Abstract
Spinach is an important dietary source of lutein and β-carotene. Their synthesis is closely linked to chlorophyll synthesis and dependent upon an adequate supply of sulfur and nitrogen. Soils may become sulfur-deficient during winter because microorganisms convert atmospheric SO2 less efficiently to sulfate. The influence of sulfur and nitrogen fertilization on the carotenoid and chlorophyll contents of spinach grown in summer or winter was investigated. Carotenoid and chlorophyll levels were positively correlated. Lutein and β-carotene were 25% higher in summer than in winter. Winter levels were increased by 35-40% by sulfur fertilization in one location but not in the other, with the impact depending upon soil type, growing location, and atmospheric conditions. Carotenoids were little or not affected by nitrogen addition in winter or sulfur addition in summer. It is concluded that sulfur fertilization of spinach in winter may modestly increase carotenoids but high carotenoid levels are best assured with carotenoid-rich cultivars grown in summer.
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Claims 8
Claim · model-written summary
Carotenoid and chlorophyll levels were positively correlated.
- Taxon
- spinach
Spinacia oleraceat0 - Compound
- chlorophylle0
- Outcome
- Carotenoide0
- Direction
- positively correlatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Carotenoid and chlorophyll levels were positively correlated.”
t0“Spinach”
Claim · model-written summary
Lutein levels were 25% higher in summer than winter.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- Luteine0
- Direction
- highere0
- Value
- 25%e0
- Comparator
- wintere0
- Setting
- summere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lutein and β-carotene were 25% higher in summer than in winter.”
t0“Spinach”
Claim · model-written summary
β-carotene levels were 25% higher in summer than winter.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- β-carotenee0
- Direction
- highere0
- Value
- 25%e0
- Comparator
- wintere0
- Setting
- summere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lutein and β-carotene were 25% higher in summer than in winter.”
t0“Spinach”
Claim · model-written summary
Winter carotenoid levels increased 35–40% with sulfur fertilization at one location.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- sulfur fertilizatione0
- Outcome
- Winter levelse0
- Direction
- increasede0
- Value
- 35-40%e0
- Qualifier
- in one locatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Winter levels were increased by 35-40% by sulfur fertilization in one location but not in the other, with the impact depending upon soil type, growing location, and atmospheric conditions.”
t0“Spinach”
Claim · model-written summary
Sulfur fertilization did not increase winter carotenoids at the other location.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- sulfur fertilizatione0
- Outcome
- Winter levelse0
- Direction
- no_changeinferredt0
- Qualifier
- the othere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Winter levels were increased by 35-40% by sulfur fertilization in one location but not in the other”
t0“Spinach”
Claim · model-written summary
Nitrogen addition had little or no effect on carotenoids in winter.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- nitrogen additione0
- Outcome
- Carotenoidse0
- Direction
- no_changeinferredt0
- Qualifier
- wintere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Carotenoids were little or not affected by nitrogen addition in winter or sulfur addition in summer.”
t0“Spinach”
Claim · model-written summary
Sulfur addition had little or no effect on carotenoids in summer.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- sulfur additione0
- Outcome
- Carotenoidse0
- Direction
- no_changeinferredt0
- Qualifier
- summere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Carotenoids were little or not affected by nitrogen addition in winter or sulfur addition in summer.”
t0“Spinach”
Claim · model-written summary
The authors recommend carotenoid-rich cultivars grown in summer to assure high carotenoid levels.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- carotenoid-rich cultivars grown in summere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high carotenoid levels are best assured with carotenoid-rich cultivars grown in summer”
t0“Spinach”
The same questions in other papers
nitrogen · physiology: pigments · Spinacia oleracea (spinach)Results differ
2 papers in the same direction as this paper · 16 in the opposite direction
- positive
- positive
- positive
15 papers more in this group
See all 19 papers →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.