Lesquerella fendleri protein fractionation and characterization

2006

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This study characterized the proteins in Cuphea (PSR23) seed to provide fundamental information on their size, amino acid profile, solubility classes, and solubility behavior. The seed contained 32% (dry basis, db) oil and 21% (db) crude protein. Over 70% of the protein was extracted at pH 11.6. Nonprotein nitrogen accounted for 9% of the total N content. Compared with the Food and Agriculture Organization/World Health Organization/United Nations University suggested pattern of requirements, Cuphea PSR23 seed protein had sufficient amounts of methionine + cystine-cysteine, considerable amounts (90%) of valine, phenylalanine + tyrosine, but was practically devoid of tryptophan. Lysine was the second-most limiting essential amino acid at 68%. Glutelins and albumins accounted for 83.5 and 15.4%, respectively, of the total protein extracted. SDS-PAGE showed that Cuphea protein subunits had M.W. ranging from <6.5 to 110 kDa. Dominant protein subunits in albumins had M.W. of 30, 40, 50, and 86 kDa. Glutelins had two major protein subunits with M.W. of 15 and 30 kDa. The distribution of essential amino acids was better in the albumin and glutelin fractions than in the defatted meal.Paper no. J11294 in JAOCS 83, 785-790 (September 2006).

“…2). Similar results were also reported for jojoba, salicornia, and lesquerella (16,29,30). SDS-PAGE of 0.6 M TCA extracts that were dialyzed (using membrane with 3.5 kDa M.W.…”

Section: Resultssupporting

confidence: 81%

Section: Resultscontrasting

confidence: 59%

Characterization of proteins in Cuphea (PSR23) seeds

Evangelista

2006

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“…SDS-PAGE was done by following the method of Wu and Hojilla-Evangelista [14]. Samples were weighed out to provide 4 mg protein/mL in 500 lL of sample buffer composed of 42 nM Tris-HCl (pH 6.8), 2% SDS, 7% glycerol, 4.4% b-mercaptoethanol, and 5 M urea.…”

Section: Sds-pagementioning

confidence: 99%

Extraction and Functional Properties of Non‐Zein Proteins in Corn Germ from Wet‐Milling

2011

This study was conducted to evaluate the extractability of wet-milled corn germ protein, characterize the recovered protein and identify its potential applications. Protein was extracted from both wet germ and finished (dried) germ using 0.1 M NaCl as solvent. The method involved homogenization, stirring, centrifugation, dialysis and freeze-drying. Factors evaluated were temperature (40, 50, or 60°C) and the presence of reducing or denaturing agents. The recovered protein was analyzed for proximate composition and functional properties. Protein recovery was greater from wet germ. For both germ samples, protein recovery was not improved by using higher temperatures; thus, subsequent extractions were done at 40°C. Addition of 2% SDS and 1% b-mercaptoethanol to the solvent nearly doubled protein yield; but, SDS-PAGE indicated some protein denaturation. The recovered freezedried proteins from both germ samples were least soluble at pH 2.0-4.0, but solubility increased at higher pH values. Wet germ protein extract was more soluble than finished germ protein at all pH values; however, the finished germ protein showed much better foaming and emulsifying properties and water-holding capacity.

“…of 15, 30, 40, and 50 kDa. These protein fractions were still heavily concentrated in the cooked and screw-pressed Cuphea samples (lanes [3][4][5][6][7][8]. There were indications, though, that heating caused some modifications, such as the faintness or disappearance of the 6 kDa (lanes 3-6 and 8) and 90 kDa (lanes 3,4, 6, and 8) bands, loss of the minor 36 kDa fraction, and the slight narrowing of protein band widths in the CF and PC.…”

Section: Resultsmentioning

confidence: 99%

“…SDS-PAGE. SDS-PAGE of reduced proteins was done by following the method described by Wu and Hojilla-Evangelista (8). Ground, unprocessed Cuphea PSR23 seeds, CF, and PC were weighed out to provide 4 mg protein/mL in 500 µL of solubilization buffer (42 nM Tris-HCl (pH 6.8), 2% SDS, 7% glycerol, 4.4% β-mercaptoethanol, and 5 M urea), and then heated in a boiling-water bath for 5 min.…”

Section: Methodsmentioning

confidence: 99%

Effects of cooking and screw‐pressing on functional properties of Cuphea PSR23 seed proteins

Evangelista

2006

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This investigation determined the effects of oil processing conditions on some functional properties of Cuphea PSR23 seed proteins to evaluate their potential for value-added uses. Flaked Cuphea seeds were cooked at 82°C (180°F) for 30, 75, or 120 min in the seed conditioner and then screw-pressed to extract the oil. Cooked flakes and press cakes were analyzed for proximate composition and protein functional properties. Results were compared with those of unprocessed ground, defatted Cuphea seeds. Protein from unprocessed Cuphea seeds had excellent emulsifying properties, poor foaming properties, poor solubility (10%) at pH 4-7, and much greater solubility at pH 2 and 10 (57 and 88%, respectively). Solubility profiles showed that cooking the flaked seeds to 82°C for 30 min resulted in a 50-60% reduction in soluble proteins. Cooking for 120 min gave <6% soluble proteins at all pH levels. Cooking for 75 min gave good oil yields but also resulted in <10% soluble proteins at pH 2-7 and 25% soluble proteins at pH 10. Seed cooking and screw pressing during oil extraction had significant detrimental effects on the solubility of Cuphea seed protein but generally improved its foaming capacity and emulsifying activity.There is great interest in developing the Cuphea plant as an alternative source of industrial oil. Its seed produces 16-42% oil that is rich in medium-chain FA (MCFA), such as caprylic, capric, lauric, myristic, and palmitic acids (1,2). These MCFA are used in detergents, cosmetics, lubricants, and fuels. The current commercial sources of MCFA are the tropical oilseeds (coconut and palm kernel oils). Cuphea oil has a strong potential to augment or replace these imported sources of MCFA (1).Cuphea, however, has some undesirable agronomic traits that are considered as major deterrents to its domestication and commercialization, including: indeterminate growth and flowering patterns, excessive seed shattering from maturing pods, and the presence of sticky substances on leaves and stems that create harvesting problems (2,3). Domestication studies at Oregon State University (Corvallis, OR) identified C. lanceolata, C. wrightii, and C. viscosissima as the most promising species for cultivation (3,4). Breeding efforts at the same institution produced PSR23, a semidomesticated hybrid from C. lanceolata and C. viscosissima that exhibits partial seed retention on maturity and contains high amounts of capric acid (4). Cuphea PSR23 has been subjected to field testing for the past 5 yr.If Cuphea oil production is successful, then it is anticipated that protein-rich meals will be also be generated because the seed contains as much as 25% crude protein (CP) (2). Current literature on Cuphea reports only the amount of protein in the whole seed. There is no information available on the quality and properties of Cuphea seed proteins. Recently, our research team completed a pioneering study that determined the SDS-PAGE profile, soluble classes, and amino acid composition of Cuphea seed protein. We detected six major subunits, a...