title: Recovery of nicotine-free proteins from tobacco leaves using phosphate buffer system under controlled conditions.
abstract: Establishment of an effective, high-throughput processing system to recover protein from tobacco with no nicotine contamination is essential and vital to the development of value-added, alternative applications for tobacco farmers. We have successfully developed a mechanism capable of processing up to 60 kg of tobacco leaves per hour with phosphate buffer (Na(2)HPO(4)-KH(2)PO(4)) simultaneously added to stabilize the protein as the plant was being disintegrated. The optimal processing parameters were identified, including the ratio of buffer to leaf (BLR) at 4.75 (w/w), buffer pH 7.85, and buffer concentration 0.085 mol/L, achieving a maximum yield of soluble protein at 12.85 mg/g fresh leaf. Acetone at -20 degrees C was the most effective among all methods investigated to remove nicotine from protein; however, it also drastically reduced the recovery rate of protein (63.3%). Ultrafiltration was only able to remove about 50% of the residual nicotine, although the protein recovery rate was high (94.7%). The residual nicotine content inherent in the recovered protein was completely removed by rinsing the protein with 85% phosphoric acid at pH 3.5 for three times with a protein recovery of 94.5%. The pilot-scale operation provides a solid foundation for further scale-up to industrial production of nicotine-free tobacco protein that could bring added value to tobacco for nonsmoking applications.
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
authors.forename: H
authors.initials: H
authors.lastname: Fu
authors.forename: P A
authors.initials: PA
authors.lastname: Machado
authors.forename: T S
authors.initials: TS
authors.lastname: Hahm
authors.forename: R J
authors.initials: RJ
authors.lastname: Kratochvil
authors.forename: C I
authors.initials: CI
authors.lastname: Wei
authors.forename: Y M
authors.initials: YM
authors.lastname: Lo
mesh_terms: D000096:Acetone / Q000737:chemistry; D000383:Agriculture / Q000379:methods; D001709:Biotechnology / Q000379:methods*; D002021:Buffers; D002623:Chemistry Techniques, Analytical; D006863:Hydrogen-Ion Concentration; D009538:Nicotine / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis*; D013696:Temperature; D014026:Nicotiana / Q000378:metabolism*
chemical_list: D002021:Buffers; D010710:Phosphates; D010756:Phosphoric Acids; D010940:Plant Proteins; D000096:Acetone; D009538:Nicotine; C030242:phosphoric acid