Comparative Study of the Phytoprostane and Phytofuran Content of indica and japonica Rice (Oryza sativa L.) Flours

Abstract

Phytoprostanes and phytofurans (PhytoPs and PhytoFs, respectively) are nonenzymatic lipid peroxidation products derived from α-linolenic acid (C18:3 n-3), considered biomarkers of oxidative degradation in plant foods. The present work profiled these compounds in white and brown grain flours and rice bran from 14 rice cultivars of the subspecies indica and japonica by ultrahigh performance liquid chromatography coupled to electrospray ionization and triple quadrupole mass spectrometry. For PhytoPs, the average concentrations were higher in rice bran (0.01-9.35 ng g) than in white and brown grain flours (0.01-1.17 ng g). In addition, the evaluation of rice flours for the occurrence PhytoFs evidenced average values 1.77, 4.22, and 10.30 ng g dw in rice bran, brown grain flour, and white grain flour, respectively. A significant correlation was observed between total and individual compounds. The concentrations retrieved suggest rice bran as a valuable source of PhytoPs and PhytoFs that should be considered in further studies on bioavailability and bioactivity of such compounds.

Identification and quantification of phytoprostanes and phytofurans of coffee and cocoa by- and co-products

“…These values are higher than the ones found in, e.g. dryfermentedcocoabeans (1.18to 13.13 ng g −1 ) 22 and white and brown rice flours and rice bran (0.69, 4.2, and 10.3 ng per g dw, on an average, respectively), 30 and similar to those reported in brown macroalgae (Ectocarpus siliculosus) (486 ng g −1 ), 39 but lower than those found in pea (Pisum sativum var. BGE-033620) (4258 ng g −1 ) 37 and dry leaves of melon plants subjected or not subjected to thermal stress (1960-2750 and 3250-4810 ng g −1 , respectively).…”

“…This compound was identified in different rice cultivars and the highest concentrations detected were 1.25, 4.21, and 12.88 ng per g dw for white flour, brown flour, and bran, respectively. 30 The highest concentration of PhytoFs was detected in CP, followed by CPH and CH. Interestingly, the same order in the concentration of ALA was observed in our investigated samples (160.7, 82.8, and 52.1 mg per g dw) in CP, CPH, and CH, respectively (Fig.…”

“…The second main compound extracted from CP (183.4 ng per g dw), CH (89.0 ng per g dw), and CPH (142.7 ng per g dw) was ent-9(RS)-12-epi-ST-Δ 10 -13-PhytoF, which was already detected in melon leaves 24 and in brown rice bran (4.6 ng per g dw). 30 The less predominant PhytoF in CP, CH, and CPH was ent-16(RS)-9-epi-ST-Δ 14 -10-PhytoF, present at 163.2, 62.8, and 43.5 ng per g dw, respectively. This compound was identified in different rice cultivars and the highest concentrations detected were 1.25, 4.21, and 12.88 ng per g dw for white flour, brown flour, and bran, respectively.…”

“…As shown in Table 4, the total PhytoF content in ng per g dw was: 543.2 (CP), 278.0 (CH), and 393.8 (CPH), showing that these by-and co-products are pounds have already been identified in different rice flours. 30 The 9-L 1t -PhytoP series has been reported in melon leaves, 24 extra virgin olive oil, 27 walnut, macadamia nuts, and pecan nuts as minor components. 17 In addition, it was observed that frying at 130 °C increased the concentration of these compounds in macadamia nuts by 2.3-fold.…”

“…24 The epimeric mixture of ent-16(RS)-13-epi-ST-Δ 14 -9-PhytoF predominates in the three samples. These compounds were identified and quantified for the first time in different nuts and seeds in concentrations up to 10 and 16.06 ng g −1 in walnut 18 and brown rice flour, 30 respectively. The second main compound extracted from CP (183.4 ng per g dw), CH (89.0 ng per g dw), and CPH (142.7 ng per g dw) was ent-9(RS)-12-epi-ST-Δ 10 -13-PhytoF, which was already detected in melon leaves 24 and in brown rice bran (4.6 ng per g dw).…”