No abstract

Pectin oligosaccharides (POS) have been indicated as a new class of potential prebiotic compounds, which can be produced from pectin-rich food byproducts. In the present study, different technological means of POS production were explored to produce tailor-made POS mixtures starting from sugar beet pulp. The overall POS production process consisted of two steps: the extraction of pectin and the hydrolysis of pectin to tailored POS by combined hydrolysis/fractionation approaches. Different extraction as well as hydrolysis and fractionation methodologies were applied. The obtained POS were characterized for their total galacturonic acid content and, at a deeper level, using a HILIC-ESI/MS methodology, for the POS structure and composition. The composition of POS fractions was studied as a function of the technology used to obtain them. Finally, the potential prebiotic properties of the POS mixtures obtained were thoroughly explored by several in vitro experiments aimed at detecting lactic acid bacteria (LAB) stimulation by POS fractions. Several fractions were very efficient in stimulation, in a species-dependent manner. The overall best fractions were in general those rich in arabinans having a low degree of polymerization, obtained from the enzymatic extraction of biomass and subsequent fractionation with low-medium molecular weight cut-off. Quite interestingly, no POS fraction was able to stimulate pathogenic E. coli strains. The data reported here clearly indicate the possibility to obtain diverse fractions with different prebiotic properties starting from the same biomass, and outline clear potential for POS obtained from sugar beet pulp with the appropriate technology to act as prebiotic compounds.

No abstract

No abstract

Sugar beet pulp pectin is an attractive source for the production of pectic oligosaccharides, an emerging class of potential prebiotics. The main aim of the present work was to investigate a new process allowing to produce pectic oligosaccharides in a continuous way by means of a cross flow enzyme membrane reactor while using a low-cost crude enzyme mixture (viscozyme). Preliminary experiments in batch and semi-continuous setups allowed to identify suitable enzyme concentrations and assessing filtration suitability. Then, in continuous experiments in the enzyme membrane reactor, residence time and substrate loading were further optimized. The composition of the obtained oligosaccharide mixtures was assessed at the molecular level for the most promising conditions and was shown to be dominated by condition-specific arabinans, rhamnogalacturonans, and galacturonans. A continuous and stable production was performed for 28.5 h at the optimized conditions, obtaining an average pectic oligosaccharide yield of 82.9 ± 9.9% (w/w), a volumetric productivity of 17.5 ± 2.1 g/L/h, and a specific productivity of 8.0 ± 1.0 g/g E/h. This work demonstrated for the first time the continuous and stable production of oligosaccharide mixtures from sugar beet pulp using enzyme membrane reactor technology in a setup suitable for upscaling.

These results suggest that DESI-MS has a potential role for the micro-environmental analysis of drug diffusion and surface distribution in polymeric matrices.

The Authors describe their diagnostic protocol for hypospadias in childhood, including the evaluation of associated malformations and degree of intersexuality. Treatment usually consists of a single-stage operation, except for perineo-scrotal hypospadias, and must be performed before the child is two years old.

No abstract