Kinetics and thermodynamics of gossypol extraction from defatted cottonseed meal by ethanol

Abstract

Gossypol is polyphenolic aldehyde, a toxic substance naturally present in cotton plant to protect it from insects, pests and diseases. Maximum gossypol is concentrated in the seed. After extraction of oil from the cottonseed, the defatted cottonseed meal which contains both the gossypol and proteinous matter is left behind. A number of attempts have been made using different solvents to extract gossypol from the seeds. However, all these efforts have remained in the realm of academic activity only as none of them could be commercialized. If a pilot plant or commercial scale plant is to be developed then the data on the kinetics and thermodynamics of the extraction process is required. In this study ethanol has been used as the solvent at temperature below 323K for removal of gossypol from the defatted seed. This study fi nds the effects of parameters viz. temperature, solvent to solid ratio (SR) and extraction time on the gossypol extraction effi ciency. The data obtained are used to establish the kinetics and thermodynamics of the extraction process.

Kinetics and thermodynamics of the solid-liquid extraction process of total polyphenols from barley

“…The value of ∆H 0 was positive, indicating that the extraction was endothermic and that the process was irreversible. The results are similar to that of Topallar and Gecgel [15] and Saxena et al [14].…”

“…The thermodynamics consideration of the extraction process was necessary to conclude whether the process was spontaneous or not. Gibb's free energy (∆G 0 ), enthalpy change (∆H 0 ) and entropy change (∆S 0 ) are calculated (6) where ct is the contents of total phenolics in the liquid extract at temperature T; cmax is the contents of phenolics in the saturated liquid extract, ∆H 0 is the enthalpy change; ∆S 0 is the entropy change and ∆G 0 is Gibb's free energy [14].…”

Ultrasound-assisted extraction of some branded tea: Optimization based on polyphenol content, antioxidant potential and thermodynamic study

“…The value of ΔH° = 8.040 kJ/ mol was recorded by the extraction of paclitaxel from biomass (Kim and Kim, 2016). Extraction of gossypol from defatted cottonseed meal (Saxena et al, 2012), extraction of oil from sunflower seeds (Topallar and Geçgel, 2000) and the extraction of oil from caster cake (Amarante et al, 2014) were found ΔH° = 27.749–28.093, 11.200 and 12.270 kJ/mol which is more than that of our present results as shown in Tables 9 and 10. Moreover, comparing values of heat of reaction (ΔH 0 ) of each brand and under the influence of two frequencies was quite variable.…”

Kinetics of the Solid-Liquid Extraction Process of Phenolic Antioxidants and Antioxidant Capacity from Hop (Humulus lupulus L.)

“…M a n u s c r i p t ∆G 0 = -RT lnk e (5) lnk e = -∆H 0 / RT + ∆S 0 /R (6) where c t is the contents of total phenolics in the liquid extract at temperature T; c max is the contents of phenolics in saturated liquid extract, ∆H 0 is the enthalpy change; ∆S 0 is the entropy change and ∆G 0 is the Gibb's free energy (22).…”