Theses

Browse

Search Results

Now showing 1 - 9 of 22

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
Design and development of a propeller pump
(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1984) Sasi, K; KAU; Remadevi, A N
“Petti and Para” a crude form of Axial flow pump is used in Kerala for dewatering agricultural fields. It is being fabricated by local blacksmiths and there is no scientific design for the pump. For low head high discharge conditions Petti and Para is very effective, but less efficient because of faulty construction. The broad objective of the project was to develop an axial flow pump with improved efficiency which could be economically used for dewatering and for lift irrigation purposes under low head conditions. In this investigation, a good amount of attention was given to the fluid dynamics inside the axial flow pump and theoretically studied the combined affect of various parameters involved in the design of an axial flow pump. Then the parameters were compared with the approximate values given by the various researchers in the field. The requirement of the pump to be designed, at field conditions, were studied thoroughly and an one dimensional design was done. After designing and fixing the dimensions, the pump was fabricated in the Kerala Agricultural University Research Workshop at Mannuthy. Because of the lack of facilities in the Research Workshop, it was tested in the hydraulics laboratory at the Government Engineering College, Trichur. The power unit used was a 15 HP electric motor. The accessories used to measure discharge and head were a rectangular notch with Hookgauge and water manometer respectively. Testing was done with two levels of water above the impeller, one 20 cm above the impeller and the other 10 cm above the impeller. For the above two conditions, at designed head (1.5m) the maximum efficiencies obtained were 33 per cent and 29.5 per cent at discharge 121 lit/sec. and 114 lit/sec. respectively. The maximum working capacity was 165.19 lit/sec. against a head of 1 m with an efficiency of 31.95 per cent (20 cm above the impeller) In the three bladed pump, the blades were fixed to the hub by welding it to the suitably shaped (curved) M.S flats and then bolting the curved M.S. flats to the hub. The blades were twisted from 160 to 240 in a uniform variation by simple blacksmithy. The efficiency of the pump can be increased by using perfectly curved blades, which reduces eddies and skin friction. Comparing with the existing Petti and Para made by local blacksmiths, it is found that the pump is cheap as well as efficient.
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
Development of cocoa drier
(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1985) Abdassalam, M; KAU; John Thomas, K
An investigation for the development of an electrically heated, multistage, agitation type cocoa drier, suitable for the Kerala conditions for drying of cocoa beans without impairing the quality, was conducted in the Agricultural Engineering Department of the College of Horticulture under the Kerala Agricultural University. The mini box fermentation method developed in Kerala Agricultural University was selected for fermentation of the beans. The fermented cocoa beans were dried in the sun. The process of sun drying continued upto seven days. The pH of dried beans was 5.2, which was very close to the pH range, 5.3 to 5.5 for good quality beans as per international standards. Hence, the quality of the beans was considered satisfactory. A bulb heated drier developed earlier in K.A.U. was tested* The capacity of the drier tested was 30 kg of fermented beans. The bean could be dried to the desired moisture content in 38 hours. The moisture content of the dried beans was about eight per cent. From the result it was found that for drying one kg of fermented beans approximately 0.760 K.W.H. of electrical energy was required. pH of the dried beans was 5.00. The bulb heated drier was modified and fitted with a 500 watts electric coil heater was also tested. Beans were dried to the desired moisture content in 34 hours. Moisture content of the dried beans was about eight per cent. The result showed that approximately 0.57 K.W.H. of electrical energy was required for drying one kg of fermented beans. The quality of the dried bean was satisfactory because pH of the dried beans was 5.0.The cost of drying per kg of fermented beans was Re.0.47. A modified C.P.C.R.I. model drier of capacity 60 kg of fermented beans was fabricated, tested and economics worked out. For attaining the required moisture content of about eight per cent, the time taken was 64 hours. The result revealed that approximately 0.533 K.W.H. of electrical energy and an amount of Re. 0.36, was required for drying one kg of fermented beans. pH of the dried bean was 5.1 and hence quality of the dried bean was also satisfactory. The modified C.P.C.R.I. model drier fitted with an half h.p. electric motor and a blower was also tested.Beans were dried to the desired moisture content in 42 hours. The result showed that for drying one kg of fermented beans approximately 0.610 K.W.H. of electrical energy was required. Cost of drying per kg of fermented bean was Re. 0.56, Quality of the dried bean was satisfactory since pH was 5.2. An agitation type electrically heated multistage drier of 90 kg capacity was designed, fabricated, tested and its economics was worked out. Tests were carried out with two quantities of cocoa (i.e. 90 kg, and 60 kg), 3 3 different quantity of air (i.e. 0.4 m /second, 0.2 m / second) and varying temperatures (i.e. 56°C, 47°C and 42°C). Air temperature and humidity at various sections of the drier were noted. Also the weight loss of the bean at every hour of drying was noted by using an infrared moisture meter, and the final pH of the dried bean by using a pH meter. From the experiment, using various quantities of beans, with different temperature and air flow, it was found that for drying 90 kg of cocoa beans a temperature of 47°C and air flow rate of 0,4 m3/sec was optimum, for this type of drier. The energy consumed/kg of bean was appromimately 0.69 K.W.H. The pH of the dried beans was found to be 5.3 and hence the quality of the dried bean was satisfactory. Cost of drying per kg of fermented bean was Re. 0.45. One of the objectives of this project was to evolve suitable design of an equipment for drying large quantities of cocoa beans. With this in view an agitation type multistage drier of 2000 kg capacity of fermented beans was designed. Prom the cost analysis it was seen that the cost of drying one kg of bean was only Re. 0.22. The cost of the drier was about Rs.23,000/-. The advantage of agitation type multistage drier are as follows. As the beans were moving in the drier better uniformity in drying was achieved and they were not exposed to high temperature continuously which helped in maintaining the quality of the beans. The drying time was reduced considerably. Energy consumption was less and cost of drying was only 50 per cent compared to other driers. Due to stage by stage drying the loss of heat is reduced and hence the thermal efficiency is high.
Open Access
Relative efficiency evaluation of drip and basin methods of irrigation in banana
(Department of Agricultural Engineering, College of Horticulture,Vellanikara, 1985) Koshy, Vargees; KAU; Varkey, V K
Well planned and efficiently utilised irrigation systems help to keep the food production in pace with the increasing population. Hence it is essential to design and adopt an efficient low cost economic irrigation system tailored to fit the local potential and needs. Out of the efficient methods of irrigation, drip method is the most promising. Drip irrigation is comparatively new to our country and needs popularisation. The relative efficiency and feasibility of a low cost drip irrigation system fabricated with the cheapest and locally available materials in relation to the conventional basin method of irrigation is tested in this experiment taking banana as the indicator crop. Plants were irrigated at the rate of 5, 10, 15 and 20 litres per day in both the methods of irrigation. Oil drums of 200 litres capacity were used as storage tanks for the drip irrigation system. 25 mm and 12 mm (dia) black low density polyethylene pipes were used for main and lateral lines respectively which were embedded at a depth of 20 cm below the ground surface. Micro-tubes of 2 mm diameter were used as drippers or emitters. The heart of this drip system was the distributor developed in K.A.U. which could deliver irrigation water at a slow rate of 1 to 2 litres per hour from each micro-tube. Physical characteristics of the soil and bio-metric observations of the plants were taken during the experiment. It was observed that there was no significant difference in the yield of plants under the drip and basin methods of irrigation. Similar results were obtained by Sivanappan et al. (1976) and Chennappa, (1977). The economy of the system was studied and it was found that, by adopting drip method of irrigation, there is a net saving of Rs. 4302 per year in one hectare. Weed growth was found to be less in the plots irrigated by drip method. Special skill is not required for the fabrication, installation, maintenance and operation of the K.A.U. drip irrigation system.
Open Access
Designing and development of an insecticide applicator for the control of brown plant hopper
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Ramachandran, V R; KAU; Muhammad, C P
The brown planthopper Nilaparvata Lugens stal. is a dangerous pest which causes, quick and serious damage to rice in South East Asia. In India a serious damage occurred in Kerala during 1973-76, and the estimated loss in this was 12 cores of rupees. An investigation on the design and development of an insecticide applicator for the control of BPH, by spraying specifically the plant base, at a height of about 15-20 cm from the field surface, was carried out
Open Access
Forms of water loss and water requirement of rice in kole lands
(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Lissy Devid, Chirayath; KAU; George, T P
Rice is the most important and extensively cultivated food crop in Kerala. Efficient use of water for crop production has been a major concern for centuries. As the water needs of rice is many times greater than other crops, a precise knowledge of water requirement of crop attains importance for increasing production. The present investigation was taken up to estimate the losses through evaporation, transpiration, percolation and to asses the total water requirement of a medium duration rice variety jaya
Open Access
Hydraulics of KAU drip irrigation system
(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Susan Cherian, K; KAU; George, T P
Irrigation advancements within the last decade has been astounding. Drip irrigation is one of the latest innovations for applying water to the field and it represents a definite advancement in irrigation technology. An attempt was made to study the hydraulics of microtube emitters of 1-3 mm size, Black polyethylene tube of 1" was used as main line. In the main line, three laterals of 1/2 diameter were connected. Discharge measurements were taken at different pressure heads. The total energy drop (H) in a microtube emitter is the summation of friction loss (Hf) and minor loss (Hm). There was no empirical equation available for calculating the friction drop from a microtube of size less than 4 mm. With the help of a computer, analysis was made to establish the relationships between pressure head H, length L, diameter D and discharge Q. The empirical equations obtained are 1. Combind flow condition H = 0.01402 Q1.23938/D3.54926 L0.86030 2. Turbulent flow condition H = 0.00764 Q1.82655/D4.61537 L0.77823 3. Flow in transition region H = 0.00817 Q1.56882/D3.83531 L0.83541 4. Laminar flow condition H = 0.00796 Q1.23461/D3.59105 L0.98712 Where Q = discharge, 1/hr L = length of tube, cm D = diameter of tube, mm The minor losses, viz. exit, entry, losses due to fittings and sudden contration can be expressed as a function of velocity head. The minor loss was significant because of the smaller size and short length of the microtube. The numerical solution for minor loss coefficient K was obtained in order to make the power of L unity in the estimating equations for head loss due to friction. The equations obtained are 1. Combind flow Hm = 2.34 V2/2g 2. Turbulent flow Hm = 2.14 V2/2g 3. Flow in transition region Hm = 3.18 V2/2g 4. Laminar flow Hm = 0.84 V2/2g Where V = Velocity, m/s G = acceleration due to gravity, m/s2 The empirical equations for friction drop were developed for different flow condition by fitting multiple log linear regression equations. The equations obtained are 1. Combined flow Hf = 0.00737 Q1.18905/D3.58352 L 2. Turbulent flow Hf = 0.00359 Q1.74866/D4.80544 L 3. Flow in transition region Hf = 0.00397 Q1.46302/D3.74436 L 4. Laminar flow Hf = 0.00743 Q1.22546/D3.58420 Similar to Blasius and general equations, the following equations were developed for friction factor in turbulent and laminar regions. f = 0.248/Re0.25 and f = 67.2/Re where f = friction factor Re = Reynolds number The KAU drip system has an additional component ‘Distributor’. Experiments were conducted to study the effect of distributor on flow rate. It was observed that the discharge rate was higher from the system with distributor than that of microtube having the same length. The frictional losses and the combined loss of minor and distributor for different flow conditions were estimated. Few combinations which satisfy the requirements of discharge, length and pressure head were selected for the design purpose of KAU drip irrigation system. The effect of clogging on discharge rate was studies and it was found that clogging was higher in 1 mm tube than the 2 mm and 3 mm tubes. Experiments were conducted to estimate friction loss in laterals. Hazen – Williams equation was found suitable for turbulent region and not for laminar and transition region. By adopting drip system we can bring more area under cultivation by maximum utilisation of available water. By combining improved agronomic practices along with an efficient drip irrigation system, it is possible to bring about a substantial progress in the farm front.

Theses

Browse

Thesis Type

Type

Author

Date

Subject

Search Results