Asparagus is widely known and appreciated for its high nutritional value and the distinctive flavour of its young shoots. To deliver a superior product, substantial volumes of waste are generated during harvest season. Hence, there may be potential to exploit these waste-streams to generate a (by-)product of significant value.
The young shoots, or spears of asparagus are consumed in either green or white form. In the Netherlands, white spears are preferred and are mainly cultivated in the south of the Netherlands, and people refer to these as ‘White Gold’. This can be explained by the laborious work required for cultivating, harvesting and postharvest processing of the asparagus spears.
A common way to exploit vegetable waste streams is to oven-dry them and generate powders for use as food ingredients. Oven-dried powders are often characterized by having little or no flavour and this is due to the loss of important aroma compounds. Spray drying is a desirable alternative to oven drying, by allowing the encapsulation and thus retention, of flavour compounds. When vegetables are cooked or processed in any way, different compounds may be formed or lost.
These compositional shifts may influence the flavour of the final product. To study the flavour, both sensory and instrumental approaches are suggested to be required. Linking outcomes from both may assist in better elucidation and understanding of the composition of flavour and the combination of compounds needed for specific sensory perception. However, before this, it is important to improve our understanding of the composition of the starting materials and how this may vary due to developmental, seasonal and genetic differences.
In this PhD thesis, mass spectrometry (MS) – based techniques hyphenated with advanced liquid chromatography (LC) and gas chromatography (GC) systems were used to investigate the metabolome of raw, cooked and processed asparagus materials.