, 1997 and Zoumas-Morse et al., 2007; however spermine was not investigated by these authors. Cao, Hua, Zhu, Hua, and Knapp (2010) investigated and detected spermine, spermidine and putrescine in dried corn. Altogether, spermidine and spermine contributed with more than 67% of
the total amines levels in fresh and dried corn, whereas it represented only 29% in the canned corn (Fig. 1). Putrescine was the prevalent amine in canned corn (71% of total levels). Cadaverine, histamine, agmatine and phenylethylamine represented less than 15% of the total amine levels in fresh and dried corn. Spermidine SB431542 was the amine which contributed the most to total levels in fresh sweet corn (62.4%). It was followed by putrescine (23.1%), spermine (6.4%), phenylethylamine (3.7%), cadaverine (3.5%) and histamine (0.9%). In canned corn, putrescine contributed the most to total amine levels selleck compound (71%), followed by spermidine (25%) and by spermine (4%). Therefore, the profile of amines in sweet corn seems to be significantly affected by the canning process. Dried corn contained mostly spermine (45.4%) followed by spermidine (30.9%), putrescine and phenylethylamine (8.3%), agmatine (5.2%) and cadaverine (1.8%). Based
on these results, the profile of free bioactive amines varied significantly among the corn products analyzed. The differences are probably associated with corn cultivars, cultivation practices, and processing steps as described by Shalaby, 2000, Liang and Lur, 2002, Gloria, 2005 and Frías et al., 2007. The total concentration of amines on a dry weight basis ranged from 10.9 to
17.1 mg/100 g in Edoxaban fresh corn, from 14.7 to 79.7 mg/100 g in canned corn, and from 5.0 to 6.9 mg/100 g in dried corn. The mean levels were 14.7, 42.0 and 6.14 mg/100 g, respectively (Fig. 2). The total amine concentration was significantly higher (p < 0.05) in canned (42 mg/100 g) compared to fresh (14.7 mg/100 g) and dried corn (6.1 mg/100 g). According to Fig. 2, the polyamines spermidine and spermine contributed with 70% of the total amines levels in fresh and dried corn; however, in canned corn the polyamines represented only 30% of the amines. The levels of putrescine in canned corn varied among samples of different brands and among lots of the same brand (data not shown). The highest concentrations of putrescine correlated significantly with storage life – the longer the storage period prior to analysis, the higher the concentration. Studies performed by Shalaby, 2000 and Cirilo et al., 2003 indicated that heating and cooking can affect amines levels. Furthermore, putrefactive amines such as putrescine usually increase during storage of food products. Different levels of amines in corn products were reported in the literature. Okamoto et al. (1997) found higher concentrations of putrescine and spermidine in fresh corn. Zoumas-Morse et al. (2007) reported lower spermidine and putrescine levels in fresh and canned corn.