Bitter taste ofBrassicavegetables: The role of genetic factors, receptors, isothiocyanates, glucosinolates, and flavor context

Abstract

It is well known that consumption of Brassica vegetables has beneficial effect on human's health. The greatest interest is focused on glucosinolates and their hydrolysis products isothiocyanates, due to their potential as cancer preventing compounds. Brassica vegetables are also rich in flavor compounds belonging to many chemical groups. The main sensory sensation related to these vegetable is their characteristic sharp and bitter taste, and unique aroma. Because of these features this group of vegetables is often rejected by consumers. Interestingly, for some people unpleasant sensations are not perceived, suggesting a potential role of inter-individual variability in bitter taste perception and sensibility. Receptors responsible for bitter sensation with the emphasis on Brassica are reviewed, as well as genetic predisposition for bitterness perception by consumers. Also the role of glucosinolates and isothiocyanates as compounds responsible for bitter taste is discussed based on data from the field of food science and molecular biology. Isothiocyanates are shown in broaded context of flavor compounds also contributing to the aroma of Brassica vegetables.

Bridging Sensory Evaluation and Consumer Research for Strategic Leafy Brassica (Brassica oleracea) Improvement

“…Regardless, these samples occupy new space on the sensory map and demonstrate the capacity of consumer clustering in understanding varietal distinction, market class plasticity, and consumer‐defined quality within leafy Brassicas. Clustering of liking patterns is reasonable in a vegetable such as kale, as bitter compounds capable of activating receptors with known polymorphisms in human populations can drive disliking in foods (Franks, Lawrence, Abbaspourrad, & Dando, ; Wieczorek, Walczak, Skrzypczak‐Zielińska, & Jeleń, ). Regular kale consumers appreciate the curly, bitter identity of traditional kale genotypes (for example, ‘Darkibor’), but also prefer thin leaves that leave little bitter aftertaste.…”

“…The instrumental measurement of texture in kale is very laborious and requires costly texture analyzers, microscopy, and anatomical work to correlate these analyses with human perception. Other traits may be easier to screen using analytical chemistry, such as the flavor contributing to “greenness” or bitterness‐imparting compounds (Hongsoongnern & Chambers, ; Wieczorek et al., ). Simon et al.…”

Wild and domesticated Moringa oleifera differ in taste, glucosinolate composition, and antioxidant potential, but not myrosinase activity or protein content

“…It may be that differences in amount, specificity, or specific activity of myrosinase, rather than the amounts of its substrate GS, are responsible for different pungencies 32 . Phytochemical content, and therefore taste, can strongly affect frequency of consumption 37 – 41 , and in turn, frequency of consumption affects phytochemical dose and the benefits that accrue from them. As an index of direct antioxidant activity, we use ABTS •+ 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) to measure the ability the endogenous antioxidants present in a leaf homogenate, to scavenge free radicals.…”

Nutritional potential of leaves and tubers of crem (Tropaeolum pentaphyllum Lam.)

“…Despite this high contribution, there is no information on the bioavailability of these minerals, which may be related to oxalates and phytates [29], which means that these minerals cannot be used by the organism. Therefore, the high concentration of sulfur (65% of the RDA) may restrict the consumption of crem leaves, as this element adds more bitterness to the taste of the leaves [30].…”