Journal of applied glycoscience最新文献

Cabbage core (CC) is regarded as a waste part of the vegetable, despite being edible and containing various nutritional and functional compounds. We investigated the properties of CC powder with particle sizes < 1 mm as a new food material. CC powder was more resistant to structural deformation than leaf-derived powder, particularly CC powder with particles ≥ 0.3 mm in size. To examine the application of CC powder in 3D printed foods, we investigated the effects of "nata puree," a disintegrated nata de coco made with tamarind seed gum (NPTG), on paste made with CC powder. NPTG promoted stable binding of paste made using CC powder, which was successfully extruded using a syringe to form a bar with a granular structure. Thus, CC powder possesses unique textural/structural properties for its application in next-generation foods.

In recent years, the importance of biomass utilization has increased, but it has not been effectively exploited. In particular, it is difficult to use hemicellulose, the second most abundant biopolymer of biomass. Therefore, in order to promote the utilization of hemicellulose, we screened for microorganisms capable of producing polysaccharides from D-xylose. The following four strains were selected from samples collected from various regions of Okinawa Prefecture: Kosakonia sp. (SO_001), Papiliotrema terrestris (SO_005), Pseudarthrobacter sp. (SO_006), and Williamsia sp. (SO_009). Observation with a scanning electron microscope (SEM) confirmed that each bacterium produced polysaccharides with different shapes. In addition, the molecular weight and sugar composition of the polysaccharides produced by each bacterium were distinct. The selected microorganisms include closely related species known to promote plant growth and known to suppress postharvest pathogens. Since these microorganisms may be used not only in known fields but also in new fields, the results of this research are expected to greatly expand the uses of hemicellulose.

D-Allose, a C3 epimer of D-glucose, has potential to improve human health as a functional food. However, its effect on the intestinal environment remains unknown. Aged humans progressively express changes in the gut, some of which deleteriously affect gastrointestinal health. In this study, we profiled the intestinal microbiome in aged mice and analyzed organic acids produced by bacteria in cecum contents after long-term ingestion of D-allose. D-Allose did not significantly change organic acid concentration. However, long-term ingestion did significantly increase the relative abundance of Actinobacteria and reduce the relative abundance of Proteobacteria. These results suggest that oral D-allose improves the proportion of favorable intestinal flora in aged mice. D-Allose significantly decreased the relative abundance of Lachnospiraceae bacteria, but increased the relative abundance of Bacteroides acidifaciens and Akkermansia muciniphila. Thus, D-allose might serve as a nutraceutical capable of improving the balance of gut microbiome during aging.

Wheat flour-based batter containing 0 to 20 % trehalose was deep-fried, dried and held in various water activity (a _w) conditions. The effects of trehalose content and a _w on oil content, water sorption, isothermal mechanical relaxation, and fracture properties were investigated. For comparison, the fracture properties of freeze-dried porous waxy corn starch solids were also investigated. The 10 % trehalose sample had the lowest oil content, water content, and a _w. A force-reduction value (∆F) of the samples was evaluated as a typical mechanical relaxation parameter. ∆F gradually increased with increasing a _w and sharply increased above a specific a _w presumed to be associated with the glass to rubber transition. Compared to ∆F values among the glassy samples, 10 and 20 % trehalose samples had higher ∆F values (were more rigid) than 0 and 5 % trehalose samples. From the fracture measurements of the glassy samples, the first fracture force increased linearly and the number of fracture peaks decreased linearly with increasing a _w. At each a _w, 10 % trehalose had the lowest first fracture force and the highest the number of fracture peaks. Freeze-dried porous waxy corn starch solids showed similar fracture properties to deep-fried samples. These findings suggest that around 10 % trehalose content is optimal for producing deep-fried foods with a brittle texture.

Pulverization is a potentially powerful solution for the resource management of surplus- and non-standard agricultural products, maintaining their nutritional values for long and ensuring their homogeneity, whereas their original textures could disappear to narrow the application ranges. Therefore, new technologies should be developed for reconstructing the powders to provide them with new physical characteristics. Herein, we developed a novel food material, nata puree (NP), by nata de coco (bacterial cellulose gel) disintegration with a water-soluble polysaccharide using a household blender. The process worked well with (1,3)(1,4)-β-glucan (BGL) as the polysaccharide, which could be substituted with barley extract. Lichenase treatment of the NP dramatically modified its physical properties, suggesting the importance of the BGL polymeric forms. NP exhibited distinct potato powder and starch binding activities, which would be attributed to its interactions with the cell wall components and a physical capture of powders by the NP network, respectively. NP supplementation into the potato paste improved its firmness and enabled its printable range shift for 3D food printing to a lower powder-concentration. NP also promoted the dispersion of powders in its suspension, and designed gelation could also be successfully performed by the laser irradiation of an NP suspension containing dispersed curdlan and turmeric powders. Therefore, NP could be applied as a powder modifier to a wide range of products in both conventional cooking, food manufacturing, and next generation processes such as 3D food printing.

Carbohydrate materials that produce lower postprandial blood glucose increase are required for diabetic patients. To develop slowly digestible carbohydrates, the effect of degree of polymerization (DP) of α-1,6 glucan on its digestibility was investigated in vitro and in vivo. We prepared four fractions of α-1,6 glucan composed primarily of DP 3-9, DP 10-30, DP 31-150, and DP 151+ by fractionating a dextran hydrolysate. An in vitro experiment using digestive enzymes showed that the glucose productions of DP 3-9, DP 10-30, DP 31-150, and DP 151+ were 70.3, 53.4, 28.2, and 19.2 % in 2 h, and 92.1, 83.9, 39.6, and 33.3 % in 24 h relative to dextrin, respectively. An in vivo glycemic response showed that the incremental area under the curve (iAUC) of blood glucose levels of α-1,6 glucan with DP 3-9, DP 10-30, DP 31-150, and DP 151+ were 99.5, 84.3, 65.4, and 40.1 % relative to dextrin, respectively. These results indicated that α-1,6 glucan with higher DP had stronger resistance to digestion and produced a smaller blood glucose response. DP 10-30 showed significantly lower maximum blood glucose levels than dextrin; however, no significant difference was observed in iAUC, indicating that DP 10-30 was slowly digestible. In addition, α-1,6 glucan was also produced using an enzymatic reaction with dextrin dextranase (DDase). This produced similar results to DP 10-30. The DDase product can be synthesized from dextrin at low cost. This glucan is expected to be useful as a slowly digestible carbohydrate source.

Erianthus arundinaceus (ER) is greatly appreciated among domestic energy crops in Japan for the production of fermentable sugars from lignocellulosic polysaccharides. In this study, we developed an efficient Ca(OH)₂-based pretreatment of both stems and leaves of ER at ambient temperature with the addition of a washing step for enzymatic saccharification. The recoveries of glucans and xylans in the pretreated ER after four countercurrent washing cycles were 91 and 76 %, respectively, the former being considerably higher than that of rice straw (RS) (72 %). Their saccharification ratios in the washed sample under the pressure of 1 atm CO₂ were 80 and 92.5 %, respectively. The application of this simple sugar production process from ER would further support the domestic bioprocess development. ER is also foreseen to provide the additional feedstock favorable for harvesting from winter to spring in Japan, preventing a risk for feedstock shortage generated by single harvesting such as RS.

We recently characterized a 3-O-α-D-galactosyl-α-L-arabinofuranosidase (GAfase) for the release of α-D-Gal-(1→3)-L-Ara from gum arabic arabinogalactan protein (AGP) in Bifidobacterium longum subsp. longum JCM7052. In the present study, we cloned and characterized a neighboring α-galactosidase gene (BLGA_00330; blAga3). It contained an Open Reading Frame of 2151-bp nucleotides encoding 716 amino acids with an estimated molecular mass of 79,587 Da. Recombinant BlAga3 released galactose from α-D-Gal-(1→3)-L-Ara, but not from intact gum arabic AGP, and a little from the related oligosaccharides. The enzyme also showed the activity toward blood group B liner trisaccharide. The specific activity for α-D-Gal-(1→3)-L-Ara was 4.27- and 2.10-fold higher than those for melibiose and raffinose, respectively. The optimal pH and temperature were 6.0 and 50 °C, respectively. BlAga3 is an intracellular α-galactosidase that cleaves α-D-Gal-(1→3)-L-Ara produced by GAfase; it is also responsible for a series of gum arabic AGP degradation in B. longum JCM7052.