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Open Access
Development of microwave assisted fluidised bed dryer for nutmeg mace
(Department of Food and Agricultural Process Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2017) Yarrakula Srinivas; KAU; Santhi Mary, Mathew
Dried mace possess great importance in international trade and are used in the preparation of extractives and volatile oils. Among various hot air drying methods, the more efficient method is fluidized bed drying for drying of foods, fruits and vegetables. Microwave drying, an alternative method for the drying of food products has gained popularity and is widely adopted. In microwave heating, heat generation takes place from inside to outside of the material due to the absorption of microwave energy by the regions with higher moisture levels. Application of microwaves solely, can result in uneven heating of certain products, depending on their dielectric and thermo physical properties. Thus, combining microwave radiation with hot air fluidization also provides an effective means of overcoming the non-uniform heating problems in conventional microwave heating. The bulk density, L*, a* and b* values of the fresh mace sample were 1191 kg/m3, 21.28, 22.23, and 9.09 respectively. At 5.1 m/s the fresh mace sample attained the fluidization condition. The developed microwave assisted fluidized bed drying system consists of a fluidized bed dryer and a microwave oven unit. The microwave oven unit consists of control panel where cooking time, power indicators and clock time are displayed and controlled. This domestic oven was modified by making a hole of 14 cm at the bottom and inserting the fluidized bed dryer through the hole. The main components of a fluidized bed dryer are drying chamber, plenum chamber, heating chamber, blower with power source and an air flow control valve. Logarithmic model was found as the best fitting model for the drying data with highest R2 value of 0.9996 and lowest χ2, SSE and RMSE values of 1.2588e-05, 0.0003 and 0.01 respectively at 50°C drying temperature and 800 W microwave power. In order to evaluate the developed microwave assisted fluidized bed dryer for nutmeg mace, the process parameters such as microwave powers of 480, 640 and 800W and drying air temperatures of 40, 45 and 50°C were chosen as independent variables. The process parameters would influence drying rate, drying temperature, energy consumption and physico-chemical 120 parameters such as colour, moisture content, bulk density and essential oil yield. These parameters were chosen as dependent variables. The optimized conditions of drying temperature and microwave power for microwave assisted fluidized bed dryer were found to be 47.76 °C and 681.73W.
Open Access
Studies on microwave steam distillation process for extraction of lemongrass essential oil
(Department of Food and Agricultural Process Engineering, Kelappaji College of Agriculural Engineering and Technology, Tavanur, 2017) Claudia, K L; KAU; Prince, M V
Essential oils are concentrated aromatic oily liquids distilled from different parts of aromatic plants. Conventionally steam distillation has been widely used for extraction. Modern technologies have been continuously developed to conquer the inadequacies of conventional methods. Microwave steam distillation is based on the interaction between water in the plant material and microwaves generated by the energy source. In this process, the steam generated outside accelerates evaporating and carrying of the essential oil, from the plant material, towards the condenser. In this study a microwave steam distillation system for extracting lemongrass essential oil was developed which composed of a microwave reactor, steam generator, cartridge, extraction unit, supporting stand, energy meter and temperature sensor and controller. In order to evaluate the developed system towards extraction of lemongrass essential oil, the effect of process parameters which would influence the essential oil yield, energy consumption and temperature of extraction such as bulk densities of 0.375, 0.675 and 0.875 g cm-3, microwave powers of 280, 420 and 560 W and soaking times of 30, 40 and 50 min were studied. The physical quality characteristics such as specific gravity, refractive index, solubility and colour of essential oil were analysed. The optimised operating conditions of bulk density, microwave power and time of extraction for lemongrass essential oil in microwave steam distillation were found to be of 0.375 g cm-3, 420 W and 30 min respectively. Scanning Electron Micrographs of lemongrass provided evidences to sudden rupture of essential oil glands with microwave steam distillation process. Gas Chromatographs of essential oil extracted through microwave steam distillation process showed higher percentage of Citral than that of steam distillation process. From the study it was concluded that microwave steam distillation could be considered as an extraction technique that results in the rapid production of high quality essential oil at shorter extraction period with minimum energy consumption.
Open Access
Development and quality evaluation of spray dried probiotic flavoured yoghurt containing
(Department of Food and Agricultural Process Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2017) Sreekutty Suresh, V; KAU; Rajesh, G K
Yoghurt is one of the most popular fermented milk products, it is a product of the lactic acid fermentation of milk by addition of a starter culture containing Lactobacillus bulgaricus and Streptococcus thermophilus . Commercial production of yoghurt has not been able to prove its supremacy in market due to its shorter shelf life. The shelf life of yoghurt can be improved by reducing its water content by drying. The dried products obtained are in shelf stable powder form which can be stored at ambient temperature. Spray drying technique has showed to be highly successful in prolonging the shelf life of food products. Considering these facts, a study was undertaken to develop a process protocol for flavored yoghurt powder. The objectives of the study are 1) Development of spray dried yoghurt powder using different carrier blend ratio and process conditions, 2) Standardisation of the process parameters and 3) Storage studies of the developed product. The physico-chemical characteristics of freshly prepared yoghurt were carried out. The spray drying of yoghurt was carried out in lab scale spray dryer with twin fluid atomizer. The spray drying experiments were conducted with different process parameters viz., carrier blend ratio (B1, B2, B3, B4 and B5), inlet air temperatures (T1, T2 and T3) and feed rates (F1, F2 and F3). Maltodextrin, corn starch and their combinations were used as wall material to produce yoghurt powder. Physicochemical properties of spray dried yoghurt powder were evaluated by standard procedures. The reconstituted yoghurt samples prepared from spray dried yoghurt powder were evaluated in terms of solubility and wettability. The process parameters were optimized based on the physico-chemical and microbiological properties of the developed yoghurt powder. By considering all the physico chemical and microbiological analyses done on the spray dried yoghurt powder at different processing conditions, powder sample processed at 170˚C inlet temperature with carrier blend B2 (3:1) at feed rate of 10 rpm was selected as optimized sample. The quality of plain yoghurt powder was improved by incorporating dried white pepper extract (C1- 2%, C2-2.5 % and C3- 3%) and ginger extract (G1-2%, G2-3% and G3-4%) at different combinations. The spices incorporated yoghurt product was spray dried at optimized operating parameters. The parameters of the flavored yoghurt powder were optimized based on physic-chemical and microbiological properties. By considering the physico-chemical qualities of the flavoured yoghurt under different processing conditions, the sample incorporated with 2.5 percent white pepper extract and 3 percent ginger extract (C2G2) was selected as the optimized sample. Flavoured yoghurt powder was packed in laminated aluminium pouches and sealed using a hand sealing machine and subjected to storage studies . Sealed pouches were stored at ambient and refrigerated storage(4°C) for a period of three months and the effect of physical, chemical and microbiological characteristics during storage was studied. The product stored at ambient condition is acceptable only up to 50 -75 days. But the product stored at refrigerated condition found safe up to 3 months.Cost analysis of the products was done and cost of production of one kilo gram was estimated as Rs.722/-.
Open Access
Comparative evalualtion of evapotranspiration parameters in a naturally ventilated polyhouse and open field
(Department of Irrigation and Drainge Engineering, Kelappapji College of Agricultural Engineering and Technology, Tavanur, 2017) Madhavi Tulluru; KAU; Rema, K P
Studies on the water requirement of horticultural crops in polyhouses are scarce and despite the water scarcity, irrigation is mainly scheduled according to farmer’s experience. Canopy development and management of some polyhouse horticultural crops is quite different from that outdoors. Differences in plant spacing, crop height and aerodynamic properties may affect the crop coefficient values. Moreover, the proportion of diffuse radiation in polyhouse is different from that outdoors. Thus it is questionable whether the standard crop coefficient values, determined experimentally outside polyhouse can be used directly to determine the evapotranspiration of the greenhouse crops. Complete data on meteorological parameters inside poly houses is very rarely obtained and it causes lot of limitations in applying indirect estimation methods of ET0 based on climatological data. Field experiment on the comparative evaluation of evapotranspiration parameters in a naturally ventilated polyhouse and open field was conducted in a naturally ventilated polyhouse and open field in the research plot of the Department of Irrigation and Drainage Engineering, in KCAET campus, Tavanur. In the study, Non-Weighing Mini-Lysimeters were used to determine evapotranspiration parameters and to develop crop-coefficient curves for Okra. Comparison with indirect methods was also done in order to assess the dependability of climatic data for evapotranspiration estimates. The study compares the data for open field and poly house conditions in order to quantify the effect of micro climatic variations. ETo estimated using climatological methods viz reduced pan, FAO -56 Penman-Monteith, FAO Blaney- Criddle and Thornthwaite were compared with measured lysimetric data using simple error analysis and linear regression. Out of all methods FAO-56 Penman-Monteith provides quite good agreement with evapotranspiration obtained by lysimetric data with a high correlation coefficient of 0.88 and 0.87 for polyhouse and open field conditions respectively. Studies on crop morphological parameters indicated that plant growth and yield parameters were not significantly different for polyhouse and open field conditions. Seasonal average ETo for polyhouse and open field were 4.74 and 5.02 mm/day. Seasonal average ETc values of Okra for polyhouse and open field conditions were 3.90 and 4.31mm/day. The calculated values of Kc for the initial, mid and late season stages were 0.58, 0.94 and 0.67 in polyhouse. Open field values were 0.61, 0.98 and 0.72 for different stages respectively. It was observed that polyhouse Kc values were lower than the open field. The variations in micro climate inside poly houses with reduced solar radiation and wind velocity combined with higher humidity and temperature may have contributed to lesser ET. The results implied that water requirement is lower inside the polyhouse compared to open field conditions. The results of this study can be used as a guideline in the computation of water requirement of poly house crops instead of depending on open field accepted values for Tavanur region. If the poly house irrigation is scheduled in such a way as to apply the right quantity of water enough to meet the evapotranspiration requirements of crops, considerable water saving can be achieved. The quality of produce is high, duration of crop season is longer and year round cultivation is possible inside poly houses which implies significant saving in water without compromising yield and product quality.
Open Access
Assessment of the impact of sand mining on the morphology of the severely affected reach of Bharathapuzha river between Pattambi and Kuttippuram using remote sensing and GIS
(Department of Irrigation and Drainage Engineering , Kellappaji College of Agricultural Engineering and Technology, Tavanur, 2017) Ardra Wilson; KAU; Vishnu, B
Rivers have been a subject of study by engineers and scientists who have been fascinated by their self-formed geometric shapes and their responses to changes in nature and human interference. Among various types of human interventions, indiscriminate extraction of sand and gravel is the most disastrous one, as it threatens the very existence of the riverine ecosystem. Bharatapuzha River in Kerala is a great victim of illegal sand mining. The effect of over exploitation of instream sand on the river morphology is very important for quantifying its effect and for exploring alternatives. The mining activity is particularly very high in the stretch between Pattambi and Kuttippuram of Bharathapuzha river. Use of remote sensing technology coupled with Geographical information system (GIS) is a quick means of gathering latest accurate information, economically. The study was undertaken to assess the morphological changes as well as the spatial and temporal variations along the reach due to sand mining The study utilized DEM imageries to evaluate the effect of sand mining. The study utilized DEM imageries to evaluate the effect of sand mining on the morphology of the river reach by analysing the cross-sectional details. LANDSAT imageries were used to analyse the spatial and temporal variations of channel in the reach. The analysis and assessment of satellite imageries were carried out using the ArcGIS 10.5 software. The Elevation profile add- in toolbar was utilised to create profile graphs by taking sections across the river course in ArcGIS and the morphological changes of the river were calculated by comparing the cross- section profiles. The spatial and temporal variations in river morphology were analysed by extracting the bank lines using Normalized difference Water Index (NDWI) and overlaying the extracted bank lines. The study revealed that the impact of sand mining was high at areas closer to Kuttippuram. Channel enlargement in the reach was found to be varying from 0.52-8.43 m/year. The reach experienced an average rate of change in width of 028m/ year. The shift in bank lines indicated the drifting of the river direction towards the north. From the study, it can be concluded that remote sensing and GIS techniques provided realistic information about the impacts of sand mining on the riverine ecosystem and have sufficient accuracy for use in morphological analysis of rivers.
Open Access
Development of attachments for four-wheel riding types rice transplanter
(Department of Farm Power Machinery and Energy, Kelappaji Colllege of Agricultural Engineering and Technology, Tavanur, 2017) Athul Chandran, K; KAU; Shaji James, P
Rice is the most important cereal food crop of the world providing major source of the food energy for more than half of the human population. Manual transplanting of paddy is being replaced by machine transplanting due to the drudgery and increased labour cost of the former. Four wheel riding type transplanters are getting popular as they can ensure speedy operation. These costly machines require an agro-economic analysis for their proper management. Another handicap in the use of these machines is that they need to be transported in another vehicle even to nearby areas, which results in increased cost of operation. The development of a suitable transport wheel system is also needed to reduce the cost of hire charges spent for transportation. The application of bio fungicides like pseudomonas and the foliar application of micro-nutrients on the mat nursery loaded in the seedling tray of these four-wheel transplanters will be a boon to farmers as this can reduce the labour cost simultaneously boosting the yield. Hence the development of an applicator attachment for spraying liquid formulations of bio-fungicides and micronutrients on the mat nursery loaded in the seedling tray of the machine, immediately before transplanting was also attempted. Economic parameters of three types of four-wheel riding type rice transplanters, viz. Yanmar Vp8D (TR1), Yanmar Vp6D (TR2) and Kubota NSPU- 68C (TR3) were estimated considering the agronomic requirements of common rice varieties Uma, Jyothi and Prathyasha. For developing transport wheel system, 6-row Kubota make transplanter was selected. The wheel hub assembly was fabricated according to the design considerations. An electrically operated applicator attachment suitable for all makes of 6-row four wheel riding type transplanters were developed and successfully field tested. From the agro economic analysis, it was found that the annual fixed cost, annual variable cost and hourly operational cost were maximum for TR1, followed by TR2 and the TR3 respectively. The Unit Area Operating Cost (UAOC) was dependent on hourly operational costs and field capacities of the machines. TR1 had the highest field capacity (0.4 ha h-1) followed by TR2 (0.38 ha h-1) and TR3 (0.33 ha h-1). TR1 had more UAOC than that of TR2 and TR3 up to the Annual Operating Hours (AOH) of 395 h. At 395 h UAOC of both TR1 and TR2 were equal. Beyond 395 h TR2 had the maximum cost of operation among the three machines. Manual transplanting by labour contract required a cost of Rs. 10000 per ha and using these transplanters is economical than manual transplanting whenever the AOH is more than 102 h. The pneumatic wheels of 680 mm diameter and width of 100 mm were selected for front wheel. The front wheel has wheel track of 1.29 m. For rear wheel it has diameter of 720 mm and 130 mm width. The rear wheel track was 1.37 m. The maximum and minimum speeds possible using these wheels are 1.14 to 9.88 km h-1. The applicator attachment had a 12 V electrically operated diaphragm pump, LDPE pipes as conduit, five solid cone nozzles fitted on a LDPE boom. The pressure developed by the pump was 620 kPa with a discharge of 1.89 l min-1. The nozzles were selected based on the patternator studies. Five nozzles were placed at an equal distance of 35 cm on the boom of 1.8 m, with a spray span overlap of 14 cm. The droplet size was measured using bromide photo papers with pigmented spray solution and IMAGE-J image analyzing computer software. The droplet size at 50 cm height was in the range of 200 - 300 microns. The field studies on effect of pseudomonas fluorescence application revealed the enhanced growth of rice plants. No fungal attack was observed in the plots which were treated with pseudomonas. The plants subjected to application of ‘Sampoorna- KAU mutimix’ had increased plant height, more number of tillers per unit area, more productive tillers, more number of grains per panicle, higher paddy yield and increased grain weight.
Open Access
Assessment of evapotranspiration models for the humid tropical region of Tavanur
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2017) Pravalika, Y R; KAU; Asha Joseph
World is facing an acute water crisis due to the increase of world population, droughts, land degradation, and food demand. This increases the concern over conservation of water. One of the most important factors related to water management is crop evapotranspiration. In the present research work, the reference crop evapotranspiration (ETo) is estimated by using ten empirical models which are widely used in Indian conditions namely, Thornthwaite (1948), Hargreaves et al., (1985), Turc (1961), Christiansen (1968) Pan Evaporation, FAO-24 Blaney-Criddle (1977), FAO-24 Modified Penman (1977), FAO-24 Open Pan (1977), Preistly-Taylor, Makkinik and FAO-56 Penman-Monteith (1991). The accuracy of these reference evapotranspiration models were evaluated by comparing it with FAO-56 Penman-Monteith using six years monthly average meteorological data for the period January, 2011-December, 2016. Then the models were validated with lysimetric data. The weekly water balance studies were conducted in lysimeter to find the actual reference evapotranspiration. The model values were estimated using weekly meteorological data for the period January-May 2017 during which the lysimeter study was conducted. Then best fit relations were developed between the estimated values (EToEST) and observed values (EToLYM) for the humid tropical region. Among the different empirical models, Turc model showed the highest ETo value (14.92 mm/day) while the Priestly-Taylor showed the lowest (0.62 mm/day). Thornthwaite, Blaney-Criddle and Modified Penman model gave closer values to each other 7.32, 8.9 and 7.09 mm/day respectively. While Christiansen, Penman-Monteith, Open Pan and Makkinik models gave values like 3.08, 3.23, 3.24 and 2.22 mm/day respectively which were slightly lower compared to the values obtained from the Hargreaves model (4.7 mm/day). The statistical comparison was made by considering FAO-56 PMM as the standard model using six year average monthly meteorological data. The Modified Penman model gave the best performance with R2 of 0.96 with RMSE 3.95 and RelRMSE 1.22 followed by Hargreaves model. The Open Pan method ranked the third one. The models, Christiansen, Priestly-Taylor and Makkinik were underestimated while Thornthwaite, Turc and Blaney-Criddle models overestimated. For validation of the models, weekly ETo estimated from models were compared with ETo observed from lysimeter for the period January-May, 2017. The Hargreaves model showed the best performance with R2 0.83 and RMSE 0.82. The Turc model was highly over estimated while Blaney-Criddle and were only slightly overestimated. The Penman- Monteith and Makkinik models were slightly underestimated while Priestly- Taylor highly underestimated with R2 0.56 and the RMSE 4.29. Hence it is concluded that Hargreaves (HAM), Open Pan (OPM) and Christiansen (CHM) models were found to be in close agreement with lysimetric data and hence these models were suggested for use in this humid tropical region. Therefore relationships were developed between these empirical model output and the lysimetric data (LYM). The relationships developed were as follows: ETo LYM = 0.79HAM + 0.45, EToLYM = 0.79CHM + 1.60 and EToLYM = 0.63OPM + 2.04. Finally the results of this research can be recommended for humid tropical region for irrigation scheduling, selection of cropping pattern, optimum allocation of water resources and efficient use of water.
Open Access
Modification and testing of tractor operated KAU banana sucker uprooting machine
(Department of Farm Power Machinery and Energy, Kelappaji College of Agriucltural Engineering and Technology, Tavanur, 2017) Naveen, B V; KAU; Jayan, P R
Banana (Musa paradisiaca) is a large perennials rhizome crops widely cultivated in India. These crops provide excellent opportunities in raising the income of farmers. Sucker is the planting material used for the cultivation of the banana. After the banan bunch harvesting, uprooting of mother corm and its suckers without damage is very essential for obtaining good quality planting material for banana cultivation and clearing of land is the main difficulty faced by banana farmers as less time is available between harvest and fresh planting of banana field. Uprooting the mother plant and suckers, clearing the land etc. are highly labour intensive in banana cultivation. As the entire state faces an acute shortage of labour, the development of suitable equipment for uprooting the banana clump in necessary. The present practice of uprooting was carried by digging out the soil-sucker composite by employing a labour using a sharp hatchets and spades the sword suckers should be dugout and separated from the mother plant. Uprooting takes lot of time and energy. In the University farms, one man labour uproots 15-20 clumps per day. At the present wage rate of Rs. 600 per man, an amount of Rs.48000 per acre is required for uprooting of banana clumps after harvest. The presently available mechanical banana uprooting device faces problems of excess fuel consumption, more time taken to uproot, high percentage of damage to suckers etc., hence a study was undertaken to modify the hydraulic operated banana sucker uprooting machine that was developed at KCAET, Tavanur. The machine was modified and field tested. . The physical and mechanical properties of banana rhizomes namely, size, shape and weight were found out using standard test procedures. Based on the effective root zone area and unit draft of the soil, the total draft force required to lift the clump was calculated. A john deer 5310 tractor 41.5 KW (55hp) was used as a prime mover. The machine (attachment) consists of a gib crane fitted with bucket with tyne at its lower end. The field performance of the machine was conducted for uprooting the banana soil-sucker in two types of soils, laterite soil at KCAET, Tavanur and clay soil at BRS Kannara. Trials were conducted to evaluate the performance of uprooter with 3 and 4 number of rectangular and triangular shape tynes. The uprooting was carried out for each of the treatment combinations. Performance analysis of the modified banana sucker uprooting machine was compared with respect to time, depth to penetration, percentage of damage of suckers and weight of soil -sucker clump separately with rectangular and triandular 3 and 4 number of tynes. The observations were separately recorded for clay soil and laterite soil. It was found that irrespective of the soil type, triangular shape with 4 number of tynes recorded lesser time for uprooting higher depth of penetration and lower percentage of damage while uprooting. Field efficiency of modified banana sucker uprooting was observed that the total time taken to uproot an area 0.0025 ha in clay soil was 1.8h. the field efficiency obtained was 75%. The total time taken to uproot an area 0.0025 ha in laterite soil was 1.5 h and field efficiency is 80%. Cost of uprooting by using uprooting machine is RS. 22,930 ha-1. the cost and time saved over manual uprooting was about 52.22% and 93.06%.
Open Access
Investigations on clamping and climbing mechanisms for the design of semi autonomous areca palm climber
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2017) Supritha; KAU; Shivaji, K P
Palms are un-branched evergreen trees cultivated mainly for its nuts and one has to climb up the tree for harvesting and other operations like spraying. Considering the difficulty and drudgery involved in this operation different types climbers were developed by researchers and innovators. These climbers essentially consist of two functional mechanisms; the clamping mechanism for gripping the unit to the trunk and climbing mechanism for vertical movement of unit. These developed palm climbers can be categorized based on the type of motion of the unit as continuous, discrete or serpentine and based on the power utilized for actuating the functional components as mechanical or robotic. Further categorization can be done based on the mechanism deployed for the actuating functional components. The biometric properties of areca palm are important for the design optimization and performance of climber. Among the quantifiable biometric properties diameter, variation of diameter along height, height and tilt angle were identified as the critical properties which has direct influence on design and operations. The diameter of areca palm determines the size of gripping unit, shape and dimensions of gripping arms or structures, their spacing and the distance through which the gripping arms are to be moved for locking and unlocking. Tilt angle is critical in optimizing the height of the climbing unit and the maximum relative movement of functional sets of components. The height of palm does not directly influence the design of the climber; it is a major parameter which affects the operation of the robotic climbers. The time required for completing the climbing is directly influenced by the height and when height increases, it will be difficult to see and operate the climber from the ground. By analyzing all these data and the past works related to mechanical and robotic climbers, their suitability and merits and demerits, a preliminary model of semi-autonomous areca palm climber was fabricated. The principle of linear actuators was adapted for the design of the climber by incorporating power screw rods and DC motors. The designed climber has two components, one was gripping unit which will provide to and fro motion to the gripping arms hence the arms grabs the tree. Another component was climbing unit which will provide up and down movement hence the climbing happens. At the beginning, the power was supplied to the lower gripping unit; by the movement of both the arms it grabs/holds the tree. Then the power was supplied to the upper gripping unit. By that both the gripping units grabs the tree trunk tightly. After that, the lower arm releases the contact and moves up by the rotation of main motor. Then lower arm holds the tree trunk, upper arm releases and moves up. This process continues until the desirable height was reached. The arms hold the entire body during climbing. During climbing part of robot was always fixed to the tree trunk. The operation of robot was controlled by wired remote controller. The prototype can be simply installed and controlled on the palm by an inexperienced operator. The device has been tested for its performance and found safe, reliable, and efficient and also reduces the problems in climbing of arecanut tree to a good extend.

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