9 research outputs found

    Mathematical Modelling and Optimisation of Low-Temperature Drying on Quality Aspects of Rough Rice

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    Rice when harvested normally has a high moisture content of 20–25% which requires immediate drying, reducing its mass loss and preventing it to spoil. This situation is more crucial with the areas under humid tropical conditions, where moisture and temperature mainly play an important role in deteriorating the quality of rough rice. Keeping the importance of quality attributes of rough rice, the study was carried out to assess the effects of low-temperature drying and suggest an optimum condition. Response surface methodology (RSM) with a central composite design was employed to study the effects of variables, i.e., temperature (X1), time (X2), and air velocity (X3) on responses, i.e., head rice yield (HRY), hardness, lightness, and cooking time. The experimental data were fitted to the quadratic model, studying the relationship between independent and dependent variables. The results revealed that the HRY, hardness, lightness, and cooking time increased with increasing variables, whereas for HRY, it particularly increased and then decreased. It was observed that temperature had more influence on the quality of rough rice followed by time and velocity. Results for analysis of variance revealed that the quality aspects of rough rice were significantly (p<0.05) affected by temperature and time, whereas for velocity, it only significantly affected hardness. The optimal drying conditions predicted by RSM for variables were 25°C, 600 min, and 1 m·s−1, and the optimal predicted HRY, hardness, lightness, and cooking time were 73.93%, 38.28 N, 71.40, and 27.58 min respectively. Acceptable values of R2, Adj R2, and nonsignificance of lack of fit demonstrated that the model applied was adequate and can be used for optimization. The study concluded that the RSM with a central composite design was successfully used to study the dependence of quality aspects of rough rice at low temperature and can be utilized by the rice processing industries

    Effect of Different Irrigation Water Qualities on Turnip Production and Water Productivity under Furrow Irrigation Method

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    A field experiment was conducted at Sindh Agriculture University Tandojam during the year 2015-16, aiming to investigate the response of turnip crop to various salinity levels of irrigation. The experiment was placed applying randomized complete block design (RCBD) with four different treatments i.e. Freshwater (I1), ECw with 2.5, 3 and ECw3.5 dS m-1 (I2, I3 and I4) respectively replicated thrice. The results for experiment placed revealed an average increase in soil ECe 0.09, 0.17, 0.26 and 0.38 dS m-1 under I1, I2, I3 and I4 respectively. An decrease in dry density (g cm-3) of soil profile, decrease in pH 0.19, 0.38, 0.5 and 0.84 in treatments I1, I2, I3 and I4 respectively and an decrease in agronomical data i.e. weight and diameter were also observed with an increase in ECw by the water being irrigated. Crop water productivity with 5.83, 4.35, 2.97 and 1.85 kg m-3 for treatmentsI1, I2, I3 and I4 respectively also decreased with an increase in ECw and Nacl. Average yield of 19.27, 14.37, 9.83 and 6.12 kg was obtained with applied treatments i.e. I1, I2, I3 and I4 respectively, thus a decrease in yield with 25.45%, 31.60% and 37.72% with treatments I2, I3 and I4 was observed when compared as treated by freshwater (I1). Therefore farmers can use irrigation water having ECw 3.5 dS m-1 for the turnip crop at reduction of 37.72% (approximately)

    Effect of Different Irrigation Water Qualities on Turnip Production and Water Productivity under Furrow Irrigation Method

    No full text
    A field experiment was conducted at Sindh Agriculture University Tandojam during the year 2015-16, aiming to investigate the response of turnip crop to various salinity levels of irrigation. The experiment was placed applying randomized complete block design (RCBD) with four different treatments i.e. Freshwater (I1), ECw with 2.5, 3 and ECw3.5 dS m-1 (I2, I3 and I4) respectively replicated thrice. The results for experiment placed revealed an average increase in soil ECe 0.09, 0.17, 0.26 and 0.38 dS m-1 under I1, I2, I3 and I4 respectively. An decrease in dry density (g cm-3) of soil profile, decrease in pH 0.19, 0.38, 0.5 and 0.84 in treatments I1, I2, I3 and I4 respectively and an decrease in agronomical data i.e. weight and diameter were also observed with an increase in ECw by the water being irrigated. Crop water productivity with 5.83, 4.35, 2.97 and 1.85 kg m-3 for treatmentsI1, I2, I3 and I4 respectively also decreased with an increase in ECw and Nacl. Average yield of 19.27, 14.37, 9.83 and 6.12 kg was obtained with applied treatments i.e. I1, I2, I3 and I4 respectively, thus a decrease in yield with 25.45%, 31.60% and 37.72% with treatments I2, I3 and I4 was observed when compared as treated by freshwater (I1). Therefore farmers can use irrigation water having ECw 3.5 dS m-1 for the turnip crop at reduction of 37.72% (approximately)

    Design and Thermal Analysis of an Air Source Heat Pump Dryer for Food Drying

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    In this study, an experimental heat pump dryer was designed. The specific moisture extraction rate and moisture extraction rate were used as performance indicators to explore the influence of environmental factors and the style of the hot air cycle on heat pump drying. The average temperature and humidity in Nanjing&rsquo;s summer, winter, and throughout the whole year were taken as the experimental ambient temperature and humidity. Garlic slices 3 mm thick, with an initial moisture content of 66.714% w.b., were dried until the end moisture content was 10% w.b. Experimental results and thermal analysis showed that the open and semi-open heat pump dryers were greatly affected by ambient temperature and humidity. The closed heat pump drying system was greatly affected by the bypass air rate

    Study on Cultivators Associating Post Harvest Losses of Onion Vegetable in Sindh’s Mirpurkhas District

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    A study was carried out in Mirpurkhas District of Sindh Province during the year 2015-16, aiming to observe post-harvest losses of onions associated with the cultivators. Following the random sampling 60 respondents were selected from 12 villages of 06 Talukas in the District. Interviews were conducted for the collection of data. Problems expressed were as; high cost of fertilizers (93.33%), high cost of pesticides (93.33%), hand weeding is labour consuming and expensive (91.66%), labour problems during harvesting (85%), ineffective and costly weedicides (80%), lack of knowledge about recommended fertilizers doses for onion crop (80%) and lack of knowledge about improved varieties (68.33%). The problems in marketing of onion include lack of remunerative price (96.66%), fluctuation in market price (93.33%) and high charges of transportation (20%). The present study suggested that training/ awareness programs should be conducted for cultivators regarding establishing technical storage and handling onion problems
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