title: Comparison of five agro-industrial waste-based composts as growing media for lettuce: Effect on yield, phenolic compounds and vitamin C.
abstract: Overall phenolic content in plants is on average higher in organic farming, including when renewable resources such as composts are used as soil amendments. In most cases, however, the composting process needs to be optimized to reach the desired outcome. Using composts obtained from chestnut, red and white grapes, olive and broccoli wastes, the relative antioxidative abilities of lettuces cultivated in greenhouse were examined. Results clearly coupled high phenolic levels with high yield in lettuce grown on the chestnut-based compost. A huge accumulation of phenolics was observed with the white grape-based compost, but this coincided with low yield. Three compounds were identified as discriminating factors between treated samples, namely quercetin 3-O-glucoside, luteolin 7-O-glucoside, and cyanidin 3-O-(6″-malonyl)-β-d-glucoside; these are also some of the compounds receiving health claims on lettuce consumption. On a negative note, all composts led to decreased vitamin C levels. Collectively, the data suggest that compost amendments can help add value to lettuce by increasing its antioxidant activity as compared to other organic resources.
authors.affiliation: Universidade Estadual do Oeste do Paraná, University Street, 2069, 85819-110 Cascavel, Brazil.
authors.forename: Francielly T
authors.initials: FT
authors.lastname: Santos
authors.affiliation: CITAB-Centre for the Research and Technology of Agro-Environment and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro (UTAD), Vila Real, Portugal. Electronic address: pgoufo@utad.pt.
authors.forename: Piebiep
authors.initials: P
authors.lastname: Goufo
authors.affiliation: CITAB-Centre for the Research and Technology of Agro-Environment and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro (UTAD), Vila Real, Portugal.
authors.forename: Cátia
authors.initials: C
authors.lastname: Santos
authors.affiliation: Departamento de Agronomia, UTAD, Apartado 1013, 5001-801 Vila Real, Portugal.
authors.forename: Donzilia
authors.initials: D
authors.lastname: Botelho
authors.affiliation: CITAB-Centre for the Research and Technology of Agro-Environment and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro (UTAD), Vila Real, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Fonseca
authors.affiliation: Departamento de Agronomia, UTAD, Apartado 1013, 5001-801 Vila Real, Portugal.
authors.forename: Aurea
authors.initials: A
authors.lastname: Queirós
authors.affiliation: Universidade Estadual do Oeste do Paraná, University Street, 2069, 85819-110 Cascavel, Brazil.
authors.forename: Mônica S S M
authors.initials: MS
authors.lastname: Costa
authors.affiliation: CITAB-Centre for the Research and Technology of Agro-Environment and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro (UTAD), Vila Real, Portugal.
authors.forename: Henrique
authors.initials: H
authors.lastname: Trindade
mesh_terms: D000872:Anthocyanins / Q000032:analysis; D000975:Antioxidants / Q000032:analysis; D001205:Ascorbic Acid / Q000032:analysis*; D005308:Fertilizers; D047309:Flavones / Q000032:analysis; D005419:Flavonoids / Q000032:analysis; D005960:Glucosides / Q000032:analysis; D007220:Industrial Waste; D018545:Lactuca / Q000737:chemistry / Q000254:growth & development*; D031658:Olea / Q000737:chemistry; D058871:Organic Agriculture / Q000379:methods*; D010636:Phenols / Q000032:analysis*; D011794:Quercetin / Q000031:analogs & derivatives; D012987:Soil / Q000737:chemistry*; D027843:Vitis / Q000737:chemistry; D047311:Luteolin
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D001205:Ascorbic Acid; D005308:Fertilizers; D047309:Flavones; D005419:Flavonoids; D005960:Glucosides; D007220:Industrial Waste; D010636:Phenols; D011794:Quercetin; D012987:Soil; C532085:quercetin 3'-O-glucoside; C017154:cyanidin; C066408:luteolin-7-glucoside; D047311:Luteolin
keywords: Antioxidants; Carotenoids; Compost; Lettuce; Organic agriculture; Phenolics; Residues; Vitamin C; Wastes