Nitrogen, Phosphorus, and Antioxidant Contents in Crop Residues for Potential Cascade Utilization

作者：Akao Satoshi^*

来源：Waste and Biomass Valorization, 2018, 9(9): 1535-1542.

DOI：10.1007/s12649-017-9929-6

• Agricultural wastes
• Stems and leaves
• Phenolics
• Carotenoids
• Carbon to nitrogen ratio

Crop residues are produced intensively in some places, such as plant factories. These residues have further potential as a source of bioactive compounds. Cascade-approach valorization, an approach to recovering bioactive compounds, energy, and fertilizer, could be used for crop residue recycling. In this study, nitrogen, mineral, and bioactive compound contents in crop residues (tomato, watermelon, broccoli, and others) were investigated. The crop residues contained higher mineral amounts than corresponding edible portions in published data, indicating that they could be utilized as an alternative fertilizer. The nitrogen content also tended to be high, and the nitrogen-to-carbon ratio was around ten for the tomato residue. Dilution of nitrogen might be required before bioconversion process such as methane fermentation. Phenolic concentrations were similar for the crop residue and the edible portion, but carotenoids were more concentrated in the residues, especially for the tomato and broccoli cases. High concentrations of quercetin in the tomato residue and chlorogenic acids in the watermelon residue were also measured. Large amounts of crop residues could therefore be a source of bioactive compounds. Because of the negative effects antioxidants have on microbial activity, extracting bioactive compounds prior to the bioconversion process might be advisable.

• 出版日期2018-9