30C-13 |
Effects of g-irradiation on antigenicity of almonds, cashew nuts, and walnuts |
M. SU1, M. Venkatachalam1, S. S. Teuber2, K. H. Roux3, and S. K. Sathe1. (1) Department of Nutrition, Food and Exercise Sciences, Florida State University, 402 Sandels Bldg., College of Human Sciences, Tallahassee, FL 32306-1493, (2) Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, 95616, (3) Department of Biological Science, Florida State University, Tallahassee, FL 32306-4370 Tree nuts are major food allergens. The best way to avoid food allergies is to eliminate the offending food from one's diet which is not always possible. It is therefore necessary to explore ways to eliminate/modify allergenic proteins. We therefore investigated effects of g-irradiation on almond, cashew nut and walnut protein antigenicity. Defatted nut flour and full fat whole nuts were subjected to 0, 1, 5, 10, and 25 kGy g-irradiation. Nut flours (~ 40 mesh) were defatted using petroleum ether. Proteins were extracted from defatted flour with borate saline buffer (BSB, 100 mM, pH 8.45) at flour to buffer ratio 1:10 (w/v) for 1 h at 250C, normalized to 1 mg protein/ml BSB and used for inhibition enzyme linked immunosorbent assays (ELISAs). Rabbit polyclonal antibodies raised against each major protein from almond, cashew nut, and walnut (105 dilution in 0.1% BSA in BSB) were used for ELISAs. ELISA results were expressed as ratio of inhibitor concentration for 50% inhibition (IC50) for sample compared to corresponding untreated control. The IC50 ratios for defatted almond, cashew, and walnut flour controls were respectively 0.5959, 1.6244, and 1.4487. The IC50 ratios for defatted almond flour subjected to 1, 5, 10, and 25 kGy were respectively 0.7373, 0.5470, 0.5714, and 0.6178 while the corresponding values for the full fat whole almonds were respectively 0.8595, 1.0681, 1.0801, and 1.0700. IC50 ratios for defatted cashew flour and full fat whole cashew nuts subjected to 1, 5, 10, and 25 kGy dose were 3.4417, 2.6909, 2.2337, and 2.7407; and 1.6301, 1.7132, 1.5364, and 1.7570 respectively. Corresponding IC50 ratios were 1.2614, 1.3888, 1.2797, and 1.6592 respectively for defatted walnut flour and 1.2537, 2.0452, 2.0847, and 1.9460 for the full fat whole walnuts subjected to 1, 5, 10, and 25 kGy irradiation doses. These data indicated that almond, cashew, and walnut proteins exposed to g-irradiation remained antigenically stable.
Session 30C, Food Chemistry: Proteins
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