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2013 - 20155
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Subject: Agricultural Processing and Food Engineering × Author: KAU × End date: 2015 × Start date: 2011 × Type: Thesis ×
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Now showing 1 - 5 of 5
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    ThesisItemOpen Access
    Post harvest evaluation of bitter gourd as influenced by growing condition, harvest maturity, prepacking and storage
    (Department of Processing Technology, College of Agricutlure,Vellayani, 2013) Gajanan Baburao, Phuke; KAU; Geethalekshmi, P R
    The present investigation on “Postharvest evaluation of bitter gourd as influenced by growing condition, harvest maturity, prepackaging and storage” was carried out at the Department of Processing Technology, College of Agriculture, Vellayani during 2011-2013, with the objective to determine the stage of harvest maturity and its influence on postharvest life along with prepackaging and storage condition for organically and conventionally grown bitter gourd (var. Preethi) and to develop a postharvest package for extended shelf life with minimum nutritional loss. The experiment was conducted in three continuous phases such as determination of harvest maturity, precooling treatments, prepackaging and storage. Growth and development studies conducted for determining harvest maturity revealed that fruit length, width, weight and flesh thickness increased periodically till 15 days of flowering and percentage of increase was negligible 15 days after flower opening. But conventional fruits recorded higher values for all these physical characters at all the stages of maturity. Considering the development of both external and internal fruit characters, 14 and 15 days after flower opening were selected as optimum harvest maturity for further postharvest studies. Hydrocooling of harvested fruits with 150 ppm sodium hypochlorite was found as the best sanitizing treatment for maintaining the postharvest quality and increased shelf life for both harvest maturities (14 and 15 days) and growing conditions (organic and conventional). Prepackaging and storage trials revealed that prepackaging treatments, growing conditions and storage temperature had significant influence on shelf life and nutritional qualities of fruits. Fruits with 14 days maturity, grown organically, prepackaged in micro ventilated polyethylene and stored under refrigerated condition had resulted in lowest PLW. Nutritional parameters of fruits viz, protein, acidity, fibre, calcium, magnesium, iron and ascorbic acid were analysed before storage and at the end of shelf life. Before storage, none of the factors except growing conditions had significantly influenced the nutritional parameters. Fruits grown conventionally had higher protein and organic fruits exhibited high fibre, Ca, Mg, Fe and ascorbic acid content. Storage studies revealed that refrigerated storage after prepackaging in micro ventilated PE had lower nutritional and physiological changes during storage. From the study it can be concluded that bitter gourd (var. Preethi) fruits can be harvested at 14 days maturity for export and long distance market and 15 days for domestic market grown under both organic and conventional system in order to reduce the postharvest losses. Harvested fruits precooled with water containing 150 ppm sodium hypochlorite, prepackaged in micro ventilated polyethylene and stored under refrigerated condition was effective for extending the shelf life with minimum nutritional loss.
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    ThesisItemOpen Access
    Development and evaluation of an ultra violet radiation assisted with ohmic heating system for preservation of pineapple juice
    (Department of Food and Agricultural Process Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2015) Dileep, Sean Y; KAU; Prince, M V
    Ultraviolet (UV) radiation is one such non-thermal processing alternative that has been shown to be effective against many types of foodborne pathogens. But there is a limitation of practical application of UV to disinfect liquid food products due to low penetration depth. Ohmic heating (OH), another promising technology, has been widely applied in food processes. This generates heat immediately in the food product, creating a rapid and uniform heating that reduces thermal abuse, as opposed to conventional thermal processing methods. Often times, ohmic heating cause heat-sensitive nutrients within food to be deteriorated by excessive current flow. These advanced technologies could contribute to shorten processing times, energy savings, and highly balanced safe food; however, they alone still cannot guarantee food safety without damaging the food’s quality. Therefore, a new concept to combine ultraviolet and ohmic heating has been extensively evaluated. This combination technology would optimize each of the individual technology’s strengths and reduce each of their individual weaknesses. The present study envisages development of a UV radiation assisted with ohmic heating system for pineapple juice and evaluation of the developed system in retaining the quality characteristics and microbial safety. In this study, a dual cylindrical ohmic and ultraviolet treatment combination continuous flow chambers was designed and fabricated to pasteurize the pineapple juice. UV treatment 800, 1200 and 1600 mJ/cm2. Ohmic treatment until the sample temperature reached 50°C, 55°C and 60°C; and ohmic heating combined with UV treatment as the temperature rose to 50 °C, 55 °C, and 60 °C along with 800, 1200 and 1600 mJ/cm2 dosages. Combined ohmic heating at 50 °C and UV treatment of 1200 mJ/cm2 were found to be superior based on biochemical, microbiological and organoleptical characteristics. Storage study of best sample revealed that could give a shelf life of 25 days under a refrigeration temperature at 4 °C retaining its biochemical characteristics while keeping the microbial level safe.
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    ThesisItemOpen Access
    Design and development of a solar refrigeration system
    (Department of Food and Agricultural Process Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2015) Rakhi, J F; KAU; George, Mathew
    When solar power, either thermal or photovoltaic, is used to provide energy to any refrigeration system, it is called as solar refrigeration system. The main objective of the study was to design and develop a solar absorption refrigeration system and performance evaluation of the developed system. In this study 40 L capacity three fluid vapour absorption refrigeration system (VARS) was designed and a commercially available three fluid absorption refrigerator working on electricity was procured and modified for using heat energy. The solar radiation at KCAET Tavanur was measured and it was observed that a maximum solar radiation intensity of 783.81 W/m2obtained at 1.00 PM at Tavanur. The performance of the modified VARS was tested using hot water obtained from solar water heater. It was found that the hot water from the solar water heater was not sufficient to produce any cooling effect. Hence a hybrid system using hot water from solar water heater and subsequent heating of the hot water using other heating sources such as electricity and LPG were utilized and the hot water was converted to steam at high temperature. Under this new set up the system worked perfectly and produced refrigeration. The performance of the modified VARS was then tested in the laboratory under simulated conditions using water at 100°C, steam at 103°C, 106°C, 116°C and 121°C and using electric heater. The experiments with low temperatures could not produce any cooling whereas steam at116°C and 121°C and electric heater at 150°C produced refrigeration effect. The corresponding generator temperature obtained were 105°C and 110°C and the ice tray temperatures were 6.8°C and 1.9°C. The temperature obtained in the cabin of the refrigerator was 10.9°C and 8.1°C which was ideal for keeping fruits vegetables and other perishable items. For effective working of this system using only on solar energy, instead of flat plate collector, a solar steam generator that could produce steam can be used.
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    ThesisItemOpen Access
    Studies on microencapsulation of vanilla extract
    (Department of Food and Agricultural Process Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2015) Sariga, S; KAU; Prince, M V
    Vanilla is one of the minor spices, most popular flavoring agent and second most expensive spice in the world. Vanillin flavour is highly volatile, heat sensitive and application in food incorporation is limited; this can be minimized by encapsulation technique with suitable wall material. The microencapsulation technique protects the vanilla extract from undesirable changes and coverts into a free flowing powder. Spray drying is the most common and commercial method for carry out the microencapsulation process. Therefore, to increase the storage stability of the microencapsulated vanilla extract powder, an investigation has been taken up to develop optimum process parameters to produce best quality microencapsulated vanilla extract powder. The microencapsulation of vanilla extract was carried out in tall type spray drier with twin fluid atomizer. Maltodextrin and maize starch were used as wall material. Different proportion of wall materials were used for the emulsification such as 100% maltodextrin, 100% maize starch, combination of 75% maltodextrin and 25% maize starch and 75% maize starch and 25% maltodextrin. The wall materials were emulsified with 10, 20 and 30% of vanilla extract for spray drying. The physico-chemical characteristics of vanilla extract and wall materials, and emulsion characteristics were carried out and the emulsions were spray dried at different inlet temperatures of 170, 180 and 1900C. The encapsulated vanilla extract powder were collected and packed in aluminum foil and stored in room temperature for five months. The powder characteristics of encapsulated vanilla extract powders were carried out and analyzed. Based on the emulsion and powder characteristics, optimum conditions for the production of best quality encapsulated vanilla extract powder were found out. The study concluded that the encapsulated vanilla extract powder produced from 100% maize starch, vanilla extract concentration of 10% and inlet air temperature of 1800C was found to be superior. The cost of one kilogram of optimised microencapsulated vanilla extract powder using spray drying technique was estimated to be Rs.850.
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    ThesisItemOpen Access
    Development and evaluation of a cassava (Manihot esculenta) storage cum packaging system
    (Department of post harvest technology and agricultural processing, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2014) Chinthana, D T; KAU; George, Mathew
    Cassava (Manihot esculenta) has its origins in South America. This tuber root crop has become the staple food of the economically weaker sections of these countries as this can be grown in most of the adverse climatic and in fertile soil condition. In India the major production today is still from Kerala followed by Tamil Nadu and Andra Pradesh where it is gaining commercial importance for the production of Sago and Starch. The shelf life of this crop starts deteriorating immediately after harvesting and becomes unmarketable within 2-3 days. Hence, this study was undertaken to develop a more practical and affordable method to increase the shelf life of cassava by keeping in mind the economically weaker sections of society worldwide. The method chosen was to store the fresh cassava roots in boxes made up of locally available materials such as (wood, plastic, plywood) and filled with easily available cheap filler materials which are within the reach of the common man. To maintain moist condition of the filler materials small quantity of water was sprinkled daily. The filler materials selected ranged from different types of soils like sand , clay and laterite soil, cheap synthetic materials like sponge and plastic cuttings, and easily available organic materials like cassava leaves, coir, saw dust and wooden shavings. For the present study, the size of the box was developed to house around 6 Kgs of the roots along with filler materials. Two locally available popular varieties of Cassava viz. M4 and Muttechi were chosen for the study. First experiment was carried out with M4 variety with nine different filler materials as explained above stored in nine wooden boxes. Quality parameters were studied periodically in a range 5 days. It was found that cassava could be stored for 40 days using wooden shavings as filler material followed by sawdust and coconut fibre for 35day. The second experiment was the repetition of the same study with another variety commonly known as Muttechi variety in Kerala. Quality parameters were studied periodically in a range 5 – 7 days. It was found that cassava could be stored for 37 days using wooden shavings as filler material followed by sawdust (32days) and coconut fibre 27days. First two experiments revealed that synthetic filler materials like sponge, plastic etc were harmful to their survival. Organic materials like cassava leaves, Sand as a filler material was good in the initial stages but could not support for longer durations. The above two experiments were conducted using wooden boxes. In order to find the impact of material of construction of box on the storage duration of cassava, a third study was done choosing three materials (wooden box, plastic box and plywood boxes). Nine boxes were used for the study (3 each for the same material). The best three filler materials coconut fibre, saw dust and wooden shavings out of nine filler materials used in first and second experiments were used in the third experiment R.H 75% and temperature was 32ºC. Results of third experiment showed that the storage box played an important role more than that of the filler materials, as the roots stored in plywood box with best of the three filler materials could not survive for more than 15 days Comparing all the quality parameters it was observed that cassava roots stored in wooden box with wooden shavings as filler materials with routine replenishing of moisture by adding small quantity of water was best suited for extending the shelf life of the cassava roots up to 37 days during winter and the results could be less during summer with the extended shelf life of around 15 days. The economic analysis of the storage system was conducted and it was found for storing 1kg of cassava in the developed storage system with wooden shavings as a filler material including labour charges was Rs. 4.62/-. Hence, it can be concluded that this simple method of extending the shelf life of cassava roots by storing them in wooden boxes with wooden shavings as filler material with retention of moisture in the boxes by sprinkling small quantity of water daily is very economical, successful and easy for quick transportation.