Luonnonväriaineet

Kirja esittelee luonnonväriaineiden tarjoamia mahdollisuuksia erityisesti tekstiilisovellutuksissa, kuten värjäämisessä ja kankaan kuvioimisessa. Teoksessa keskitytään väriainelähteisiin, jotka kasvavat Suomen luonnossa tai soveltuvat viljeltäviksi ainakin maan eteläisissä osissa. Lukijalle esitellään eri lähteistä saatavat värisävyt sekä annetaan ohjeita värjäykseen ja kankaanpainantaan. Perinteisesti luonnonväriaineet on yhdistetty pienimuotoiseen käsityöläisyyteen, mutta nykyään niitä voidaan hyödyntää jopa teollisen mittakaavan tuotannossa. Kirjassa pohditaan monipuolisesti luonnonväriaineiden ominaisuuksia, kuten ekologisuutta, UV-suojaavuutta ja antimikrobiaalisuutta. Teos sopii tietokirjaksi ja värjäysoppaaksi luonnonväriaineista kiinnostuneille sekä oppimateriaaliksi taide- ja käsityöalan koulutuksiin

Examining Safety of Biocolourants from Fungal and Plant Sources-Examples from Cortinarius and Tapinella, Salix and Tanacetum spp. and Dyed Woollen Fabrics

Biocolourants have been investigated as alternatives to synthetic dyes. However, natural origin per se is not a label of harmlessness and research is needed to obtain safe dyes. We studied the cytotoxicity of the extracts from fungal (Cortinarius semisanguineus, Tapinella atrotomentosa) and plant (Tanacetum vulgare, Salix phylicifolia) sources and the woollen fabrics dyed with the extracts. Cytotoxicity in vitro using hepa-1 mouse hepatoma cells for 24 h and 72 h exposure was observed as the highest tolerated dose. All biocolourants produced intensive colour on fabrics with fastness properties from moderate to good. The Salix and Cortinarius samples did not show any cytotoxic effects, whereas the Tanacetum and Tapinella samples had slightly higher test values but were not interpreted as being significantly toxic. Higher than zero values of the undyed fabrics showed the importance of examining their toxicity as well. It was found that the cytotoxicity of the samples dyed with the biocolourants did not differ significantly from the undyed wool fabric. The concentrations of dyes used in the assays were very low, imitating the dose of the user. In addition to colouring properties, natural dyes may have pharmaceutical and antibacterial properties which would enhance the interest in using them in products for added value

Metabolic and molecular analysis of white mutant Vaccinium berries show down-regulation of MYBPA1-type R2R3 MYB regulatory factor

Main conclusion MYBPA1-type R2R3 MYB transcription factor shows down-regulation in white mutant berries of Vaccinium uliginosum deficient in anthocyanins but not proanthocyanidins suggesting a role in the regulation of anthocyanin biosynthesis. Berries of the genus Vaccinium are among the best natural sources of flavonoids. In this study, the expression of structural and regulatory flavonoid biosynthetic genes and the accumulation of flavonoids in white mutant and blue-colored wild-type bog bilberry (V. uliginosum) fruits were measured at different stages of berry development. In contrast to high contents of anthocyanins in ripe blue-colored berries, only traces were detected by HPLC-ESI-MS in ripe white mutant berries. However, similar profile and high levels of flavonol glycosides and proanthocyanidins were quantified in both ripe white and ripe wild-type berries. Analysis with qRT-PCR showed strong down-regulation of structural genes chalcone synthase (VuCHS), dihydroflavonol 4-reductase (VuDFR) and anthocyanidin synthase (VuANS) as well as MYBPA1-type transcription factor VuMYBPA1 in white berries during ripening compared to wild-type berries. The profiles of transcript accumulation of chalcone isomerase (VuCHI), anthocyanidin reductase (VuANR), leucoanthocyanidin reductase (VuLAR) and flavonoid 3′5′ hydroxylase (VuF3′5′H) were more similar between the white and the wild-type berries during fruit development, while expression of UDP-glucose: flavonoid 3-O-glucosyltransferase (VuUFGT) showed similar trend but fourfold lower level in white mutant. VuMYBPA1, the R2R3 MYB family member, is a homologue of VmMYB2 of V. myrtillus and VcMYBPA1 of V. corymbosum and belongs to MYBPA1- type MYB family which members are shown in some species to be related with proanthocyanidin biosynthesis in fruits. Our results combined with earlier data of the role of VmMYB2 in white mutant berries of V. myrtillus suggest that the regulation of anthocyanin biosynthesis in Vaccinium species could differ from other species studied

Biocolourants from onion crop side streams and forest mushroom for regenerated cellulose fibres

Biocolourants and sustainable textile materials have gained growing interest. Traditionally natural dyes have been used for dyeing wool and silk, but demand for cotton and regenerated cellulose fibres increases because of their popularity especially in clothing. This study expands the natural dye research to one of the latest innovations among regenerated cellulosic fibres, i.e. Ioncell®. It explains for the first time the dyeability of Ioncell–F fibres with biocolourants and compares the results with three other regenerated cellulose fibres, i.e. viscose, bamboo viscose and lyocell, using protein fibre wool as a reference. The colourants from the food side stream, the yellow onion (Allium cepa cv. Settonia) and the forest mushroom Cortinarius semisanguineus were used as dyes. The composition of colourants in each dye sources was analyzed in detail. Methods of exhaust dyeing (80 °C, 1 h), with alum, FeSO4 and tannin as mordants, and the high temperature high pressure dyeing (130 °C, 1 h) were applied. The colour of the dyed materials was studied as CIE L*, a*, b*, C*ab, hab and the K/S (λ420/480 nm) values. The colourfastness to washing and light was examined according to the ISO standards. The results showed that for regenerated cellulose fibres the strongest colour was obtained with polyphenols in acidic conditions, whereas with the anthraquinones the dyeing results remained light revealing hindering forces between the dye and the fibre. The colourfastness values were at highest for iron and aluminium mordanted samples, which indicate the metal ions’ ability to stabilize the organic compound’s structure and form strong coordination bonding between the fibre and the dye. The colourfastness varied from poor to moderate. The exhaustion levels between different regenerated cellulose fibres varied very little. The search for sustainable colourants, fibres and their applications in long lifetime artefacts is strongly supported by the sustainability goals, and colourant production in connection with forest and agricultural industries support this emerging field.Peer reviewe

Phenolic compounds and antioxidant capacity in different-colored and non-pigmented berries of bilberry (Vaccinium myrtillus L.)

Strnad, Miroslav/0000-0002-2806-794X; Gruz, Jiri/0000-0002-8546-9697; GRUZ, Jiri/0000-0002-8546-9697WOS: 000416708300010Bilberries and their products are popular worldwide and represent a very interesting source of dietary antioxidants. Berries of eight different-colored and non-pigmented bilberry (Vaccinium myrtillus L.) samples from Finland were evaluated in terms of antioxidant capacity and total phenolic compounds (range, 220.06 - 3715.21 mg/100 g dw) and total monomeric anthocyanin (range, 206.18 - 867.52 mg/100 g dw) contents. Delphinidin (range, 5915.93-18108.39 mu g/g dw) was the major anthocyanin moiety, while sinapic acid was the major phenolic acid in the free form (range, 0.01 - 6.06 mu g/g dw), and p-coumaric acid in the ester (range, 26.39 - 110.78 mu g/g dw), glycoside (range, 15.83 - 57.73 mu g/g dw) and ester-bound (range, 2.32 - 14.20 mu g/g dw) forms. The white colored berry samples did not contain any anthocyanins, but the colored berries did contain them. Antioxidant capacity was much higher in colored (pink to blue/black) berry samples than in the white sample, and it was more related to the total phenolic concentration rather than to the anthocyanin concentration. This is the first time that these different-colored berry phenotypes of bilberry (V. myrtillus L.) have been analyzed within the same study