Effect of Novel Drying Techniques on the Drying Kinetics and Physiological Quality of Soybean Seeds PDF Download

Author: Ayushi Anand
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
"Every year one-third of the food produced worth the US $1 trillion gets spoiled during post-harvest operations. The world population is expected to be to 9.1 billion by the end of 2050 and approximately 70% extra food production is required for maintaining food security. Most of this population rise is expected to be in developing countries which are already facing an issue of food hunger and insecurity.Drying is already an energy extensive process in the industry and in the case of seed grade grain drying, the energy requirement is even higher because of the low drying rate requirement employed worldwide. Microwave drying has evolved in the last two decades and the application of it can be seen in many food industries. However, in the seed industry, the application of novel techniques are not that popular, and the literature doesn’t report sufficient studies on it. In this study, microwave-assisted air drying, fluidized drying, and microwave-assisted fluidized bed of soybean seeds were carried out at the laboratory scale and the viability, vigor and the seed coat quality was studied post drying. In microwave-assisted air drying, thin layer drying at an air temperature (30, 40 and 50°C) and microwave power density (0, 0.5 and 1 W/g) were carried out using face-centered response surface methodology. A 0 W/g microwave power density was studied to highlight the comparison between air and microwave drying. The results showed that drying kinetics was improved by the incorporation of the microwaves with an increase in drying rate, shown by drying rate constant and moisture diffusivity. Also, the drying time was significantly reduced during the microwave-assisted air drying. However, the viability and the vigor of the seeds were damaged during microwave-assisted air drying. The cracking percentage was low, but the fissure percentage was high when the microwave was incorporated. This depicts that the incorporation of microwave in the thin layer drying of soybean is not capable of producing seed grade soybean. Moreover, fluidized bed drying of soybean seeds was carried out at different air temperatures (30, 40 and 50 °C) and air velocity (1, 4 and 7 m/s) with a bed depth of 30 to 32 mm. Air velocity of 1m/s was employed to study the comparison between fixed and fluidized bed. The results showed that fluidization at low velocity improved the drying kinetics with a relatively low negative influence and an increase in air temperature had more influence on drying kinetics. The seeds dried in fluidized bed drying had germination percentage greater than 77% with a reduction in seed vigor. More than 60% of the seeds had a damaged seed coat and the seed coat hardness. In addition to this, microwaves were employed in the fluidized bed drying of soybean seeds and the drying kinetics was further improved as compared with fluidized bed drying. Also, seeds dried in microwave-assisted fluidized bed drying were able to germinate with reduced vigor to the fresh seeds. In microwave fluidized bed drying almost all the seeds had damaged seed coat and the hardness of the seed coat was decreased as compared to fluidized bed drying. The fluidized bed drying technique combined with a microwave can solve the problem of non-homogeneity in bed and low drying rates in the seed drying. However, seed coat damage is a problem which requires attention in adapting these drying techniques as it could lead to spoilage and loss of viability in the seeds during storage"--