It is comparatively free from complex problems associated with modern agriculture and is eco-friendly as it conserves the natural resource of farming without polluting the atmosphere, soil and water resources. It also enhances the biomass availability to use as a source of renewable energy in rural areas. Increasing consumer awareness of health and social equity issues, as well as the environmental problems associated with industrial-scale agriculture, has resulted in widespread interest in organic food production systems.
The demand for organic food is steadily increasing both in the developed and developing countries with an annual average growth rate of 20-25 percent (Ramesh et al., 2005). Organic agriculture, without doubt, is one of the fastest-growing sectors of agricultural production. However, before embarking on a large conversion to organic agriculture, it should be judged over inorganic farming in terms of production, the effect on the environment, cost of production and quality. Keeping this in view, the present investigation was undertaken with a view to compare the effect of organic and inorganic methods of cultivation on the quality of Rice. MATERIALS AND METHODS Samples of organically as well as inorganically produced rice (Pant Basmati -1) were obtained from the produce of “Project On Comparative Study of Organic & Conventional System of Crop Production With Reference To Yield Quality, Soil Health & Biology” (University Funded Project) grown in Organic Agriculture Technology Block-C at practical crop production centre of G.B. Pant University of Agriculture and Technology, Pantnagar, Distt. Udham Singh Nagar. Rice was cleaned to remove dust, grit and other impurities. Paddy was milled in a laboratory mill (Department of Post Harvest Process & Food Engineering, COT). For the analysis of physical characteristics and cooking characteristics, whole grains were used. For chemical analysis, grains were ground using an electric grinder to get a semi coarse powder.
Thousand Grain weights were determined using methods given by Jackson et al. (1988). Grain hardness was determined using the Grain Hardness Tester (Kiya Seisakusho Ltd., Japan). Hydration capacity and seed volume were evaluated using methods given by Williams et al. (1983). Bulk density and true density were determined according to the method given by Bhattacharya et al. (1972). Percent porosity was calculated using the following formulae. Per cent porosity = Rice was also analyzed for length to breadth ratio; amylose content (Sowbhagya and Bhattacharya, 1971) and alkali score (Little et al., 1958). The milling quality of rice was assessed in terms of hulling yield, milling yield and degree of polishing. In Cooking quality analysis the sample of organically and inorganically produced grains of rice was subjected to open pan cooking and pressure cooking for different timings and per cent cooking was observed in each case. All the estimations were done in triplicate. The cooking quality of rice was assessed in terms of elongation ratio and swelling rate. In Sensory quality analysis the panel members were selected for evaluating sensory quality of rice, using triangle test. Then organic and inorganic samples rice was cooked in a similar manner. The sensory evaluation was done using sensory scorecard with parameters viz. color, taste, flavor, texture, appearance and overall acceptability by the selected panel members.
Nutrient composition of both organic and inorganic samples of all the crops was done by estimating proximate composition, in-vitro protein digestibility, and minerals. Proximate analysis was done using methods of AOAC (1975). In-vitro protein digestibility was determined following the procedure of Akeson and Stahman (1964) for digestion of protein and determining protein by Degroot and Stump (1961) method. Iron was estimated by Wong’s method (Raghuramulu et al., 2003), phosphorus by Fiske and Subba Row method (Ranganna, 1986), calcium by the method of AOAC (1975). Manganese, cobalt, and copper were estimated using atomic absorption spectrophotometer. All the values are reported as the mean of six replicates. RESULTS AND DISCUSSION The physical characteristic of the rice was assessed in terms of grain quality (Rice Grain Quality). Table 1 represents the grain quality of rice. Organic rice had higher thousand kernel weight (22.50 g) than their inorganic counterparts (21.48 g), however, the difference was not significant in any of the case.
The values for kernel hardness were higher in inorganic samples of rice (10.52 kg/grain,) as compared to that inorganic one (8.41 kg/grain) and the difference was found significant in both the cases, which suggests dense packing of biochemical substance in kernels of inorganic crops. The present findings are in line with those of Ghosh (2005). Singh et al. (1999) reported grain hardness adversely affects water absorption and delays the cooking process. This was also seen in the present study as hydration capacity of organic samples was more (0.03 g for rice,) than that of inorganic ones (0.02 g for rice,). No significant difference was seen in bulk density of organically produced and inorganically produced samples of rice i.e. the effect of mode of cultivation on bulk density was not seen but the true density and per cent porosity were found significantly higher in rice. Seed volume was found to be slightly higher in organic samples of rice (1.36 ml/100 grains) than that in inorganic samples (1.05 ml/100 grains). The higher seed volume of organic samples may be one reason for their increased hydration capacity as also reported by Kaur et al. (2005) that seed volume with seed weight is positively correlated to hydration capacity. Rice quality means different properties to various groups in the post harvest system for example farmer quality means high yield, minimum moisture content & minimum spoilage and microbial deterioration.
Miller quality means Length. Breadth, translucency, high head rice yield. Length/breadth ratio in organic rice was 3.53 against a value of 2.95 in inorganic rice, which shows that organic rice is finer than inorganic one and in India; the preference is for “fine-grained” as opposed to “coarse-grained” rice. The amylose content in organic rice was more (29.48) than that in inorganic rice (23.46). On the basis of classification given by IRRI (1973), organic rice was found to have high amylose content whereas inorganic rice had intermediate amylose content. The differences in amylose content may be attributed to the application of fertilizers as also reported by Paule et al. (1979) that amylose content decreases slightly with the application of nitrogen fertilizers. Alkali score of organic rice was 6 against a value of 4 in inorganic rice and the values obtained were in accordance with the values reported by Ram (2000) and Bhattacharya et al. (2002). On the basis of Alkali score, gelatinization temperature of organic and inorganic rice was found to be low and intermediate, respectively. Significantly higher values were observed for per cent hulling yield and per cent milling yield in inorganic rice as compared to that in organic rice whereas the average value for per cent degree of polishing was slightly more in organic rice as compared to inorganic rice with a non-significant difference between the two.
The reason for lesser milling yield in organic rice may be that thinner kernels of organic rice with lower grain hardness were more susceptible to breakage during milling. Paul and Siddiq (1986) reported varieties with high protein content resisted more abrasion as compared to varieties with low protein content. This might be another reason for higher milling yield in inorganic rice (with significantly higher protein as compared to organic one) in comparison to that in organic rice. Organic rice showed slightly higher elongation ratio (1.64) and swelling rate (0.73) as compared to inorganic rice (1.45 and 0.54, respectively) suggesting the better cooking quality of organic rice, which is a highly desirable trait in good quality rice (Fig 1). Organic and inorganic boiled rice were subjected to sensory evaluation using sensory scorecard by panel members selected on the basis of triangle test(Table 3). From statistical analysis of data obtained for different parameters, it could be inferred that panel members were not able to find any difference between organic and inorganic samples of boiled rice as both were rated in the same range. The nutritional quality of the rice was assessed in terms of proximate composition, and mineral and trace element composition.
The inorganically grown samples of the rice crops showed significantly higher values for moisture content (14.48 %)as compared to that by organic samples (11.77 %), thus suggesting more nutrient density in organic rice. Inorganic rice showed significantly higher protein (7.25 %) as compared to organic rice (5.57 %). crude fat i.e. in case of rice, inorganic sample showed significantly higher values (1.02 %) as compared to organic one (0.86 %) which might be due to different milling proportions. The total ash content was found to be slightly higher in organic samples of rice; however, the difference was not significant. The control decomposition of organic matter, high retention of inorganic nutrients and buffering action of organic matter regulates the release of inorganic constituents in the soil (Chhabra and Chhabra, 2003). This might be the reason for higher ash content in the organic sample. No definite trend was seen for crude fiber and available carbohydrate. As for crude fiber in case of rice, the inorganic sample showed higher values.
Similarly for carbohydrate, organic rice showed higher values in comparison to their counterparts. However, the difference was non-significant. No effect of mode of cultivation on energy value was apparent. The quality of protein was better in organic rice and the value for in-vitro protein digestibility was more (46.34 %) as compared to that in inorganic samples of rice (41.95 %).However, statistical analysis revealed that effect of mode of cultivation on in-vitro protein digestibility of rice crops was not significant. The values for all the minerals were higher in organic samples of the rice but a statistically significant difference was seen for iron (1.32 mg/100 g) and phosphorus (92.55 mg/100 g) in case of organic rice. The significantly higher levels of these minerals in organic crops may be attributed to decreased leaching losses and increased availability of nutrients with the use of organic matter (Chhabra and Chhabra, 2003). Acknowledgment The author is highly thankful to Directorate of Experiment Station, GBPUA&T, for providing the necessary facilities to carry out the research on Comparative Study of Organic & Conventional System of Crop Production With
ReferenceYTo Yield Quality, Soil Health & Biology. Table 1: Grain quality of inorganic and organic Rice Sample Bulk density (g/ml) True density (g/ml) #Hardness (kg/grain) 1000 kernel weight (g) Hydration capacity (g) Seed volume (ml) Per cent porosity (%) IR 0.74 1.57 10.54 21.50 0.02 1.05 51.41 OR 0.77 1.38 8.44 22.30 0.03 1.36 44.18 t-value 0.932 8.845* 2.442* -11.381 -3.360 -3.162 10.875* Note: Values are mean of six observations tabulated t-value: 2.571 *Significant difference # Values are mean of ten observations # tabulated t-value: 2.262 IR-Inorganic rice, OR-Organic rice Table 2: Quality of inorganic and organic Rice Parameter Inorganic rice Organic rice t-value Amylose content 23.46 29.46 -36.737 Hulling yield (%) 74.00 72.40 3.408* Milling yield (%) 64.04 63.31 5.165* Degree of polishing (%) 12.44 12.68 -3.343 #Length/breadth ratio 2.95 3.53 -10.384 Alkali score 4 6 -77.459 Note: Values are mean of six observations tabulated t-value: 2.57 *Significant difference # Values are mean of ten observations # tabulated t-value: 2.262 IR-Inorganic rice, OR-Organic rice Table 3: Sensory quality of inorganic and organic Rice Sample Texture Color Taste Flavor Appearance Overall acceptability IR 7.7 7.8 7.6 7.7 7.6 7.6 OR 8.0 7.9 8.0 7.8 7.9 7.9 t-value -5.581 -3.000 -6.508 -3.000 -8.216 -4.025 Note: Values are mean of ten observations tabulated t-value: 2.262 *Significant difference IR-Inorganic rice, OR-Organic rice Table 4: Proximate composition of inorganic and organic Rice Sample Available carbohydrate (%) Moisture (%) Crude protein (%) Crude fat (%) Total ash (%) Crude fibre (%) Energy (kcal) IR 76.31 14.49 7.25 1.02 0.65 0.26 344 OR 80.70 11.76 5.60 0.86 0.89 0.21 353 t-value -17.820 39.637* 8.126* 6.708* -10.679 2.381 -19.988 Note: Values are mean of six observations tabulated t-value: 2.571 *Significant difference IR-Inorganic rice, OR-Organic rice Table 5: Mineral and trace element composition (mg/100 g) of inorganic and organic Rice Sample Iron Phosphorus Calcium Manganese Cobalt Zinc Copper IR 0.60 112.80 15.17 1.137 0.013 3.376 0.044 OR 1.32 92.55 16.70 1.214 0.019 3.580 0.052 t-value 5.084* 7.537* -1.589 -1.333 -4.108 -5.719 -2.185 Note: Values are mean of six observations tabulated t-value: 2.571 *Significant difference IR-Inorganic rice, OR-Organic rice