Are Physicochemical Properties Shaping the Allergenic Potency of Plant Allergens?

This review searched for published evidence that could explain how different physicochemical properties impact on the allergenicity of food proteins and if their effects would follow specific patterns among distinct protein families. Owing to the amount and complexity of the collected information, this literature overview was divided in two articles, the current one dedicated to protein families of plant allergens and a second one focused on animal allergens. Our extensive analysis of the available literature revealed that physicochemical characteristics had consistent effects on protein allergenicity for allergens belonging to the same protein family. For example, protein aggregation contributes to increased allergenicity of 2S albumins, while for legumins and cereal prolamins, the same phenomenon leads to a reduction. Molecular stability, related to structural resistance to heat and proteolysis, was identified as the most common feature promoting plant protein allergenicity, although it fails to explain the potency of some unstable allergens (e.g. pollen-related food allergens). Furthermore, data on physicochemical characteristics translating into clinical effects are limited, mainly because most studies are focused on in vitro IgE binding. Clinical data assessing how these parameters affect the development and clinical manifestation of allergies is minimal, with only few reports evaluating the sensitising capacity of modified proteins (addressing different physicochemical properties) in murine allergy models. In vivo testing of modified pure proteins by SPT or DBPCFC is scarce. At this stage, a systematic approach to link the physicochemical properties with clinical plant allergenicity in real-life scenarios is still missing.

Objective assessment of olfactory function using functional magnetic resonance imaging.

OBJECTIVE: To show the results of a device that generates automated olfactory stimuli suitable for functional magnetic resonance imaging (fMRI) experiments. MATERIAL AND METHODS: Ten normal volunteers, 5 women and 5 men, were studied. The system allows the programming of several sequences, providing the capability to synchronise the onset of odour presentation with acquisition by a trigger signal of the MRI scanner. The olfactometer is a device that allows selection of the odour, the event paradigm, the time of stimuli and the odour concentration. The paradigm used during fMRI scanning consisted of 15-s blocks. The odorant event took 2s with butanol, mint and coffee. RESULTS: We observed olfactory activity in the olfactory bulb, entorhinal cortex (4%), amygdala (2.5%) and temporo-parietal cortex, especially in the areas related to emotional integration. CONCLUSIONS: The device has demonstrated its effectiveness in stimulating olfactory areas and its capacity to adapt to fMRI equipment.

Aronia-enriched lemon juice: a new highly antioxidant beverage.

Lemon juice (LJ) was enriched with aronia concentrate (AC) in two different proportions (2.5 and 5%, v/v) to design new beverages rich in bioactive ingredients. The phytochemical composition (anthocyanins, flavanones, flavones, flavonols, and hydroxycinnamic acids) and stability of the beverages were analyzed by high-performance liquid chromatography with a diode array detector (HPLC-DAD), as well as color alterations and in vitro antioxidant activity (DPPH(*) assay). Results showed that, although anthocyanin degradation was higher than 90% after 60 days of storage, the new beverages retained an attractive red color. Also, the in vitro antioxidant activity of the new mixtures was 2-fold higher when 5% AC was added compared to pure LJ. Thus, an addition of only 5% AC could effectively increase the antioxidant properties of LJ, as well as improving certain organoleptic characteristics, rendering an interesting beverage in the growing market of food for health.