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Journal of Food Engineering 80 (2007) 805–812

Microencapsulation of anthocyanin pigments of black carrot(Daucuscarota L.) by spray drier

Seda Ersus *, Unal Yurdagel

Ege University, Engineering Faculty, Food Engineering Department, 35100 Bornova, Izmir, Turkey

Received 23 June 2005; accepted 27 July 2006Available online 20 November 2006

Abstract

The acidified ethanol extracts of black carrots which has a high anthocyanin content (125 ± 17.22 mg/100 g) were spray dried using arange of maltodextrins [Stardri 10 (10DE), Glucodry 210 (20–23DE) and MDX 29 (28–31 DE)] as a carrier and coating agents, at 3different inlet/outlet air temperatures with constant feed solid content (20%). Higher inlet/outlet air temperatures caused greater antho-cyanin loss during spray drying.

The quality attributes of the powders which were produced at optimum drying temperatures (160 �C) were characterized by theiranthocyanin content, antioxidant capacity, L*, a*, b*, C* and H� values, dry matter content and hygroscopicity. The best dried pigmentcontaining powder was found where the Glucodry 210 was used as wall material. Scanning electron microscope was used for monitoringthe structures and size (3–20 lm) of the powders. For determination the stability and half-life period of microencapsulated pigments,samples were stored under different storage temperatures (4 �C and 25 �C) and light illumination (3000 lx).� 2006 Elsevier Ltd. All rights reserved.

Keywords: Black carrot (Daucus carota L.); Anthocyanins; Antioxidant capacity; Microencapsulation; Spray drier; Powder stability

1. Introduction

There has been an increased interest in the developmentof food colorants from natural sources as alternatives tosynthetic dyes because of both legislative action and con-sumer concern (Giusti & Wrolstad, 1996). Anthocyaninswhich are highly colored substances found in plants arepossible for use in food, nutraceutical and pharmaceuticalpreparations for having most of the red, purple and bluecolors (Doughall, Baker, Gakh, Redus, & Whittemore,1998) and have high potential as colorants because of theirlow toxicity (Brouillard, 1982). Possibility of the usage ofblack carrot anthocyanins as a natural colorant in the pro-duction of confectionery, jellies, jams, preserves and frozendesserts was discussed by Birks (1999).

0260-8774/$ - see front matter � 2006 Elsevier Ltd. All rights reserved.

doi:10.1016/j.jfoodeng.2006.07.009

* Corresponding author. Tel.: +90 535 9594208; fax: +90 232 3427592.E-mail addresses: seda.ersus@ege.edu.tr, seda1920032004@yahoo.-

com, ersusuyan@yahoo.com (S. Ersus).

It has been reported that black carrot (Daucus carota,L.) has six anthocyanins with only cyanidin as aglycone(Glassgen, Wray, Dieter, Metzger, & Seitz, 1992). Canbas�(1985), Harborne (1967), Narayan and Venkataraman(2000) were studied on the identification of anthocyaninsin Daucus carota, L.

Factors which affect the color and stability of anthocya-nins include structure and concentration, pH, temperature,light, presence of copigments, self association, metallicions, enzymes, oxygen, ascorbic acid, sugar and their deg-radation products, proteins and sulphur dioxide (Francis,1989; Mazza & Miniati, 1993; Rodriguez-Saona, Giusti,& Wrolstad, 1999). Microencapsulation by using spraydrier is an economical method for preservation of naturalcolorants by entrapping the ingredient in a coating material(Cai & Corke, 2000). Main, Clydesdale, and Francis (1978)spray dried anthocyanins from three different sources,Concord grape, cranberry and Rosella calcyces, but thereare no reports on spray dried black carrot anthocyaninextracts. Maltodextrins are water soluble materials and

Table 1Operating conditions for spray drying of black carrot anthocyanins

Drying air temperature (�C)

Inlet Outlet

160 107 ± 2180 118 ± 2200 131 ± 2

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protects encapsulated ingredient from oxidation (Shahidi &Han, 1993), they have low viscosity at high solids ratio andare available in different molecular weights which providesdifferent wall densities around the sensitive materials (Cai& Corke, 2000; Desorby, Netto, & Labuza, 1997; Wagner& Warthesen, 1995).

The objectives of this study were production of spraydried anthocyanin extracts from black carrot and to deter-mine the effects of different spray drying temperatures onthe anthocyanin content of the powders, to evaluate theeffects of maltodextrins with different dextrose equivalenton the properties of spray dried powders and their storagestability.

2. Materials and methods

2.1. Materials

Black carrot (Daucus carota L.) samples for pigmentextraction were grown in Mersin-Turkey and transferredto Ege University, Food Engineering Department pilotplant in about 25 kg plastic bags which contains holes forperforming respiration and kept at �25 �C until furtherextraction.

2.2. Carrier agents for spray drying

Maltodextrin MDX 29 (28–31 DE) was obtained fromSorini Corporation Tbk, Glucodry 210 (20–23 DE) wasfrom Tate Lyle Amyloum Group, Belgium and Stardri 10(10 DE) was obtained from A.E. Staley ManufacturingCompany, USA.

2.3. Extraction of anthocyanins from black carrot

Ethanolic extracts of anthocyanins were prepared as fol-lows: frozen material was ground with Crypto Peerles, Arm-field type grinder without thawing, twice volume of 96%ethanol:1.5 N HCl (85:15 v/v) blend was added to black car-rots to extract anthocyanins and macerated for 8 min in ablender and samples were transferred to 500 ml balloonand blender was washed with extra 50 ml extraction solventfor taking the residue. Extraction was performed where theextract temperature was kept 35 �C with water bath and con-tinuously stirring was applied by rotary evaporator for 2 h.Solid part was separated from blend by using filter paperthen filtered extract was passed through Whatman #1 filterpaper by using Buchner funnel with vacuum. Extractionsolvent was evaporated at 50 �C under vacuum (Kerkhof& Thijssen, 1974). The solid residue was dissolved with purewater until solid content was regulated to 6% by using PR-100 digital refractometer (Atago Co, Ltd. Japan).

2.4. Preparation of feed mixtures

Carrier agents (MDX 29, Glucodry 210 and SD 10) werecombined with the pigment concentrate (6% solid content)

and stirred to homogeneity with Silverson L4R mixer for30 min. Maltodextrins were added until reaching to the20% final solid content. For processed 1 or 2 liters feedmixtures were prepared.

2.5. Spray drying

The feed mixtures were spray dried in a Lab Plant SD4spray drier (Lab Plant Ltd., England) with the main cham-ber (380 mm long · 110 mm). The drier was operated atthree different air inlet/outlet temperatures which are givenin Table 1.

The pomp power was kept at 20% to maintain feed flowrate 5 ml/min, air blowing and compressor capacities weremaximum. During drying processes, temperature of thefeed mixture was 25 �C.

2.6. Pigment powder storage

Pigment powders were stored in brown bottles withscrew caps and placed at 4 �C and 25 �C to determinethe effects of storage temperatures on anthocyanin con-tents of powders. Powdered samples were put in55 · 10 mm petri dishes and exposed to 3000 lx of lightwhich is measured with digital light measuring device(Lutron, LX 105) at a constant temperature as 25 �Cfor determining the light effect. Degradation of anthocya-nins was followed for 8 weeks of storage and the antho-cyanin content was analysed weekly according toGlassgen et al. (1992).

2.7. Moisture and hygroscopic moisture of powders

Moisture of the samples were determined by using vac-uum oven method 934.06 (Anon, 1995). Moisture gain of2 g powder samples were measured under saturation solu-tion of Na2SO4. After 1 week, hygroscopic moisture wasexpressed as g of moisture per 100 g dry solids (g/100 g)to determine hygroscopicity (Cai & Corke, 2000).

2.8. Total anthocyanin content

Purple carrots were extracted by grinding in a blenderwith MeOH–HOAc–H2O (50:8:42, MAW). The filteredextract was used for determination of the anthocyanin con-tent by measuring absorbance at 530 nm and calculating

S. Ersus, U. Yurdagel / Journal of Food Engineering 80 (2007) 805–812 807

with log e = 4.48 for cyanidin 3-galactoside (Glassgen et al.,1992).

2.9. Antioxidant capacity determination

2.9.1. Preparation of sample extractsFifty grams raw or blanched samples were homogenized

in a blender with 150 ml methanol for 5 min. After recov-ery of homogenate, 75 ml methanol was used for washingthe blender and mixed with first homogenate. Mixturewas centrifuged at 4500g for 15 min at room temperature.Supernatants were filtered using Blue Ribbon no 589 filterpaper. The methanolic extract volume was made up to250 ml with methanol.

Dried powder samples (0.40 g) were dissolved in metha-nol and volume was made up to 100 ml. After centrifuga-tion, extract was also filtered by using Blue Ribbon no589 filter paper.

2.9.2. Determination of the scavenging effect on DPPH

radical

The effect of the purple carrot samples and Trolox as areference antioxidant compound on DPPH radical wasestimated according to the procedure described in reference(Brand-Williams, Cuvelier, & Berset, 1995; Parejo, Codina,Petrokis, & Kefalas, 2000). An appropriate dilution series(1–5 mg of soluble solids/ml at least five different concen-trations) were prepared for methanolic extract and for1.0 · 10�3, 7.5 · 10�4, 5.0 · 10�4, 2.5 · 10�4, 1.0 · 10�4 MTrolox in methanol and 0.1 ml of each dilution was addedto 3.9 ml of a 6.0 · 10�5 M methanolic solution of DPPH,followed by vortexing. The reaction was allowed to takeplace in the dark at room temperature to reach steady stateconditions, after which time the decrease in the absorbancewas determined at 515 nm. Methanol was used to zerospectrophotometer. The absorbance of the DPPH radicalwithout any sample (control) was measured daily. Theexact initial DPPH concentration (CDPPH) in the reactionmedium was calculated from calibration curve with theequation

A(515nm) = 23.92748 · CDPPH (mg/ml) + 7.84459 · 10�3,r2 = 0.99987, as determined by linear regression with con-taining different concentration of DPPH radical (Brand-Williams et al., 1995; El & Karakaya, 2003).

For each sample concentration tested, the percentage ofDPPH remaining at the steady state was calculated as fal-lows: DPPHrem% = (DPPH)T/(DPPH)T = 0, where T = 0 isinitial concentration of DPPH and T is the concentrationof DPPH at steady state. These values were plotted ontoanother graph showing the percentage of residual DPPHat the steady state as a function of the milligram ratio ofsample to milligram DPPH. Antiradial activity was definedas the amount of the sample and Trolox necessary todecrease the initial DPPH concentration by 50% (Efficientconcentration = EC50). The antiradial efficiency (AE) wascalculated as 1/EC50 (Brand-Williams et al., 1995; El &Karakaya, 2003).

2.10. Color

L*, a*, b* color values of the samples were measuredusing a spectral photometer (Datacolour, textflash, USA).After standardization L*, a*, b* values were measured onraw, blanched and dried samples. C* for the metric chromaand H� for the hue angle were calculated by the transfor-mation of the a*and b* the following equations:

C� ¼ ða�2 þ b�2Þ1=2

H � ¼ tan�1ðb�=a�Þ

On the chromatic circle, H� values are stepped from 0 to360� (megenta red) across a continuously fading hue circle,the other reference values of which are 90� (yellow), 180�(bluish green) and 270� (or �90�) (blue) (Malien-Aubert,Dangles, & Amiot, 2001).

2.11. Scanning electron microscopy (SEM)

Particle structures of the powder microcapsules wereevaluated by JEOL JSM-5200 model (Tokyo, Japan) scan-ning electron microscope. Powders were attached to SEMstubs using a 2-sided adhesive tape and left in desiccatorcontaining phosphorus pentoxide for 48 h. Samples werecoated with 200 A gold under vacuum before examination.SEM was operated at 20 kV · 3500.

2.12. Physical and chemical analysis

pH (Anon, 1974), acidity (Anon, 1972), solid contentwhich is not dissolved in alcohol (Anon, 1991), ash content(Anon, 1995), total and invert sugar content (Egan, Kirk,& Sawyer, 1981) analysis were done.

2.13. Statistical analysis

One-way ANOVA test was used for determination ofdifferences between processes with SPSS 9.5 package pro-gram. A probability level of p 6 0.05 was considered tobe significant for all statistical procedures. Regression anal-ysis was also done between anthocyanin content and anti-oxidant capacity of the samples. All measurements andtrials were done in duplicate.

3. Results and discussion

Black carrot was used as a raw material for anthocyaninextract preparation. According to analysis results the blackcarrot has 11.90 ± 0.14� Brix values where its dry matterwas determined as 13.15 ± 0.08 g/100 g fresh weight. Inanother research the similar purple carrot’s dry matter con-tent was found 18.85 g/100 g fresh weight (Ersus, Baysal,Yurdagel, & El, 2004). It is possible to have different drymatter contents because of different climate conditionsand harvesting time. Alcohol-insoluble dry matter of blackcarrots was determined as 6.50 ± 0.53 g/100 g where the

feed flow rate: 6.37 ml/min, air outlet: 103˚ C

0

100

200

300

400

500

600

700

MDX 29 Glucodry 210 SD 10An

tho

cyan

in c

on

ten

t (m

g/1

00g

DM

)

160˚ C

Fig. 2. Anthocyanin content of microencapsulated powders which arespray dried with different DE maltodextrins at 160 �C constant air inlettemperature.

808 S. Ersus, U. Yurdagel / Journal of Food Engineering 80 (2007) 805–812

pH value as 6.02 ± 0.04, acidity content as citric acid0.14 ± 0.01 g/100 g, invert sugar content as 3.80 ± 1.42 g/100 g, total sugar content as 7.73 ± 0.14 g/100 g, ash con-tent as 1.2 ± 0.12 g/100 g found. The color values of blackcarrots was measured as L*, a*, b* values and found26.95 ± 3.82, 11.35 ± 8.39, �0.73 ± 0.59, respectively. C*

value was calculated as 11.37 and H� value was found cal-culated �3.68. Malien-Aubert et al. (2001) were mentionedthat the purple carrot at pH 4.0; has H� = 2.3 andC* = 25.6. Our samples had a negative H� value which isranged �3.68 to �23.96 corresponding to a bluish hue.

The anthocyanin extract of black carrot (6� Brix) wasregulated to 20� Brix as a feed solid content with differentDE maltodextrins as coating agents and spray dried at 160,180 and 200 �C air inlet temperatures and changes ofanthocyanin contents of the powders are given in Fig. 1.

For given inlet temperatures, measured outlet tempera-tures are given in Table 1. The results were compared foreach maltodextrin separately. It was shown that increasedspray drying temperatures reduced the moisture contentof powders and moisture content ranged from 1.09 to3.76% for powders where the flow rates were kept constantas 5 ml/min. Anthocyanin content of the powders spraydried with MDX 29 was evaluated statistically and at160 �C drying temperature anthocyanin content of powderwas found highest and statistically important at 95% confi-dence interval according to 180 and 200 �C. The sameresults were taken for Glucodry 210 as MDX 29 where dry-ing temperature effect on SD 10 microencapsulation hadnot showed any significant effect statistically. Thus, for sys-tems containing lower DE maltodextrins, up to the 180 �Cair inlet temperatures can be used. Cai and Corke (2000)were also reported that higher drying temperature (>180)is not suitable for spray drying of betacyanins. So for com-paring the effect of different DE maltodextrins, air inlettemperatures at spray drying process kept constant as160 �C. To decrease the air outlet temperature from107 �C to 102 �C, feed flow rate was increased to 6.37 ml/min. Changes in anthocyanin contents of powders whichwere dried at 160 �C are given in Fig. 2.

0

100

200

300

400

500

600

MDX 29 Glucodry 210 SD 10

An

tho

cyan

in c

on

ten

t (m

g/1

00g

dry

mat

ter) 160˚ C

180˚ C

200˚ C

Fig. 1. Anthocyanin contents of the microencapsulated powders whichare spray dried with different DE maltodextrins at 160, 180 and 200 �C airinlet temperature.

Because of the increase in feed flow rate, moisture con-tents of the powders were also increased and found 5.50%for MDX 29, 5.48% for Glucodry 210 and 6.03% SD 10.The anthocyanin content of the powders which are micro-encapsulated with Glucodry 210 (630 mg anthocyanin/100 g dry matter of powder) was found 28.45% higherthan MDX 29 and SD 10 and this difference was foundstatistically important at the 95% confidence level. Mainet al. (1978) were also spray dried grape concentrate with10–13 DE maltodextrin and found anthocyanin content as492 mg/100 g dry powder. When the outlet air tempera-ture was decreased from 107 �C to 102 �C at 160 �C con-stant air inlet drying temperatures, anthocyanin contentsof powders was increased (36.83% for MDX 29, 16.05%for Glucodry 210, 7.9% for SD 10). This results revealedthat higher DE maltodextrins are more sensitive to higheroutlet air temperatures because lower molecular weightmaltodextrins contained shorter chains and oxidationreactions of aldehydes at the open sides of the moleculesmay lead to structural deformations during heating pro-cesses. As a result for 20% feed solid content and 160–180 �C drying temperatures, black carrot anthocyaninscan be microencapsulated with 20–21 DE Glucodry 210.Wagner and Warthesen (1995) were found 15 DE hydro-lysed starch provided higher stability according to 4 DE,25 DE and 36.5 DE for surface carotene retention of car-rot coagulum.

The anthocyanin content and EC50 values of samplesare given in Table 2. According to the Pearson correlationtest results between total anthocyanin content and EC50

values of samples, correlation coefficient was found to be�0.957 where the correlation is significant at the 0.05 level(2-tailed). Negative correlation value means with theincreasing anthocyanin content, EC50 value decreases sothe necessary amount of sample needs to decrease the ini-tial DPPH concentration (EC50) by 50% becomes lower(Brand-Williams et al., 1995; Parejo et al., 2000; Sanchez-Moreno, Larrauri, & Saura-Calixto, 1998). Previousresearchers (Camire, Chaovanalikit, Dougherty, & Briggs,2002; Moyer, Hummer, Finn, Frei, & Wrolstad, 2002;Wang, Cao, & Prior, 1997) reported antioxidant activityhas high correlation with anthocyanin content and totalphenolic composition of food materials.

Table 2EC50, antiradial efficiency and correlation coefficients of samples

Samples Anthocyanin content (mg/100 g) EC50A AEB SlopeC Correlation coefficient

Black carrot 125.17 ± 17.22 30.23 ± 1.65d 0.033 �0.037 0.994Anthocyanin extract (6� Brix) 2721.61 ± 5.92 2.74 ± 0.21a 0.365 �0.220 0.997Anthocyanin powder microcapsulated with MDX 29 482.96 ± 1.46 23,64 ± 0.50c 0.042 �0.029 0.990Anthocyanin powder microcapsulated with Glucodry 210 630.92 ± 15.71 17.12 ± 0.85b 0.058 �0.040 0.999Anthocyanin powder microcapsulated with SD 10 499.39 ± 22.23 22.88 ± 0.69c 0.044 �0.029 0.989Trolox 0.107a 9.34 �8.305 0.952

a–d Different letters in the same column indicate significant difference at p 6 0.05.A Efficient concentration (EC50: mg sample/mg DPPH).B Antiradial efficiency (AE: 1/EC50).C Exponential regression, ln(DPPHrem%) = x (mg sample/mg DPPH) + y.

0

100

200

300

400

500

600

700

0 7 15 22 29 36 43 52 57 64

Time (day)

An

tho

cyan

in c

on

ten

t (m

g/1

00 g

)

SD10

Glu210

MDX29

Fig. 3. Storage stability of anthocyanins encapsulated in different DEmaltodextrins by spray drier at +25 �C.

S. Ersus, U. Yurdagel / Journal of Food Engineering 80 (2007) 805–812 809

Changes in color of microencapsulated powder with dif-ferent DE maltodextrins are compared in Table 3.

Differences in DE of maltodextrins had significant effects(p 6 0.05) on L* values. With decreasing DE, L* values ofpowders were increased. a* and C* values of samples withMDX 29 were found to be significantly lower than the sam-ples produced with Glucodry 210 and SD 10. No changeswere found on b* values of samples statistically. H� valuesof MDX 29 samples were found to be higher according toother samples and difference was found statistically impor-tant. Higher a* and lower H� indicates bright and purpleshade of red colour. It is concluded with increasing DE, col-our of anthocyanins becomes more pale color.

The hygroscopic moisture of spray dried powders wasincreased with increasing DE value of maltodextrin, hygro-scopic moisture of samples is shown in Table 4 which ran-ged from 72.83 to 83.33%. Lower molecular weightmaltodextrins contained more hydrophilic groups (Cai &Corke, 2000).

3.1. Storage stability evaluation

Stability of anthocyanins in spray dried microencasu-lated powders was evaluated under various conditions of

Table 3L*, a*, b*, C* and H� values of microencapsulated powders

Microencapsulated powders with different DE maltodextrins Production L

MDX 29 1 52 5

Glucodry 210 1 52 5

SD 10 1 52 5

a–k: Different letters in the same column indicate significant difference at p 6 0

Table 4The properties of spray dried pigment powders

Microencapsulated powders with different DE maltodextrins spray driedat 160 �C air inlet/102 �C air outlet temperature

MDX 29Glucodry 210SD 10

storage temperature and light. The anthocyanin contentsof encapsulated powders were decreased by 33% at theend of 64 days storage period at 25 �C (Fig. 3). At 4 �Cstorage temperature, loss of anthocyanins was determinedas 11% (Fig. 4).

* a* b* C* H�

0.69 ± 0.38a 26.02 ± 0.30d 5.91 ± 0.19f 26.68 ± 0.26g 12.79 ± 0.53i

0.68 ± 0.41a 24.42 ± 0.69d 5.50 ± 0.27f 25.04 ± 0.09g 12.69 ± 0.60i

3.82 ± 0.21b 29.16 ± 0.19e 5.83 ± 0.17f 29.74 ± 0.22h 11.31 ± 0.28k

4.46 ± 0.25b 29.23 ± 0.02e 5.21 ± 0.02f 29.69 ± 0.02h 10.10 ± 0.06k

5.91 ± 0.28c 29.53 ± 0.35e 5.18 ± 0.07f 29.98 ± 0.33h 9.95 ± 0.21k

6.82 ± 0.18c 31.11 ± 0.22e 5.08 ± 0.20f 31.52 ± 0.25h 9.28 ± 0.30k

.05.

Total dry matter content (g/100 g) Hygroscopic moisture (g/100 g)

94.53 ± 0.58 83.3393.97 ± 0.56 76.6494.51 ± 0.79 72.83

0

100

200

300

400

500

600

700

0 7 15 22 29 36 43 52 57 64

Time (day)

An

tho

cyan

in c

on

ten

t (m

g/1

00 g

)

SD10

Glu210

MDX29

Fig. 4. Storage stability of anthocyanins encapsulated in different DEmaltodextrins by spray drier at +4 �C.

810 S. Ersus, U. Yurdagel / Journal of Food Engineering 80 (2007) 805–812

At the end of 8 weeks storage period, the pink color ofthe samples was not changed at 4 �C where it was turned tobrown color at 25 �C. The kinetics of degradation of antho-cyanins were monitored over the storage period, rate con-

Table 5Kinetic degradation data for SD 10, Glucodry 210 and MDX 29 spraydried microencapsulated powders under different storage conditions

Storageconditions

Microencapsulatedsample withmaltodextrins

k (103 day�1) t1/2

(month)

+4 �C SD 10 0.8 28Glucodry 210 0.8 28MDX 29 0.9 25

+25 �C SD 10 2.3 10Glucodry 210 2.3 10MDX 29 2.5 9

Light exposure(3000 lx at 25 �C)

SD10, Glucodry 210,MDX 29

2.4 9

0

100

200

300

400

500

600

700

0 7 15 22 29 36 43 52 57 64

Time (day)

An

tho

cyan

in c

on

ten

t (m

g/1

00 g

)

SD 10

Glu 210

MDX 29

Fig. 5. Storage stability of anthocyanins encapsulated in different DEmaltodextrins by spray drier exposed to 3000 lx of light at a 25 �C constanttemperature.

stants and half life values of reactions were determined.Previous works on anthocyanin degradation showed thatreaction followed in first order degradation kinetics (Calvi& Francis, 1978; Cemeroglu, Velioglu, & Is�ık, 1994; Kırca,Ozkan, & Cemeroglu, 2003; Markasis, 1974). An increasein storage temperature led to an increase in rate constants.Rate constants were predicted with the use of equations aslog (Co/Ct) = k · t and t1/2 = �ln0.5/k where k is the slope,Co is the initial anthocyanin content, Ct is the anthocyanincontent at a specific time and t is time. Half life (t1/2) valueswere then determined and are given in Table 5.

Fig. 6. Micrographs of microcapsules of spray dried powders of blackcarrot anthocyanin pigments containing various wall materials (a) MDX29, (b) Glucodry 210, (c) SD 10.

S. Ersus, U. Yurdagel / Journal of Food Engineering 80 (2007) 805–812 811

Half life of anthocyanins at 4 �C storage temperature wasfound 25 months where it is 10 months for 25 �C storage tem-perature. Light exposure at 25 �C caused 9 months half livesfor samples where the degradation was caused both light andtemperature effect. Changes in anthocyanin contents ofpowders under 3000 lx light exposure are shown in Fig. 5.

No effect was found between microencapsulated pow-ders with usage of different maltodextrin types as a wallmaterial during storage period.

3.2. Particle size and microstructure

SEM migrographs of particles which were spray dried at160 �C air inlet temperature with 20� Brix feed solid levelsshowed that the particle size of powders ranged from 3 lmto 20 lm approximately (Fig. 6).

All of the spray dried capsules containing maltodextrinswith different dextrose equivalent looked like smoothspheres. It was found that the particles microencapsulatedwith MDX 29 showed less resistance to the applied vacuumduring experiment.

4. Conclusion

For spray drying of black carrot anthocyanins, higherair inlet temperatures (>160–180 �C) caused more anthocy-anin losses. 20–21 DE maltodextrin which is Glucodry 210as a wall material gave the highest anthocyanin contentpowder at the end of drying process. As a natural colorantin powder form from black carrot anthocyanins, the possi-bility of maltodextrin usage as a wall material and spraydrying technology were discussed in that study. Storageat 4 �C increased half life of spray dried anthocyanin pig-ments 3 times according to 25 �C storage temperature.

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