Die Testung von Äpfeln auf ihre Allergenität

Apples have several allergens which, when eaten, lead to symptoms in the mouth within 5-10 min-and therefore cannot be eaten by those suffering from apple allergies. In Germany around 7.5 million people have developed specific antibodies against the main allergen (Mal d 1) in apples and are thus sensitized. At least 3.5 million of them develop the sometimes-considerable allergic symptoms as an expression of an Oral Allergy Syndrome. So far there is no drug therapy for this allergy. Apple allergy sufferers can therefore only do without apples entirely, or eat apples that have been heated beforehand or look for varieties that contain few allergens and can therefore be described as "allergy-friendly" apple varieties. Solely determinations of allergens in the laboratory cannot predict whether an apple can be eaten by apple allergy sufferers without allergic symptoms; clinical trials are required for this. We describe a standardized clinical, oral provocation test that can be used to characterize a low-allergen, allergy-friendly apple or apple variety. The results of such at least three-year tests can be used to award the ECARF seal for allergy-friendly products

Die Testung von Äpfeln auf ihre Allergenität

Äpfel besitzen mehrere Allergene, die beim Essen innerhalb von 5–10 min zu Symptomen im Mundbereich führen – und deshalb von Apfelallergikern nicht gegessen werden können. In Deutschland haben rund 7,5 Mio. Menschen spezifische Antikörper gegen das Hauptallergen (Mal d 1) in Äpfeln entwickelt und sind damit sensibilisiert. Mindestens 3,5 Mio. von ihnen entwickeln die teilweise erheblichen allergischen Symptome als Ausdruck eines Oralen Allergie-Syndroms. Es gibt bisher keine medikamentöse Therapie gegen diese Allergie. Apfelallergiker können daher nur auf Äpfel ganz verzichten, oder vorher erhitzte Äpfel essen oder Sorten suchen, die wenig Allergene enthalten und deshalb als allergikerfreundliche Apfelsorten bezeichnet werden können. Alleinige Bestimmungen von Allergenen im Labor können nicht voraussagen, ob ein Apfel ohne allergische Symptome von Apfelallergikern gegessen werden kann; dazu bedarf es klinischer Prüfungen. Wir beschreiben eine standardisierte klinische, orale Provokationstestung, die zur Charakterisierung eines allergenarmen, allergikerfreundlichen Apfels bzw. Apfelsorte benutzt werden kann.. Die Ergebnisse solcher mindestens dreijährigen Tests können zur Verleihung des ECARF-Siegels für allergikerfreundliche Produkte genutzt werden

Improved stable isotope dilution assay for dietary folates using LC-MS/MS and its application to strawberries

Folates play an important role in the human body and a deficiency of this vitamin can cause several diseases. Therefore, a reliable analytical method is crucial for the determination of folate vitamers in strawberries and other dietary folate sources. A stable isotope dilution LC-MS/MS method for analyzing folates in food was developed and validated. The folate vitamers Pteroylmonoglutamic acid, tetrahydrofolate, 5-methyltetrahydrofolate, and 5-formyltetrahydrofolate were quantified using C-13-labeled internal standards. Validation of the assay was accomplished by determining linearity, precision, recovery, limit of detection, and limit of quantification and revealed to be a precise, sensitive, and accurate method to determine folate vitamers. Strawberries are worldwide consumed and known to be a good dietary source of nutritive compounds. Using this method, folate concentrations in selected commercial strawberry cultivars and experimental breeding lines grown in Germany and Australia were investigated. Total folates varied from 59 to 153 mu g/100 g on fresh weight basis. Furthermore, folate content after lyophilizing or freezing did not show any significant differences compared to fresh strawberries. However, significant losses of total folates in pureed strawberries could be observed after 5 days of storage with only 16% of the original concentration retained. In summary, some of the investigated strawberry cultivars/breeding lines can be considered as rich dietary sources of natural folates

Durian fruits discovered as superior folate sources

Durian (Durio zibethinus) is a tropical fruit grown in Southeast Asia and highly appreciated by consumers throughout Asia. Folates are a group of vitamins and are essential nutrients for humans. Here we present the folate analysis of different durian cultivars as well as diverse durian products. An LC-MS/MS method and the application of a stable isotope dilution assay (SIDA) was used for quantitation of the folate vitamers 5-methyftetrahydrofolate, 5-formyltetrahydrofolate, 10-formylfolate, tetrahydrofolate, and pteroylmonoglutamic acid by using [C-13(5)]-labeled internal standards. Total folates varied from 175 to 440 mu g/100g for durian arils and from 15.0 to 417 mu g/100g for durian products. These contents are extraordinarily high compared to other fruits and may be correlated to the upregulated methionine biosynthesis pathway reported recently. In summary, the tropical fruit durian can be considered as a very rich dietary source of natural folates

Identification of allergenomic signatures in allergic and well-tolerated apple genotypes using LC-MS/MS

The apple fruit (Malus domestica L. Borkh) is one of the most popular fruits worldwide. Beyond their beneficial properties, apples contain proteins that trigger allergic reactions in susceptible consumers. Mal d1 to d4 are allergens present in a variety of different isoforms in apples. In this study, we used proteomics to quantify all four Mal d proteins in 52 apple genotypes with varying allergenic potentials. A total of 195, 17, 14, and 18 peptides were found to be related to Mal d1, d2, d3, and d4 proteins, respectively of which 25 different Mal d proteins could be unambiguously identified. The allergenic potential of the Mal d isoforms was characterized by comparing the isoform abundance with the allergenic score of genotypes from oral challenge tests. The detected Mal d peptides presumably have different IgE binding properties and could be used as potential molecular markers to discriminate between hypoallergenic and hyperallergenic cultivars