Free and Conjugated Polyamines and Phenols in Raw and Alkaline-Clarified Sugarcane Juices

Abstract

Sugarcane juice contains a lot of sucrose associated with several monosaccharides, defined as low molecular mass carbohydrates (LMMC), as well as some polysaccharides and glycoproteins, which are defined as mid and high molecular mass carbohydrates (MMMC and HMMC, respectively). These three categories of carbohydrates can be separated by size-exclusion chromatography through Sephadex G-10 and Sephadex G-50 columns, but elution profiles change drastically after juice clarification performed by adjusting the pH value of the juice to 8.0. In addition, polyamines and some phenolics are currently associated with carbohydrate preparations, and the distribution pattern of these conjugates also changes after clarification. Polyamine levels generally decrease after juice clarification. Cadaverine is completely removed from the different carbohydrate preparations, whereas spermidine is the main polyamine occurring in association with sugarcane carbohydrates, as free or acid-soluble form in LMMC preparation or as acid-soluble and -insoluble forms in both MMMC and HMMC preparations. Polyamines, presumably spermidine, conjugate to p-hydroxybenzoic acid in LMMC, mostly to caffeic acid in MMMC, and to syringic acid in HMMC preparations. HMMC-associated polyamines appear in both acid-soluble and -insoluble fractions. Syringic acid also occurs in the LMMC preparation, but juice clarification changes it from acid-soluble to free form, and it coelutes with sucrose.

Effect of incorporating alum in cane juice clarification efficiency and sucrose losses

“…This could also be seen in the initial settling rates where higher ISRs were observed in the WPT than in the NPT cane juices (Table 6). This was in agreement with studies by Eggleston, Monge, and Pepperman (2002) and de Armas et al (1999) who reported formation of larger flocs and faster settling rates leading to higher turbidity removal upon preheating of the mixed cane juice before liming. These results therefore suggest that incorporating alum in WPT intermediate liming has a great potential for turbidity removal in cane juice clarification.…”

“…However, as observed in Table 2 there was a mean decrease in invert sugar concentrations from the MJ to the AFTINCB samples. The one and a half minute heating time probably minimised inversion and could be that some invert sugars may have been removed with heatinduced precipitation of colloids, macromolecules (starch, dextran polysaccharides and proteins) and colour (de Armas, Martinez, Vicente, & Legaz, 1999;Saska, Zossi, & Liu, 2010a). The decrease in • Brix from the MJ to the AFTINCB could be further evidence of this.…”

“…By pre-heating and incubating the MJ, juice colour was significantly removed (p<0.05) from 13271 IU in MJ to 11041 IU in AFTINCB. The colour removal preceding the incubation is considered to be heat-induced and is associated with the precipitation of colloids and macromolecules, including starch, dextran polysaccharides and proteins (de Armas et al, 1999;Saska et al, 2010a). Eggleston, Monge, and Pepperman (2002) reported a 29% colour removal in intermediate liming from the mixed juice when 30% of the mixed juice was pre-heated before incubation.…”

Sugarcane glycoproteins are required to the production of an active UDP-glucose dehydrogenase byXanthomonas albilineans

“…Elution was carried out also with MilliQ-grade water. The void volume (22 mL) was discarded whereas the following 14 mL contained both HMMG and MMMG (de Armas et al, 1999), defined as glycoproteins after separation by HPLC and carbohydrate and fluorescence emission analyses. Two filtration processes were required to obtain 28 mL of these glycoproteins.…”

Cadaverine

“…In addition to presence of Cad in various plants, it is reported in table olive, 34 sugarcane juice. 11,35 It is challenging to define the relevance of Cad in these products. The variability in content is a less understood and remain unelucidated in terms of physiochemical significance.…”