Abstract
Abstract Background During the processing of spent coffee grounds (SCGs) several residues are obtained, which are mostly disposed of in landfills. There is an urgent need for a comprehensive waste management strategy for these residues. This study evaluates the potential of SCGs as a biofertilizer by assessing their effects on lettuce leaves and the release of antioxidants following in vitro digestion and fermentation. Results Lettuce plants were grown with different amounts of SCGs (0–150 g kg −1 ) in the substrate. High SCG concentrations in the soil generated lighter colored tissues, a decrease in the green color, less root development, and lower dry weight of leaves ( P < 0.05). The SCG levels also affected the release of antioxidants by the final product. This effect was more pronounced in the digested fraction: applying the Ferric Reducing Antioxidant Power (FRAP) method, the addition of SCGs from 10 g kg −1 to 125 g kg −1 increased the amount of antioxidant from 43.88 ± 4.81 to 105.96 ± 29.09 μmol Trolox g −1 of dry weight ( P < 0.05). The Indigo Carmine Reducing Capacity (IC RED ) method also showed a similar trend, but in this case the highest value was obtained with 150 g kg −1 of SCGs (16.41 ± 3.93 mmol catechin g −1 of dry weight) ( P < 0.05). Moreover, in the fermented fraction a significant increase in the antioxidant released was found with low levels of SCG( P <0.05), while lettuces fertilized with intermediate amounts of SCGs (25 and 50 g kg −1 ) presented the highest amount of insoluble antioxidant ( P < 0.05). Conclusion A compromise should be found in order to achieve a product with a high antioxidant capacity and an acceptable visual quality. © 2024 Society of Chemical Industry.
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Claims 9
Claim · model-written summary
High spent coffee ground concentrations made lettuce tissues lighter and less green.
- Taxon
- lettuce
Lactuca sativat0 - Treatment
- High SCG concentrationse0
- Outcome
- lighter colored tissues, a decrease in the green colore0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High SCG concentrations in the soil generated lighter colored tissues, a decrease in the green color”
t0“lettuce”
Claim · model-written summary
High spent coffee ground concentrations reduced lettuce root development.
- Taxon
- lettuceLactuca sativat0
- Treatment
- High SCG concentrationse0
- Outcome
- root developmente0
- Direction
- lesse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High SCG concentrations in the soil generated lighter colored tissues, a decrease in the green color, less root development”
t0“lettuce”
Claim · model-written summary
High spent coffee ground concentrations reduced lettuce leaf dry weight.
- Taxon
- lettuceLactuca sativat0
- Treatment
- High SCG concentrationse0
- Outcome
- dry weight of leavese0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High SCG concentrations in the soil generated lighter colored tissues, a decrease in the green color, less root development, and lower dry weight of leaves ( P < 0.05)”
t0“lettuce”
Claim · model-written summary
Spent coffee ground levels affected antioxidant release.
- Taxon
- lettuceLactuca sativat0
- Treatment
- SCG levelse0
- Outcome
- release of antioxidantse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The SCG levels also affected the release of antioxidants by the final product.”
t0“lettuce”
Claim · model-written summary
In digested lettuce, increasing spent coffee grounds from 10 to 125 g kg −1 increased FRAP antioxidant amount from 43.88 ± 4.81 to 105.96 ± 29.09 μmol Trolox g −1 dry weight.
- Taxon
- lettuceLactuca sativat0
- Treatment
- SCGs from 10 g kg −1 to 125 g kg −1e0
- Outcome
- amount of antioxidante0
- Direction
- increasede0
- Value
- 105.96 ± 29.09 μmol Trolox g −1 of dry weighte0
- Qualifier
- 43.88 ± 4.81e0
- Comparator
- 10 g kg −1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the addition of SCGs from 10 g kg −1 to 125 g kg −1 increased the amount of antioxidant from 43.88 ± 4.81 to 105.96 ± 29.09 μmol Trolox g −1 of dry weight ( P < 0.05)”
t0“lettuce”
Claim · model-written summary
The IC RED assay found the highest antioxidant value at 150 g kg −1 spent coffee grounds.
- Taxon
- lettuceLactuca sativat0
- Treatment
- 150 g kg −1 of SCGse0
- Outcome
- highest valuee0
- Direction
- higheste0
- Value
- 16.41 ± 3.93 mmol catechin g −1 of dry weighte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the highest value was obtained with 150 g kg −1 of SCGs (16.41 ± 3.93 mmol catechin g −1 of dry weight) ( P < 0.05)”
t0“lettuce”
Claim · model-written summary
Low spent coffee ground levels significantly increased antioxidant release in the fermented fraction.
- Taxon
- lettuceLactuca sativat0
- Organ / stage
- fermented fractione0
- Treatment
- low levels of SCGe0
- Outcome
- antioxidant releasede0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in the fermented fraction a significant increase in the antioxidant released was found with low levels of SCG( P <0.05)”
t0“lettuce”
Claim · model-written summary
Intermediate spent coffee ground amounts produced the highest insoluble antioxidant amount.
- Taxon
- lettucesLactuca sativae0
- Treatment
- intermediate amounts of SCGs (25 and 50 g kg −1 )e0
- Outcome
- amount of insoluble antioxidante0
- Direction
- higheste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lettuces fertilized with intermediate amounts of SCGs (25 and 50 g kg −1 ) presented the highest amount of insoluble antioxidant ( P < 0.05)”
Claim · model-written summary
The authors recommend balancing antioxidant capacity with visual quality.
- Taxon
- lettuceLactuca sativat0
- Outcome
- a product with a high antioxidant capacity and an acceptable visual qualitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A compromise should be found in order to achieve a product with a high antioxidant capacity and an acceptable visual quality.”
t0“lettuce”
The same questions in other papers
Coffea · molecular: metabolites · Lactuca sativa (garden lettuce)Results agree
1 paper in the same direction as this paper
- positive
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.