Intake and sources of dietary fibre and dietary fibre fractions in Finnish children.

The current definition of dietary fibre was adopted by the Codex Alimentarius Commission in 2009, but implementation requires updating food composition databases with values based on appropriate analysis methods. Previous data on population intakes of dietary fibre fractions are sparse. We studied the intake and sources of total dietary fibre (TDF) and dietary fibre fractions insoluble dietary fibre (IDF), dietary fibre soluble in water but insoluble in 76 % aqueous ethanol (SDFP) and dietary fibre soluble in water and soluble in 76 % aqueous ethanol (SDFS) in Finnish children based on new CODEX-compliant values of the Finnish National Food Composition Database Fineli. Our sample included 5193 children at increased genetic risk of type 1 diabetes from the Type 1 Diabetes Prediction and Prevention birth cohort, born between 1996 and 2004. We assessed the intake and sources based on 3-day food records collected at the ages of 6 months, 1, 3 and 6 years. Both absolute and energy-adjusted intakes of TDF were associated with age, sex and breast-feeding status of the child. Children of older parents, parents with a higher level of education, non-smoking mothers and children with no older siblings had higher energy-adjusted TDF intake. IDF was the major dietary fibre fraction in non-breastfed children, followed by SDFP and SDFS. Cereal products, fruits and berries, potatoes and vegetables were major food sources of dietary fibre. Breast milk was a major source of dietary fibre in 6-month-olds due to its human milk oligosaccharide content and resulted in high SDFS intakes in breastfed children.

Sprouts and Needles of Norway Spruce (Picea abies (L.) Karst.) as Nordic Specialty-Consumer Acceptance, Stability of Nutrients, and Bioactivities during Storage.

Developing shoots, i.e., sprouts, and older needles of Norway spruce (Picea abies (L.) Karst.) have traditionally been used for medicinal purposes due to the high content of vitamins and antioxidants. Currently, sprouts are available as, for example, superfood and supplements. However, end-product quality and nutritive value may decline in the value-chain from raw material sourcing to processing and storage. We studied (1) impacts of different drying and extraction methods on nutritional composition and antioxidative properties of sprouts and needles, (2) differences between sprouts and needles in nutritional composition and microbiological quality, and (3) production scale quality of the sprouts. Additionally, (4) sprout powder was applied in products (ice-cream and sorbet) and consumer acceptance was evaluated. According to our results, older needles have higher content of dry matter, energy, and calcium, but lower microbial quality than sprouts. Sprouts showed a higher concentration of vitamin C, magnesium, potassium, and phosphorus than older needles. Freeze-drying was the best drying method preserving the quality of both sprouts and needles, e.g., vitamin C content. The antioxidative activity of the sprout extracts were lower than that of needles. Ethanol-water extraction resulted in a higher content of active compounds in the extract than water extraction. Sensory evaluation of food products revealed that on average, 76% of consumers considered sprout-containing products very good or good, and a creamy product was preferred over a water-based sorbet.

Presence of 1-->3-linked 2-O-beta-d-xylopyranosyl-alpha-l-arabinofuranosyl side chains in cereal arabinoxylans.

The presence of a fairly uncommon side chain 2-O-beta-D-xylopyranosyl-alpha-L-arabinofuranosyl in arabinoxylans (AX) from eight different cereal by-products was investigated, using (1)H NMR spectroscopy and high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) after Shearzyme (GH10 endo-1,4-beta-D-xylanase) hydrolysis. This disaccharide side group was present in significant amounts in AX extracted from corn cobs and barley husks. For the first time, it was also detected in AX from oat spelts and rice husks, and in lesser amounts in wheat straw AX. Arabinoxylo-oligosaccharide (AXOS) containing the 2-O-beta-D-Xylp-alpha-L-Araf side chain was purified from the oat spelt AX hydrolysate and the structure was fully analyzed using 1D and 2D NMR spectroscopy. The AXOS was identified as beta-D-Xylp-(1-->2)-alpha-L-Araf-(1-->3)-beta-D-Xylp-(1-->4)-D-Xyl. To our knowledge, such a structure with 2-O-beta-D-Xylp-alpha-L-Araf attached to the O-3 of the nonreducing end of xylobiose has not been described previously. New information on substitution of AX from various cereal by-products was obtained by combining NMR and enzyme-assisted HPAEC-PAD analysis.

In vitro fermentation of arabinoxylan-derived carbohydrates by bifidobacteria and mixed fecal microbiota.

Bifidobacterium adolescentis ATCC 15703, Bifidobacterium breve ATCC 15700, Bifidobacterium longum ATCC 15707, and human fecal microbiota were cultivated in vitro with d-xylose, l-arabinose, xylo-oligosaccharides (XOS), and arabinoxylo-oligosaccharides (AXOS) as carbon sources. The pH, formation of volatile fatty acids, and carbohydrate utilization profiles were followed. In the pure bifidobacteria cultures optical density and in the fecal slurries pressure and H(2) were also detected. A differing substrate preference was observed among the various bifidobacteria strains. B. adolescentis grew on XOS, slowly on d-xylose, but not on l-arabinose. In contrast, B. longum preferred l-arabinose and did not grow on pure d-xylose or XOS. Both strains were able to utilize AXOS but with differing strategies, since after the cleavage of l-arabinose B. adolescentis consumed the XOS formed, whereas B. longum fermented the l-arabinose released. B. breve grew poorly on all of the substrates provided. A bifidobacterial mixture and the fecal microbiota were able to utilize pure singly substituted AXOS almost completely, but pure AXOS with a doubly substituted xylose residue was fermented only by the fecal microbiota. Thus, AXOS appear to be potential candidates for slowly fermenting prebiotics, but their prebiotic effects may be dependent on the type of arabinose substitution and the presence of other carbohydrates.

Step-wise enzymatic preparation and structural characterization of singly and doubly substituted arabinoxylo-oligosaccharides with non-reducing end terminal branches.

Shearzyme (GH10 endo-1,4-beta-D-xylanase) and two different alpha-L-arabinofuranosidases (AXH-m and AXH-d3) were used stepwise to manufacture arabinoxylo-oligosaccharides (AXOS) with alpha-L-Araf (1-->2)-monosubstituted beta-D-Xylp residues or alpha-L-Araf (1-->2)- and (1-->3) doubly substituted beta-D-Xylp residues from wheat arabinoxylan (AX) in a rather straightforward way. Four major AXOS (d-I, d-II, m-I and m-II) were formed in two separate hydrolyses. The AXOS were purified and the structures were confirmed using TLC, HPAEC-PAD, MALDI-TOF-MS and 1D and 2D NMR spectroscopy. The samples were identified as d-I: alpha-L-Araf-(1-->2)-[alpha-L-Araf-(1-->3)]-beta-D-Xylp-(1-->4)-beta-D-Xylp-(1-->4)-D-Xylp, d-II: alpha-L-Araf-(1-->2)-[alpha-L-Araf-(1-->3)]-beta-D-Xylp-(1-->4)-D-Xylp, m-I: alpha-L-Araf-(1-->2)-beta-D-Xylp-(1-->4)-beta-D-Xylp-(1-->4)-D-Xylp and m-II: alpha-L-Araf-(1-->2)-beta-D-Xylp-(1-->4)-D-Xylp. To our knowledge, this is the first report on structural (1)H and (13)C NMR analysis of xylobiose-derived AXOS d-II and m-II. The latter compound has not been reported previously. The doubly substituted AXOS were produced for the first time in good yields, as d-I and d-II corresponded to 11.8 and 5.6 wt% of AX, respectively. Singly alpha-L-Araf (1-->2)-substituted AXOS could also be prepared in similar yields by treating the doubly substituted AXOS further with AXH-d3.