Lemon yellow #15 a new highly stable, water soluble food colorant from the peel of Citrus limon

Article abstract of DOI:10.1016/j.foodchem.2018.07.055

To provide stable and low-cost naturally derived yellow pigments, a variety of food byproducts were evaluated and the constituents of lemon peel have emerged yielding a highly promising natural product with applications as a food dye. Here we report a new, highly stable and water soluble food dye called yellow #15 from the ethanol extract of the zest of Citrus limon. The structure of lemon yellow #15 was carefully assigned on the basis of spectroscopic data, including 1D and 2D NMR spectroscopy, and the absolute configuration was established by comparison of the experimental CD with calculated electronic circular dichroism (ECD) spectral data. CIELAB values and Delta CIELAB were measured and revealed this new water-soluble pigment has superior light stability relative to other natural products used as food dyes.

Full text of DOI:10.1016/j.foodchem.2018.07.055

Accepted Manuscript
Lemon Yellow #15 A New Highly Stable, Water Soluble Food Colorant from
the Peel of Citrus limon
Xiaoyan Chen, Yuanqing Ding, Billy Forrest, Joonseok Oh, Stephanie M.
Boussert, Mark T. Hamann
PII:
S0308-8146(18)31194-4
DOI:
https://doi.org/10.1016/j.foodchem.2018.07.055
FOCH 23170
Reference:
Food Chemistry
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Revised Date:
Accepted Date:
25 March 2018
6 July 2018
9 July 2018
Please cite this article as: Chen, X., Ding, Y., Forrest, B., Oh, J., Boussert, S.M., Hamann, M.T., Lemon Yellow
#15 A New Highly Stable, Water Soluble Food Colorant from the Peel of Citrus limon, Food Chemistry (2018),
doi: https://doi.org/10.1016/j.foodchem.2018.07.055
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Lemon Yellow #15 A New Highly Stable, Water Soluble Food Colorant from the Peel of
Citrus limon
Xiaoyan Chena, Yuanqing Dingb, Billy Forrestc, Joonseok Ohc, Stephanie M. Boussertd, Mark T.
Hamanna,*
aDepartment of Drug Discovery and Biomedical Sciences, College of Pharmacy, Medical
University of South Carolina, Charleston, SC 29425, USA; bNational Center for Natural
Products Research, Department of BioMolecular Sciences, Division of Pharmacognosy, and
Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of
Mississippi, Oxford, MS 38677;c Division of Pharmacognosy, School of Pharmacy, The
University of Mississippi, Oxford, MS 38677d Department of Chemistry and Biochemistry,
College of Charleston, Charleston, SC 29401, USA;
*Corresponding author: Mark T. Hamann,
70 President Street, Room 406 DDB, Charleston, SC 29425, USA
Phone: 843-876-2316
Email: hamannm@musc.edu
1

ABSTRACT
To provide stable and low-cost naturally derived yellow pigments, a variety of food byproducts
were evaluated and the constituents of lemon peel have emerged yielding a highly promising
natural product with applications as a food dye. Here we report a new, highly stable and water
soluble food dye called yellow #15 from the ethanol extract of the zest of Citrus limon. The
structure of lemon yellow #15 was carefully assigned on the basis of spectroscopic data,
including 1D and 2D NMR spectroscopy, and the absolute configuration was established by
comparison of the experimental CD with calculated electronic circular dichroism (ECD) spectral
data. CIELAB values and Delta CIELAB were measured and revealed this new water-soluble
pigment has superior light stability relative to other natural products used as food dyes.
Keywords: Lemon Yellow #15; food colorant; Citrus limon; 3-Hydroxy-3-methylglutaryl (HMG)
2

1. Introduction
The last few years have witnessed a movement by food companies to replace artificial dyes and
preservatives with natural products. This movement has been in response to consumer demands
for natural and safer plant-based food ingredients (Rozin, Spranca, Krieger, Neuhaus, Surillo,
Swerdlin, et al., 2004; Sigurdson, Tang, & Giusti, 2017). Public opinion is that plant-based food
additives present less danger than petroleum or synthetic derived ingredients and based on the
structural features this is reasonable in many cases (Dickson-Spillmann, Siegrist, & Keller, 2011;
Lalor, Madden, McKenzie, & Wall, 2011). This ideation has grown from an expanding number
of reports of adverse reactions, toxicity, carcinogenicity, behavioral and neurocognitive effects
related with synthetic food colorants and a substantial number of associated impurities (Amin,
Abdel Hameid, & Abd Elsttar, 2010; Martins, Roriz, Morales, Barros, & Ferreira, 2016). The
most commonly used synthetic yellow food dyes, FD&C yellow No.5 and FD&C yellow No.6,
were implicated in a variety of adverse reactions including cytotoxicity, genotoxicity and
carcinogenicity (Amchova, Kotolova, & Ruda-Kucerova, 2015; Mpountoukas, Pantazaki,
Kostareli, Christodoulou, Kareli, Poliliou, et al., 2010; Soares, Araujo, Ramos, Pinto, Khayat, De
Oliveira Bahia, et al., 2015). In 2009, European Food Safety Authority (EFSA) re-evaluated the
safety of tartrazine (FD&C yellow No. 5) and concluded that the daily use of tartrazine within
the Acceptable Daily Intake (ADI) of 7.5 mg/kg bw/day was safe (Amchova, Kotolova, & Ruda-
Kucerova, 2015). In 2014, the ADI for sunset yellow (FD&C yellow No. 6) was raised to 4
mg/kg bw/day from a temporary ADI of 1 mg/kg bw/day that was established in 2009 (EFSA
Panel on Food Additives and Nutrient Sources added to Food, 2014). In the USA, Food and
Drug Administration Food Advisory Committee reviewed the relationship between exposure to
color additives and hyperactivity in children and did not find casual evidence to support the link
3

in normal consumption (Amchova, Kotolova, & Ruda-Kucerova, 2015). The current tendency of
the food industry to voluntary use more naturally derived colors is due to consumer demands. In
addition to increased safety, naturally derived colorants may in many cases possess desirable
health benefits, which can be evidenced with the nature-derived dye, annatto. Annatto is a
yellow–orange dye obtained from Bixa orellana, primarily composing of the carotenoids bixin
and norbixin (Scotter, 2009), and has been shown to exert antioxidant, anti-carcinogenic, and
anti-inflammatory properties in vitro and in rats (Shahid ul, Rather, & Mohammad, 2016). The
administration of bixin was able to protect against the atherosclerotic lesion in
hypercholesterolemic rabbits and stimulate immune response in dogs (Park, Mathison, & Chew,
2016; Somacal, Figueiredo, Quatrin, Ruviaro, Conte, Augusti, et al., 2015). Any therapeutic
effects that colorants have are dependent on sufficient bioavailability through the diet and
enhancing the bioavailability to improve biological efficacy of naturally derived colorants have
been the subject of numerous investigations (McGhie & Walton, 2007; Stanic, 2017). The
naturally-derived food colorants explored thus far fall primarily into five main groups including
the anthocyanins, carotenoids, betalains, chlorophylls, and phenolic compounds (Rodriguez-
Amaya, 2016). Some natural product groups have a long history of use in the food industry as
well as a long history of use in the human diet (Bridle & Timberlake, 1997). Annatto, β-carotene,
and turmeric are among the most commonly used yellow color additives approved by both
European Food Safety Authority (EFSA) and US FDA (Wrolstad & Culver, 2012). However
relative to their synthetic counterparts, application of naturally derived colorants in the food
industry is still limited, especially considering the strong desire both by consumers and food
manufacturers to replace artificial food additives with natural ingredients (Rodriguez-Amaya,
2016). The primary limitations include the instability and high cost of naturally derived colorants
4

(Delgado-Vargas, Jimenez, & Paredes-Lopez, 2000; Rodriguez-Amaya, 2016). For example, the
major pigments of turmeric (E100), are curcumin, demethoxycurcumin, and bis-
demethoxycurcumin. These pigments are susceptible to light, heat, oxygen and alkaline
conditions that limit turmeric's use in foods (C. & R.W., 1996; D.M., C.R., & V.R.N., 2015). The
poor water solubility of most current utilized naturally-derived colorants need them to be
dispersed in other suitable matrices before they can be utilized to water based foods (Alison &
Paul, 2000). It is important to emphasize that a colorant has to be approved for use in foods
despite the artificial or natural source and the regulation varies among different countries, which
gives rise to another challenge for a new emerging colorants (Magnuson, Munro, Abbot,
Baldwin, Lopez-Garcia, Ly, et al., 2013).
The yellow pigments from lemon peel represents a potentially useful byproduct of lemon that
could be isolated and prepared after the generation of juice and essential oils. This application
may become more economically and environmentally sensible considering that up to 50 to 65%
of the whole fruits remain as peel byproduct (Mandalari, Bennett, Bisignano, Saija, Dugo, Lo
Curto, et al., 2006) and lemon processing totaled 2.88 million tons during the 2014-2015 season
(United States Department of Agriculture, National Agricultural Statistics Service, 2015). In
addition to lemon yellow #15 reported here, the lemon peel byproducts contain flavonoids
including naringin, hesperidin, narirutin, neohesperidin, and related metabolites
-Lidón, & Ortuño, 2004; Miyake, Yamamoto, Morimitsu, & Osawa,
1998). Besides adding color, these flavonoids have been shown to possess health beneficial
effects. These molecules are well known for antioxidant properties that have been evaluated
extensively in vitro (Benavente-García, Castillo, Marin, Ortuño, & Del Río, 1997; Miyake,
Yamamoto, Morimitsu, & Osawa, 1997). The effectiveness of citrus flavonoids pertaining to
5

cancer prevention and anti-inflammation has been assessed in vitro and using animal studies
(Manthey, Grohmann, & Guthrie, 2001). The intake of citrus limon peel extract provided
protection from renal damage on experimentally induced urolithic rats (Sridharan, Michael, Arya,
Mohana Roopan, Ganesh, & Viswanathan, 2016). To increase the quality of food and address
customer demands for food safety by using natural, plant-based ingredients and additives, we
carried out a project investigating colorants from fruits and vegetables. This investigation into
the components of lemon peel was part of this project and aimed at discovery of new stable,
water-soluble, and obtainable yellow colorants. Here we reported a structure that emerged during
our study that showed great potential as a future colorant.
2. Material and Method
2.1 Raw Material.
Citrus limon was obtained from a local grocery store and the peel (flavedo) was removed,
lyophilized and ground to 1mm particle size using a grinder. 132.9 g dried material was
generated from 305.6 g raw peel.
2.2 Extraction and Isolation.
The dried and ground zest was extracted immediately with ethyl acetate, ethanol, and water in
sonicator for one hour, successively. The yield for each solvent was calculated according to yield
(%) = weight of extract / weight of dried peel: EtOAc 14.3%, EtOH 19.7%, and water 5.32%.
Ethanol extract (5g) was subjected to column chromatography on C18 silica gel and eluted with
g di n f E OH─H2O (0%; 20%; 40%; 80%; 100%EtOH) to afford five fractions. Fraction B
(600mg) was further separated on Sephadex LH-20 eluted with MeOH-H2O (0%; 20%; 100%
MeOH, 200mL per gradient) to afford 39 subfractions. Fraction B-36 and Fraction B-37 were
combined and purified by preparative HPLC using gradient EtOH-H2O (0-100%, 120m) and 0.1%
6

ethanoic acid as the mobile phase (13mL/min) to yield lemon yellow #15 (4 mg, tR 42 min).
Precoated silica gel 60 F254 plates from Merck were used for TLC. HPLC was carried out with a
h n n x Si i n 10 × 250 5 μ ) f ip p iv inj i n wi h W
dual pump model 510 and a UV absorbance detector model 486 and with fraction collection.
Sephadex LH-20 (GE), and C18 silica gel (40-63 μm, sorbent) were used for column
chromatography. Spots were visualized by spraying with 10% H2SO4 in EtOH followed by
heating.
2.3 The spectroscopic and physical data of lemon yellow #15.
The HRESIMS, 1H NMR, 13C NMR, HSQC (Heteronuclear Single Quantum Correlation),
HMBC (Heteronuclear Multiple Bond Correlation), and IR spectra of lemon yellow #15 were
collected and analyzed to identify the planar structure as limocitrol 3-O-6''-[3-hydroxyl-3-
methylglutaryl)]-glucopyranoside (Supplementary Material). After the hydrolysis of lemon
yellow #15, the D-configuration of glucose was determined by optical rotation. A β glucosidic
linkage of the glucopyranosyl unit was assigned via the 3J1",2" coupling constant (6.0 Hz).
HRESIMS was performed using a Bruker Impact II TOF spectrometer. NMR spectra were
obtained using a Bruker Avance 400 MHz spectrometer and IR spectra with a Bruker Alpha FT-
IR spectrometer using Opus 6.5 software.
ECD calculations for two possible diastereomers were conducted to determine the absolute
configuration at C-3‴. The calculated ECD spectrum of 3‴S diastereomer was consistent with the
experimental spectrum, which determined the absolute configuration of lemon yellow #15 to be
S (Figure 3). Therefore, lemon yellow #15 was deduced as limocitrol 3-O-6''-[(S)-3-hydroxyl-3-
methylglutaryl)]-β-D-glucopyranoside (Figure 1). All calculations at quantum mechanics level
were performed by using the Gaussian 09 software package. Experimental ECD spectrum was
7

acquired with an Olis CD spectrophotometer. The concentration of the sample was 0.32 mg/mL
in methanol and the path length was 1 cm.
The optical rotation was measured with a Autopol V polarimeter. The UV spectrum was
collected with a Cary 50 spectrophotometer.
Limocitrol 3-O-6''-[(S)-3-hydroxyl-3-methylglutaryl)]-β-D-glucopyranoside: amorphous yellow
p wd ; [α]20D -8.8 (c 0.16, MeOH); UV λ x g ε) 205.0 (4.15), 277.0 (3.79), 351.0 (3.67)
n ; I ν x 1714.96, 1649.52, 1558.14, 1427.32, 1282.43, 1021.85, 990.16 cm−1; 1H NMR
(DMSO-d6, 400 MHz) and 13C NMR (DMSO-d6, 100 MHz) see Table S1; negative-ion
HRESIMS [M - H]- m/z 681.16927 (calcd for C30H33O18, 681.16724).
2.4 Acid Hydrolysis of lemon yellow #15.
Lemon yellow #15 (3 mg) was refluxed in 6% HCl (5.0 mL) at 80°C for 2 h. Each reaction
mixture was extracted with CHCl3 (3 × 6 mL), and the H2O phase was dried using a N2 stream.
The residues were separately subjected to column chromatography over silica gel with EtOAc-
MeOH-H2O (7:5:1) as eluent to yield (+)-D-glucose. The solvent system EtOAc-MeOH-H2O
(7:5:1) was used for TLC identification.
2.5 Color Measurements.
Color measurements were carried out by the Cary 50 UV-vis spectroscopy using illuminant
D65 and CIE standard observer 2°. Lemon yellow #15, curcumin, and crocin were dissolved in
methan in n n i n f 769 ηg/ L 40ηg/ L nd 48 ηg/ L, respectively. Spectral
reflectivity curve of lemon yellow #15 is presented in Fig 1 (E) in the range of 830-360 nm. The
three solutions were set on a window to expose to sunshine at room temperature (Image S1). One
month later their color values were measured again. The glass vials were purchased from VWR
(catalog number 470151-622 and 470157-602).
8

3. Results and Discussion
3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) is an important intermediate in various
metabolic pathways like in the synthesis of cholesterol and other isoprenoids (Friesen & Rodwell,
2004). (S)-HMG is usually inferred as naturally occurring considering the stereospecific
activities of enzymes (Van der Heijden, de Boer-Hlupá, Verpoorte & Duine, 1994; Bergot, Baker,
Lee & Schooley, 1979). Tsunashi Kamo et al. developed a method by reduction and amidation to
confirm absolute configuration of the HMG group in natural products (Hattori, Horikawa,
Makabe, Hirai, Hirota, & Kamo, 2007). Here we employed electronic circular dichroism (ECD)
computational approaches to establish the absolute configuration of HMG in lemon yellow #15
(Ding, Li, & Ferreira, 2009). Both R- and S- configurations at C3"' in lemon yellow #15 (denoted
as (3"'R)1 and (3"'S)1, respectively) were evaluated using a conformational search using the
OPLS_2005 force field in the MacroModel software package of Schrodinger Suite with an
energy window of 130 kJ/mol. Eighteen of 488 (3"'R)1 and 15 of 510 (3"'S)1 conformers within
an energy cutoff of 20 kJ/mol were chosen for geometry optimization and harmonic vibrational
frequency computations at the B3LYP/6-31G** level in the gas phase (Figure 2). Boltzmann
conformational distribution was calculated using the electronic and zero-point energies provided
the above mentioned optimization process (Table 1 and 2, respectively). The conformers (3"'R)1-
8 and (3"'S)1-12 were found to be the respective major conformers (90.5 and 98.8% of the
(3"'R)1 and (3"'S)1 configurations). Interestingly, the HMG in (3"'R)1-8 formed a
(C5'"O)H⋯O(C8) hydrogen-bond from the front of A/C plane in (3"'R)1 configuration, whereas
such a bond in (3"'S)1-12 was found from the rear of A/B plane in (3"'S)1. The conformers
(3"'R)1-7 and (3"'S)1-10 were calculated to possess only 9.2 and 1.2% of the (3"'R)1 and (3"'S)1
configurations, respectively, and the (C5'"O)H was found to form a hydrogen-bond with O(C7)
9

instead of O(C8) both from the front of A/C plane. Notably, the (C5'"O)H⋯O(C7) distance in
conformer (3"'S)1-10 is 0.07 Å longer than that in (3"'R)1-7, whereas the (C5'"O)H⋯O(C8)
distance in (3"'S)1-12 is 0.09 Å shorter than that in (6"'R)1-8. These structural and energetic
differences indicate that HMG in both (3"'R)1 and (3"'S)1 favors the formation of the
(C5'"O)H⋯O(C8) hydrogen-bond more than (C5'"O)H⋯O(C7) hydrogen-bond. Furthermore
(3"'R)1 prefers the generation of the hydrogen bond from the front of A/B plane whereas (3"'S)1
prefers from the rear. The ECD spectra for the two enantiomers were computed at the B3LYP/6-
31G** level in the gas phase, and only the weighted ECD of (3"'S)1 matches the experimental
ECD data of lemon yellow #15 (Figure 3). Exemplified by the predominant conformer (3"'S)1-12,
the n → π* ni x i i n 361 nd 303 n n ib d h xp i n y b v d
negative Cotton effect (CE) at the broad wavelength range of 400–291 nm, that at 266 nm
corresponded to the low-amplitude positive CE at 290–273 nm, whereas the high-amplitude
negative CE at 272–210 nm can be attributed to the excited states at 272, 229, 216, 214, 211, 209,
208, and 206 nm, respectively. This analysis unambiguously assigns the HMG as S-
configuration, leading the full structure of lemon yellow #15 defined as limocitrol 3-O-6''-[(S)-3-
hydroxyl-3-methylglutaryl)]-β-D-glucopyranoside.
10

Figure 1. (A) Peel of Citrus limon was extracted for isolation of yellow pigment. (B) Pure lemon yellow #15 dissolved in water.
(C) Filter paper dyed by curcumin (a), crocin (b) and yellow #15 (c) at 1 mg/ml, 2 mg/ml, 15 mg/ml separately in methanol
considering curcumin is difficult to be dissolved in water. (D) Structure of lemon yellow #15. (E) Reflectance spectrum of yellow
#15 i n 769 ηg/ L in h n .
Table 1. Conformational Analysis of (3"'R) 1 at the B3LYP/6-31G** Level in the Gas Phase.
(3"'R)1*
E†
E†
P% ‡
0.0
0.0
0.0
0.2
0.0
0.0
9.2
90.5
0.0
P% ‡
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
(3"'R)1*
10
1
2
3
4
5
6
7
8
9
4.52
5.16
7.66
3.74
7.12
6.90
1.35
0.00
7.30
11.40
7.30
6.49
6.96
12.07
11.07
4.79
6.81
8.58
11
12
13
14
15
16
17
18
*Conformer number, † Relative energy (kJ/mol), ‡Conformational population.
11

Table 2. Conformational Analysis of (3"'S)1 at the B3LYP/6-31G** Level in the Gas Phase.
P%‡
P%‡
E†
E†
(3"'S)1*
(3"'S)1*
1
2
3
4
5
6
7
8
12.51
7.11
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
9
5.57
2.60
15.44
0.00
7.34
12.04
6.68
0.0
1.2
0.0
98.8
0.0
0.0
0.0
10
11
17.50
7.02
12
13
14
15
15.76
12.45
10.50
20.70
* Conformer number, †Relative energy (kJ/mol), ‡ Conformational population.
12

Figure 2. Optimized geometries of predominant conformers of lemon yellow #15 with S- and R-
configurations at C3'" in the 3-hydroxy-3-methylglutaryl group (HMG).
13

Figure 3. Experimentally observed ECD curve and weighted ECD spectra of lemon yellow #15
with S- and R- configurations at C3'" in the 3-hydroxy-3-methylglutaryl group (HMG).
What needs to be noticed is the correlation between anomeric hydrogen and C-3 can be
observed in HMBC spectrum when the delay for evolution of long-range couplings was
optimized to a JHC of 4 Hz. If with JHC =8 Hz or 12Hz, the correlation cannot be observed.
To assess the potential of lemon yellow #15 as a colorant, the color parameter values of it and
two commercially available yellow colorants, curcumin and crocin, were measured (Table 3). L*
describes the lightness of the color, ranging from black (L* = 0) to white (L* = 100). a* denotes
the red (+)/green (-) value and b* denotes the yellow (+)/blue (-) value (Zarena & Udaya Sankar,
14

2012). According to the L* values, lemon yellow #15 has similar degree of lightness with the two
commercial pigments. To test the stability of the three samples, the solution of lemon yellow #15,
curcumin, and crocin were exposed to sunlight at room temperature for one month. Then these
color parameter values were measured again and the total color changes were calculated from L*,
a*, and b* coordinates by means of the expression: ΔE* = [(ΔL2)+ (Δa2)+ (Δb2)]1/2, which shows
lemon yellow #15 is more stable than curcumin and crocin. In this study we found lemon yellow
#15 is easy to dissolve in water, while curcumin and crocin showed lower solubility in water.
And due to the low price and availability of lemon peel, lemon yellow #15 possesses a high
probability to be developed as a yellow colorant for the food industry. This metabolite has been
previously detected in the polar extract from lemon using MS/MS without the detailed
assignment of NMR data, stereochemistry determination and color measurements (Ledesma-
Escobar, Priego-Capote, & Luque de Castro, 2015).
Table 3. Colorimetric coordinates of lemon yellow #15 and commercial pigments§
sample
Time (weeks)
L*
a*
b*
ΔE*
0
97.2779
11.5872
32.2425
lemon
yellow
#15
6.3
4
97.5677
96.6245
99.2772
98.2925
99.1405
9.7207
26.2324
0
20.7154 107.4093
2.6029 7.7897
18.4518 58.4755
13.1145 34.0024
curcumin
101.3
4
0
crocin
25.0
4
§For this colour measurement, lemon yellow #15, curcumin, and crocin were dissolved in
h n in n n i n f 769 ηg/ L 40ηg/ L nd 48 ηg/ L p iv y
15

4. Conclusion
There is a movement in the food industry to replace synthetic yellow food dyes with the
naturally derived alternatives. However, the instability and high cost of existing natural product
derived yellow colorants has hindered their utilization by the food industry. The new food dye,
lemon yellow #15, was obtained from lemon peels and has revealed significant advantages as a
food colorant. This compound possesses much greater light stability than curcumin which is the
most stable natural dye of turmeric according to observable color changes with naked eye and
the values of ΔE*. In ddi i n n y w #15 i high y w -soluble, which makes its
extraction, isolation and utility to food products more effective. Finally, the abundance of lemon
peel, a byproduct of lemon juice production assures that its availability and production will be
highly cost-effective.
Calculated electronic circular dichroism (ECD) was employed here and unambiguously
determined the absolute configuration of the HMG group by comparison with the experimental
CD, which is a convenient method and without loss of sample compared to the previous reported
methods through making derivatives.
Acknowledgment
We thank the Mississippi Center for Supercomputing Research for the computational facilities.
This research was funded by Kraft Heinz (Kraft Foods at the time), and in part (ECD: Electronic
Circular Dichroism) by the US Department of Agriculture (No. 58-6408-2-0009) to LW.
Conflicts of Interest
The authors declare no conflict of interest.
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Highlights



The new food dye, lemon yellow #15, was obtained from lemon peels and possesses much greater
light stability than current natural-derived food dyes.
Lemon yellow #15 is highly water-soluble, which makes its extraction, isolation and utility to food
products more effective.
The abundance of lemon peel, a byproduct of lemon juice production assures that its availability and
production will be highly cost-effective.
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