67C-21 |
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R. S. TIWARI1, M. Venkatachalam1, S. S. Teuber2, K. H. Roux3, and S. K. Sathe1. (1) Dept. of Nutrition, Food & Exercise Sciences, Florida State Univ., 402 Sandels Bldg., Mail Code 1493, Tallahassee, FL 32306-1493, (2) School of Medicine, Univ. of California, Davis, Div. of Rheumatology, Allergy & Clinical Immunology, 2221 Stockton Blvd., Sacramento, CA 95817, (3) Dept. of Biological Science, Florida State Univ., 335 Biology Unit 1, Mail Code 4370, Tallahassee, FL 32306-4370 Tree nuts are among the major food allergens. Almonds lead the global tree nut production and consumption and US is the largest almond producer and exporter. We have developed a rabbit polyclonal antibody based inhibition enzyme linked immunosorbent assay (ELISA) that detects amandin, the major storage protein in almonds. The assay is robust, reproducible, and sensitive in detecting trace amounts of almonds. Since almonds are used in a variety of food products that may contain many non-almond components, it is important to know whether the presence of such components affects ability to detect and quantify almonds. A wide range of foods and food ingredients were defatted with petroleum ether and 100 mg of defatted sample was spiked with amandin (100, 10, or 1 mg). The spiked samples and appropriate controls were extracted with 1 ml of 0.1 M borate saline buffer (pH 8.45), centrifuged (13,000g, 5 min), and supernatants were evaluated for amandin recovery using an inhibition ELISA. Amandin recovery was not adversely affected at spike levels 100 and 10 mg amandin/100 mg sample. At 1 mg spike level, amandin recovery was quite variable without any clear trend. With few exceptions, amandin was quantitatively recovered from cereals and cereal products, dairy products, and several tree nuts (80-120% recovery). Legumes and oilseeds caused higher amandin recovery (range 100-200%). Spices gave lower recoveries (range 16-80%), with a few exceptions, where higher recoveries (range 80-190%) were noted. Dark and milk chocolate (range 17-49%), baker’s chocolate (range 20-70%), sugar and jaggery (range 20-45%) resulted in lower recoveries. Most vegetable matrixes increased amandin recovery (range 120-400%). Salt (black and white), tea (black and green), and cocoa decreased amandin recovery (range 10-50%). The results suggest that food matrix effects need to be carefully evaluated in allergen detection development assays.
Session 67C, Food Chemistry: Food analysis, irradiation and toxicology
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