Biochemical Changes in Cottonseed During Germination

Abstract

Changes in oil, protein, carbohydrate, fiber, ash and gossypol contents of cottonseed during germination were studied. Highest reduction in kernel dry weight and highest oil, protein and carbohydrate consumptions occurred after the 8th day. Percentage carbohydrate consumption was always higher than oil or protein consumptions. Only little changes in fatty acid composition of oil was detected even during most rapid loss from kernels. The rate of losses of the three major fatty acids from kernels were in the following order:linoleic>oleic>palmitic. There was a continuous increase in the percentage total phospholipids as germination proceeds.The lecithin-cephalin ratio was I : 1.5 up to iodays germination, after which the ratio was lowered. The data indicate significant changes in the fatty acid constitution of the phospholipids throughout the germination period. The changes in the oil characteristics and the fatty acid proportions during germination differ with different seeds. WHITE [21] reported that during germination the rate of depletion of linoleic, oleic and saturated acids in cottonseed was proportional to their amounts in the reserve oil.No precise; information appeared in the literature concerning the changes in cottonseed phospholipids during germination. WEISS [23] indicated that although phosphatide phosphorus showed a little change in cereals and legumes, yet in oilseeds it increases.The present study was designed to investigate the changes in cottonseed constituents during germination. Changes in oil characteristics including : unsaturation, free acidity, and fatty acid constitution are also reported. Total and individual phospholipid contents of the oil as well as the fatty acids of the mixed phospholipids were studied. Materials and MethodsThe cottonseed (Gossypium barbadense, variety Bahteem-1 I I ) used in the present investigation was kindly supplied by Ministry of Agriculture Experimental Stations. CHESTER method [24] was used to separate sound seeds. The germination technique is basically the standard technique proposed by SIMPSON [25]. Fifty gram samples of sound resting seeds were germinated for 2 to 18 days in dark a t 28 'C. At the end of each germination period the seed samples were heated in an air oven a t 80 "C for 4 hours. The partially dried seeds were decorticated. Care was taken to separate the germinated kernels, which were then completely dried a t 105 "C for 12 hours, placed in a desiccator and weighed.

Priming treatments for improvement of germination and emergence of cotton seeds at low temperature

“…When the amounts of oil, protein, carbonhydrate, ash, fiber and gossypol present in germinating cotton seeds were examined, it was found that most of the reduction in seed dry coat weight, oil, protein and carbohydrate consuption°C cured eight days after germination. Total phospholipid percentage, on the other hand, was observed to increase during germination while phospholipid structures were changing (El-Nockrashy et al, 2006). Since vegetative period in cotton takes a relatively long time, producers might prefer early (sub of optimum temperature for cotton growing) sowing; however, it needs to be considered that cotton radicle formation and growing stop when the soil temperature drops below 14.5°C (Jackson, 1986).…”