This review is concerned with the summary and evaluation of the results from more than 150 investigations comparing the quality of conventionally and organically produced food or of foods produced with the aid of di †erent fertilisation systems. Cereals, potatoes, vegetables, fruits, wine, beer, bread, cakes and pastries, milk, meat, eggs and honey, as well as products made from them, have been included in the review. Most of the studies evaluated are physicochemical investigations of concentrations of desirable and undesirable ingredients, pesticide residues, contaminants, sensory analyses and feed experiments with animals. Nutritional studies in humans and experiments which used holistic methods of analysis are also included. Since di †erent methods of sampling were used in the investigations, a summary evaluation of individual results is extremely difficult. Even when the sampling methods are of the same type, a great many factors have to be taken into consideration which are not directly related to the production system but which do inÑuence food quality to a large degree. Despite the heterogeneity of the sample material, some di †erences in quality between products from conventional and organic farming or foods produced with the aid of di †erent fertilisation systems have been identiÐed.

The rates of sensitization and allergy to four birch pollen related plant foods were investigated in a group of 167 patients who were sensitive to at least one kind of pollen and one particular food. Sensitivity was concluded from a positive skin prick test or the determination of specific IgE, whereas allergy was based on anamnestic data. The positivity rates for sensitization and allergy, respectively, were: apple, 93 and 84%; hazelnut, 90 and 78%; celery, 70 and 14%; carrot, 60 and 37%. Comparative testing by skin prick test and enzyme allergosorbent test (EAST) with extract from native and microwaved (750 W, 30 min, 100^oC) celery root was performed on 46 of these patients. At least one positive test result (either prick test or EAST) was obtained for native celery in 36/46 (78%) and for heated celery in 20/46 (43%) of these patients. Although the concordance between the EAST and the skin test was very low, extended control experiments of both test procedures revealed no evidence for nonspecificity. Immunoblot analyses of extract from native celery and sera of 60 patients with a positive EAST (class ≥ 2, ≥ 0.7 U/ml) for celery resulted in the following rates of IgE binding to known cross-reactive celery allergens: Api g 1:33%, celery profilin: 17%; multiple bands most probably due to carbohydrate epitopes: 32%. The rate of binding to other allergens was below 10%. Since these three important structures are also present in birch pollen, no allergen could be identified as a candidate to mediate an exclusive celery/mugwort association. Investigation of extract from native and heated celery by immunoblotting pointed to a high lability of Api g 1, whereas profilin and carbohydrate epitopes appeared to be more resistant to heat. It has been concluded that sensitization to celery in German patients is without clinical significance in the majority of cases, in contrast to other birch-pollen-related plant foods such as apple and hazelnut. For the particular kind of extract used, neither the EAST nor the skin test alone represents an appropriate diagnostic method for testing sensitization to celery.

Celery roots were processed by microwave heating, cooking, drying, γ‐irradiation, ultra high pressure treatment and high voltage impulse treatment. The immunochemical stabilities of the three known allergenic structures of celery were tested with sera from patients who were sensitised to celery. In addition, rabbit antisera were used to detect the allergens profilin and Api g 1 on celery immunoblots. The specificity and reactivity of IgE from the patients' sera were investigated by immunoblotting, by an enzyme allergosorbent test (EAST) and by dose‐related IgE inhibition experiments. The results of all three methods agreed closely and indicated high antigenic and allergenic activity in native celery which was reduced by thermal processing. The heat‐stability of the known celery allergens decreased in the following order: carbohydrate epitopes> profilin>Api g 1. In contrast, the allergenicity was only mildly reduced by non‐thermal processing. The results obtained with human IgE were confirmed by an in vitro mediator‐release assay that is based on rat basophil leukemia cells (RBL cells) which were passively sensitised with celery‐specific murine IgE. With sera from mice that had been immunised with native celery, the native sample and non‐thermal celery preparations elicited the strongest mediator release, whereas a weak response was obtained with samples from heat‐processed celery. These results agreed closely with the data obtained in allergic patients whose IgE antibodies were directed against the major protein allergen Api g 1. Our results may be helpful in risk assessment and in selecting food preparations which can be consumed without symptoms by a subgroup of celery‐allergic patients with a known sensitisation pattern. ©1997 SCI

Increased “global” migration into food simulants has been described as a consequence of irradiation, particularly with fatty media; development of off-odors and taint transfer into food simulants have been observed with various plastics. Additives, especially antioxidants, are destroyed during irradiation, and increased “specific” migration values have been observed under certain circumstances. Organotin stabilizers in PVC are ultimately degraded to SnCl4, and increased migration of tin compounds was observed after gamma irradiation. Degradation products of phenol antioxidants, that were also found as migrants, have only recently been identified; some of these structures seem to be radiation specific.

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