Chemical and antioxidative assessment of dietary turnip (Brassica rapa var. rapa L.)

Abstract

The phenolic compounds and organic acids of turnip (Brassica rapa var. rapa L.) edible parts (leaves and stems, flower buds and roots) were determined by HPLC-DAD and HPLC-UV, respectively. The results revealed a profile composed of 14 phenolics (3-p-coumaroylquinic, caffeic, ferulic and sinapic acids, kaempferol0 -disinapoyl-2-feruloylgentiobiose, kaempferol 3-O-glucoside and isorhamnetin 3-O-glucoside) and six organic acids (aconitic, citric, ketoglutaric, malic, shikimic and fumaric acids). The quantification of the identified compounds showed kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, isorhamnetin 3,7-O-diglucoside and isorhamnetin 3-O-glucoside as the main phenolics, and malic acid as the organic acid present in highest amounts. A screening of the antioxidative potential was also performed by means of the DPPH radical scavenging assay. Turnip flower buds exhibited the strongest antioxidant capacity.

Application of ultra performance liquid chromatography-photodiode detector-quadrupole/time of flight-mass spectrometry (UPLC-PDA-Q/TOF-MS) method for the characterization of phenolic compounds of Lepidium sativum L. sprouts

“…Next, dihexoside moiety (2 9 162 amu = 324 amu) is lost which gives rise to a deprotonated kaempferol ion (m/z 285.0403) as a base peak. This kind of fragmentation indicates the occurrence of glycosylation in accordance with literature data which show that in Brassica species, only sugar moieties such as glucose and rhamnose are predominantly bound in positions -7 [19,32,33,35,36]. In the disaccharide moieties present in analyzed compounds [2,3,5, and 6 (Table 1)] after fragmentation, the loss of 324 amu and low abundance of 162 amu selon occur, which, according to Ferreres et al [31], corresponds to a diglucoside with a 1-6 linkage, that is, gentiobioside.…”

“…sylvestris L., flower of B. rapa [32], and leaves, stems, and flower buds of B. rapa var. rapa L. [33].…”

Evaluation of beetroot (Beta vulgaris L.) leaves during its developmental stages: a chemical composition study

“…In plants, compounds or classes of phenolic compounds such as phenolic acids are responsible for antioxidant activity (Angelo & Jorge, 2007;Lako, 2007) and are present in vegetable leaves (Moon & Shibamoto, 2009;Fernandes et al, 2007). According to Maisuthisakula (2008), in some species of plants, the antioxidant activity is correlated with their phenolic compounds, while in others, it is not.…”

Inflorescences of Brassicacea species as source of bioactive compounds: A comparative study

“…It is generally assumed that the beneficial effects of vegetables are partly attributed to the complex mixture of phytochemicals possessing antioxidant activity (Liu, 2003;Podsę dek, 2007). These comprise both phenolic compounds and organic acids (Liu, 2003;Podsę dek, 2007;Pulido, Bravo, & Saura-Calixto, 2000;Silva et al, 2004), which contribute to their organoleptic features (Vaughan & Geissler, 1997), despite being applied in the quality control of several matrices (Fernandes et al, 2007;Ferreres et al, 2005;Sousa et al, 2005). Furthermore, plant compounds are known for their antimicrobial capacity (Cowan, 1999;Tim Cushnie & Lamb, 2005), which may be relevant considering the existing problem of resistance to antimicrobial agents.…”

“…acephala (Heimler, Vignolini, Dini, Vincieri, & Romani, 2006;Romani et al, 2003) and B. rapa var. rapa (Fernandes et al, 2007;Liang et al, 2006), referring distinct profiles between them. Recent publications also report the organic acids (Ayaz et al, 2006;Fernandes et al, 2007;Ferreres et al, 2007Ferreres et al, , 2006Sousa et al, 2005) and the antioxidant potential (Fernandes et al, 2007;Ferreres et al, 2007Ferreres et al, , 2006Heimler et al, 2006;Vrchovská et al, 2006) of these three species.…”