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Open Access
Development and evaluation of process protocol for vacuum fried carrot chips (Daucus Carota L)
(Department of Processing and Food Engineering, KCAET, Tavanur, 2021) Babu, P; KAU; Rajesh, G K
Carrots are highly nutritious vegetable, which can be consumed in raw and processed form throughout the world. Carrot plays a vital role in the development and protection of human body. Carrot contains vitamins viz., B1(Thiamine), B2(Riboflavin), B6(Niacin) and B12 (Cobalamin) besides rich in source of βcarotene and dietary fibre which are helpful to prevent cancer and other dreadful diseases occur in human body. In Kerala state, carrot production is very limited, but its consumption is more. The postharvest losses of carrot were estimated as 18- 20%. The development of value-added products from carrot was an idealistic solution to reduce the postharvest losses by adopting new processing technologies. At present, due to consumer’s awareness, there is a lot of demand for healthy and tasty snack products with less oil content which provide good health. In this context, investigation on processing technologies focus on producing high quality fried products with less oil content and good textural property. The technology of vacuum frying is a best option for the production of novel snacks which fulfil the consumers demand and meet nutritious requirements. Vacuum frying is a novel technology, in which the food is heated under lower temperature and pressure(<6kPa). Vacuum frying lowers the water activity, oil content, retains the color and preserve nutrients in the fried product. The batch type vacuum frying system consists of two chambers viz., frying chamber (3kg capacity) and oil storage chamber (30-35L capacity). The refined palm oil was used for vacuum frying and de-oiling was done at 1000 rpm for 10 min. After every batch of vacuum frying, the oil was collected for quality analysis. Prior to the research, the physico-chemical properties of raw carrot (Ooty-1) was determined. The pre-treatments viz., blanching, blanching cum drying, blanching cum freezing, freezing and gum coating were optimized based on the quality of vacuum fried carrot chips. The freezing pre-treatment obtained the best results among other pre-treatments in terms of less oil content (14.48 %), water activity (0.214), moisture content (2.67%), hardness (1.282 N) and red color retention of a* value (22.85). The standardization of process parameters were done using RSM (CCRD) based on the quality characteristics of VF-carrot chips. The process parameters seected in this study were frying temperature (100,110 and 1200C), frying pressure (11,13 and 15 kPa) and frying time (16,18 and 20 min). The optimum operating conditions of vacuum frying viz., frying temperature, vacuum pressure and frying time were found to be 100°C, 11 kPa and 16 min respectively. At optimum operating conditions of 100°C, 11 kPa and 16 min, the quality parameters were oil content (11.31%), bulk density(0.873 g/cm3 ), true density(1.714 g/cm3 ), moisture content(3.28%), water activity (0.384), hardness (1.31 N),thickness expansion (60.42%), L*(43.48), a*( 14.36) b*(28.12) and energy content(1021 KJ/100g). Packaging and storage studies were conducted for the treatments which had high sensory score. The laminated aluminium flexible pouch with N2 gas filling was found to be the best packaging technique to enhance the shelf life of VF carrot chips to a storage period of 4 months. The oil quality parameters viz., total polar compounds (TPC), viscosity, peroxide, free fatty acids (FFA) etc were within the allowable limits even after 40 batches of vacuum frying. The total production cost of 1kg of vacuum fried carrot chips was found to be Rs. 355/-.
Open Access
Investigations on high rate anaerobic bioreactor for energy production from rubber latex processing effluent
(Department of Farm Machinery and Power Engineering, Kelappaji College of Agricultural Engineering and Technology,Tavanur, 2020) Megha, A S; KAU; Shaji James, P
Agro-processing industries often contribute significantly in pollution due to discharge of untreated effluents. By anaerobic digestion of these organic effluents, methane rich gas can be produced which is suitable to generate electricity and process heat. But conventional biogas plants are slow in operation with long hydraulic retention times of 35 to 40 days which necessitates large digester volumes. So, anaerobic digestion of high volume agro-processing effluents is feasible only through high rate bioreactors which can reduce hydraulic retention time to few hours. Rubber latex processing effluent (RLPE) is a dilute waste water for which high rate anaerobic treatment can be an affordable technology. Hence, an investigation was taken up to study the performance of Up-flow Anaerobic Hybrid Bioreactor for energy conversion of rubber latex processing effluent (RLPE). Physico-chemical characteristics of RLPE samples were tested and found that RLPE was a dilute waste water with pH in the acidic range. BOD: COD ratio of 0.44 obtained in this study showed good biodegradability of RLPE. A batch anaerobic digestion study was conducted as a preliminary experiment to investigate the biomethanation characteristics of RLPE. The experiment consisted of four treatments having different composition of RLPE with inoculums replicated thrice. This study could prove that RLPE could be subjected to biomethanation and cow dung slurry can be used as inoculum. Even at a lower inoculum: substrate ratio of 1:2, the system could be started up yielding substantial amount of biogas coupled with good TS reduction. Performance of field scale Up-flow Anaerobic Hybrid Bioreactors (UAHBR) was assessed by operating them at different HRTs of 10, 7, 5, 3 and 2 day. During the study an interruption of 2 months in operation occurred due to shut down of the processing unit due to Covid 19. After interruption of 2 months reactor recovered within one month and it proved that hybrid bioreactor could be restarted easily after a shutdown for few months. Reactor was stable in operation during 10, 7, 5, 3 and 2 day HRTs and exhibited good process efficiency with better pollutant reduction and biogas production. Performance was seen deteriorated beyond 5 day HRT. The bioreactors were operated successively at reduced loading rates corresponding to the longer HRTs after reaching the shortest HRT of 2 day. It was observed that there was no considerable difference in daily biogas production with the earlier values obtained during the progressive decrease in HRT. This revealed that the bioreactors would have achieved the maximum possible microbial population already and there was no further improvement in performance on further passage of time. The performance parameters obtained in the investigations with field scale reactors were used for evolving guidelines to design a full scale anaerobic bioreactor. The UAHBR performance was quite satisfactory at 5 day HRT with respect to pollutant reduction as well as energy production. Hence as criteria, full scale plant was proposed to be operated at 5 day and the corresponding reactor volume was 27 m 3 with 7.2 m 3 gas holder volume. The biogas expected to be produced from the full scale plant can be used in a biogas fired rubber sheet dryer which can save about 500 kg of fire wood per day currently used for drying rubber sheets.
Open Access
Optimum thresher parameters for high moist paddy
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1993) Hamza, Mollakadavath; KAU; Sivaswami, M
The study undertaken by the newly development 1 hp paddy thresher to optimise its parameters for high moist paddy revealed that the peripheral velocity from 10.80 to 21.72 m/s on the rasp – bar, spike tooth, double directional spiral cylinders didn’t influence much on the threshing efficiency. When the moisture content was increased to 35 per cent, the threshing efficiency was brought down from 98.4 to 92 per cent for rasp – bar cylinder and was increased from 88 per cent to 94 per cent in the case of double directional spiral cylinder. The maximum threshing efficiency of 99 percent was achieved for spike tooth cylinder at 19.2 per cent moisture level. The maximum threshing efficiency of 94% and the maximum output of 340 kg/h were achieved with the double directional spiral cylinder when the moisture content was 35% per cent. The proto – type thresher was found to reduce the cost of threshing to 81 per cent and reduction in labour to 85.16 per cent compared to the manual threshing.
Open Access
Design, fabrication and evaluation of the performance characteristics of hydraulic ram by varying the various parameters
(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1989) Suseela, P; KAU; George, T P
In India, the agricultural production in many areas especially in hilly areas is very much affected by the non – availability of adequate power to lift water for irrigation. Main problems in enhancing irrigation facilities in hilly regions are their highly uneven topography and non availability of conventional sources of energy. The rapid depletion of conventional sources of energy and increasing demands have now focussed the attention on the need for developing a new economical and effective water lifting device which does not use the conventional sources of energy. A hydraulic ram may meet these requirements in hilly regions and can lift water without any external source of energy in the form of fuel or electricity. A hydraulic ram was designed and fabricated with cheap and commercially available materials. A constant supply head of 1.955 m was provided. Ram was designed for a maximum delivery head of 10 m. Provisions were given to vary the weight and stroke length of both the delivery valve and waste valve. A flange joint was incorporated valve and waste valve. A flange joint was incorporated between the delivery valve and air chamber to facilitate the quick opening and reinstallation of air chamber. Air chamber was fabricated with provisions to alter the volume, by changing the length of air chamber – the diameter of the air chamber was kept constant. The performance of hydraulic ram was evaluated mainly observing the delivery head – delivery discharge relationships. In each case the efficiency of the ram was evaluated. Typical performance characteristic curves were plotted for each of the changes in the conditions of operation. Effect of volume of air chamber on the performance of hydraulic ram was studied. The study revealed that the efficiency of the ram increases 1. as the weight of delivery valve increases 2. as the stroke length of delivery valve decreases 3. as the volume of air chamber increases 4. as the stroke length of waste valve decreases There is a steep reduction in delivery discharge with unit increase in delivery head. For a particular combination of waste valve, delivery valve and volume of air chamber, the maximum efficiency occurs at a moderate delivery head. For an increase in the stroke length of waste valve, there is a large reduction in best frequency. The beat frequency increases as the delivery head increases. The rate of decrease of best frequency with respect to the stroke length is higher for lower weights of was to valve. The ram stops functioning at certain low value of delivery head. This low valve of delivery head increases with increase in weight of delivery valve. Corresponding to a certain weight of delivery valve, there is a minimum weight of waste valve at which the ram functions satisfactorily. Further investigations are necessary to standardise different parts of the hydraulic rams for optimising their performance under varying conditions.
Open Access
Design development and evaluation of a low cost paddy thresher
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1991) Mathew, John; KAU; Sankaranarayanan, M R
Though several high capacity threshers are available in the country for different crops, no thresher is found suitable for small and marginal rice farmers. Hence a low cost portable paddy thresher was developed and tested. The power operated machine consists of base, side frames, front grain shield and wire-loop cylinder. The power from the 0.5 hp motor is transmitted to the cylinder shaft by belt and pully arrangement. The optimum cylinder speed is 400 rpm. The capacity of the thresher at 14.26 per cent moisture content is 451.84 kg paddy per hour and threshing efficiency is 95.08 per cent. The mechanical damage of the grain is negligible. Two labourers are required for the whole operation. The size of the thresher is 635 x 500 x 715 mm having a gross weight of 47 kg. The cost of the thresher was worked out to be around Rs. 3600 and the cost of operation for threshing paddy was Rs. 3.00 per quintal. The unit can be fabricated by local artisans from the readily available materials and can successfully be maintained by small and marginal farmers.
Open Access
Development and performance evaluation of a rotary tillage attachment to the KAU garden tractor
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1990) Jose, C M; KAU; Sivaswami, M
Considering the advantages of rotary tillers over non-powered tillage tools, and in order to make the KAU garden tractor a versatile farm power unit, a rotary tillage attachment for the garden tractor was developed and tested. The main components of the rotary tillage attachment are mainframe, power transmission system, blade assembly, hitching mechanism and protective cover. The depth of tillage obtained is 10 to 15 cm and the effective width of field coverage is 30 to 32 cm. The actual field capacity of the machine is 0.054 ha per hr and the quantity of fuel required to operate the machine is 0.860 1 per hr. Operator can easily walk behind the rotary tiller and turn the garden tractor to either side. The cost of production of the rotary tillage attachment is Rs. 1500.00 and the total cost of ploughing per hectare using the machine is Rs. 450.00.
Open Access
Design, fabrication and testing of a savonius type windmill with a deflector augmentor
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1989) Satyajith, Mathew; KAU; Wilson, K I
The study was conducted with the objectives of developing and testing a savonius wind mill and analysing the effect of a deflector augmentor on the performance characteristics of the rotor. The wind mill was consisted of two rotors of 2 m x 3 m size fixed one below the other at 90 degree out of phase. A 100 mm galvanised iron pipe of 12 m length acts as the shaft. The shaft passes through two ‘30220’ taper roller bearings. Lower bearing was fixed on a I m x I m x I m foundation and the upper bearing was positioned by four 4 mm guy wires. The guy wires were equidistant and forms an angle of 45 degree with the shaft. This wind mill was tested under field conditions. Power developed by the wind mill was calculated by measuring the torque and rotor speed, and power delivered to the rotor was calculated by taking corresponding wind velocity. The coefficient of power and coefficient torque were calculated for different tip speed ratios. The wind mill was found to attain a maximum coefficient of power 0.155 at a tip speed ratio 1.0. Maximum torque coefficient attained was 0.185 at a tip speed ratio 0.75 Optimum tip speed ratio of the wind mill was found to be in a range of 0.5 to 0.9. A deflector augmentor of 6.93 m2 effective wind facing area was fixed at an angle of 60 degree with the wind direction. Wind mill was again tested with the deflector augmentor. Power coefficient was found to attain a maximum value of 0.32 at a tip speed ratio 1.54. The maximum torque coefficient was 0.385 at a tip speed ratio of 0.56. Optimum tip speed ratio of the wind mill with the deflector augmentor was found to be in a range of 0.5 to 1.5. When the deflector augmentor was attached to the wind mill, power coefficient was increased by 106.5 percent and torque coefficient was increased by 108 percent. The wind mill was found to work in higher tip speed ratios. The cut in velocity was reduced from 2.4 m/s to 1.4 m/s. Cost of operation of the wind mill was Rs.1.45 per bhp.hr which is comparable with diesel and electric power.
Open Access
Development and performance evaluation of a low cost water-wheel for lifting water at low heads
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1992) Jayan, P R; KAU; Sankaranarayanan, M R
A low cost water wheel was designed, fabricated and tested in the distributory canal of KCAET farm, Tavanur. The device was operated by the stream current with no additional power source and was tested for different submergence depths varying from 0.12 to 0.25 m. Water wheel with eight cups of 30 cm x 7 cm x 2 cm intake compartment was found to be the most efficient under various operating conditions. A maximum efficiency of 48% was obtained at 0.23 m of submergence depth. The device can lift water without additional operating cost as long at the mean stream velocity is greater than or equal to 0.44 m/sec for the optimum depth of submergence at 23 cm. The corresponding discharge of the system is 19.2 lpm at 0.6 m head. The investment cost of the device is Rs. 800/- and the annual operating cost is Rs. 204/- with low maintenance cost. Though the power output and the discharge capacity were low, it has a two fold advantage of functional reliability and simplicity of design and fabrication at village level. It can successfully be utilised by the small farmers when the cultivating fields are adjuscent to the canal water courses.
Open Access
Dynamics of power transmission in tractor mounted paddy reaper
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Sushilendra; KAU; Sivaswami, M
A tractor front mounted 2.2 m wide paddy reaper windrower was evaluated to find out the optimum forward speed, cutterbar speed, conveyor belt speed and engine speed for different field conditions to achieve better harvesting and windrowing pattern, Maximum field capacity and field efficiency with less harvesting losses. Three PTO pulleys of 17.78 cm, 19.03 cm and 20.32 cm diameter with internal splines were fabricated and used with an engine speed from 1000 to 2000 rpm with four gears in low range and first gear in high range. In addition to pneumatic tyres, a pair of special cage wheels and a simple collection unit were developed and evaluated. In water submerged fields with special cage wheels and PTO pulley of 17.78 cm diameter better results were observed when reaper was operated at an engine speed of 1500 rpm with third low gear with a forward speed of 0.95 m/s. The optimum cutterbar index and conveyor index were found to be 1.56 and 2.30 respectively. The actual field capacity was 0.38 ha/hr and field efficiency was 54 per cent. The crops were found to throw within 10 cm from the discharge plate with an tiller angle of more than 85 degree with only 1.54 per cent of total loss of grain. When the soil is moist and pneumatic wheels fail to give sufficient traction, the special cage wheels were used with a PTO pulley of 19.03 cm diameter. An engine speed of 1400 rpm with third gear and with a forward speed 0.90 m/s was found to give satisfactory performance. The optimum cutterbar index was 1.66 and conveyor index was 2.45. The reaper had the field capacity of 0.36 ha/hr with field efficiency of 53 per cent. The windrowed crop were found to throw within a distance of 13.5 cm with 85 degree of tillers angle with total grin loss of 1.55 per cent. For dry fields, the reaper with pneumatic wheels was found to operate satisfactorily with 20.32 cm diameter PTO pulley at an engine speed of 1300 rpm with fourth gear and with a forward speed of 1.00 m/s. The optimum cutterbar index was 1.48 and conveyor index was 2.19. The actual field capacity was 0.38 ha/hr and field efficiency was 50.66 per cent. The tillers angle was 85 degrees with total grain loss of 1.62 per cent. It is found that the better field performance was achieved when the reaper is operated at a cutterbar speed of 1.50 m/s and conveyor belt speed of 2.20 m/s. A simple crop collection unit of size 1. 5m x 0.7m x 0.35m was developed with the provision for conveying the windrowed crop directly into the collection box. The unit was field evaluated with reaper. The box was found to fill within 10 m of travel and problems were observed in its manoeuv reability, loading and unloading of box and increased idle time.

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