Eco Printing of Linen and Tencel Substrates with Onion Skins and Red Cabbage

Red cabbage (RC) and purple sweet potato (PSP) are naturally rich in acylated cyanidin glycosides that can bind metal ions and develop intramolecular π-stacking interactions between the cyanidin chromophore and the phenolic acyl residues. In this work, a large set of RC and PSP anthocyanins was investigated for its coloring properties in the presence of iron and aluminum ions. Although relatively modest, the structural differences between RC and PSP anthocyanins, i.e., the acylation site at the external glucose of the sophorosyl moiety (C2-OH for RC vs. C6-OH for PSP) and the presence of coordinating acyl groups (caffeoyl) in PSP anthocyanins only, made a large difference in the color expressed by their metal complexes. For instance, the Al3+-induced bathochromic shifts for RC anthocyanins reached ca. 50 nm at pH 6 and pH 7, vs. at best ca. 20 nm for PSP anthocyanins. With Fe2+ (quickly oxidized to Fe3+ in the complexes), the bathochromic shifts for RC anthocyanins were higher, i.e., up to ca. 90 nm at pH 7 and 110 nm at pH 5.7. A kinetic analysis at different metal/ligand molar ratios combined with an investigation by high-resolution mass spectrometry suggested the formation of metal–anthocyanin complexes of 1:1, 1:2, and 1:3 stoichiometries. Contrary to predictions based on steric hindrance, acylation by noncoordinating acyl residues favored metal binding and resulted in complexes having much higher molar absorption coefficients. Moreover, the competition between metal binding and water addition to the free ligands (leading to colorless forms) was less severe, although very dependent on the acylation site(s). Overall, anthocyanins from purple sweet potato, and even more from red cabbage, have a strong potential for development as food colorants expressing red to blue hues depending on pH and metal ion.

Download Full-text

Novel konjac glucomannan films with oxidized chitin nanocrystals immobilized red cabbage anthocyanins for intelligent food packaging

Food Hydrocolloids ◽

10.1016/j.foodhyd.2019.105245 ◽

2020 ◽

Vol 98 ◽

pp. 105245 ◽

Cited By ~ 20

Author(s):

Chunhua Wu ◽

Yaoling Li ◽

Jishuai Sun ◽

Yinzhu Lu ◽

Cailing Tong ◽

...

Keyword(s):

Food Packaging ◽

Konjac Glucomannan ◽

Red Cabbage

Download Full-text

Young shoots of red cabbage are a better source of selected nutrients and glucosinolates in comparison to the vegetable at full maturity

European Food Research and Technology ◽

10.1007/s00217-020-03593-x ◽

2020 ◽

Vol 246 (12) ◽

pp. 2505-2515

Author(s):

Mariola Drozdowska ◽

Teresa Leszczyńska ◽

Aneta Koronowicz ◽

Ewelina Piasna-Słupecka ◽

Dominik Domagała ◽

...

Keyword(s):

Cruciferous Vegetables ◽

Human Diet ◽

Red Cabbage ◽

Anticancer Properties ◽

Fatty Acids Profile ◽

Fresh Food ◽

Calcium Magnesium ◽

First Time ◽

Intensive Growth ◽

Full Maturity

AbstractCruciferous vegetables are a valuable source of ingredients with health benefits. The most characteristic compounds of cruciferous vegetables with identified anticancer properties are glucosinolates. Young shoots and sprouts of red cabbage are becoming a popular fresh food rich in nutrients and bioactive compounds. The objective of this research was to determine, for the first time in a comprehensive approach, whether young shoots of red headed cabbage are a better source of selected nutrients and glucosinolates in the human diet in comparison to the vegetable at full maturity. The proximate composition (protein, fat, digestible carbohydrates, fiber), fatty acids profile, minerals (calcium, magnesium, potassium, sodium, iron, zinc, manganese, copper), as well as glucosinolates were examined. The red headed cabbage was characterized by a significantly larger amount of dry matter, and total and digestible carbohydrates in comparison to young shoots. The ready-to-eat young shoots, which are in the phase of intensive growth, are a better source of protein, selected minerals, and especially glucosinolates. The level of some nutrients can be enhanced and the intake of pro-healthy glucosinolates can be significantly increased by including young shoots of red cabbage into the diet.

Download Full-text