Preparation, structural analysis and prebiotic potential of arabinoxylo-oligosaccharides

Arabinoxylo-oligosaccharides (AXOS) can be prepared enzymatically from arabinoxylans (AX) and AXOS are known to possess prebiotic potential. Here the structural features of 10 cereal AX were examined. AX were hydrolysed by Shearzyme® to prepare AXOS, and their structures were fully analysed. The prebiotic potential of the purified AXOS was studied in the fermentation experiments with bifidobacteria and faecal microbiota. In AX extracted from flours and bran, high amounts of a-L-Araf units are attached to the b-D-Xylp main chain, whereas moderate or low degree of substitution was found from husks, cob and straw. Nuclear magnetic resonance (NMR) spectroscopy showed that flour and bran AX contain high amounts of a-L-Araf units bound to the O-3 of b-D-Xylp residues and doubly substituted b-D-Xylp units with a-L-Araf substituents at O-2 and O-3. Barley husk and corn cob AX contain high amounts of b-D-Xylp(1→2)-a-L-Araf(1→3) side chains, which can also be found in AX from oat spelts and rice husks, and in lesser amounts in wheat straw AX. Rye and wheat flour AX and oat spelt AX were hydrolysed by Shearzyme® (with Aspergillus aculeatus GH10 endo-1,4-b-D-xylanase as the main enzyme) for the production of AXOS on a milligram scale. The AXOS were purified and their structures fully analysed, using mass spectrometry (MS) and 1D and 2D NMR spectroscopy. Monosubstituted xylobiose and xylotriose with a-L-Araf attached to the O-3 or O-2 of the nonreducing end b-D-Xylp unit and disubstituted AXOS with two a-L-Araf units at the nonreducing end b-D-Xylp unit of xylobiose or xylotriose were produced. Xylobiose with b-D-Xylp(1→2)-a-L-Araf(1→3) side chain was also purified. These AXOS were used as standards in further identification and quantification of corresponding AXOS from the hydrolysates in high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) analysis. The prebiotic potential of AXOS was tested in in vitro fermentation experiments. Bifidobacterium adolescentis ATCC 15703 and B. longum ATCC 15707 utilized AXOS from the AX hydrolysates. Both species released L-arabinose from AXOS, but B. adolescentis consumed the XOS formed, whereas B. longum fermented the L-arabinose released. The third species tested, B. breve ATCC 15700, grew poorly on these substrates. When cultivated on pure AXOS, the bifidobacterial mixture utilized pure singly substituted AXOS almost completely, but no growth was detected with pure doubly substituted AXOS as substrates. However, doubly substituted AXOS were utilized from the mixture of xylose, XOS and AXOS. Faecal microbiota utilized both pure singly and doubly substituted AXOS. Thus, a mixture of singly and doubly substituted AXOS could function as a suitable, slowly fermenting prebiotic substance. This thesis contributes to the structural information on cereal AX and preparation of mono and doubly substituted AXOS from AX. Understanding the utilization strategies is fundamental in evaluating the prebiotic potential of AXOS. Further research is still required before AXOS can be used in applications for human consumption.Ravintokuidulla tarkoitetaan hiilihydraatteja, jotka eivät pilkkoudu ja imeydy ihmisen ohutsuolessa mutta fermentoituvat ainakin osittain paksusuolessa. Hemiselluloosia, joista suurimman ryhmän muodostavat ksylaanit, esiintyy kaikissa kasveissa ja ne luokitellaan ravintokuiduiksi. Ksylaanit ovat selluloosan jälkeen kasvikunnan toiseksi yleisimpiä hiilihydraatteja. Pitkäketjuiset ksylaanit koostuvat toisiinsa liittyneistä ksyloosiyksiköistä, joihin on sitoutunut erilaisia sivuryhmiä. Arabinoksylaaneissa (AX), joita esiintyy runsaasti mm. viljakasveissa (< 10 % kokojyvissä ja noin 25-35 % akanoissa, korsissa ja lehdissä), sivuryhmät ovat pääosin arabinoosia, mutta eri kasveista ja kasvinosista eristettyjen ksylaanien kemiallinen rakenne vaihtelee runsaasti. Maataloudessa ja teollisuudessa syntyy hyödyntämättä jäävää biomassaa, josta voidaan eristää suuria määriä arabinoksylaaneja. Koska kasvit ovat uusiutuva luonnonvara ja sivuvirtoja on runsaasti saatavilla, niiden hyödyntämisessä on sekä ekonomisia että ekologisia mahdollisuuksia. Pitkäketjuisia arabinoksylaaneja voidaan pilkkoa valittujen entsyymien avulla hallitusti lyhyemmiksi pätkiksi, joita kutsutaan arabinoksylo-oligosakkarideiksi (AXOS). Oligosakkaridien, kuten frukto-, xylo- ja galakto-oligosakkaridien (FOS, XOS ja GOS), tiedetään lisäävän paksusuolessa terveyttä edistävien maitohappo- ja bifidobakteerien määrää (= prebioottinen vaikutus) ja mahdollisesti suojaavan paksusuolensyövältä fermentoitumisen aikana muodostuvien lyhytketjuisten rasvahappojen avulla. Hitaan fermentoitumisen aikana lyhytketjuisia rasvahappoja syntyy eniten, mutta edellä mainitut suoraketjuiset oligosakkaridit saattavat kuitenkin fermentoitua liian nopeasti. Tämän vuoksi halutaan löytää hitaammin fermentoituvia oligosakkarideja, jollaisia voisivat olla mm. haaroittuneet AXOS:it. Tämän väitöskirjatyön tarkoituksena oli tutkia eri viljoista peräisin olevien pitkäketjuisten AX:ien rakenteita, valmistaa AX:eista lyhytketjuisia AXOS:eja ja tutkia AXOS:ien mahdollisia prebioottisia vaikutuksia. Työssä valmistettiin kuusi rakenteeltaan erilaista AXOS:ia pilkkomalla pitkäketjuista arabinoksylaania entsyymien avulla. AXOSit koostuivat 3-5 sokeriyksiköstä ja niitä pystyttiin valmistamaan hyvillä saannoilla. Tämä on ensimmäinen tutkimus, jossa selvitettiin puhdistettujen AXOS:ien prebioottisia vaikutuksia. Bifidobakteerit pystyivät fermentoimaan osan haaroittuneista AXOS:eista, mutta kaikkein haaroittuneimmat AXOS:it osoittautuivat niille liian haastaviksi. Tutkitut yksittäiset bifidobakteerilajit käyttivät selektiivisesti vain osan AXOS:ien sokeriyksiköistä, mutta useat bifidobakteerilajit yhdessä pystyivät fermentoimaan sekä AXOS:ien sisältämät ksyloosi- että arabinoosiyksiköt. AXOS:ien fermentoitumista tutkittiin myös sekapopulaatioilla ulostekasvatusten avulla. Ulosteen sisältämät mikrobit pystyivät fermentoimaan kaikki AXOS:it täydellisesti ja AX:it lähes kokonaan. Tämän työn perusteella voidaan sanoa, että prebioottisesti vaikuttavan tuotteen tulisi sisältää eriasteisesti haaroittuneita AXOSeja sekä mahdollisesti pitkäketjuisia AX:ja, joista suolistossa muodostuu AXOS:ja mikrobien vaikutuksesta. Ennen kuin AXOS:eja voidaan hyödyntää ihmisen ravinnossa, tarvitaan kuitenkin vielä lisää tutkimusta niiden ominaisuuksista ja fysiologisista vaikutuksista

Dietary fibre in legumes, seeds, vegetables, fruits and mushrooms : Comparing traditional and semi-automated filtration techniques

The method AOAC 2011.25 was used to analyze all the dietary fibre (DF) components included in the latest definition by the Codex Alimentarius Commission (2009). The traditional filtration technique, described in the method AOAC 2011.25, was compared with a new semi-automated filtration technique using Fibertec" 1023 system. For the comparisons, a statistical similarity approach was chosen to evaluate the results of six food matrixes (wheat flour, edible boletus, strawberry, tomato, green pea and horse radish). The total DF contents of the tested matrixes fit within 16% tightest data-induced similarity limit of the manual mean, with one exception (strawberry; 30%). Thus, it was concluded that both techniques are suitable for use with the method AOAC 2011.25, and therefore either technique was used to analyze a wide selection of legumes, seeds, vegetables, fruits and mushrooms (44 foods). Seeds were excellent sources of total DF, as well as water-insoluble (IDF) and water-soluble (SDFP) polysaccharides. A substantial amount of oligosaccharides (SDFS) was found in red onions. Generally, the DF contents were higher in this study than in earlier studies. Higher DF results can be partially explained by the more effective analytical method, and partly by changed varieties.Peer reviewe

The nitrogen-to-protein conversion factor of two cricket species - Acheta domesticus and Gryllus bimaculatus

The Kjeldahl method is the most utilized method for total protein content analysis in food. Using the universal nitrogen-to-protein conversion factor of 6.25, the protein content of insects is likely to be overestimated due to their chitin content. We have calculated nitrogen-to-protein conversion factors for two crickets, house cricket (Acheta domesticus) and field cricket (Gryllus bimaculatus), which are used for food and feed in Europe. By analyzing their nitrogen and amino acid content we were able to show that a conversion factor of 5.09 could be used for house cricket and 5.00 for field cricket in protein content calculation. Based on these results with a reservation about slight variation in farming conditions, we suggest a nitrogen conversion factor of 5.0 for both crickets

Perceptions and practices of Finnish dairy producers regarding disbudding of calves

We designed and mailed a questionnaire to 1000 Finnish dairy producers and published the same questionnaire on the internet. A total of 451 questionnaires (45 %) were returned from the random sample and 738 dairy producers responded in the internet. Thus, we got responses from 10,6 % of all 11244 dairy farms in Finland. We found out that 84 % of Finnish dairy producers disbud their calves, and 69 % of these farms use a veterinarian at least sometimes to medicate their calves prior to disbudding

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

Nordic co-operation on food information : Activities of the Nordic Food Analysis Network 2013–2016

Quality of food composition information is of great significance considering the vast and important use of the data: for national dietary advice, for food nutrient labelling, and in epidemiological research. In order to have good quality data for foods consumed in the Nordic countries, sampling and analysis of food needs to be performed to determine the nutrient composition of interest. The Nordic Food Analysis Network project (NFAN), that was carried out between 2013–2016, focused on creating a common, simple communicational platform to share history and plans on chemical food analyses. In addition, it focused on sharing developments in the areas of new analytical methods, especially of dietary fibre, iodine and sodium (i.e. salt). An extranet site was set up, where partners updated their chemical food analysis activities, for others to observe and be aware of. The platform was found to be informative, although updating it was sometimes found to be cumbersome or forgotten. This kind of activity needs active coordination to become useful. Also, comparative analyses of fibre, iodine and sodium concentrations of selected Nordic foods were carried out with external funds and the results were shared, discussed and disseminated among the project group and a broader audience. The comparative analyses showed diverging results, even when the same analytical methods and procedures are used. A comparison, organized by the network, of the conditions in the different countries, showed several reasons for this. The main reasons for different nutrient compositions between the countries was found to be differences in fortification programmes and in animal feeding practices between the countries. The NFAN network organized three physical meetings and one open satellite symposium during the project, which served as platforms to update the partners on national developments in the field and discuss future visions – even wild ideas. The meetings were highly appreciated, partly due to the fact that the critical mass of competence, both for food composition data compilers and food chemists at the national level, in all Nordic countries, is declining. The discussions not only focused on the tasks of this project, but also served as a forum to discuss the broader challenges in the area as well as strategies to better disseminate food data and how to improve the dialogue between data providers from the food industry, and the data users and other stakeholders. For future actions, the Network has recommended that: 1) The Nordic countries should continue to keep each other informed about chemical food analysis plans to facilitate possible common analyses and to facilitate other synergistic activities and method development. Moreover, there is a continuous need for a well-structured and simple-to-use communicational platform in the future, where all the information is stored and updated. 2) New chemical analysis data should be compiled in the food composition databases and be more widely used in the future. 3) The background information on the analysed nutrient values, e.g. the sampling procedures, methods, sample description (e.g. fortification practices, animal feeding practices in the country) are crucial for the data users, and therefore, should be disseminated together with the values. 4) A common Nordic training programme for young actors in the fields of chemical food analysis and food composition data compilation should be considered, to assure high quality outputs, in the future. 5) Harmonization efforts for the production of food composition information, according to established guidelines (e.g. Greenfield & Southgate, 2003) and updated rules to calculate the activity of nutrients (Institute of Medicine 2000, Nordic Council of Ministers 2012), should be continued. 6) Re-evaluation of the rules and procedures for use of existing food composition data should be carried out. This could be done by performing an updated evaluation on the handling of the nutrient values, i.e. to carry out an update of the former Norfoods 2000 project (Norfoods 2000-project group, 2002)

Are gluten-free products a healthier alternative? : A pilot study on nutrients and heavy metals​

With the aim to improve knowledge on the content of nutrients and heavy metals in gluten-free products, this pilot study, was carried out between 2017 and 2020. Nutrients and heavy metals were analysed in 37 gluten-free products. For statistical comparisons, similar data was collected for gluten-containing branded products and generic products from Nordic food composition databases (n=163).In conclusion, the gluten-free products contained significantly less protein, copper, potassium, phosphorus, zinc, and manganese, whereas the contents of starch, chromium, nickel and lead were significantly higher than the included gluten-containing products. Considering the nutritional composition, gluten-free products are not healthier compared to similar gluten-containing products. In addition, the content of some heavy metals is higher in the gluten-free products studied

Vasikan uni hyvinvointitutkimuksissa

Riittävä uni on tärkeää vasikan hyvinvoinnille. Erityisen tärkeää uni ja lepo ovat nuorille kasvaville eläimille, joiden aivot kehittyvät vielä. Uni ja leporytmin muutokset ovat uusimpia hyvinvointia kuvaavia mittareita.Tuotantotiloilla saattaa olla pikkuvasikan uneen merkittävä vaikutus, sillä epämiellyttävät&nbsp; ympäristöolosuhteet voivat heikentää unen laatua. Useat erilaiset ympäristötekijät vaikuttavat yksilön uneen, samoin kipu. Kivuliaan yksilön uni sirpaloituu ja kipu heikentää unen laatua, kun taas unen puute vahvistaa kipukokemusta. Tuotantoeläinten unesta ja kivusta ei ole tehty tieteellisiä tutkimuksia. Tähän asti vasikan unta on tuotantoympäristöissä voitu mitata vain kannettavalla EEG-laitteistolla tai tarkkailemalla eläinten käytöstä. EEG-laitteisto on kallis ja häiritsee eläintä. Käyttäytymistarkkailu puolestaan vie paljon aikaa. Tavoitteenamme oli kehittää langaton mittalaite, aktigrafi, vasikan unen mittaamiseen.Kiinnitimme kevyen, langattoman kiihtyvyysanturin 10 vasikan kaulapantaan. Vasikat olivat alle 6 viikon ikäisiä ja ne pidettiin tutkimuksen ajan olkikuivitetussa ryhmäkarsinassa. Laite kiihtyvyyden kolmen akselin suhteen 25 Hz taajuudella ja 2 g:n mittausalueella. Videoimme vasikoiden käytöstä yhtäjaksoisesti 24 tunnin ajan ja rekisteröimme keskimääräisen päivittäisen keston kokonaisuniajalle sekä, vilkeunelle (REM) ja hidasaaltounelle (NREM) vasikan lepoasennoista käyttäen CowLog-ohjelmaa.Alustavat tulokset ovat valmiina kuudelta vasikalta. Aluksi unta ennustava malli (SVM luokittelija) kehitettiin kolmella vasikalla ja mallin toimivuus testattiin kolmella muulla vasikalla. Lopulliset tulokset saadaan 10 vasikalta. Aktigrafidatasta unta ennustivat parhaiten mallissa keskimääräinen kiihtyvyys, kiihtyvyyden vaihtelu ja wavelet-varianssi. Mallin antamien ennusteiden ja käyttäytymistarkkailun tulosten eroavaisuutta verrattiin t-testillä.Malli ennusti kokonaisuniajan 93 ∓&nbsp; 3 % tarkkuudella sekä päivittäisen NREM- ja REM-unen määrän 89 ∓&nbsp;9 % ja 83 ∓&nbsp; 2 % tarkkuudella. Kokonaisuniajassa sekä NREM- ja REM-unen kokonaiskestoissa ei ollut tilastollisesti merkitseviä eroja käyttäytymistarkkailun ja unta ennustavan mallin välillä (621 vs. 602 min, 351 vs. 339 min, 316 vs. 351 min).Kehitimme aktigrafin, jolla mitata vasikoiden unikäyttäytymistä langattomasti yhtä tarkasti kuin käyttäytymistä tarkkaillen. Laite mahdollistaa vasikoilla jatkuvan unimittauksen tuotantoolosuhteissa häiritsemättä eläintä