Metabolomics and sensory evaluation of white asparagus ingredients in instant soups unveil important (off-)flavours.

Split-stream processing of asparagus waste stream is a novel approach to produce spray-dried powder and fibre. Asparagus ingredients processed by this method and a commercial asparagus powder were compared by evaluating their flavour profile in a soup formulation. Professional sensory panel and untargeted metabolomics approaches using GC-MS and LC-MS were carried out. Unsupervised and supervised statistical analyses were performed to highlight discriminatory metabolites and correlate these to sensory attributes. The spray-dried powder scored higher on asparagus flavour compared to the commercial powder. The fibre negatively impacted the taste and mouthfeel of the soups. GC-O-MS confirmed the role of dimethyl sulphide, 2-methoxy-3-isopropyl pyrazine and 2-methoxy-3-isobutyl pyrazine in asparagus odour. Seven new volatile compounds are also proposed to contribute to asparagus flavour notes, most of which were more abundant in the spray-dried powder. This research demonstrates the feasibility of upcycling asparagus waste streams into flavour-rich ingredients with good sensorial properties.

Sensory and analytical characterization of the "cool-melting" perception of commercial spreads.

Butters, margarines and table spreads are water-in-oil emulsions. Melting characteristics of these products are important for flavor release and consumer acceptance. One characteristic that is believed to discriminate butters from margarines is a cooling sensation perceived in-mouth while consuming these products. Here, we investigated different methods to characterize sensorically and analytically the "cool-melting" properties of commercial butter and margarines. Our results show that butter indeed can be distinguished from margarines based on their "cool-melting" properties. Furthermore, changes in enthalpy as measured through DSC and solid fat content are good predictors of the "cool-melting" effect of spreads. PRACTICAL APPLICATIONS: By understanding the mechanisms of the "cool-melting" perception of spreads, and linking them to analytical measurements, we can create an in-vitro quantification method of "cool-melting." This method can eventually help directing product development to achieve the desire product profile and increase consumer acceptance and liking of margarines and low-fat spread products. In this study we did not assess the impact of "cool-melting" on consumer perception, which would be the next step in understanding the drivers of liking of spread products.