Analysis of glabrous canary seeds by ELISA, mass spectrometry, and Western blotting for the absence of cross-reactivity with major plant food allergens.

Glabrous (hairless) canary seed belongs to the Poaceae (Gramineae) family and could serve as an alternative source of gluten-free cereal grain. In this study, allergenic cross-reactivities between hairless, dehulled canary seeds (Phalaris canariensis) and major allergenic proteins from gluten, soy, peanuts, tree nuts, sesame, and mustard were studied using commercial enzyme-linked immune sorbent assay (ELISA) kits specific for these target allergens. Mass spectrometry (MS) and immunoblotting were further used to assess for the presence of gluten-specific protein fragments. MS results revealed the likely presence of proteins homologous with rice, oat, corn, carrot, tomato, radish, beet, and chickpea. However, no presence of celiac-related gluten fragments from wheat, rye, barley, or their derivatives was found. Immunoblotting studies yielded negative results, further confirming the absence of gluten in the canary seed samples tested. No cross-reactivities were detected between canary seeds and almond, hazelnut, mustard, peanut, sesame, soy, walnut, and gluten using ELISA.

In vitro protein digestibility and physico-chemical properties of flours and protein concentrates from two varieties of lentil (Lens culinaris).

The chemical composition of whole lentil flours and lentil protein concentrates prepared by alkaline extraction and iso-electric precipitation from Blaze and Laird varieties of lentil were studied. The protein composition of the flours and concentrates, determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and size-exclusion high-performance liquid chromatography (SE-HPLC) showed that the extracted proteins were composed mainly of globulins and albumins. Trypsin inhibitor activity ranged between 0.94 and 1.94 trypsin inhibitor units (TIU) mg(-1) for the flours, but was markedly lower in the protein concentrates ranging between 0.17 and 0.66 TIU mg(-1). In vitro protein digestibility ranged between 75.90 and 77.05% for the flours, whereas significantly (P < 0.05) higher values, ~82.80 to 83.20%, were determined for the concentrates. Significant (P < 0.05) differences in colour (ΔE) were observed between the flours and the concentrates from both varieties. Thermal properties of both flours as studied by differential scanning calorimetry (DSC) were comparable. However, the endothermic parameters of the two protein concentrates were significantly (P < 0.05) different. Overall, the results show that in vitro protein digestibility of lentil protein concentrates is higher than that of the flours, however, both lentil flours and protein concentrates contain useful proteins that could serve as value-added ingredients in food formulations.

Food allergies in developing and emerging economies: need for comprehensive data on prevalence rates.

Although much is known today about the prevalence of food allergy in the developed world, there are serious knowledge gaps about the prevalence rates of food allergy in developing countries. Food allergy affects up to 6% of children and 4% of adults. Symptoms include urticaria, gastrointestinal distress, failure to thrive, anaphylaxis and even death. There are over 170 foods known to provoke allergic reactions. Of these, the most common foods responsible for inducing 90% of reported allergic reactions are peanuts, milk, eggs, wheat, nuts (e.g., hazelnuts, walnuts, almonds, cashews, pecans, etc.), soybeans, fish, crustaceans and shellfish. Current assumptions are that prevalence rates are lower in developing countries and emerging economies such as China, Brazil and India which raises questions about potential health impacts should the assumptions not be supported by evidence. As the health and social burden of food allergy can be significant, national and international efforts focusing on food security, food safety, food quality and dietary diversity need to pay special attention to the role of food allergy in order to avoid marginalization of sub-populations in the community. More importantly, as the major food sources used in international food aid programs are frequently priority allergens (e.g., peanut, milk, eggs, soybean, fish, wheat), and due to the similarities between food allergy and some malnutrition symptoms, it will be increasingly important to understand and assess the interplay between food allergy and nutrition in order to protect and identify appropriate sources of foods for sensitized sub-populations especially in economically disadvantaged countries and communities.

Detection and quantification of soy allergens in food: study of two commercial enzyme-linked immunosorbent assays.

The objective of this study was to evaluate the efficacy of 2 commercially available soy enzyme-linked immunosorbent assays (ELISA) and use them in detecting soy proteins in selected food commodities. Both ELISA kits exhibited high sensitivity. The determined limits of detection (LOD) (approximately 2 and <1 microg/mL for Tepnel Biosystems and Elisa Systems kits, respectively) were lower than those claimed by the manufacturer. Quantification range for both kits was, however, narrower and in a lower concentration range than defined by the kit providers. Our examination revealed a positive cross-reactivity with chickpea proteins and matrix interferences for both kits. The immunoreactivity of soy proteins, when tested by the Tepnel Biosystems kit, was partially reduced by papain and bromelain hydrolysis; it was significantly decreased by protein glycation (>47%). Nondenatured and nonheated soy protein isolate (SPI) samples were also significantly less antigenic than the treated ones.