Distribution of Eleven Flavor Precursors, S-Alk(en)yl-L-Cysteine Derivatives, in Seven Allium Vegetables

Abstract

Using high-performance liquid chromatography, 11 sulfur-containing flavor precursors were determined quantitatively in seven Allium vegetables: garlic (Allium sativum), onion (A. cepa), Welsh onion (A. fistulosum), Chinese chive (A. tuberosum Rotter), rakkyo (A. chinense G. Don), 'asatsuki' (A. schoenoprasum), and leek (A. porrum). Keywords: alliin, Alliums, flavor precursor, glutamyl peptide, high-performance liquid chromatography, isoalliin, S-alk(en) yl-L-cysteine *To whom correspondence should be addressed. E-mail: yoshihisa_yamazaki@aomori-itc.or.jp The determinants were S-alk(en)yl-L-cysteine derivatives, methiin, alliin, isoalliin, cycloalliin, deoxyalliin, N-(γ-glutamyl)-S-methyl-L-cysteine, N-(γ-glutamyl)-S-(2-propenyl)-L-cysteine, N-(γ-glutamyl)-S-(E-1-propenyl)-L-cysteine (Glu-PEC), N-(γ-glutamyl)-S-(2-propenyl)-Lcysteine sulfoxide, N-(γ-glutamyl)-S-(E-1-propenyl)-L-cysteine sulfoxide (Glu-PECSO) and S-(2-carboxy IntroductionAllium vegetables, such as garlic (A. sativum L.) and onion (A. cepa L.), have been used as seasoning vegetables worldwide (Block, 1992(Block, , 2010. Allium vegetables contain large amounts of S-alk(en)yl-L-cysteine derivatives (SACs, Fig. 1) (Kubec et al., 2000). When these vegetables are cut or crushed, S-alk(en)yl-L-cysteine sulfoxides (SACSOs), i.e., methiin, alliin, isoalliin, are cleaved by alliinase (cysteine sulfoxide lyase: EC 4.4.1.4) to give the corresponding alk(en) yl sulfenic acids (Stoll and Seebeck, 1951). The sulfenic acids are transformed via continuous reactions to thiosulfinates (e.g., diallyl thiosulfinate (allicine)) and other organosulfur volatile compounds (e.g., diallyl disulfide) to produce characteristic flavors . These organosulfur volatile compounds have been reported as flavor compounds of food, in addition to bioactive compounds (Block, 1994), or causal compounds of processed food discoloration (Kubec et al., 2004;Imai et al., 2006).The degrees of the respective contributions of these organosulfur volatile compounds to flavor, bioactivity, and food discoloration depend on their alkyl moieties: they are dominated by the kinds and quantities of SACSO as substrates of alliinase in Allium vegetables. Allium vegetables also contain γ-glutamyl peptides of S-alk(en)yl-L-cysteine (Glu-SAC) corresponding to SACSOs that are storage compounds during dormancy (Tuboi et al., 1989;Lancaster and Shaw, 1991;Lawson et al., 1991;Ichikawa et al., 2006b). These SACSOs as well as Glu-SAC in Allium vegetables should be evaluated as Glu-SAC is metabolized to SACSO depending on the storage conditions.Comparing the contents of SACs in individual Allium ical Industries Ltd. (Osaka, Japan). Water purified using a Milli-Q instrument (Millipore Corp., MA, USA) was used for all sample preparations and mobile phases. Reference compounds, and N-(γ-glutamyl)-S-(2-propenyl)-L-cysteine sulfoxide (Glu-ALCSO) (98%) were isolated from garlic cloves. Isoalliin (99%), N-(γ-glutamyl)-S-(E-1-propenyl)-L-cysteine sulfoxide (Glu-PECSO) (96%), and S-2-carboxy propyl gluthathion (2CPGTH) (98%) ...

Isolation and Identification of Causal Constituents of Green Discoloration in Garlic Puree

“…This conclusion is supported by a previous report using synthetic thiosulfinates (Kubec et al, 2004). These results indicate that the main causal agents involved originally in garlic bulbs are alliin, isoalliin and alliinase (Yamazaki et al, 2011).…”

Antioxidant activity, S-alk(en)yl-l-cysteine sulfoxide and polyphenol content in onion (Allium cepa L.) cultivars are associated with their genetic background

“…Sturon, although other authors reported a prevalence of isoalliin (Yamazaki et al 2010;Bernaert et al 2012). Starkenmann et al (2011) found a much higher level of isoalliin than alliin in onion tissues.…”

“…Food Sci., 34, 2016(2): 127-132 doi: 10.17221/268/2015 between numerous onion cultivars. It has also been reported that the content of secondary metabolites in Allium species changes after harvest (Yamazaki et al 2010;Bernaert et al 2013). Such information is important for consumers.…”

Causes and Remedies for Green Discoloration of Processed Garlic Puree: Effects of Storage Conditions on Ingredient Bulbs

“…The freeze-dried samples were powdered using a food blender and stored at −20℃ until analysis. The sample powders were evaluated according to procedures previously described (Yamazaki et al, 2011). Briefly, the sample powders (500 mg) were extracted with 25 mL of methanol-water-formic acid (50:50:1, v/v/v).…”

“…Recently, it was reported that S-(2-propenyl)-L-cysteine sulfoxide (alliin) is also a discoloration factor (Kubec et al, 2004;Imai et al, 2006a). In contrast to alliin, isoalliin is usually abundant in onion but scarce in garlic (Yamazaki et al, 2011). Reportedly, the alliinase (EC 4.4.1.4) product of isoalliin, presumed to be 1-propenyl 1-propenethiosulfinate, reacts with amino acids to produce pigment precursors.…”