![Author ORCID: We display the ORCID iD icon alongside authors names on our website to acknowledge that the ORCiD has been authenticated when entered by the user. To view the users ORCiD record click the icon. [opens in a new tab]](https://chemrxiv.org/engage/assets/public/chemrxiv/images/logos/orcid.png)
Abstract
Glucosinolate-derived isothiocyanates are valuable for human health as they exert health promoting effects. Here, the stability and reactivity of 12 different isothiocyanates during aqueous heating at 100 °C and pH 5 to pH 8 were investigated. The formation of their corresponding amines and N,N’-dialk(en)yl thioureas was quantified. Further, the potential to form odor active compounds was investigated using a HRGC-MS-olfactometry approach. A strong structure-reactivity relationship was found for the isothiocyanates: shorter side chains and electron withdrawing groups increase the reactivity of the isothiocyanate and 3-(methylsulfonyl)propyl isothiocyanate was least stable. The main degradation product was found to be the corresponding amine (up to 69% recovery after 4 h of heating at pH 5) and formation of N,N’-dialk(en)yl thioureas is only relevant at neutral to basic pH values. Apart from allyl isothiocyanate also 3-(methylthio)propyl isothiocyanate is precursor to many sulfur containing odor active compounds that will contribute to the boiled cabbage flavor.
Supplementary materials
Title
Supplemental Figure 1
Description
Effect of aqueous heating of isothiocyanates (ITC) at 100°C at pH 5 (A), pH 6 (B) and pH 8 (C) on the formation of N,N’-dialk(en)ylthioureas. The abbreviations of the alk(en)yl residues of the thioureas (TUs) correspond to the ITC-side chains depicted in Figure 1.
Actions
Title
Supplemental Figure 2
Description
Obtained EI mass spectra of unknown products from A) 3-butenyl isothiocyanate (ITC), and B) 4-(methylthio)butyl ITC by GC-MS-olfactometry.
Actions
Title
Supplemental Tables 1, 2, and 3
Description
Supplemental Table 1: Heat treatment times (100°C) of models and plant homogenates.
Supplemental Table 2: Half-lifes of isothiocyanates (ITCs) heated at 100°C in model systems or as natural ITCs in plant homogenates. AV- average, SD- standard deviation
Supplemental Table 3: Overview of isothiocyanate (ITC) and N,N-dialkenylthiourea (TU) levels (mM) after aqueous heating for different times at 100°C levels and calculated recovery of the ITC as TU in %.
Actions
