Abstract
Organic vegetables have been suggested to produce higher levels of phytochmemicals, which play active roles in disease prevention. We measured total phenolic and aglycone flavonoid (apigenin, kaempferol, luteolin, and quercetin) contents in leaves of organically- and conventionally-grown lettuce (`Kalura' and `Red Sails'), collards (`Top Bunch') and Pak Choi (`Mei Qing') greens during spring and summer trials, using the Folin assay and HPLC, respectively. Postharvest changes in phenolic contents of organic and conventional lettuce were also investigated after 17-day storage at 4 °C. Production system did not cause a significant difference in total phenolic levels of lettuce and collards in either trial, but total phenolics were significantly higher in organic Pak Choi in the summer trial, possibly due to greater flea beetle damage in the organic plots. Organic production did not affect the aglycone flavonoid levels of lettuce and collards in the spring trial except that apigenin increased in organic samples. In the summer trial, however, concentrations of kaempferol, luteolin and quercetin tended to increase in organic lettuce and collards; only luteolin showed promising increase in Pak Choi. Species and cultivars both had significant effects on total phenolic and flavonoid contents. After 17-day storage, total phenolic content significantly increased in both organic and conventional lettuce although the concentrations of aglycone flavonoids remained relatively constant. Total phenolic content was higher in organic `Red Sails' at a marginal significance level after storage, while it did not differ between organic and conventional `Kalura'. We noted a dominant presence of glycoside flavonoids in lettuce before and after storage, which warrants further study.
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Claims 12
Claim · model-written summary
Production system did not significantly change total phenolics in lettuce and collards in either trial.
- Taxon
- lettuce and collards
Brassica oleracea var. viridis
Lactuca sativae0 - Treatment
- Production systeme0
- Outcome
- total phenolic levelse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Production system did not cause a significant difference in total phenolic levels of lettuce and collards in either trial”
Claim · model-written summary
Organic Pak Choi had higher total phenolics in summer.
Not reportedComparator
Verbatim
e0“total phenolics were significantly higher in organic Pak Choi in the summer trial”
Claim · model-written summary
Organic production did not affect lettuce and collard aglycone flavonoids in spring apart from apigenin.
- Taxon
- lettuce and collardsBrassica oleracea var. viridisLactuca sativae0
- Treatment
- Organic productione0
- Outcome
- aglycone flavonoid levelse0
- Qualifier
- spring triale0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Organic production did not affect the aglycone flavonoid levels of lettuce and collards in the spring trial except that apigenin increased in organic samples”
Claim · model-written summary
Apigenin increased in organic samples in spring.
- Taxon
- lettuce and collardsBrassica oleracea var. viridisLactuca sativae1
- Treatment
- organice0
- Outcome
- apigenine0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“apigenin increased in organic samples”
e1“lettuce and collards in the spring trial”
Claim · model-written summary
Kaempferol, luteolin and quercetin tended to increase in organic lettuce and collards in summer.
- Taxon
- lettuce and collardsBrassica oleracea var. viridisLactuca sativae0
- Treatment
- organice0
- Outcome
- concentrations of kaempferol, luteolin and quercetine0
- Direction
- increasee0
- Qualifier
- tendede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“concentrations of kaempferol, luteolin and quercetin tended to increase in organic lettuce and collards”
Claim · model-written summary
Luteolin showed a promising increase in Pak Choi in summer.
Not reportedTreatmentComparator
Verbatim
e0“only luteolin showed promising increase in Pak Choi”
Claim · model-written summary
Species and cultivar significantly affected total phenolic and flavonoid contents.
- Taxon
- Lettuce, Collards and Chinese CabbageBrassica oleracea var. viridisLactuca sativa
Brassica rapa subsp. pekinensist0 - Material
- cultivarse0
- Outcome
- total phenolic and flavonoid contentse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Species and cultivars both had significant effects on total phenolic and flavonoid contents”
t0“Lettuce, Collards and Chinese Cabbage”
Claim · model-written summary
Total phenolics increased after storage in organic and conventional lettuce.
- Taxon
- lettuceLactuca sativae0
- Treatment
- 17-day storagee0
- Outcome
- total phenolic contente0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After 17-day storage, total phenolic content significantly increased in both organic and conventional lettuce”
Claim · model-written summary
Aglycone flavonoid concentrations remained relatively constant after storage.
- Taxon
- lettuceLactuca sativat0
- Treatment
- 17-day storagee1
- Outcome
- concentrations of aglycone flavonoidse0
- Direction
- remained relatively constante0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“concentrations of aglycone flavonoids remained relatively constant”
t0“Lettuce”
e1“After 17-day storage”
Claim · model-written summary
Organic Red Sails had higher phenolics after storage at marginal significance.
- Taxon
- lettuceLactuca sativat0
- Material
- Red Sailse0
- Treatment
- organice0
- Outcome
- Total phenolic contente0
- Direction
- highere0
- Qualifier
- marginal significance levele0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total phenolic content was higher in organic `Red Sails' at a marginal significance level after storage”
t0“Lettuce”
Claim · model-written summary
Organic and conventional Kalura did not differ in total phenolics after storage.
- Taxon
- lettuceLactuca sativat0
- Material
- Kalurae0
- Treatment
- organice0
- Outcome
- Total phenolic contente1
- Direction
- did not differe0
- Comparator
- conventionale0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it did not differ between organic and conventional `Kalura'”
t0“Lettuce”
e1“Total phenolic content was higher”
Claim · model-written summary
Glycoside flavonoids dominated lettuce before and after storage.
- Taxon
- lettuceLactuca sativae0
- Outcome
- dominant presence of glycoside flavonoidse0
- Qualifier
- before and after storagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dominant presence of glycoside flavonoids in lettuce before and after storage”
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Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.