Effects of Different Cooking Methods on Antioxidant Profile, Antioxidant Capacity, and Physical Characteristics of Artichoke

Abstract

In this study, the effects of three common cooking practices (i.e., boiling, steaming, and frying) on the artichoke phenolic compounds pattern were evaluated by LC-MS/MS analysis. The variation of carotenoids, antioxidant capacity, and artichoke physical properties after cooking was also investigated. The major phenolic compounds present in the raw sample were 5- O-caffeoylquinic and 1,5-di- O-caffeoylquinic acids; after cooking treatments, an increase of the overall caffeoylquinic acids concentration due to the formation of different dicaffeoylquinic acid isomers was observed. Steamed and fried samples showed similar patterns of dicaffeoylquinic concentrations, which were higher with respect to the boiled samples. On the other hand, all cooking practices, particularly frying, decreased flavonoid concentration. The antioxidant capacity of cooked artichokes, measured by three different assays, enormously increased after cooking, particularly after steaming (up to 15-fold) and boiling (up to 8-fold). The observed cooking effect on the artichoke antioxidant profile is probably due to matrix softening and increased extractability of compounds, but the increase of antioxidant capacity is much higher than the increase of antioxidant concentration. These results suggest that some common cooking treatments can be used to enhance the nutritional value of vegetables, increasing bioaccessibility of health-promoting constituents.

Comparative Chemomapping of Phytoconstituents from Different Extracts of Globe Artichoke - Cynara Scolymus L.

“…Our study was meant to identify all possible phytoconstituents with the used experimental setup, and as a consequence 49 and 51 molecules were described in the aqueous and hydro-alcoholic artichoke extracts, respectively. Some of the newly identified compounds were confirmed by standards, while other compounds have already been reported by others [15][16][17][18][19][20][21][22][23][24][25][26].…”

“…It contains proteins, minerals, a low amount of lipids, dietary fibre and a high proportion of phenolics [1][2]. Among phenolics there were identified compounds like cynarin (1,3-di-O-caffeoylquinic acid), luteolin, cynaroside (luteolin-7-O-glucoside), scolymoside (luteolin-7-rutinoside); phenolic acids such as caffeic, coumaric, hydroxycinnamic, ferulic, caffeoylquinic acid derivatives; mono-and dicaffeoylquinic acids, including chlorogenic; acid alcohols; flavonoid glycosides [2][3]. The content of phytoconstituents was shown to vary among different cultivars and conditions related to cultivation, harvest, post-harvest and cooking [4][5].…”

Infusions of artichoke and milk thistle represent a good source of phenolic acids and flavonoids

“…15,37,40 Compound 20 presented a pseudomolecular ion [M − H] − at m/z 461 releasing a fragment ion at m/z 285 ([M − 176] − , loss of a glucuronyl moiety); although the position of the glycosyl moiety could not be established it was assigned to luteolin 7-O-glucuronide, owing to the identification of that compound in leaves, heads, hearts, juices, pomaces and dietary supplements of artichoke, mostly obtained after hydroalcoholic extraction. 13,15,16,32,33,[35][36][37]39,40 In accordance with their UV and mass spectra characteristics, different apigenin derivatives were also detected in the analysed samples. Compounds 24, 27 (artichoke) and 26 (artichoke and milk thistle) showed pseudomolecular and fragment ions coherent with deoxyhexosyl-hexoside, hexoside and glucuronide derivatives of apigenin, respectively.…”

“…Despite the many articles reporting the phenolic composition of artichoke hydroalcoholic extracts, 13,15,16,[31][32][33][34][35][36][37][38][39][40] the present work characterizes the phenolic composition in infusions. Moreover, infusion is the most common form to consume this plant and, to our knowledge, this is also the first report presenting results for the whole plant material and not seeds.…”

“…41 Dicaffeoylquinic acids have been extensively reported in Table 2 Retention time (Rt), wavelengths of maximum absorption in the visible region (λ max ), mass spectral data, identification and quantification of phenolic compounds in hydromethanolic extract and infusion of milk thistle (mean ± SD) a hydroalcoholic extracts obtained from different parts of artichoke, as mentioned above. 13,15,16,[31][32][33][34][35][36][38][39][40] Four signals in artichoke (compounds 4, 9, 11 and 13) showed a pseudomolecular ion ([M − H] − ) at m/z 337 (Tables 1 and 2). These compounds were assigned as the 3-acyl, 4-acyl and 5-acyl isomers of p-coumaroylquinic acid based on their HPLC retention and MS 2 fragmentation characteristics, as previously reported by Clifford et al 29,42 Thus, compound 4 (artichoke) was tentatively identified as 3-p-coumaroylquinic acid, yielding the base peak at m/z 163 ([coumaric acid-H] − ).…”