Eight almond (Prunus dulcis L.) cultivars from 12 different California counties, collected during crop years 2004 to 2005 and 2005 to 2006, were extracted with petroleum ether. The extracts were subjected to GC-MS analyses to determine fatty acid composition of soluble lipids. Results indicated palmitic (C16:0), oleic (C18:1), linoleic (C18:2), and alpha-linolenic (C18:3) acid, respectively, accounted for 5.07% to 6.78%, 57.54% to 73.94%, 19.32% to 35.18%, and 0.04% to 0.10%; of the total lipids. Oleic and linoleic acid were inversely correlated (r=-0.99, P= 0.05) and together accounted for 91.16% to 94.29% of the total soluble lipids. Statistically, fatty acid composition was significantly affected by cultivar and county.

Cashew nut seeds were subjected to processing including autoclaving (121 degrees C for 5, 10, 20, and 30 min), blanching (100 degrees C for 1, 4, 7, and 10 min), microwave heating (1 and 2 min each at 500 and 1000 W), dry roasting (140 degrees C for 20 and 30 min; 170 degrees C for 15 and 20 min; and 200 degrees C for 10 and 15 min), gamma-irradiation (1, 5, 10, and 25 kGy), and pH (1, 3, 5, 7, 9, 11, and 13). Proteins from unprocessed and processed cashew nut seeds were probed for stability using anti-Ana o 2 rabbit polyclonal antibodies and mouse monoclonal antibodies directed against Ana o 1, Ana o 2, and Ana o 3 as detection agents. Results indicate that Ana o 1, Ana o 2, and Ana o 3 are stable regardless of the processing method to which the nut seeds are subjected.

Effects of different solvents, ionic strength, and pH on Inca peanut seed protein solubility were assessed by quantitatively analyzing solubilized proteins using Lowry and Bradford methods. Soluble proteins were fractionated using Osborne procedure and the polypeptide composition of solubilized proteins was determined by one dimensional 25 % monomer acrylamide linear gradient SDS-PAGE. Osborne protein fractions were analyzed by the 2D gel electrophoresis. Total seed proteins were efficiently solubilized by 2 M NaCl among the tested solvents. The soluble seed proteins registered a minimum solubility at pH ~4.0. Osborne protein fractions, albumins, globulins, prolamins, and glutelins accounted for 43.7, 27.3, 3.0, and 31.9 %, respectively, of the total aqueous soluble proteins. Soluble seed flour proteins are mainly composed of polypeptides in the MW range of 6-70 kDa of which the predominant polypeptides were in the 20-40 kDa range. Prolamin fraction was mainly composed of four polypeptides (MW < 15 kDa). Glycoprotein staining indicated 32-35 and <14 kDa peptides to be positive.

On an edible portion basis, pecan moisture, protein, lipid, total soluble sugars, and ash contents ranged from 2.1% to 6.4%, 6.0% to 11.3%, 65.9% to 78.0%, 3.3% to 5.3%, and 1.2% to 1.8%, respectively. With the exception of a high tannin (2.7%) Texas seedling, pecan tannin content was in a narrow range (0.6-1.85%). Unsaturated fatty acids (>90%) dominated pecan lipid composition with oleic (52.52-74.09%) and linoleic (17.69-37.52%) acids as the predominant unsaturated fatty acids. Location significantly influenced pecan biochemical composition. Pecan lipid content was negatively correlated with protein (r = -0.663) and total sugar (r = -0.625). Among the samples tested using SDS-PAGE a common pattern, with minor differences, in subunit polypeptide profiles was revealed. Rabbit polyclonal antibody-based immunoblotting experiments (Western blot) also illustrated the similarity in polypeptide profiles with respect to immunoreactivity. All tested cultivars registered similar immunoreactivity when their protein extracts (each at 1 mg/mL) were assessed using inhibition ELISAs (mean +/- standard deviation = 0.89 +/- 0.20; n = 27) with the USDA "Desirable" cultivar as the reference standard (immunoreactivity designated as 1.0).

The solubility of almond, Brazil nut, cashew nut, hazelnut, macadamia, pecan, pine nut, pistachio, walnut, and peanut proteins in several aqueous solvents was qualitatively and quantitatively assessed. In addition, the effects of extraction time and ionic strength on protein solubility were also investigated. Electrophoresis and protein determination (Lowry, Bradford, and micro-Kjeldahl) methods were used for qualitative and quantitative assessment of proteins, respectively. Depending on the seed, buffer type and ionic strength significantly affected protein solubility. The results suggest that buffered sodium borate (BSB; 0.1 M H(3)BO(3), 0.025 M Na(2)B(4)O(7), 0.075 M NaCl, pH 8.45) optimally solubilizes nut seed proteins. Qualitative differences in seed protein electrophoretic profiles were revealed. For a specific seed type, these differences were dependent on the solvent(s) used to solubilize the seed proteins. SDS-PAGE results suggest the polypeptide molecular mass range for the tree nut seed proteins to be 3-100 kDa. The results of native IEF suggested that the proteins were mainly acidic, with a pI range from >4.5 to <7.0. Western immunoblotting experiments indicated that rabbit polyclonal antibodies recognized substantially the same polypeptides as those recognized by the corresponding pooled patient sera IgE.

Native, undenatured amandin and anacardein secondary structures were estimated to be, respectively, 56.4 and 49% β-sheet, 14 and 23.7% α-helix, and 29.6 and 27.4% random coil. Circular dichroic (CD) and fluorescence spectroscopy were used to assess structural changes in amandin and anacardein subjected to denaturing treatments that included heat (100 °C, 5 min), guanidium HCl (GuHCl), urea, sodium dodecyl sulfate (SDS), and reducing agent, 2% v/v β-mercaptoethanol (βME) + heat. Mouse monoclonal antibodies (mAbs) 4C10 and 4F10 directed against amandin and 1F5 and 4C3 directed against anacardein were used to assess the influence of denaturing treatments on the immunoreactivity of amandin and anacardein. Among the denaturing treatments investigated, SDS and β-ME caused a significant reduction in the immunoreactivity of amandin and anacardein when probed with mAb 4C10 and 4C3, respectively.

No abstract

For various reasons, a considerable majority of the global population must rely on plant proteins obtained from cereals, legumes (including oilseeds), fruits, vegetables, and nuts to satisfy dietary protein needs and requirements. Edible seeds are a significant source of proteins in livestock production and in the manufacture of pet foods. In addition, edible seeds are important sources of carbohydrates (including dietary fiber), minerals, and certain vitamins in human and animal food supply. For various reasons, edible seeds are underutilized as human food. To fully exploit this renewable natural resource to its full potential, focused research efforts are warranted. With increased number of seed proteins being identified as food allergens, renewed interest in seed proteins is evident. In this article, a brief overview of seed proteins with special reference to their allergenicity is provided. An attempt is made to identify areas needing further research.