Development and validation of a standardized double-blind, placebo-controlled food challenge matrix for raw hazelnuts

Background: Double-blind, placebo-controlled food challenge (DBPCFC) is considered the gold standard for food allergy diagnosis. However, this test is rarely performed routinely in clinical practice because of various practical issues, e.g. the lack of a standardized matrix preparation. The aim of this study was to develop and validate a convenient DBPCFC matrix, that can easily be implemented in daily clinical practice. The focus of this study was the blinding of hazelnuts, whereby the hazelnuts retained as much as possible their allergenicity and could be mixed homogenously in low-doses to the matrices. Methods: A basophil-activation test (BAT), microbial tests and an LC-MS/MS test were performed to assess respectively the allergenicity of the used hazelnuts, the microbial stability of the novel developed matrices and the homogeneity of the hazelnuts in the matrices. A sensory test was conducted to validate the blinding of the hazelnuts in the matrices. A pilot DBPCFC study included eight patients as proof of concept. Results: The BAT-test gave the first insights concerning the retained allergenicity of the hazelnuts. The microbial safety could be assured after 12 months of storage. Sufficient masking was assessed by several sensory tests. Homogeneous hazelnut distribution could be achieved for the different hazelnut concentrations. The DBPCFC's results showed diverse allergic responders (from no reactions to distinct objective symptoms). Conclusion: A novel stable and validated DBPCFC matrix using raw hazelnuts has been developed that allows easy preparation in a standardized way for convenient use in daily clinical practice

Studie van de dynamica van microtubuli met relaxatiespectrometrie

KULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainSIGLEBEBelgiu

Tyrosinolering van tubuline door tubuline: tyrosine ligase Substraatspecifiteit en gebruik bij het doelgericht merken van tubuline

SIGLEKULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainBEBelgiu

Voor wat de ubiquitine-afhankelijke proteine-afbraak betreft, is de N-terminus-regel vooral van toepassing op gedenatureerde en a rtificiele eiwitten

SIGLEKULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainBEBelgiu

Destabilization and off-flavors generated by Pseudomonas proteases during or after UHT-processing of milk

Abstract Background Pseudomonads play a major role in the spoilage of UHT processed dairy products, due to their growth-related protease production in raw milk. Results To assess the off-flavor generating capacity of these AprX proteases in milk after UHT-processing, six major milk spoiling Pseudomonas groups were investigated. Sensory evaluation of the different processed milk samples showed large differences in the degree of proteolysis related to onset of off-flavors. Nevertheless, it was illustrated that P. fragi has the greatest spoilage potential within the tested Pseudomonas groups, when it comes to generating off-flavors. Conclusions No clear correlation could be obtained between protein hydrolysis and the presence of off-flavors in UHT milk

Influence of milk fatty acid composition and process parameters on the quality of ice cream

There has been considerable interest in recent years in altering the fatty acid composition of milk fat in dairy products to improve the long-term health of consumers. The objective of this study was to investigate the influence of altering the fatty acid composition and varying two process parameters (homogenization pressure and ageing temperature) on the quality of ice cream. The quality of ice cream (8% fat) was monitored before and after heat shock by assessing fat droplet size, solvent extractable fat content, texture analysis, meltdown tests and sensory analyses. The results suggest that a high solid fat content and low homogenization pressure correlated well with large particles and high amounts of solvent extractable fat, which resulted in firm ice cream with slow melting behaviour and good structure retention. In contrast, ageing temperature did not significantly influence fat destabilization. Following heat shock, the results suggested that the hardness of ice cream was not determined by any of the parameters investigated, but was probably dominated by the amount of ice crystals. A good melting behaviour was retained after heat shock, provided that a strong matrix of destabilized fat was produced during the freezing process. Even though differences could be observed in hardness and melting behaviour for different milk fats or process conditions, these differences were hardly identified by trained sensory panels. These results suggest that high-quality ice cream can be produced with an altered fatty acid composition without any alteration in the conventional production process, provided that ice cream is stored and consumed under ideal circumstances

The influence of a different fatty acid profile on the crystallization of milk fat as measured by pNMR, DSC and X-ray diffraction

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