Continuous production of pectic oligosaccharides from sugar beet pulp in a cross flow continuous enzyme membrane reactor

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.

Sugar Beet Pulp in the Context of Developing the Concept of Circular Bioeconomy

“…Microwave-assisted extraction [68] Galacturonic acid Enzymatic release of galacturonic acid [113] L-arabinose Few steps, including treatment with aqueous alkali [115] L-Arabinose and oligosaccharides Xylanase and acid hydrolysis [116] L-arabinose and a galacturonic acid-rich backbone Enzymatic hydrolysis of sugar beet pulp [89] Arabino-oligosaccharides Hydrothermal treatment [117] Pectic oligosaccharides Enzyme membrane reactor technology [118] Succinic acid Fed-batch fermentations with the bacterial strain Actinobacillus succinogenes [31] Ferulic acid and feruloylated oligosaccharides…”

“…The release of products from sugar beet pulp was carried out with the actinomycete strains [119] Source: [31,68,89,90,[113][114][115][116][117][118][119].…”

“…Pectin-rich residues, including sugar beet pulp, show the potential to be processed into pectic oligosaccharides, which can be used as potential prebiotic compounds [118]. Pectic oligosaccharides are investigated for antibacterial potentials [118].…”

Comparative evaluation of Aspergillus niger strains for endogenous pectin-depolymerization capacity and suitability for d-galacturonic acid production

“…Media supplementation with (hemi-)cellulosic substrates and thereby induced expression of (hemi-)cellulases during pectinase production could further contribute to d-GalA release from complex biomasses [11,30]. Research in this field is still actively ongoing, but mostly focusing on process engineering, as recently demonstrated for continuous generation of d-GalA from SBPP pectin extracts in membrane enzyme reactors [15]. Genetic engineering may provide additional means to induce (hemi-)cellulase expression for improved d-GalA release from complex pectinaceous biomasses.…”

Production of Oligosaccharides from Agrofood Wastes

“…Though pectin is a typical food ingredient for jellies, marmalades and jams, its slow degradation in the intestine permits its use with calcium salts to treat diarrhea, it can ameliorate diverse colon cancer, promoting gut health by controlling microbiota populations (a prebiotic effect) [27,28]. Oligosaccharides derived from pectin potentially maintain and even increased pectin bounties in gut health, and can be produced from a diversity of peels and pulps from beet, citrus species, apple pomace and other fruit waste [9,12,28].…”