Abstract
Volatile compounds are a crucial component of hard apple (Malus ✕domestica Borkh.) cider aroma, flavor, and consequent marketability. Amino acids are used by Saccharomyces cerevisiae yeast in the production of volatiles and their precursors. This study hypothesized that foliar applications of nitrogen to apple trees would elevate the concentration of amino acids in the fruit, thus increasing the concentration of sensorially distinguishable aromatic volatiles in cider. In this experiment, urea foliar fertilizer was applied to ‘Ellis Bitter’ and ‘Harry Masters Jersey’ apple trees to create Control (0 applications), Low (3 weekly applications), and High (5 weekly applications) treatments. Total leaf nitrogen increased with the number of foliar urea applications, demonstrating plant uptake. The total fruit yield and fruit efficiency (total harvested fruit mass relative to trunk cross-sectional area) did not differ among treatments within the same cultivar. Similarly, fruit maturity, size, total phenolics, pH, and soluble solids concentration did not differ among treatments. Yeast assimilable nitrogen (YAN) and amino acids in the juice increased with the number of foliar urea applications, as did fermentation rates. Relative to the Control, the High treatment had 130% greater YAN in ‘Ellis Bitter’ and 145% in ‘Harry Masters Jersey’. Over 90% of the YAN in all juice samples was composed of primary amino nitrogen (PAN), and the majority of the PAN among all treatments was asparagine. Ester and fatty acid content in hard ciders increased with the number of urea applications; however, higher alcohols showed a mixed relationship with the number of applications in the cultivar ‘Ellis Bitter’. Aroma and flavor differences among treatments were discernible by triangle discrimination test panelists; however, the sensory differences were not easily identifiable with untrained panelists. This study demonstrated that late season foliar urea applications to apples trees can increase juice YAN and aromatic compounds in finished cider.
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Claims 13
Claim · model-written summary
Leaf nitrogen increased with foliar urea applications.
- Taxon
- apple
Malus domesticat0 - Treatment
- foliar urea applicationse0
- Outcome
- Total leaf nitrogene0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total leaf nitrogen increased with the number of foliar urea applications, demonstrating plant uptake.”
t0“apple trees”
Claim · model-written summary
Fruit yield and fruit efficiency did not differ among treatments within cultivar.
- Taxon
- appleMalus domesticat0
- Treatment
- urea foliar fertilizere1
- Outcome
- total fruit yield and fruit efficiencye0
- Direction
- did not differe0
- Qualifier
- within the same cultivare0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The total fruit yield and fruit efficiency (total harvested fruit mass relative to trunk cross-sectional area) did not differ among treatments within the same cultivar.”
t0“apple trees”
e1“urea foliar fertilizer was applied”
Claim · model-written summary
Fruit maturity, size and total phenolics did not differ among treatments.
- Taxon
- appleMalus domesticat0
- Treatment
- urea foliar fertilizere1
- Outcome
- fruit maturity, size, total phenolicse0
- Direction
- did not differe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fruit maturity, size, total phenolics, pH, and soluble solids concentration did not differ among treatments”
t0“apple trees”
e1“urea foliar fertilizer was applied”
Claim · model-written summary
Fruit pH and soluble solids did not differ among treatments.
- Taxon
- appleMalus domesticat0
- Treatment
- urea foliar fertilizere1
- Outcome
- pH, and soluble solids concentratione0
- Direction
- did not differe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fruit maturity, size, total phenolics, pH, and soluble solids concentration did not differ among treatments”
t0“apple trees”
e1“urea foliar fertilizer was applied”
Claim · model-written summary
Juice YAN and amino acids increased with urea applications.
- Taxon
- appleMalus domesticat0
- Treatment
- foliar urea applicationse0
- Outcome
- Yeast assimilable nitrogen (YAN) and amino acidse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Yeast assimilable nitrogen (YAN) and amino acids in the juice increased with the number of foliar urea applications, as did fermentation rates.”
t0“apple trees”
Claim · model-written summary
Fermentation rates increased with foliar urea applications.
Not reportedTaxonComparator
Verbatim
e0“Yeast assimilable nitrogen (YAN) and amino acids in the juice increased with the number of foliar urea applications, as did fermentation rates.”
Claim · model-written summary
High treatment increased Ellis Bitter YAN by 130% relative to Control.
- Taxon
- appleMalus domesticat0
- Material
- ‘Ellis Bitter’e0
- Treatment
- High treatmente0
- Outcome
- YANe0
- Direction
- greatere0
- Value
- 130%e0
- Comparator
- Controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Relative to the Control, the High treatment had 130% greater YAN in ‘Ellis Bitter’ and 145% in ‘Harry Masters Jersey’.”
t0“apple trees”
Claim · model-written summary
High treatment increased Harry Masters Jersey YAN by 145% relative to Control.
- Taxon
- appleMalus domesticat0
- Material
- ‘Harry Masters Jersey’e0
- Treatment
- High treatmente0
- Outcome
- YANe0
- Direction
- greatere0
- Value
- 145%e0
- Comparator
- Controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Relative to the Control, the High treatment had 130% greater YAN in ‘Ellis Bitter’ and 145% in ‘Harry Masters Jersey’.”
t0“apple trees”
Claim · model-written summary
Over 90% of juice YAN was PAN.
- Taxon
- appleMalus domesticat0
- Outcome
- primary amino nitrogen (PAN)e0
- Value
- Over 90%e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Over 90% of the YAN in all juice samples was composed of primary amino nitrogen (PAN)”
t0“apple trees”
Claim · model-written summary
Asparagine comprised the majority of PAN in all treatments.
- Taxon
- appleMalus domesticat0
- Outcome
- asparaginee0
- Qualifier
- the majority of the PANe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the majority of the PAN among all treatments was asparagine”
t0“apple trees”
Claim · model-written summary
Cider ester and fatty acid contents increased with urea applications.
Not reportedTaxonComparator
Verbatim
e0“Ester and fatty acid content in hard ciders increased with the number of urea applications”
Claim · model-written summary
Higher alcohols had a mixed relationship with applications in Ellis Bitter.
Not reportedTaxonDirection
Verbatim
e0“higher alcohols showed a mixed relationship with the number of applications in the cultivar ‘Ellis Bitter’”
Claim · model-written summary
Triangle panelists discerned treatment aroma and flavor differences, which untrained panelists could not easily identify.
- Outcome
- Aroma and flavor differencese0
- Qualifier
- the sensory differences were not easily identifiable with untrained panelistse0
Not reportedTaxon
Verbatim
e0“Aroma and flavor differences among treatments were discernible by triangle discrimination test panelists; however, the sensory differences were not easily identifiable with untrained panelists.”
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See all 39 papers →8 of 13 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
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.