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Anand Agricultural University, Anand

Anand Agricultural University (AAU) was established in 2004 at Anand with the support of the Government of Gujarat, Act No.(Guj 5 of 2004) dated April 29, 2004. Caved out of the erstwhile Gujarat Agricultural University (GAU), the dream institution of Sardar Vallabhbhai Patel and Dr. K. M. Munshi, the AAU was set up to provide support to the farming community in three facets namely education, research and extension activities in Agriculture, Horticulture Engineering, product Processing and Home Science. At present there seven Colleges, seventeen Research Centers and six Extension Education Institute working in nine districts of Gujarat namely Ahmedabad, Anand, Dahod, Kheda, Panchmahal, Vadodara, Mahisagar, Botad and Chhotaudepur AAU's activities have expanded to span newer commodity sectors such as soil health card, bio-diesel, medicinal plants apart from the mandatory ones like rice, maize, tobacco, vegetable crops, fruit crops, forage crops, animal breeding, nutrition and dairy products etc. the core of AAU's operating philosophy however, continues to create the partnership between the rural people and committed academic as the basic for sustainable rural development. In pursuing its various programmes AAU's overall mission is to promote sustainable growth and economic independence in rural society. AAU aims to do this through education, research and extension education. Thus, AAU works towards the empowerment of the farmers.

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Subject: Agricultural Engineering × End date: 1999 × Start date: 1980 × Thesis Type: M.Tech ×
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    STUDIES ON PHYSICAL AND MECHANICAL PROPERTIES OF FRESH AND STORED WATERMELON
    (AAU, Anand, 1997) GABANI, S. H.; Siripurapu, S C B
    Watermelon (Citrullus Vulgaris Schrad) is one of the important fruits because of its special nutritive value. It is widely grown as a summer fruit crop all over India. It has good flavour, taste and colour which attract the consumers. Generally only fleshy parts of the ripened watermelon fruit is consumed while the rest madeup of rind and seeds are discarded. Fresh matured watermelons are harvested and transported to the market and stored till they are ripened. Generally the watermelons are stored either in a simply shaded open structure or in a room or vakhar type closed structure. The losses in handling occurs due to physical and mechanical injuries which include cuts, punctures, scars and scuffmarks. Therefore the physical and mechanical properties of fruits are important to the researcher, design engineer, the food industry and the consumer alike. A knowledge on the basic physical and mechanical properties is essential for the development of transportation models, machines and storage structures. Therefore, the present investigation was undertaken to study the physical and mechanical properties of fresh and stored watermelon. Fresh watermelon fruits of variety Sugar baby were selected and handpicked from the field. The physical properties, static friction coefficients on different materials and mechanical properties were determined. The average three axial dimensions viz., maximum equatorial, minimum equatorial, and polar diameter and geometrical mean diameter of the watermelon are 166.5, 161.1, 165.9 and 164.4 mm respectively. The average sphericity and shape factor are 96.8 per cent and 1.008 respectively. The average volume and weight are 2616 CC and 2.356 kg respectively and the average weight density and average bulk density are 890 and 550.2 kg m-3 respectively. The packing factor/bulk porosity is 38.13 per cent. The frequency distribution curves of the axial dimensions are following a normal distribution with slight skew and have high peaks close to their mean average dimensions. The per cent sphericity frequency distribution graph is following a skew distribution and a maximum of 27 per cent fruits have the per cent sphericity of 98 and about 84 per cent fruits have per cent sphericity between 95-100. The frequency distribution of the shape with respect to volume range is indicating that the shape is a function of size and with increase in size, the shape tends to change from oblate to prolate. The volume and weight frequency curves are following normal distribution with slight skew. Volume, weight and weight density are having highest frequencies of 29, 35 and 39 per cent respectively close to their average values. It is found that models based on linear relationship are adequate to describe the relationship between dimensions, between cube of dimensions and volume/weight and between volume and weight. The average coefficients of friction of watermelon are 0.511, 0.529, 0.548 and 0.562 on galvanised iron, mild steel, aluminium and plywood sheets, respectively. Mechanical properties, namely, average quasi-static compression rupture force, puncture strength, static compression rupture stress and impact rupture energy per unit weight for watermelon are 1638.3 N, 885.1 N, 44321 N m-2 and 12.49 N m/kg, respectively The best fitted empirical models were developed to describe the effect of watermelon weight on different quasi-static rupture force parameters. It is observed that the per cent shinkage in volume, weight loss and weight density reduction is increased with storage for both indoor and outdoor storage treatments. It is found that maximum shrinkage of volume is 3.59 and 3.61 per cent, maximum weight loss is 11.47 and 10.69 per cent and maximum reduction of weight density is 8.49 and 7.07 per cent for outdoor and indoor stored watermelon fruits respectively, at the end of the fifth week. It is observed in all the cases that static friction coefficient is decreasing linearly with storage for both the treatments. It is observed that quasi-static rupture force decreases with storage for both the storage treatments. It is also observed that quasi-static compression rupture force is higher till the end of second week of storage and subsequently it was lower for indoor stored fruits compared to the open system. It is found that the puncture strength is decreasing with storage at a decreasing rate for both the storage treatments. The static compression test parameters, namely, rupture force, stress and stress-strain ratio of stored watermelon are decreasing with storage for both indoor and outdoor stored samples. In this case also, the rupture force for indoor stored samples was more than that of outdoor stored samples. It is further observed in impact test that rupture energy per unit weight of fruit is decreasing at decreasing rate with storage for both the storage treatments. It is found that the impact rupture energy per unit weight is more for indoor stored fruits compared to fruits stored in open in the veranda. From the results obtained in the present investigation, an inference can be drawn that indoor stored fruits are stronger than the outdoor stored fruits. It is also found that after the fifth week of the storage, in both outdoor and indoor storage systems, the watermelon fruits were unfit for human consumption. The data generated in the present study and models developed will be useful in the design of handling, transportation and storage systems for watermelon.