TY  - JOUR
A1  - Heinze, Mandy
A1  - Hanschen, Franziska S.
A1  - Wiesner-Reinhold, Melanie
A1  - Baldermann, Susanne
A1  - Gräfe, Jan
A1  - Schreiner, Monika
A1  - Neugart, Susanne
T1  - Effects of Developmental Stages and Reduced UVB and Low UV Conditions on Plant Secondary Metabolite Profiles in Pak Choi (Brassica rapa subsp chinensis)
JF  - Journal of agricultural and food chemistry : a publication of the American Chemical Society
N2  - Pak choi (Brassica rapa subsp. chinensis) is rich in secondary metabolites and contains numerous antioxidants, including flavonoids; hydroxycinnamic acids; carotenoids; chlorophylls; and glucosinolates, which can be hydrolyzed to epithionitriles, nitriles, or isothiocyanates. Here, we investigate the effect of reduced exposure to ultraviolet B (UVB) and UV (UVA and UVB) light at four different developmental stages of pak choi. We found that both the plant morphology and secondary metabolite profiles were affected by reduced exposure to UVB and UV, depending on the plant’s developmental stage. In detail, mature 15- and 30-leaf plants had higher concentrations of flavonoids, hydroxycinnamic acids, carotenoids, and chlorophylls, whereas sprouts contained high concentrations of glucosinolates and their hydrolysis products. Dry weights and leaf areas increased as a result of reduced UVB and low UV. For the flavonoids and hydroxycinnamic acids in 30-leaf plants, less complex compounds were favored, for example, sinapic acid acylated kaempferol triglycoside instead of the corresponding tetraglycoside. Moreover, also in 30-leaf plants, zeaxanthin, a carotenoid linked to protection during photosynthesis, was increased under low UV conditions. Interestingly, most glucosinolates were not affected by reduced UVB and low UV conditions. However, this study underlines the importance of 4-(methylsulfinyl)butyl glucosinolate in response to UVA and UVB exposure. Further, reduced UVB and low UV conditions resulted in higher concentrations of glucosinolate-derived nitriles. In conclusion, exposure to low doses of UVB and UV from the early to late developmental stages did not result in overall lower concentrations of plant secondary metabolites.
KW  - flavonoids
KW  - hydroxycinnamic acids
KW  - carotenoids
KW  - glucosinolates
KW  - nitriles
KW  - UVB reduction
Y1  - 2018
U6  - https://doi.org/10.1021/acs.jafc.7b03996
SN  - 0021-8561
SN  - 1520-5118
VL  - 66
IS  - 7
SP  - 1678
EP  - 1692
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Klopsch, Rebecca
A1  - Baldermann, Susanne
A1  - Voss, Alexander
A1  - Rohn, Sascha
A1  - Schreiner, Monika
A1  - Neugart, Susanne
T1  - Narrow-Banded UVB Affects the Stability of Secondary Plant Metabolites in Kale (Brassica oleracea var. sabellica) and Pea (Pisum sativum) Leaves Being Added to Lentil Flour Fortified Bread: A Novel Approach for Producing Functional Foods
JF  - Foods
N2  - Young kale and pea leaves are rich in secondary plant metabolites (SPMs) whose profile can be affected by ultraviolet B (UVB) radiation. Carotenoids and flavonoids in kale and pea exposed to narrow-banded UVB, produced by innovative light-emitting diodes (LEDs), and subsequently used for breadmaking were investigated for the first time, thus combining two important strategies to increase the SPMs intake. Breads were also fortified with protein-rich lentil flour. Antioxidant activity in the ‘vegetable breads’ indicated health-promoting effects. Lentil flour increased the antioxidant activity in all of the ‘vegetable breads’. While carotenoids and chlorophylls showed a minor response to UVB treatment, kaempferol glycosides decreased in favor of increasing quercetin glycosides, especially in kale. Additionally, breadmaking caused major decreases in carotenoids and a conversion of chlorophyll to bioactive degradation products. In ‘kale breads’ and ‘pea breads’, 20% and 84% of flavonoid glycosides were recovered. Thus, kale and pea leaves seem to be suitable natural ingredients for producing innovative Functional Foods.
KW  - narrow-banded UVB
KW  - thermal processing
KW  - antioxidant activity
KW  - kale
KW  - pea
KW  - flavonoids
KW  - carotenoids
Y1  - 2019
U6  - https://doi.org/10.3390/foods8100427
SN  - 2304-8158
VL  - 8
IS  - 10
PB  - MDPI
CY  - Basel
ER  -