Saponite-anthocyanin derivatives: The role of organoclays in pigment photostability

Abstract

Hybrid pigments based on organo-saponite (cetyltrimethyl ammonium bromide (CTAB-Sap) and a commercial anthocyanin (ACN) dye, Crystal Red Grape, were prepared. The interactions between organic dye guest and hosts (including saponite and organo-saponite) were investigated by X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy. The pigments exhibit different colors function of their host-guest interactions. The blue color of organo-clay-anthocyanin indicates the stabilization of quinoidal base form of the dye. The hybrids have good stability against visible light irradiation and basic pH conditions. These dyed materials are environmentally friendly and can be promising candidates in different application fields.

Nanostructured pH‐Indicator Films Based on Cassava Starch, Laponite, and Jambolan (Syzygium cumini) Fruit Manufactured by Thermo‐Compression

“…[2] In the current research, a reduction in the alteration of a* values in the films suggests that Lap could protect the anthocyanins in the films against visible light irradiation. Similar results were informed in anthocyanins from acerola juice, [15] as well as in dry anthocyanins , [16][17][18] both stabilized with nanoclays.…”

“…[2] A recent alternative to improve the stability of anthocyanins is through their interaction with nanoclays; this approach has been used to stabilize anthocyanins in acerola juice, [15] and most recently to manufacture dry powders containing natural pigments (biohybrids) with potential food and pharmacological applications. [16][17][18] Laponite (Lap) is a nanoclay used to improve physicochemical properties of food packaging materials based on biopolymer [19][20][21][22][23] or to manufacture biohybrids containing anthocyanins. [17] To date, no study has explored the use of nanoclays and particularly the use of Lap to stabilize anthocyanins during the manufacturing process and film application.…”

Uses of Nanoclays and Adsorbents for Dye Recovery: A Textile Industry Review

“…It possesses negatively charged layers that are, in turn, neutralized by other ions with positive Na + Mg 2+ charges. Saponite's cation exchange capacity (CEC) has been quantified as 100 cmol•kg −1 [194][195][196][197][198]. XRD and SEM/EDX characterizations shows the clay mineral has the structural formula INT Na TET [Si 7 Al] OCT [Mg 6 ]O 20 (OH) 4 [199].…”

“…Compared to other nanoclay minerals such as MMT, it can be stated that Sap offers greater thermal stability [201], a smaller particle size (approx. 50 nm) [194][195][196][197][198], and is simpler to delaminate and exfoliate in nanoplate units, or as individual nanolayers in aqueous solution [202]. However, the downside of natural Spa is that it is not abundantly available.…”

Anthocyanin Hybrid Nanopigments from Pomegranate Waste: Colour, Thermomechanical Stability and Environmental Impact of Polyester-Based Bionanocomposites

“…Li et al [21] incorporated ACNs extracted from fresh blue berry fruits into different clay minerals including tubular halloysite, fibrous sepiolite, lamellar kaolinite and montmorillonite to obtain reversible allochronic hybrid pigments. Lima et al [26] developed hybrid pigments based on organo-saponite (cetyltrimethylammonium bromide) and ACNs from red grape. They observed a stabilization of the different chemical structures of ACNs (blue quinoidal base form and red flavylium cation), exhibiting the resulting hybrid reversible acid/base chromism from blue to red and vice versa.…”