POLISH JOURNAL OF FOOD AND NUTRITION SCIENCES

Pol. J. Food Nutr. Sci. 2005, Vol. 14/55, No 2, pp. 107–116

ACYLATED ANTHOCYANINS AS STABLE, NATURAL FOOD COLORANTS – A REVIEW

Anna B¹kowska-Barczak

Department of Fruit, Vegetable and Cereal Technology, Agricultural University, Wroc³aw

Key words: acylated anthocyanins, intramolecular copigmentation, natural food colorants, red cabbage, black carrot

There is a demand for food colorants from natural sources that can serve as alternatives to the use of synthetic dyes due to the consumer con-
cerns over the use of synthetic additives. Documented health benefits of anthocyanin extracts intensified the interest in anthocyanin-rich food.
Anthocyanins, between other benefits, are potent antioxidants and may be useful to cure noninsulin-dependent diabetes.
The finding that anthocyanin pigments containing acyl substituent are incredibly stable opens new opportunities for food producers. The sta-
ble acylated anthocyanins are present in large amounts in vegetables such as: red cabbage, black carrot, red radish, red potatoes or red corn. These
pigments indicate a low sensibility to pH changes and an increased heat and light stability. For this reason, acylated anthocyanins are suitable to
be applied not only for food with low pH but also for neutral and slightly alkaline products (dairy products, powdered and ready-to-eat desserts).

INTRODUCTION R

An attractive and stable colour is important in the mar- 3' OH

ketability of foods and beverages. Synthetic coloring agents +
B
have commonly been used in the food industry. The safety HO O 5'
7
of synthetic dyes, however, has been questioned, leading to R
A
a reduction in the number of permitted colorants. Due to 3
this limitation and the worldwide tendency towards the con- 5 OH
sumption of natural products, the interest in natural col-
orants has increased significantly. However, replacing syn- OH
thetic dyes with natural colorants poses a challenge due to
the higher stability of synthetic colorants with respect to Substitution Visible max
light, oxygen, temperature and pH, among other factors. Name Visible colour (nm) in
R3’ R5’
MeOH-HCL
ANTHOCYANIN COMPOUNDS Pelargonidin H H red 520
Cyanidin OH H magenda 535
Anthocyanins demonstrate a high potential to be used Delphinidin OH OH purple 546
as natural colorants due to their attractive orange, red and Peonidin OCH3 H magenda 532
purple colours and water solubility that allows their incor- Petunidin OCH3 OH purple 543
poration into aqueous food systems [Brouillard, 1982; Malvidin OCH3 OCH3 purple 542
Mazza & Miniati, 1993; Shahidi & Naczk, 1995]. Antho- FIGURE 1. Basic structure of anthocyanins in flavylium cation (adop-
cyanins belong to the widespread class of phenolic com- ted from [Mazza & Miniati, 1993]).
pounds collectively named flavonoids. They are glycosides
of polyhydroxy and polymethoxy derivatives of 2-phenyl- Besides the C-3 position, other sugars can also be attached
benzopyrylium salts (Figure 1) [Brouillard, 1982]. Antho- at any one of the hydroxyls at C-5, C-7, C-3’, C-5’, and even
cyanins occurring in nature contain several anthocyanidins C-4’ [Brouillard, 1982; Mazza & Miniati, 1993; Wilska-
or aglycones, but only six are common in foods – cyanidin, -Jeszka, 1994; Zaj¹c & Wilska-Jeszka, 1991, 1994]. Usually
peonidin, pelargonidin, malvidin, delphinidin, and petuni- anthocyanidin glycosides are 3-monosides and 3, 5-diglyco-
din [Cooper-Driver, 2001; Horuba³a, 1996; Kong et al., sides. Sometimes 3, 7-diglycosides or 3-triglycosides are also
2003]. In general, anthocyanidins are less soluble than their known to occur [Clifford, 2000]. The most common sugar is
corresponding glycosides (anthocyanins) and they are not, glucose, but rhamnose, xylose, galactose, arabinose, and
therefore, found in nature [Brouillard, 1982; von Elbe & fructose as well as rutinose (6-O-a-L-rhamnosyl-D-glu-
Schwartz, 1996]. With a few exceptions anthocyanins are cose), sophorose (2-O-b-D-xylosyl-D-glucose), gentobiose
always glycosylated at C-3 position [Takeoka & Dao, 2002]. (6-O-b-D-glucosyl-D-glucose), sambubiose (2-O-b-D-xylo-

Author’s address for correspondence: Anna B¹kowska, Department of Fruit, Vegetable and Cereals Technology, Agricultural University of Wro-
c³aw, ul. Norwida 25, 50-375 Wroc³aw, Poland; tel.: (48 71) 320 54 74; fax: (48 71) 320 54 77; e-mail: annab@star.ar.wroc.pl
108 A. B¹kowska-Barczak

OH
O O
OH
HO OH
+ HO
HO O OH
OH
O OH O
HO
O succinic acid malic acid
HO OH
O O
OH
O OH
O O
HO O

OH OH HO
O
HO OH HO
O
OH O
O
O
malonic acid oxalic acid acetic acid

FIGURE 2. Chemical structure of delphinidin-3-malonylglucoside-5- FIGURE 4. Common aliphatic acid acylated with sugar moieties of
-glucoside isolated from flowers of Scutellaria baicalensis G [Oszmiañ- anthocyanins.
ski et al., 2004].

syl-D-glucose), xylosylrutinose and glycosylrutinose may BIOLOGICAL ACTIVITY

also be present [Clifford, 2000; Shahidi & Naczk, 1995;
Takeoka & Dao, 2002]. The sugar residues may be further Beside the colour attributes, interest in anthocyanins
acylated with organic acids [Giusti et al., 1998b; Honda & has intensified because of their possible health benefits.
Saito, 2002; Mahmoud et al., 2001; Mazza & Miniatti, 1993; Health benefits associated with anthocyanins extracts
Stinzing et al., 2002] (Figure 2). Common acylating agents include the enhancement of sight acuteness [Lamer-
include cinnamic acids such as caffeic, p-coumaric, ferulic -Zarawska & Oszmiañski, 1991, 1994], anticancerogenic
and sinapic acid (Figure 3), as well as a range of aliphatic activity [Katsube et al., 2003], antioxidant capacity [Ga-
acids such as acetic, malic, malonic, oxalic, and succinic acid brielska et al., 1999; Kähkönen & Hainonen, 2003; Käh-
(Figure 4). Cinnamic acids may themselves bear glycosidic könen et al., 2003; Kong et al., 2003; Lamer-Zarawska &
sugars. Aromatic and aliphatic acylation may occur in the Oszmiañski, 1994; Wang et al., 1997], antiulcer activity
same molecule, forming the polyacylated structure [Bloor, [Cristoni & Magistretti, 1987], the maintenance of normal
1997, 2001; Bloor & Abrahams, 2002; Clifford, 2000; Giusti vascular permeability (vitamin P) [Lamer-Zarawska & Osz-
et al., 1998a, b; Gonzales et al., 2001; Harborne & Williams, miañski, 1991, 1994]. The results presented by Jayapra-
2000, 2001; Hosokawa et al., 1995a,b; Nakatani et al., 1995; kasam et al. [2005] showed that isolated and purified antho-
Norbaek & Kondo, 1998, 1999, Norbaek et al., 2002; Ta- cyanins from fruit and vegetable may be useful in the
tsuzawa et al., 1997; Takeoka & Dao, 2002; Yoshida et al., treatment of type 2-diebetes (noninsulin-dependent dia-
1990]. Acyl substituents are usually bonded to the C-6 sugar betes). The most significant function of anthocyanin
[Giusti & Wrolstad, 2003; Honda & Saito, 2002; Otsuki extracts is their antioxidant activity. Ghiselli et al. [1998]
et al., 2002]. For a few pigments, they have been shown to be investigated an antioxidant activity of anthocyanin fractions
attached to the 2-hydroxy [Reiersen et al., 2003; Strack et al., from Italian red wine. The results showed that the antho-
1992], 3-hydroxy [Andersen & Fossen, 1995] or 4-hydroxy cyanins were the most effective both in scavenging reactive
[Fossen et al., 2003]. oxygen species and in inhibiting lipoprotein oxidation and
platelet aggregation. Those authors suggested that antho-
H3C cyanins could be the key component in red wine that pro-
O tects against the cardiovascular disease. Another report on
the antioxidative activity was published by Tamura and
Yamagami [1994]. They found that anthocyanins acylated
HO HO O
HO HO O by p-coumaric acid are much better antioxidants than
O a-tocopherol or (+)-catechin. Besides the antioxidant activ-
p-coumaric acid H3C sinapic acid ity, anthocyanins possess also free radical scavenging activi-
ty. Anthocyanin radical is more stable than other radicals
generated in human body, hence duration of this radical is
HO HO longer [Wolniak, 2002]. Wang and Mazza [2002] were first
to report that anthocyanins had strong inhibitory effects on
NO production. Anthocyanins with their 3’, 4’-dihydroxy
O HO HO O OH
O groups can rapidly chelate metal ions to form stable antho-
H3C cyanin-metal complexes [Sarma et al., 1997]. As a result,
ferulic acid caffeic acid
anthocyanins with the ortho-dihydroxyl groups have the
potential to scavenge hydroxyl radical through the inhibi-
FIGURE 3. Common cinnamic acid acylated with sugar moieties of tion of ·OH generation by chelating iron [Noda et al., 1998;
anthocyanins. 2000], and to prevent iron-induced lipid peroxidation [Wang
Acylated anthocyanins 109

et al., 1999]. The ortho-dihydroxyl group also helps to form

anthocyanin-metal-copigment complexes at physiological
pH ranges with various organic compounds such as ascorbic
acid [Sarma et al., 1997] and partially through this mecha-
O
nism to spare vitamin C. The results of a research described +
O
by Sarma and Sharma [1999] indicate that cyanidin-DNA
copigmentation may be a potential defense mechanism
against the oxidative damage of DNA and may have in vivo
physiological functions attributable to the antioxidant activ- O O
ity of anthocyanins. It has been suggested that anthocyanins
have the ability to stabilize DNA triple-helical complexes HO
[Mas et al., 2000].
The Joint FAO/WHO Expert Committee on Food
O
Additives (JECFA) concluded that anthocyanin-containing HO
extracts are of a very low order of toxicity, based on limited
toxicological studies including mutagenicity, reproductive OH
toxicity and teratogenicity. In a two-generation reproduc-
FIGURE 5. Intramolecular copigmentation of acylated anthocyanins
tion study, the no-observed-effect-level (NOEL) for young [http://www.arches.uga.edu].
rats was determined to be 225 mg/kg body weight (diet con-
taining 7.5% grape skin extract, or 3% anthocyanin pig-
ments, equivalent to 7500 mg diet per kg body weight). formed when the aromatic acids are substituted in ring B of
Based on the above result, in 1982 the estimated acceptable flavylium cation than in ring A [Yoshida et al., 2002].
daily intake (ADI) for man, calculated using the equation of Acylating substituents at C-3’ and C-7 which are specific to
ADI=NOEL/100 [Joint FAO/WHO Food Additives Series the pigments of Orchidaceae and Senecio completely protect
17; Clifford, 2000] accounted for 2.5 mg/kg body weight. these anthocyanins against hydrolysis throughout the acidic
The presented health benefits make anthocyanins an attrac- to neutral pH range [Harborne & Williams, 2001]. Another
tive alternative to synthetic dyes. important factor for colour stabilization is the free malonyl
group attached to the glucose at the C-3 position. This mal-
STABILITY OF ANTHOCYANIN COMPOUNDS onic acid group preserves colour by increasing medium
acidity in the cell vacuole. This function of the malonyl
The stability of anthocyanin pigments is determined by sev- residue applies more generally to any anthocyanin pigments
eral factors, including structure and concentration of the pig- with 3-(6-malonylglucoside) substitution [Figueiredo et al.,
ment, pH, temperature, light intensity and quality, the pres- 1999].
ence of copigments, metal ions, enzymes, oxygen, ascorbic Acylated anthocyanins are also more resistant to colour
acid, sugars and their degradation products and sulfur dioxide, fading with increased pH than their unacylated analogs. In
among others [Brouillard, 1982; Mazza & Brouillard, 1990]. aqueous media, four anthocyanin structures exist in equilib-
With respect to molecular structure, some anthocyanins rium: flavylium cation, carbinol pseudobase, quinonoidal
are more stable than the others. Generally, increased base and chalcone [Amiæ et al., 1990; Baranac & Amiæ,
hydroxylation decreases stability, whereas increased methy- 1990; Carbita et al., 2000; Dao et al., 1998; Mazza &
lation increases it [Brouillard, 1982]. The colour of foods Brouillard, 1987; Melo et al., 2000; Mirabel et al., 1998;
containing anthocyanins that are rich in pelargonidin, cyani- Musoke, 2002]. In strongly acidic aqueous media (pH 1),
din, or delphinidin aglycones is less stable than that of food the red-colored flavylium cation is the predominant species.
containing petunidin or malvidin aglycones. Moreover, Unacylated anthocyanins are only stable at pH values where
anthocyanins containing galactose are more stable than the flavylium cation dominates [Heredia et al., 1998; Zaj¹c
those containing arabinose [von Elbe & Schwartz, 1996]. & Wilska-Jeszka, 1994]. Between pH values of 2 and 4, the
Recent researches have shown that anthocyanins with acy- uncharged blue quinonoidal unstable species prevails, and if
lating substituents are more stable during processing and the pH is increased, the ionization of the hydroxyl groups
storage than other natural pigments [Cevallos-Casals & forms the anionic blue quinonoidal unstable species. At
Cisneros-Zevallos, 2004; Fossen et al., 1998; Giusti & pH 5 and 6, unacylated anthocyanins are unstable and
Wrolstad, 2003; Honda & Saito, 2002; Inami et al., 1996; decolorize quickly by hydration at the 2-position of the
Malien-Aubert et al., 2001; Rodriguez-Saona et al., 1998, anthocyanidin skeleton (carbinol pseudobase and chalcone
1999; Sapers et al., 1981]. The improved stabilization has structures are formed) [Brouillard, 1982; Dao et al., 1998;
been attributed to the stacking of the acyl groups with the Mazza & Miniati, 1993]. Evidence has been provided that
pyrylium ring of the flavylium cation, thereby reducing the the chroma of some pelarginidin derivatives increased when
susceptibility of nucleophile attack of water and subsequent the pH was further increased to neutral conditions [Giusti
formation of a pseudobase or a chalcone (intramolecular & Wrolstad, 2003]. Cevallos-Casals & Cisneros-Zevallos
copigmentation) (Figure 5) [Brouillard et al., 1982, 2003; [2004] showed that colorants rich in acylated anthocyanins,
Dangles et al., 1992, 1993; Davies & Mazza, 1993; Fi- such as sweet potato and purple carrot, were more resistant
gueiredo et al., 1996, 1999; Mazza & Miniati, 1993; Osawa, to the solution pH than colorants rich in unacylated antho-
1982]. Full colour stabilization is best achieved when the cyanins such as red grape. The other researchers confirmed
anthocyanins bear aromatic than aliphatic ones [Giusti & the unusual stability of acylated anthocyanins at pH over 5.0
Wrolstad, 2003]. In addition, more stable complexes are [Idaka, 1991; Fossen et al., 1998].
110 A. B¹kowska-Barczak

It is generally recognized that light accelerates degrada- is offset by a high tinctorial strength. Available in a liquid or
tion of anthocyanins. This adverse effect has been demon- sprayed-dried form, the extracts are water-soluble and,
strated in several fruit juices and red wines. In fruit juices it because of the presence of acylated anthocyanins, demon-
has been established that acylated anthocyanins are more strate improved stability to heat and light [Giusti, 2002].
stable than unacylated derivatives [Inami et al., 1996]. In Slight changes in pH have a large effect on the resulting
addition, the absorbance of juices tested was observed to hue, and therefore, pH control of the final product becomes
increase after exposure to light. Further investigations crucial.
demonstrated that anthocyanins containing cinnamoyl The commercialization of red cabbage anthocyanins was
derivatives are able to isomerize from trans to cis form pioneered by the Overseal Natural Ingredients Ltd under
[George et al., 2001; Yoshida et al., 1990, 2000, 2002, 2003 a, their brand name MagentoTM [http://www.overseal.co.uk].
b]. The reaction of isomerization evokes colour intensifica- The interest in and success of red cabbage–derived antho-
tion and resistance to pyrilium ring hydration. cyanins lie in the fact that they: produce a bright pink shade
High temperature is another factor inducing degrada- at low pH on clear bases and pink/mauve shades in white
tion of anthocyanin colorants [B¹kowska et al., 2003; Fur- bases; provide mauve/blue shades at more neutral pH val-
tado et al., 1993; Garcia-Viguera et al., 1999; Horuba³a, ues; have no unpleasant taste due to minimized odour
1996]. The results presented by Dyrby et al. [2001] showed notes; demonstrate superior stability to heat and light over
that acylated anthocyanins from red cabbage were more sta- anthocyanins from more traditional sources such as grape-
ble than the unacylated anthocyanins obtained from red skin and elderberry; are naturally low in polyphenols redu-
grape, black currant and elderberry. The high stability of cing the risk of hazing with proteins; are available all year
red cabbage anthocyanins during heating at 80°C was con- round; and demonstrate potential health benefits when
firmed by our unpublished data. included into the diet [http://www.overseal.co.uk].
Giusti and Wrolstad [2003] tested the viability of using
ACYLATED ANTHOCYANINS AS COLORANTS FOR acylated anthocyanins from red cabbage to colour of dairy
THE FOOD INDUSTRY products such as yogurt or sour cream, with pH levels of
about 4.2–4.5. These anthocyanins gave an attractive purple
The confirmed large stability of anthocyanins, including colour, resembling the colour of blueberries.
acidic substituent, and their wide colour range caused that Other excellent source of acylated anthocyanins is black
searches for acylated anthocyanin-rich material have begun. carrot (Daucus carota L). It has been grown and consumed
Taking into consideration low prices, big surface of in the East for at least 3,000 years. Historical records indi-
tillage and high amounts of anthocyanins, red cabbage cate that it was cultivated in parts of Europe in the 12th cen-
(Brassica oleracea L) is the most valuable source of the sta- tury and in Holland by the 14th century. It was commonly
ble form of anthocyanins for the Polish food industry. Red consumed until about 1750 when Dutch breeders developed
cabbage contains about 15 anthocyanins (mostly diacylated) the orange variety which we are all familiar with [Pszczola,
being derivatives of cyanidin-3-diglucoside-5-glucoside acy- 1999]. The black carrot is still consumed in some parts of
lated with ferulic, sinapic and/or p-coumaric acids (Figure the world, such as Spain, Pakistan, Afghanistan, Turkey, and
6) [Baublis et al., 1994; Giusti et al., 1999; Mazza & Miniati, Egypt. Nowadays black carrots are also cultivated in Europe
1993; Murai & Wilkins, 1990]. (including Poland) on a large scale.
The extract of red cabbage anthocyanins is one of the The colour of this vegetable is determined by 5 main
most expensive anthocyanin concentrates, but its high cost anthocyanins, being derivatives of cyanidin-3-rutynoside-
-glucoside-galactoside acylated with one cinnamic acid (p-
OH
-coumaric, ferulic or sinapic) (Figure 7) [Dougall et al., 1997,
OH 1998; Gakh et al., 1998; Giusti, 2002; Giusti & Wrolstad,
2003; Glässgen et al., 1992; Kammerer et al., 2004; Lazcano
HO O+
R4 OH et al., 2001; Narayan & Venkatarman, 2000]. It was the GNT
O group that pioneered the development of food colorants
HO O OH
O from black carrot [Pszczola, 1999]. The coloring extract sold
HO O OH under EXBERRY® brand name is pleasantly fruity in taste
O OH
HO R2 O
OH and free of off flavours. The black carrot extract is also pro-
OH R10 duced by the Overseal Foods Ltd under its brand name
O
Carantho® [Downham & Collins, 2000]. EXBERRY® and
R3 Carantho® extracts offer the following features and bene-
fits: they provide an excellent bright strawberry red shade in
O
acidic products, up to pH 4.5; they exhibit mauve to blue
tones under neutral pH conditions; they are an excellent
1. R1 = R2 = R3 = R4 = H
vegetarian and kosher alternative to carmine; they contain
2. R1 = R3 = R4 = H R2 = OCH3
low levels of polyphenols, which are naturally present in
3. R1= R4 = H R2 = R3 = OCH3
4. R1 = R2 = R3 = H R4 = sinapic acid
grapeskin anthocyanins and which can cause hazing and pre-
5. R1 = R3 = H R2 = OCH3 R4 = sinapic acid cipitation problems; and finally they offer improved stability
6. R1 = H R2 = R3 = OCH3 R4 = sinapic acid to heat, light and SO2 [http://www.overseal.co.uk].
Other permitted sources of stable acylated anthocyanins
FIGURE 6. Chemical structure of main acylated anthocyanins from are also under evaluation. One of them is red radish (Ra-
red cabbage (Brassica oleracea) [Mazza & Miniati, 1993]. phanus sativus L). This vegetable contains 12 acylated
Acylated anthocyanins 111

OH powdered and ready-to-eat desserts, panned products and

OH milk drinks [Giusti, 2002; Giusti & Wrolstad, 2003;
http://www.overseal.co.uk].
HO O+
OH
CONCLUSIONS
HO
O OH Acylated anthocyanins have been shown to be a promis-
O
O
OH ing alternative to synthetic colorants in food systems.
O
Depending on anthocyanin structure and pH of food
R
matrix, a wide variety of hues can be achieved. Acylation of
O OH
OH
anthocyanins improves colour and pigment stability. There
O O is an increased market for nutraceutical or medicinal food
HO
HO and consumers are interested in foods that may help to pre-
OH
vent diseases. Identification of health promoting properties
in anthocyanin extracts would increase the demand for
R= H or these natural pigments, and would open a new window of
opportunities for their use in a variety of food applications.
X O
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Y
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Acylated anthocyanins 115

ANTOCYJANY ACYLOWANE JAKO STABILNE, NATURALNE BARWNIKI ¯YWNOŒCI – ARTYKU£

PRZEGL¥DOWY

Anna B¹kowska-Barczak

Katedra Technologii Owoców, Warzyw i Zbó¿, Akademia Rolnicza we Wroc³awiu

Wraz ze wzrostem œwiadomoœci konsumentów roœnie ich zainteresowanie produktami spo¿ywczymi, które oprócz
zaspokojenia g³odu, spe³niaj¹ dodatkowe funkcje fizjologiczno-¿ywieniowe, wp³ywaj¹c na poprawê zdrowia lub zapobie-
gaj¹c chorobom takim jak: nowotwory, cukrzyca, mia¿d¿yca, nadciœnienie czy próchnica. Te szczególne potrzeby kon-
sumentów zmuszaj¹ producentów ¿ywnoœci do rezygnacji ze stosowania barwników syntetycznych i zastosowania natural-
nych, aktywnych biologicznie barwników, m.in. antocyjanowych, do barwienia ¿ywnoœci. Zwi¹zane to jest jednak ze
znacznymi ograniczeniami, gdy¿ naturalne barwniki antocyjanowe s¹ zwi¹zkami bardzo niestabilnymi. Odkrycie antocy-
janów acylowanych o du¿ej stabilnoœci budzi nadziejê, ¿e barwniki te nadadz¹ po¿¹dany, trwa³y kolor produktom ¿ywnoœ-
ciowym. Wysoka stabilnoœæ barwników acylowanych zwi¹zana jest z utworzeniem kompleksu w formie „kanapki”, który
os³ania cz¹steczkê przed hydratacj¹ w pozycji C-2 i C-4. Kompleks ten powstaje w wyniku utworzenia wi¹zania pomiêdzy
reszt¹ aromatyczn¹ grupy acylowej a pierœcieniem pyryliowym kationu flawyliowego (rys. 5).
Antocyjany acylowane wystêpuj¹ w wielu kwiatach, owocach i warzywach, jednak zastosowanie w przemyœle mo¿e
znaleŸæ jedynie kilka z nich. S¹ to: czarna kapusta zawieraj¹ca w wiêkszoœci poliacylowane antocyjany (rys. 6), czarna
marchew (zawieraj¹ca pojedynczo acylowane antocyjany (rys. 7), czerwona rzodkiewka czy czerwona kukurydza. Preparaty
acylowanych antocyjanów otrzymane z wymienionych surowców cechuj¹ siê ma³¹ wra¿liwoœci¹ na zmiany pH, wysok¹ sta-
bilnoœci¹ podczas ogrzewania i naœwietlania oraz ma³¹ zawartoœci¹ polifenoli, dziêki czemu dodatek tych preparatów do
produktów zawieraj¹cych bia³ka nie powoduje zmêtnieñ.
Te wyj¹tkowe zalety preparatów antocyjanów acylowanych stwarzaj¹ realne nadzieje na wykorzystanie ich do barwienia
produktów o obojêtnym lub lekko zasadowym odczynie, jak produkty mleczne, desery w proszku czy polewy lukrowe.