process standardization for development of spray-dried lemon juice powder and optimization of...

PROCESS STANDARDIZATION FOR DEVELOPMENT OFSPRAY-DRIED LEMON JUICE POWDER AND OPTIMIZATION OFAMLA-LEMON BASED RTS (READY-TO-SERVE) DRINK USINGRESPONSE SURFACE METHODOLOGYPOONAM MISHRA1,3, GYANENDRA KUMAR RAI2 and CHARU LATA MAHANTA1

1Department of Food Engineering & Technology, School of Engineering, Tezpur University, Tezpur, Assam 784028, India2Center of Food Technology Science, Faculty Campus, University of Allahabad, Allahabad, India

3Corresponding author.TEL: 91-03712-267007, 267007 (5705);FAX: 91-03712-267005, 267006;EMAIL: [email protected]

Received for Publication March 1, 2014Accepted for Publication June 28, 2014

doi:10.1111/jfpp.12338

ABSTRACT

Lemon juice powder was obtained from its juice under optimized conditions byspray drying with maltodextrin at 10, 15 and 20% levels. The effect of inlet tem-peratures of 125, 150, 175 and 200C and maltodextrin levels on the physicochemi-cal properties, total phenolic content (TPC) and diphenyl picryl hydrazyl (DPPH)scavenging activity of spray-dried lemon juice powder was studied. Spray-driedlemon juice powder was incorporated with spray-dried amla juice powder (pro-cessing conditions optimized in previous reported work) to develop a dry mix forready-to-serve (RTS) drink along with citric acid and glucose. Spray-dried lemonjuice powder was used to enhance the acceptability and nutritive value of amla-based RTS fruit drink. The amla-lemon based RTS drink had good nutritionalquality and TPC. Refrigerated storage with nitrogen flushing prevented colorchange and reduced TPC and DPPH loss. The optimized product got good scoreson sensory evaluation.

PRACTICAL APPLICATIONS

Amla and lemon fruits are known for their health benefits. The present investiga-tion studied the effect of spray drying conditions on total phenolic content andDPPH* radical scavenging activity of the spray-dried lemon powder. Spray-driedlemon powder may be used for further product development and also to enrichthe functional and nutritive properties of the food. The present investigation alsooptimized the amla-lemon based RTS drink and also studied the storage stabilityof the developed RTS drink.

INTRODUCTION

Fruit juice powders have a number of advantages over theirliquid counterparts like reduced weight, volume, cost ofpackaging, convenient handling and transportation andlonger shelf life (Goula and Adamopoulous 2005). Fruitpowders produced by spray drying have good reconstitutingcharacteristics and low water activity, and are also good forstorage. Spray drying technique is an appropriate techniquefor thermosensitive constituents. Maltodextrin is a com-monly used drying aid in spray drying due to itsconstructive role as an encapsulating agent or as a carrieragent.

Being a rich source of flavonoids, vitamin C, citric acidand minerals, lemon provides several health benefits(Gonzalez-Molina et al. 2008b). Lemon is the third mostimportant citrus crop, and therefore its availability is alsogood (Gonzalez-Molina et al. 2008b). Amla (Emblicaofficinalis), being very astringent in nature, has poor accept-ability as a raw fruit in comparison to other commerciallyavailable fruit. Hence, processing becomes necessary toenhance the palatability of amla. Several value-added prod-ucts like squash, preserve, candy (Devi and Mishra 2009)and ready-to-eat chutney (Mishra et al. 2011) have beenprocessed from amla. But excessive processing reduces thevaluable components from the amla significantly. The paper

Journal of Food Processing and Preservation ISSN 1745-4549

Journal of Food Processing and Preservation •• (2014) ••–•• © 2014 Wiley Periodicals, Inc. 1

mailto:[email protected]

presents the results of two separate but correlated works. Inthis study, processing conditions for development of spray-dried lemon juice powder were standardized. Further, spray-dried amla juice powder was obtained with optimizedconditions from our previous study (Mishra et al. 2014) andspray-dried lemon juice and amla juice powders were takenas raw materials for development of amla-lemon basedready-to-serve (RTS) drink to improve the acceptability ofamla using response surface methodology. The developedRTS drink was further investigated.

MATERIALS AND METHODS

Materials

Chemicals for present work, i.e., Folin–Ciocalteu reagent(FCR), sodium carbonate, 2,2,diphenyl picryl hydrazyl(DPPH) and ethanol, were purchased from Merck, India.Maltodextrin with 20 dextrose equivalent was purchasedfrom Himedia, India.

Raw Materials

Chakaiya variety of amla fruits was collected from localmarket of Allahabad, India, whereas lemon of Kaji varietywas procured from local market of Assam, India. The lemonwas washed thoroughly to remove adhered dust and wipedwith muslin cloth.

Process Standardization for Development ofSpray-Dried Lemon Juice Powder

Maltodextrin was added to the lemon juice at 10, 15 and20% levels. The levels chosen were deduced from literatureand preliminary runs in the laboratory (not reported here).Preliminary trials showed that when the maltodextrin con-centration was lower than 10% most of the material stuckto chamber wall, and when the maltodextrin concentrationwas higher than 20% there was a significant decrease in thefree radical scavenging activity of powder. Lemon juicetaken for present study had pH of 2.5 and acidity of5.42 ± 0.3% in terms of citric acid, and contained0.29 ± 0.2 g/100 mL sucrose and had 7.33° Brix value. Feedmaterial for all the formulations was taken from a singlebatch of lemon juice.

The feed mixtures containing maltodextrin and juicewere dried in lab spray dryer (Labultima, Mumbai, India).The inlet/outlet temperatures used were 125C/83C, 150C/92.5C, 175C/101C and 200C/113C. The compressor pres-sure, air flow rate and feed rate were kept constant at0.06 MPa, 65 ± 2 m3/h and 13–15 mL/min, respectively(Kha et al. 2010). All formulations for drying were carried

out in duplicate. Flow chart for preparation of spray-driedlemon juice powder is shown in Fig. 1.

Physicochemical Properties of Spray-DriedLemon Juice Powder

Water solubility index (WSI), hygroscopicity, bulk densityand color characteristics of the spray-dried lemon juicepowder were analyzed by the method of Anderson et al.(1969), Cai and Corke (2000), Goula and Adamopoulous(2005), and Duangmal et al. (2008), respectively.

Total Phenolic Content

Estimation of total phenolic content (TPC) was performedby FCR method as described by Liu et al. (2008) with somemodifications. Briefly, 250 mg of sample was properly dis-persed in 10 mL of 60% acetone and kept in incubatorshaker at 30C for 30 min. Then 60 μL of supernatant,300 μL of FCR and 750 μL of 20% sodium carbonate inwater were added in 4.75 mL of water. The mixture was keptin incubator at 37C for 30 min. The absorbance was read at765 nm by using double beam spectrophotometer (Evolu-tion 600, Thermo Scientific Waltham, MA) and the resultswere expressed as mg of gallic acid equivalent.

FIG. 1. FLOWCHART FOR THE PREPARATION OF SPRAY-DRIED LEMONJUICE POWDER

AMLA-LEMON BASED RTS DRINK P. MISHRA, G.K. RAI and C.L. MAHANTA

Journal of Food Processing and Preservation •• (2014) ••–•• © 2014 Wiley Periodicals, Inc.2

DPPH* Radical Scavenging Activity

The DPPH* scavenging activity of extract of powder wasestimated by the method of Luo et al. (2011) with slightmodifications. Briefly, 50 mg of the extracted powder wasdissolved in 5 mL of methanol solution and shaken in anincubator shaker at 150 rpm at 25C for 30 min. About 2 mLof filtered mixture of methanolic extract was mixed with2 mL of methanolic solution containing 0.1 mM DPPH.The reaction mixture was mixed vigorously and then kept inthe dark for 30 min. The absorbance at 517 nm wasrecorded. The absorbance of control was measured byreplacing the sample with methanol.

DPPH scavenging activity

absorbance of sample

ab

∗ ( )

= −( ) ×%

1 100

ssorbance of control

Scanning Electron Microscopy

Particle morphology was analyzed by scanning electronmicroscopy (SEM). Powders were attached to a double-sided adhesive tape on SEM stubs, coated with 3–5 mA pal-ladium under vacuum and were examined with a JEOLSEM (JSM-6390 LV, Japan, PN junction type, semiconduct-ing detector). SEM was operated with 15 kV at magnifica-tion of 5500X and 6500X.

Development of Spray-Dried AmlaJuice Powder

Spray-dried amla juice powder was obtained as per theprocess outlined by Mishra et al. (2014). The flow chart forthe optimized process is given in Fig. 2.

Optimization of Amla-Lemon BasedRTS Drink

A central composite rotatable design with three numericalfactors was employed to design the experiments. Thenumerical factors were amla juice powder, lemon juicepowder and citric acid. The minimum and maximum levelsof the variables were varied with 15–35%, 15–35% and1–2% for amla juice powder, lemon juice powder and citricacid, respectively. Amla juice powder 25%, lemon juicepowder 25% and citric acid 1.5% were repeated five times ascentral point. The formulation was made up to 100% withglucose powder. A total of 20 experiments were performed(Table 1). The whole mixture was homogenized in a mixer.All 20 combinations were subjected to sensory qualityevaluation by semi-trained panelists who were in age groupof 21–28 years. Proximate analysis of the optimized productwas carried out by AOAC (2010).

Mineral Analysis

Minerals were analyzed by the method given by Foodand Agriculture Organization of the United Nations(FADA/SIDA) (1983) with slight modifications. Briefly, 2 gof sample was placed in Kjeldahl tubes and freshly preparednitric acid-sulfuric acid mixture (25 mL) in the ratio of1.5:1 was added. The sample was digested at 250C for 2–3 hor until a clear solution was obtained. After cooling, thesolution was diluted with 100 mL deionized water andthe residue was filtered through an ashless filter paper. Themineral content of the sample was determined by atomicabsorption spectroscopy (ICE 2000, Thermo Scientific,Waltham, MA) with air acetylene flame for Ca, P, Fe, Naand K.

Sensory Analysis

For sensory evaluation, 2.5 g of the optimized formulationsand 15 g of sugar were mixed with 100 mL of water andkept at refrigerator temperature before serving to the panel-ists. A panel comprising of 15 trained panelists sat in indi-vidual booths and were asked to grade each sample on a9-point hedonic scale with respect to color, flavor,mouthfeel and overall acceptability (Murray et al. 2001).

Storage Study

The amla-lemon based RTS drink was packed in laminatesunder two different conditions, i.e., (1) with N2 flushing and(2) without N2 flushing, and the packed samples were

FIG. 2. FLOWCHART FOR THE PREPARATION OF SPRAY-DRIED AMLAJUICE POWDER (MISHRA et al. 2014)

P. MISHRA, G.K. RAI and C.L. MAHANTA AMLA-LEMON BASED RTS DRINK


further stored at two different temperatures, i.e., ambientand refrigeration (7C) temperatures. The relative humidity(RH) was kept constant at 75%. The samples were drawn atan interval of 15 days and were analyzed for DPPH*scavenging activity, TPC, moisture content and colorcharacteristics.

Statistical Analysis

The experiments were carried out in duplicate and obtainedmean values were analyzed by analysis of variance(ANOVA). The graphs of mean value and error bar werecreated using Excel version 2003.

RESULTS AND DISCUSSIONS

Effect of Spray Drying Conditions onPhysical Properties of Lemon Juice Powder

The effect of maltodextrin concentration, aspiration speedand different drying temperatures on the physical proper-ties of lemon juice powder is given in Table 2. Maltodextrinwas taken at 10, 15 and 20% levels. Increase in the concen-tration of maltodextrin resulted in a decrease in moistureconcentration in the finished powder from 4.59 to 3.57%when produced at 175C (Table 2). Abadio et al. (2004)reported that on increasing the level of maltodextrin from10 to 15% (w/v), there was a decrease in moisture contentduring spray drying of pineapple juice powder. Ferrari et al.

(2013) also reported that the addition of maltodextrin iseffective in reducing the final moisture content of spray-dried blackberry powder. Increased level of maltodextrinincreased the level of feed solids which subsequentlyreduced the level of total moisture for evaporation(Grabowski et al. 2006; Kha et al. 2010).

A similar trend was found at inlet temperatures of 125,150, 175 and 200C. A significant decrease in moisturecontent from 7.03 to 3.89% was observed (Table 2). This isdue to the greater driving force for evaporation of moistureat higher temperature (Quek et al. 2007; Ferrari et al. 2012;Solvol et al. 2012). The present findings were consistentwith the results obtained for spray-dried tomato powder(Goula and Adamopoulous 2005), orange juice powder(Chegini and Ghobadian 2005), cactus pear juicepowder (Rodriguez-Hernandez et al. 2005), black carrotpowder (Ersus and Yurdagel 2007) and gac juice powder(Kha et al. 2010).

The maltodextrin level significantly (P < 0.05) affectedthe hygroscopicity of the lemon juice powder; hygroscopic-ity was lowest with maximum maltodextrin concentration.Similar findings were stated by Cai and Corke (2000) andRodriguez-Hernandez et al. (2005) in spray-driedbetacyanin pigments and cactus juice powder, respectively.On the other hand, inlet temperature influenced the hygro-scopicity of the powder positively. The highest hygroscopic-ity value of 19.44 g/100 g of lemon powder (with 10%maltodextrin) was obtained at 200C inlet temperature.

TABLE 1. CENTRAL COMPOSITE ROTATABLE DESIGN WITH EXPERIMENTAL VALUES OF RESPONSE VARIABLES FOR OPTIMIZATION OFAMLA-LEMON BASED RTS DRINK

Amlapowder (%)

Lemonpowder (%)

Citricacid (%)

Glucose(%) Flavor Color Mouthfeel

Overallacceptability

TPC(mg GAE/100 g)

15.00 15.00 1.00 69.00 7.10 7.60 7.00 6.80 2.3225.00 25.00 2.34 47.66 6.50 7.20 6.70 6.70 4.8135.00 35.00 2.00 28.00 5.80 7.70 5.40 5.20 6.4135.00 35.00 1.00 27.00 6.80 7.50 5.50 5.90 6.4815.00 15.00 2.00 68.00 7.50 7.70 5.80 6.00 2.2925.00 25.00 1.50 48.50 7.20 7.20 7.30 7.80 4.5625.00 25.00 1.50 48.50 7.20 7.20 7.30 7.80 4.5615.00 35.00 1.00 49.00 6.50 7.60 6.90 6.80 2.8925.00 25.00 1.50 48.50 7.20 7.20 7.30 7.80 4.5641.82 25.00 1.50 31.68 5.10 7.10 4.10 5.10 7.388.18 25.00 1.50 65.32 7.50 8.20 7.50 8.00 1.12

25.00 8.18 1.50 65.32 6.60 6.50 5.70 6.20 4.3125.00 25.00 1.50 48.50 7.20 7.20 7.30 7.80 4.5625.00 41.82 1.50 31.68 7.20 6.80 6.70 7.10 5.2635.00 15.00 1.00 49.00 6.10 7.40 5.20 5.20 6.1025.00 25.00 1.50 48.50 7.10 7.50 7.10 7.70 4.5625.00 25.00 1.50 48.50 7.20 7.50 7.60 7.70 4.5635.00 15.00 2.00 48.00 4.90 7.70 4.80 4.80 6.1525.00 25.00 0.66 49.34 6.90 7.50 6.90 7.00 4.5115.00 35.00 2.00 48.00 7.00 7.70 7.60 8.10 2.79

GAE, gallic acid equivalent; RTS, ready-to-serve; TPC, total phenolic content.



Tonon et al. (2008) explained that at increased inlet tem-perature, lower moisture content provides greater waterconcentration gradients between the products and sur-rounding air that increases the tendency of the powder toadsorb moisture. The present findings are in agreementwith Goula and Adamopoulous (2005) and Tonon et al.(2008) for their work on spray drying of tomato pulp andacai juice, respectively, but contradict the findings ofMoreira et al. (2009).

Drying temperature showed no significant effect on WSIof lemon powder (Table 2) at 5% probability level (Table 2).During drying of tomato powder, Sousa et al. (2008) alsoobserved that drying conditions had no effect on WSI ofpowder. In the present study, WSI of lemon juice powderranged from 94.34 to 98.08%. These values were higher ascompared to 17.65–26.3% in spray-dried tomato powder(Moreira et al. 2009), 36.91–38.25% in gac powder (Khaet al. 2010) and 81.56% in pineapple juice powder (Abadioet al. 2004). The excellent WSI of lemon juice powder indi-cates its suitability for reconstitution and for furtherproduct development.

Maltodextrin level had no effect on bulk density of lemonjuice powder whereas inlet temperature significantlyreduced the bulk density of powder (Table 2). This findingis in agreement with Walton and Mumford (1999), Cai andCorke (2000), Goula and Adamopoulous (2005) and Khaet al. (2010). Several scientists explained that as rate ofdrying was rapid at very high temperature, there was lessshrinkage of droplets that resulted in lower density of thepowder (Jumah et al. 2000; Walton 2000; Duangmal et al.2008).

Particle Morphology

Figure 3 shows the SEM micrograph of the powdersproduced with 15% maltodextrin at different inlet

TABLE 2. PHYSICOCHEMICAL PROPERTIES OF SPRAY-DRIED LEMON POWDER

Maltodextrin(%)

Temperature(C) MC (%)

Bulk density(g/mL)

Hygroscopicity(g/100 g) WSI (%)

10 125 7.03 ± 0.6a 0.56 ± 0.1a 16.69 ± 0.3a 98.09 ± 1.1a

150 6.37 ± 0.4b 0.51 ± 0.1b 17.64 ± 0.5b 97.44 ± 1.0a

175 4.59 ± 0.3c 0.48 ± 0.0c 17.89 ± 0.4c 97.94 ± 1.0a

200 3.89 ± 0.23d 0.44 ± 0.03d 19.44 ± 0.23d 97.47 ± 1.03a

15 125 6.58 ± 0.3a 0.54 ± 0.02a 14.44 ± 0.3a 97.37 ± 0.9a

150 5.83 ± 0.4b 0.50 ± 0.03b 15.10 ± 0.3b 94.42 ± 1.4a

175 4.12 ± 0.3c 0.46 ± 0.03c 15.70 ± 0.2c 94.86 ± 1.5a

200 3.32 ± 0.26d 0.43 ± 0.06d 16.46 ± 0.27d 96.51 ± 1.89a

20 125 5.27 ± 0.4a 0.55 ± 0.04a 13.92 ± 0.4a 97.90 ± 1.5a

150 4.20 ± 0.3b 0.50 ± 0.0b 14.28 ± 0.3b 96.88 ± 1.1a

175 3.67 ± 0.3c 0.47 ± 0.0c 14.64 ± 0.3c 96.52 ± 1.6a

200 2.97 ± 0.12d 0.44 ± 0.02d 15.21 ± 0.17d 96.20 ± 2.10a

Note: Values = mean ± SD. The values of the same column with different superscript letters differ significantly (P < 0.05).MC, moisture content; WSI, water solubility index.

FIG. 3. MICROGRAPHS OF PARTICLES AT DIFFERENT INLETTEMPERATURE AND CONSTANT MALTODEXTRIN LEVEL (15%) ANDMAGNIFICATIONS(a) 150C, 5500X. (b)150C, 6500X. (c) 175C, 5500X. (d) 175C, 6500X. (e) 200C, 5500X. (f) 200C, 6500X.



temperatures. Inlet temperature showed no effect onthe surface smoothness of the particles of the lemonjuice powder which contradicts the observations ofAllamila-Beltran et al. (2005), Nijdam and Langrish (2006),and Tonon et al. (2008), who reported that increased inlettemperature produced particles with smooth surface ascompared to powder produced at low inlet temperature. Itwas observed that the average particle size of powder driedat higher inlet temperature was smaller than that of powderdried at lower inlet temperature, and the present findingagreed with Cai and Corke (2000), but contradicted those ofNijdam and Langrish (2006) and Tonon et al. (2008).

Color Characteristics of Powder

The color parameter of lightness and chroma was found tobe influenced by increase in level of maltodextrin and inlettemperature (Fig. 4a,b). Lightness increased with level ofmaltodextrin while a reverse trend was observed for chromawhich may be credited to the protective effect ofmaltodextrin.

The 15 and 20% maltodextrin-incorporated powders hadcloser lightness and chroma values at the different inlet

temperatures studied. Interestingly, the a/b and hue anglevalues showed that the effect of spray drying with 20%maltodextrin level at temperatures of 125, 150, and 175Cwas in between that of 10 and 15% maltodextrin levels(Fig. 4c). However, at 200C, the 20% maltodextrin levelsubstantially decreased as compared to 15% maltodextrinlevel.

Higher maltodextrin level and higher inlet temperatureresulted in lower a/b value and lower hue angle which con-tradicts Chen et al. (1995). The probable reason may be thatspray drying increased the surface area causing rapidpigment oxidation (Desobry et al. 1997).

Effect of Spray Drying Conditions on TPC ofLemon Powder

Figure 5a shows the effect of processing conditions on TPCof spray-dried lemon juice powder. TPC was significantly(P < 0.001) reduced when inlet temperature was increasedfrom 125 to 200C temperature, indicating the thermal deg-radation of phenolics. Ersus and Yurdagel (2007) observedgreater anthocyanin losses during spray drying of black

FIG. 4. COLOR CHARACTERISTICS OF SPRAY-DRIED LEMON JUICE POWDER OF (a) LIGHTNESS, (b) CHROMA, (c) HUE ANGLEmaltodextrin 10%; maltodextrin 15%; maltodextrin 20%.

FIG. 5. EFFECT OF SPRAY DRYINGCONDITIONS ON (a) TOTAL PHENOLICCONTENT AND (b) DPPH* SCAVENGINGACTIVITY OF LEMON JUICE POWDER

maltodextrin 10%; maltodextrin15%; maltodextrin 20%.



carrot at higher air inlet temperatures (>160–180C) andoutlet temperatures (107–131C). Fang and Bhandari (2011)also reported that operating temperatures are very impor-tant for spray drying of heat-sensitive nutrients.

The TPC content of the lemon juice powders was reducedwhen the concentration of the maltodextrin was increasedfrom 10 to 20%. This can be explained to be due to the dilu-tion effect of maltodextrin. No significant difference wasobserved in the sample having 20 and 15% of maltodextrinwhen produced at 200C inlet temperature.

Effect of Spray Drying Conditions on DPPH*Scavenging Activity of Powder

Figure 5b shows the effect of processing conditions of spraydrying on DPPH* scavenging activity of lemon juicepowder. Maltodextrin level and drying temperature showeda statistically significant effect (P < 0.05) on the DPPH*scavenging activity of the powder. DPPH* scavenging activ-ity of the lemon juice powder was significantly affected byincrease in inlet temperature. Similar findings were reportedby Kha et al. (2010) in case of gac juice powder. The possibleexplanation for the low free radical scavenging activity maybe due to the exposure to higher temperatures whichadversely affected the structure of phenolics causing itsbreakdown and subsequent reduction in the antioxidantactivity.

Increase in maltodextrin concentration resulted in lowerDPPH* scavenging activity in spray-dried lemon juicepowder which can be attributed to the dilution effects ofmaltodextrin. These results contradicted the result of Khaet al. (2008), who did not find any significant effect ofmaltodextrin level from 10 to 20% on total antioxidantactivity of gac juice powder.

Experimental Design for Development ofAmla-Lemon Based RTS Drink

For amla-lemon RTS drink, lemon juice was spray dried at175C inlet temperature with 10% maltodextrin and amlajuice was dried separately at 175C inlet temperature with7% maltodextrin. Significant terms in the model wereobserved by ANOVA. Model adequacy was checked by R2,predicted R2, adequacy precision and lack of fit test. Pre-dicted R2 comparable to fitted R2, low predicted residualerror sum of squares (PRESS) and adequacy precisiongreater than 4 (Corzo et al. 2008; Erby and Icier 2009;Mohapatra and Bal 2010) for flavor, mouthfeel, overallacceptability and TPC shows that model terms were signifi-cant and fitted adequately for these attributes, whereas thenegative value of predicted R2 for color shows that modelterms were not fitted adequately for color value.

Response Surface

Figure 6a shows the effect of lemon juice powder and amlajuice powder on flavor acceptability of the RTS drink.Increase in concentration of amla juice powder was fol-lowed by decrease in the flavor acceptability of the product.In particular, higher concentration of amla juice powderwith lower concentration of lemon juice powder decreasedthe flavor acceptability of the product. For color, the modelwas not found significant at 5% probability level, suggestingthat the variation in levels of amla juice powder, lemon juicepowder and citric acid did not affect the color of theproduct as evident from Figs. 6b, 7b and 8b.

Figure 6c presents the interactive effect of lemon juicepowder and amla juice powder on mouthfeel of the opti-mized RTS drink. Increase in level of amla juice powderdecreased the mouthfeel acceptability of the product whichmay be correlated with the astringency of the amla juicepowder because panelist clearly remarked that lower rating ofthe product was related to the increased astringency of thesample. Increase in the level of lemon juice powder improvedthe mouthfeel attributes of the RTS drink. The surfaceresponse of overall acceptability as a function of lemon juicepowder and amla juice powder is given in Fig. 6d. As the levelof lemon was increased, the product was found to be moreacceptable by the panelists and the acceptability level hadincreased from 5.67 to 8.2, but when the level of lemon juicepowder was increased along with the amla juice powder, theproduct secured less rating by the panelist which can beattributed to astringency in the amla juice powder. Thesurface response of TPC as a function of amla and lemonjuice powders is shown in Fig. 6e. Amla juice powder had astrong positive effect on TPC at 1% probability level.However, interaction of lemon and amla juice powder wasnot found significant at 5% probability level.

Figure 7a presents the surface response of flavor as afunction of citric acid and lemon juice powder. Lemon juicepowder showed significance at 5% whereas citric acid wassignificant at 1% probability level. The interactive effect oflemon juice powder and citric acid was not found signifi-cant on flavor acceptability of the RTS drink. Increase in thelevel of citric acid from 1 to 2% did not show any significanteffect on mouthfeel attribute of the RTS drink, whereasincrease in level of lemon juice powder showed a significantand positive effect on mouthfeel of the RTS drink (Fig. 7c).Figure 7d presents the surface response of overall accept-ability as a function of lemon juice powder and citric acid.Lemon juice powder showed a positive effect at 5% signifi-cance level whereas citric acid was not found effective at 5%significance level. The interactive effect of lemon juicepowder and citric acid was also not found significant at 5%probability level. Figure 7e shows the interactive effect ofcitric acid and lemon juice powder on TPC of RTS drink. As



the level of lemon juice powder increased, the TPC was sig-nificantly increased. Citric acid showed no significant effecton TPC of developed product. The interactive effect ofcitric acid and amla juice powder on flavor acceptability ofthe RTS drink is given in Fig. 8a. Both powder and citricacid showed a positive effect on the flavor acceptability.Increase in the level of amla juice powder decreased themouthfeel acceptability; however, citric acid showed a posi-tive effect on mouthfeel of RTS drink (Fig. 8c). The sameinferences can be drawn for the overall acceptability of theproduct where amla juice powder was found more effectivein increasing the acceptability of the product (P < 0.01) ascompared to citric acid (Fig. 8d). When lemon juice powderwas increased the TPC content was significantly increased,but the increase in level was comparatively less than in caseof increase in level of amla juice powder, confirming thepresence of significantly high level of phenolic content inamla juice powder as compared to lemon juice powder(Fig. 8e). The composition of 25.94% amla juice powder,32.02% lemon juice powder, 1.72% citric acid and 40.32%glucose powder was found optimum. Triplicate sampleswere prepared using the optimum conditions and were ana-lyzed for organoleptic quality and TPC; the corresponding

values for flavor, color, overall acceptability, TPC andmouthfeel were 7.18, 7.28, 7.78, 4.56 and 7.45, respectively,which showed an excellent agreement with the predictedresponses and the actual value (Table 3). Hence, the modelwas found satisfactory.

Chemical Composition and Storage Stabilityof Optimized Amla-Lemon Based RTS Drink

Optimized amla-lemon based RTS drink was analyzed forits nutritional quality and data were given in Table 4.

FIG. 6. RESPONSE SURFACE AND CONTOUR PLOTS FOR (a) FLAVOR, (b) COLOR, (c) MOUTHFEEL, (d) OAA AND (e) TPC (AT CONSTANT % OFCITRIC ACID)

TABLE 3. OPTIMUM CONDITIONS FOR THE DEVELOPMENT OFAMLA-LEMON RTS DRINK

Particular Predicted Optimum

Flavor 7.18 7.32Color 7.28 7.68Mouthfeel 7.32 7.45Overall acceptability 7.78 7.91TPC mg/100 g GAE equivalent 4.56 4.48

GAE, gallic acid equivalent; RTS, ready-to-serve; TPC, total phenoliccontent.



Finished formulations had moisture content with meanvalue of 4.3% and contained good amount of K, Ca and P.The significant amount of TPC and free radical scavengingactivity makes it suitable as a health drink.

Figure 9 presents the color stability of the RTS drinkduring storage. Room temperature adversely affected thelightness of the stored product whereas the refrigeratedproduct had better stability during the same period ofstorage (Fig. 9a). During the first 30 days of storage no sta-tistically significant difference in overall color difference ofthe sample was observed in refrigerated samples, while inroom temperature the overall color difference also increasedsimultaneously in the stored sample as the storage time pro-gressed (Fig. 9b). Increased rate of darkness and total colordifference of sample at room temperature may be due to theincreased rate of formation of iron tannate (present in amlajuice powder) that causes an increased degree of rednessand darkness in the sample (a common phenomenon). Theresult is consistent with Mishra et al. (2010), where sun-dried amla powder had significantly lower L value as com-pared to freeze-dried or vacuum-dried amla powder. N2

flushing inside the package reduced the rate of degradationof color during storage at both ambient and refrigerationtemperatures (Fig. 9a,b). The reason for better retention ofcolor in samples stored in the environment flushed withnitrogen may again be correlated with rate of formation ofiron tannate. For the formation of iron tannate the presenceof oxygen is essential, hence packing with N2 flushing

FIG. 7. RESPONSE SURFACE AND CONTOUR PLOTS FOR (a) FLAVOR, (b) COLOR, (c) MOUTHFEEL, (d) OAA AND (e) TPC (AT CONSTANT % OFAMLA JUICE POWDER)

TABLE 4. CHEMICAL COMPOSITION OF OPTIMIZED AMLA-LEMONBASED RTS DRINK

Particular Composition

Moisture (%) 4.63 ± 0.3*Protein (%) 0.04 ± 0.1Fat (%) 0.05 ± 0.1Carbohydrates (%) 95.64 ± 0.8Calcium (mg/100 g) 31.50 ± 1.0Phosphorous (mg/100 g) 22.40 ± 1.2Iron (mg/100 g) 2.45 ± 0.6Sodium (mg/100 g) 98 ± 1.7Potassium (mg/100 g) 184 ± 1.4Total phenolic content (g/100 g) GAE equivalent 4.48 ± 0.6DPPH* scavenging activity (%) 87.64 ± 1.5L 89.56 ± 2.1a −0.41 ± 0.01b 9.58 ± 0.6kcal/100 g of powder 383.17 ± 1.1

* Mean ± standard deviation.GAE, gallic acid equivalent; RTS, ready-to-serve.



hampered the reaction of iron and tannic acid and soretained the color of the sample during the storage.

Stability of TPC in RTS drink during storage can be seenin Fig. 10a. Storage temperature showed a significant effecton retention of TPC in the product. The sample stored at

room temperature had increased rate of degradation ofTPC as compared to the sample stored at 7C. The samplestored with N2 flushing and at ambient temperature hadbetter retention of phenolic content as compared to thesample stored at refrigeration temperature, which suggested

FIG. 8. RESPONSE SURFACE AND CONTOUR PLOTS FOR (a) FLAVOR, (b) COLOR, (c) MOUTHFEEL, (d) OAA AND (e) TPC (AT CONSTANT % OFLEMON JUICE POWDER AT CENTRAL POINT)

FIG. 9. EFFECT OF STORAGE TEMPERATURE ON COLOR CHARACTERISTICS OF AMLA-LEMON RTS DRINK(a) Lightness and (b) total color difference. ambient temperature (N2 flushing); room temperature; stored at refrigerationtemperature; refrigeration temperature (N2 flushing).



that the absence of oxygen is more important to retard therate of degradation of phenolics as compared to refrigera-tion temperature. The rate of oxidation of TPC may beincreased due to storage at room temperature, which causesthe reduction in overall TPC. The lowering of TPC at refrig-eration temperature may be due to the precipitation of fla-vonoids (Gil-Izquierdo et al. 2004; Gonzalez-Molina et al.2008b).

Figure 10b presents the DPPH* scavenging activity of theamla-lemon based RTS drink during storage. The samplestored at room temperature lost DPPH* scavenging activityat rapid rate as compared to refrigeration temperature,which may be due to the degradation of the phenolics.Mutual degradation of TPC and free radical scavengingactivity has been broadly reported. Degradation rate of freeradical scavenging activity was comparatively higher thanTPC at both storage temperatures. Being secondarymetabolites, phenolic compounds are probably synthesizedor broken down into new components which adverselyaffected the free radical scavenging activity of RTS drink.Figure 10 also showed that the sample stored with N2 iseffective to retain the bioactive properties like TPC andDPPH* scavenging activity.

CONCLUSIONS

The effect of spray drying conditions on physicochemicalproperties of spray-dried lemon juice powder was evalu-ated. Maltodextrin concentration (10–20%) and dryingtemperature (125–200C) significantly affected moisturecontent, bulk density, hygroscopicity, color attributes, TPCand DPPH* scavenging activity. However, WSI was not sig-nificantly influenced by varying the concentration ofmaltodextrin or inlet temperature. The developed lemonjuice powder showed excellent water solubility that is essen-

tial for reconstitution. The juice powder dried at 125C tem-perature and maltodextrin concentration of 10% showedbetter retention of phenolic content and free radical scav-enging activity, but due to excessive stickiness it can not berecommended as a product. Lemon juice dried at 175Ctemperature and 10% maltodextrin concentration is recom-mended. It was ascertained by response surface methodol-ogy (RSM) that 25.94% amla juice powder, 32.02% lemonjuice powder, 1.72% citric acid and 40.32% glucose powderwere found optimum for RTS drink development.

REFERENCES

ABADIO, F.D.B., DOMINGUES, A.M., BORGES, S.V. andOLIVERA, V.M. 2004. Physical properties of powderedpineapple juice (Annas comosus) juice: Effect of malto dextrinconcentration and atomization speed. J. Food Eng. 64,285–287.

ALLAMILA-BELTRAN, L., CHANONA-PERE, J.J.,JIMENEZ-APARICIO, A.R. and GUTIERREZ-LOPEZ, G.F.2005. Description of morphological changes of particles alongspray drying. J. Food Eng. 67, 179–184.

ANDERSON, R.A., CONWAY, H.F., PFEFER, V.F. and GRIFFIN,E.L. 1969. Gelatinization of corn grits by roll and extrusioncooking. Cereal Sci. Today. 14, 4–11.

AOAC. 2010. Official Methods of Analysis of Association ofAnalytic Chemists, 18th Ed., Assoc. of OfficialAnalytical Chemists, Washington, DC.

CAI, Y.Z. and CORKE, H. 2000. Production and properties ofspray dried Amaranthus Betacyanin pigments. J. Food Sci. 65,1248–1252.

CHEGINI, G.R. and GHOBADIAN, B. 2005. Effect of spraydrying conditions on physical properties of orange juicepowder. Drying Technol. 23, 657–658.

CHEN, B.H., PENG, H.Y. and CHEN, H.E. 1995. Changesof carotenoids, color and vitamin A content during

FIG. 10. EFFECT OF STORAGE ON (a) TOTAL PHENOLIC CONTENT OF RTS DRINK AND (b) DPPH* SCAVENGING ACTIVITY OF RTS DRINKambient temperature (N2 flushing); room temperature; stored at refrigeration temperature; refrigeration temperature (N2

flushing).



processing of carrot juice. J. Agric. Food Chem. 43,1912–1918.

CORZO, O., BRACHO, N., VÁSQUEZ, A. and PEREIRA, A.2008. Optimization of thin layer drying process for corobaslices. J. Food Eng. 85, 372–380.

DESOBRY, S.A., NETTO, F.M. and LABUZA, T.P. 1997.Comparison of spray drying, drum drying and freeze –dryingfor β-carotene encapsulation and preservation. J. Food Sci. 62,1158–1162.

DEVI, S. and MISHRA, P. 2009. Development of Aonla candy.Beverage Food World 36, 43–44.

DUANGMAL, K., SAICHEAU, B. and SUEEPRASAN, S. 2008.Color evaluation of freeze dried roselle extract as natural foodcolorants in model system of a drink. LWT – FoodSci Technol. 41, 1437–1445.

ERBY, Z. and ICIER, F. 2009. Optimization of hot air drying ofolive leaves using response surface methodology. J. Food Eng.91, 533–541.

ERSUS, S. and YURDAGEL, U. 2007. Microencapsulation ofanthocyanin pigments of black carrot (Daucus carota L.) byspray drier. J. Food Eng. 80, 805–812.

FANG, Z. and BHANDARI, B. 2011. Effect of spray drying andstorage on the stability of bayberry polyphenols. Food Chem.129, 1139–1147.

FERRARI, C.C., GERMER, M.P.S. and AGUIRRE, J.M. 2012.Effects of spray drying conditions on the physicochemicalproperties of blackberry powder. Drying Technol. 30,154–163.

FERRARI, C.C., GERMER, M.P.S., ALVIM, D.I. and AGUIRRE,J.M. 2013. Storage stability of spray dried blackberry powderproduced with maltodextrin or gum Arabic. Drying Technol.31, 470–478.

FOOD AND AGRICULTURE ORGANIZATION OF THEUNITED NATIONS (FADA/SIDA). Manual Method inAquatic Environment Research, Part 9, Analysis of Metals andOregano-Chlorine in Fish, Section 2, pp. 14–20, F.A.O. FishTechnical Paper, 212, Rome, 1983.

GIL-IZQUIERDO, A., RIQUELME, M.T., PORRAS, I. andFERRERES, F. 2004. Effect of rootstock and interstock graftedin lemon tree (Citrus limon (L) Burm) on the flavonoidcontent of lemon juice. J. Agric. Food Chem. 52, 324–331.

GONZALEZ-MOLINA, E., MORENO, D.A. andGARCIA-VIGUERA, C. 2008b. Aronia-enriched lemon juice:A new highly antioxidant beverage. J. Agric. Food Chem. 56,1242–1246.

GOULA, A.M. and ADAMOPOULOUS, K.G. 2005. Stabilityof lycopene during spray drying of Roselle extracts(Hibiscus sabdariffa L.). Plant Foods Hum. Nutr. 64,62–67.

GRABOWSKI, J.A., TRUONG, V.D. and DAUBERT, C.R. 2006.Spray drying of amylase hydrolyzed sweet potato puree andphysiochemical properties of powder. J. Food Sci. 71,E209–E217.

JUMAH, R.Y., TASHTOUSH, B., SHAKHER, R.R. and ZRAIY,A.F. 2000. Manufacturing parameters and quality

characteristics of spray dried jameed. Drying Technol. 18,967–984.

KHA, C.T., NGUYEN, H.M. and ROACH, D.P. 2010. Effects ofspray drying conditions on the physicochemical andantioxidant properties of the Gac (Momordica cochinchinensis)fruit aril powder. J. Food Eng. 98, 385–392.

LIU, X., CUI, C., ZHAO, M., WANG, J., LUO, W., YANG, B. andJIANG, Y. 2008. Identification of phenolics in the fruit ofEmblica (Phyllanthus emblica L.) and their antioxidantactivities. Food Chem. 109, 909–915.

LUO, W., ZHAO, M., YANG, B., REN, J., SHEN, G. and RAO, G.2011. Antioxidant and antiproliferative capacities of phenolicspurified from Phyllanthus emblica L. fruit. Food Chem. 126,277–282.

MISHRA, P., SRIVASTAVA, V., VERMA, D., CHAUHAN, O.P.and RAI, G.K. 2010. Physico-chemical properties of Chakaiyavariety of Amla (Emblica officinalis) and effect of differentdehydration. Afr. J. Food Sci. 3, 303–306.

MISHRA, P., VERMA, M., MISHRA, V., MISHRA, S. and RAI,G.K. 2011. Studies on development of ready to eat amla(Emblica officinalis) Chutney and its preservation byusing class one preservatives. Am. J. Food Technol. 6,244–256.

MISHRA, P., MISHRA, S. and MAHANTA, C.L.M. 2014. Effectof maltodextrin concentration and inlet temperature duringspray drying on physicochemical and antioxidant propertiesof amla (Emblica officinalis) juice powder. Food Bioprod.Process. 92, 252–258.

MOHAPATRA, D. and BAL, S. 2010. Optimization of polishingconditions for long grain basmati rice in a laboratory abrasivemill. Food Bioprocess Technol. 3, 466–472.

MOREIRA, G.E.G., COSTA, M.G.M., RODRIGUES-DE SOUZA,C.A., BRITO-DE, S.E., MEDIIROS- DE, D.F.D.M. andAZEREDO–DE, M.C.H. 2009. Physical properties of spraydried acerola pomace extract as affected by temperatureand drying aids. LWT – Food Sci Technol. 42, 641–645.

MURRAY, J.M., DELAHUNTY, C.M. and BAXTER, I.A. 2001.Descriptive sensory analysis: past, present and future.Food Res. Int. 34, 461–471.

NIJDAM, J.J. and LANGRISH, T.A.J. 2006. The effect of surfacecomposition on the functional properties of milk powders.J. Food Eng. 77, 919–925.

QUEK, S.Y., CHOK, N.K. and SWEDLAND, P. 2007. Thephysiochemical properties of spray dried watermelonpowders. Chem. Eng. Process 46, 386–392.

RODRIGUEZ-HERNANDEZ, G.R., GONZALEZ-GARCIA, R.,GRAZALES-LAGUNES, A., RUIZ-CABRERA, M.A. andABUD-ARCHILA, M. 2005. Spray drying of cactus pear juice(Opuntia streptacantha): Effect on the physiochemicalproperties of the powder and reconstituted product.Drying Technol. 23, 955–973.

SOLVOL, K.M., SUNDARAJAN, S., ALFARO, L. and SATHIVEL,S. 2012. Development of cantaloupe (Cucumis melo) juicepowder using spray drying technology. LWT – FoodSci Technol. 46, 287–293.



SOUSA, A.S.D., BORGES, S.V., MAGALHAES, N.F., RICARDO,H.V. and AZAVEDO, A.D. 2008. Spray dried tomato powder:Reconstitution properties and color. Braz. Arch. Biol. Technol.51, 807–817.

TONON, V.R., BRABET, C. and HUBINGER, D.M. 2008.Influence of process conditions on the physicochemicalproperties of acai (Euterpe Oleraceae Mart.) powder producedby spray drying. J. Food Eng. 88, 411–418.

WALTON, D.E. 2000. The morphology of spray driedparticles a qualitative view. Drying Technol. 18,1943–1986.

WALTON, D.E. and MUMFORD, C.J. 1999. Spray driedproducts-characterization of particle morphology.Chem. Eng. Res. Des. 77, 21–38.



process standardization for development of spray-dried lemon juice powder and optimization of...

Documents