Changes in the content of health-promoting compounds and antioxidant activity of broccoli after domestic processing

Abstract

The effect of water- and steam-cooking on the content of vitamin C, polyphenols, carotenoids, tocopherols and glucosinolates, as well as on the antioxidant activity of broccoli, are reported. Flavonoids, phenolic acids, vitamins C and E, beta-carotene, lutein, and glucosinolates in domestically processed broccoli were quantified using high-performance liquid chromatography (HPLC) methods; total polyphenols were determined with Folin-Ciocalteu reagent. The antioxidant capacities of broccoli extracts were evaluated using the Trolox equivalent antioxidant capacity (TEAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. The results indicated that steam-cooking of broccoli results in an increase in polyphenols, as well as the main glucosinolates and their total content as compared with fresh broccoli, whereas cooking in water has the opposite effect. Steam-cooking of broccoli has no influence on vitamin C, whereas cooking in water significantly lowers its content. Both, water- and steam-cooking of broccoli results in an increase in beta-carotene, lutein, and alpha- and gamma-tocopherols as compared with fresh broccoli. Similar effects of steaming and water-cooking of broccoli on their antioxidant activity were observed.

Effects of different defrosting methods on the stability of bioactive compounds and consumer acceptability of frozen broccoli

“…Defrosting methods SM1, SM2, and MM2 showed lower total glucosinolates levels (~16%,~60%, and~20%, respectively) as compared with the control, whereas MM1 showed no significant difference (p > 0.05). Similar results were reported by other authors regarding boiling of raw broccoli (Cieslik, Leszczyńska, Filipiak-Florkiewicz, Sikora, & Pisulewski, 2007;Gliszczyńska-Świglo et al, 2006;Miglio et al, 2008;Vallejo et al, 2002;Yuan et al, 2009). Analysis of water used for cooking broccoli suggested that glucosinolates were lost mainly due to leaching into water, while~10% of the Table 1.…”

“…In agreement to reports by Gliszczyńska-Świglo et al (2006) and Miglio et al (2008), lutein and β-carotene showed an increase after moderate time boiling (26% and 28% more, respectively). Violaxanthin showed significant losses only after microwaving, but its concentration raised with SM1 and showed no significant changes with SM2.…”

“…Lutein concentration presented herein was in the range of reported data, though, β-carotene values were lower than those reported in the literature (Gliszczyńska-Świglo et al, 2006;Miglio et al, 2008;Zhang & Hamauzu, 2004).…”

“…Vitamin C content was mainly affected by boiling water methods. Previous reports have shown that ascorbic acid content dramatically decreases during boiling of broccoli florets (Borges-Marques, Von Atzingen, Pinto, & Silva, 2004;Gliszczyńska-Świglo et al, 2006;Miglio et al, 2008;Vallejo et al, 2002;Yuan, Sun, Yuan, & Wang, 2009). Zhang and Hamauzu (2004) reported that this loss is due to a reduced retention of vitamin C in the tissues.…”

Screening of Antioxidant Properties of the Apple Juice Using the Front-Face Synchronous Fluorescence and Chemometrics

“…The TAC of juices was determined by the Trolox equivalent antioxidant capacity (TEAC) assay according to Re et al (1999), as described in detail in Gliszczyńska-Świgło et al (2006). The TEAC value was expressed in millimoles of Trolox per liter of juice (mM).…”