Bioactive amines in sorghum: Method optimisation and influence of line, tannin and hydric stress

• Published in: Food chemistry 2015-04, Vol.173, p.224-230
• Main Authors: Paiva, Caroline Liboreiro, Evangelista, Warlley Pinheiro, Queiroz, Valéria Aparecida Vieira, Glória, Maria Beatriz Abreu
• Format: Article
• Language: English
• Subjects: Bioactive amines; Biogenic Amines - analysis; Chromatography, High Pressure Liquid; Droughts; Extraction; Hydric stress; Particle Size; Polyamines; Sorghum; Sorghum - chemistry; Sorghum bicolor L; Tannins - analysis
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.10.039

•Bioactive amines were reported for the first time in sorghum.•A procedure for the extraction of amines from sorghum was optimised and validated.•Sorghum without tannin has higher amines levels compared to sorghum with tannin.•Hydric stress caused accumulation of spermidine in sorghum grains.•Sorghum is a significant source of polyamines. The profile and levels of bioactive amines in different sorghum lines were reported for the first time. The amines were quantified by ion-pair HPLC, post-column derivatisation with o-phthalaldehyde and fluorimetric detection. The extraction procedure was optimised: 420μm particle size, extraction with 5% trichloroacetic acid and three extractions. The screening of 22 sorghum lines showed that four of the ten amines investigated were detected. Spermine and spermidine were the prevalent amines (100%), followed by putrescine (77%) and cadaverine (14%). Total amines ranged from 5.8 to 41.4mg/100g, and the polyamines represented 60–100% of the total. Sorghum without tannin had higher amines levels compared to sorghum with tannin and cadaverine was specific to samples without tannin. Hydric stress caused accumulation of spermidine in the grains and affected the levels of other amines at rates depending on the presence or not of tannin. Sorghum is a significant source of polyamines.