Enhancement Of Glucosinolate and Isothiocyanate Profiles in Brassicaceae Crops: Addressing Challenges in Breeding for Cultivation, Storage, and Consumer-Related Traits

Abstract

Glucosinolates (GSLs) and isothiocyanates (ITCs) produced by Brassicaceae plants are popular targets for analysis due to the health benefits associated with them. Breeders aim to increase the concentrations in commercial varieties; however, there are few examples of this. The most well-known is Beneforté broccoli, which has increased glucoraphanin/sulforaphane concentrations compared to those of conventional varieties. It was developed through traditional breeding methods with considerations for processing, consumption, and health made throughout this process. Many studies presented in the literature do not take a holistic approach, and key points about breeding, cultivation methods, postharvest storage, sensory attributes, and consumer preferences are not properly taken into account. In this review, we draw together data for multiple species and address how such factors can influence GSL profiles. We encourage researchers and institutions to engage with industry and consumers to produce research that can be utilized in the improvement of Brassicaceae crops.

Growing Conditions Affect the Phytochemical Composition of Edible Wall Rocket (Diplotaxis erucoides)

“…Environmental factors have been proven to affect the leaf morphology of wall rocket [29]. In addition, environmental factors have been proven to influence the accumulation of secondary metabolites and nitrates in different crops [41][42][43]. Thus, the quality of wall rocket in terms of bioactive compounds and nitrates may be affected as well.…”

“…However, both AA and TP had lower correlations with the content of SIN. As with AA and phenolic phytochemicals, the accumulation of glucosinolates in plant tissues is part of the plant response mechanism against abiotic stress conditions and can therefore be affected by environmental factors such as light intensity, season or fertilization [16,27,41], but it is also highly related to the biotic stress by pests and pathogens [16,27]. The combined effect of both biotic and abiotic stress could be responsible for this lower correlation.…”

“…On the other hand, a negative correlation between the antioxidant phytochemicals and the percentage of moisture was found. This may correspond to a concentration effect in the tissues [41], although it could be also related to the plant behavior and defense system against cold stress. Król et al [56] found that leaves of grapevine developed under cold stress reduce their percentage of moisture, although the total phenolics were also decreased; on the contrary, Oh et al [26] found that the exposure of lettuce to chilling conditions increased the total phenolics against oxidative damage.…”

Taste and Flavor Perceptions of Glucosinolates, Isothiocyanates, and Related Compounds

“…It is also not sufficient to assume that GSL/ITC content will be preserved over generations if they are not constantly and quantitatively measured. This also applies across growing environments and climates, where changes to GSL biosynthesis (as well as other phytochemicals) can have a large impact upon taste, flavor, and pungency of Brassicales crops . Breeding of Brassica plants to optimize GSL or ITC content must also consider how the plant will be processed before consumption.…”

“…This also applies across growing environments and climates, where changes to GSL biosynthesis (as well as other phytochemicals) can have a large impact upon taste, flavor, and pungency of Brassicales crops. [35] Breeding of Brassica plants to optimize GSL or ITC content must also consider how the plant will be processed before consumption. Accounting for all of these influencing factors is a considerable challenge, and requires large amounts of investment in both breeding programs and conducting the required phytochemical analyses.…”