Journal of Food Engineering, Vol.34, No.1, 77-90, 1997
Fracture resistance of karingda (Citrullus lanatus (Thumb) Mansf) seeds to compressive loading
Karingda seed (Citrullus lanatus (Thumb) Mansf), one species of the Cucurbitaceae family, and its kernel at various moisture contents were subjected separately to quasi-static compressive loading under longitudinal (vertical) and transverse (horizontal) orientations. The results showed that, for both orientations the rupture force of the sample (hull of the seed or kernel), the corresponding deformation and the energy absorbed at rupture individually followed quadratic relationships with respect to moisture content. At any moisture content of the seed tested between 3% and 19% (db), the hull rupture force was more in the vertical than the horizontal orientation with peak values of 107 and 77N at 11% (db) respectively. The forces required for kernel rupture at various moisture contents (3-17%, db) were higher for horizontal orientation with a peak value of 12N at around 11.0% (db) -5.5N more than for vertical orientation. The maximum deformations of the kernel at rupture were 2.36 mm (vertical) and 1.60 mm (horizontal), while for the seed at hull rupture these values were 1.52 and 1.08 mm, respectively. The seed required higher energy to rupture the hull when compressed in the vertical (45-67mJ) than, in the horizontal (12-36 mJ) orientation. For rupturing the kernel, these values were quite low: 4.5-8.5 mJ for horizontal and 2.4-5.4 mJ for vertical orientation.
Keywords:MELON SEEDS