Brassicaceae plants are renowned for their taste, aroma and trigeminal characteristics; predominantly bitter taste, sulfurous aroma, and pungency. Compounds responsible for these sensations include the glucosinolates (GSLs) and their hydrolysis products, particularly isothiocyanates (ITCs), but also sulfur-containing volatile compounds. This article reviews the relative importance of taste and flavor perceptions resulting from such compounds; collating evidence from papers where findings are based on sensory analytical correlations, and those that have extracted specific compounds prior to sensory evaluation. Where specific GSLs impart bitterness and many ITCs impart pungency, this is clearly not true for all GSLs and ITCs. Designing crop improvement strategies for sensory traits based on total GSL content would be flawed, as it does not consider the relative differences in sensory characteristics of different GSLs and ITCs, nor the contribution from other GSL hydrolysis products. In addition, some Brassicaceae plants are consumed raw, whilst others are cooked; this affects not only the hydrolysis of GSLs, but also the generation and release of sulfides. Therefore, in breeding new plant varieties, it is prudent to consider the individual GSLs, the typical cooking conditions the plant is subjected to, enzyme stability, and resultant composition of both GSL hydrolysis products (including ITCs) and sulfides.

Protein fortified products are regularly recommended to older adults to improve nutritional status and limit sarcopenia. However protein fortification can elicit negative sensory attributes such as mouthdrying. Sensitivity to mouthdrying can increase with age, yet the influence of saliva flow and mucoadhesion remain uncertain. Here, two studies tested different whey protein beverages (WPB); 22 healthy younger volunteers completed a pilot and 84 healthy volunteers from two age groups (18–30; 65+) completed the main study. In both studies salivary flow rates (mL/min) were measured and saliva samples were collected at time intervals post beverage consumption to measure mucoadhesion to the oral cavity, where protein concentration was analysed by Bradford Assay. Volunteers rated perception and acceptability of WPBs in the main study. WPB consumption resulted in significantly increased protein concentration (p < 0.0001) in saliva samples compared with a control whey permeate beverage. Older adults had significantly lower unstimulated saliva flow (p = 0.003) and significantly increased protein concentration (p = 0.02) in saliva samples, compared with younger adults. Heating of WPB significantly (p < 0.05) increased mouthdrying and thickness perception and reduced sweetness compared with unheated WPB. Mucoadhesion is concluded to be a true phenomenon in WPBs and increases with age.

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It is widely accepted that the distinctive aroma and flavour traits of Brassicaceae crops are produced by glucosinolate (GSL) hydrolysis products (GHPs) with other non-GSL derived compounds also reported to contribute significantly to their aromas. This study investigated the flavour profile and glucosinolate content of four Brassicaceae species (salad rocket, horseradish, wasabi, and watercress). Solid-phase microextraction followed by gas chromatography-mass spectrometry and gas chromatography-olfactometry were used to determine the volatile compounds and odorants present in the four species. Liquid chromatography-mass spectrometry was used to determine the glucosinolate composition, respectively. A total of 113 compounds and 107 odour-active components were identified in the headspace of the four species. Of the compounds identified, 19 are newly reported for ‘salad’ rocket, 26 for watercress, 30 for wasabi, and 38 for horseradish, marking a significant step forward in understanding and characterising aroma generation in these species. There were several non-glucosinolate derived compounds contributing to the ‘pungent’ aroma profile of the species, indicating that the glucosinolate-derived compounds are not the only source of these sensations in Brassicaceae species. Several discrepancies between observed glucosinolates and hydrolysis products were observed, and we discuss the implications of this for future studies.

HighlightsFlavour of medium and long shelf-life Charentais cantaloupe melons was compared.Volatile and semi-volatile profiles were correlated with sensory data using multifactorial analysis.Maturity at harvest has a significant impact on the flavour of medium-shelf life fruit.Maturity at harvest had much less impact on a long shelf-life genotype.Esters and sulphur-compounds were more abundant in mature medium shelf-life fruit.