(Psidium Guajava) Powder - Science Direct

Available online at www.sciencedirect.com

ScienceDirect Agriculture and Agricultural Science Procedia 2 (2014) 74 – 81

“ST26943”, 2nd International Conference on Agricultural and Food Engineering, CAFEi2014”

Physical Properties of Spray-dried Pink Guava (Psidium guajava) Powder M.R.I. Shishira, F.S. Taipa,*, N.A. Aziza, R.A. Taliba a

Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPMSerdang, Selangor, Malaysia

Abstract Spray drying of pink guava puree is important for preservation, volume reduction and prolongation of its shelf-life. This investigation was carried out to assess selected physical properties of its powder dried using lab plant spray dryer SD-05. The juice (brix 10.0±0.1) of pink guava puree was mixed with MD at 10%, 15% and 20% and dried using temperatures 150, 160 and 170°C at feed flow rate 350 ml/hr. Quality powder in terms of final moisture content, particle size, powder yield, bulk density, tapped density, flowability and color was found to be yielded at drying temperature of 150°C with 15% maltodextrin.

© Authors. Published Published by by Elsevier ElsevierB.V. B.V. This is an open access article under the CC BY-NC-ND license © 2014 2014 The The Authors. (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the Scientific Committee of CAFEi2014. Peer-review under responsibility of the Scientific Committee of CAFEi2014 Keywords:Pink guava puree; spray drying; maltodextrin DE 10; physical properties

1. Introduction Most fruits are harvested seasonally in abundance and due to their high moisture content and short lifespan and to meet the market demand throughout the year in all parts of the world, the product needs further treatmentsuch as drying. One of the most suitable preservation methods for fruits or fruit juice/puree is drying into powder form. Even though most of the drying methods are traditional, primeval and simple, there is an urgingrequirement to apply advanced techniques such as spray drying, with the objectives of increasing productivity and getting better control on process to gain the product quality. The use of spray drying to obtain powdered food products has been investigated by several researchers (Patil et al., 2014; Fazaeli et al., 2012; Kha et al., 2010). Studies have shown that

* Corresponding author. Tel.: +603-89466357; fax: +603-89464440. E-mail address:[email protected]

2210-7843 © 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the Scientific Committee of CAFEi2014 doi:10.1016/j.aaspro.2014.11.011

M.R.I. Shishir et al. / Agriculture and Agricultural Science Procedia 2 (2014) 74 – 81

the properties of spray-dried powders are mainly affected by process conditions such as air inlet and outlet temperatures, air flow rates, atomizer type and pressure and feed properties and flow rates (Fazaeli et al., 2012). The process conditions not only affect the physical properties of the powders, but also they are affected by the drying agents such as maltodextrin used during spray drying operations (Torres et al., 2013). Pink guava (Psidiumguajava) belonging to Myrtaceaefamily that is cultivated in many tropical and subtropical countries (CanoChauca et al., 2005) especially in Malaysia, the largest pink guava producer in Asia (Sime Darby Beverages Sdn. Bhd., 2011). It is very rich in antioxidants especially lycopene that is responsible for its pink color (Thuaytong, 2011). Since pink guava has delicate color and flavor properties and drying conditions may have great effect on the physical properties of the final product, drying operations need to be carefully designed to preserve the best quality. However, as literature shows, there are some limitations in producing fruit powder by spray drying. Guava powder is very sticky due to its higher sugar content that leads to wall deposition problems resulting in lower product yield with poor quality (Patil et al., 2014; Mahendran, 2010). Even though the addition of maltodextrin can minimize the stickiness and hygroscopicity problems (Patil et al., 2014), higher MD concentrations lead to the condition the higher the feed viscosity, larger the droplets resulting in larger particle size (Jinaponget al., 2008). Also, changes on the drying temperature can affect on the color, final moisture content and bulk density of powder (Tonon et al., 2011). Therefore, the information on physical properties of spray-dried pink guava powder in processing and storage will be of great significance. This justifies why the aim of this study was to produce spray-dried pink guava powder and assess the effect of drying parameters such as air inlet temperature and the maltodextrin concentration on some identified physical attributes of the final product. Nomenclature MD CI HR TSS

Maltodextrin DE 10 Carr Index Hausner Ratio Total soluble solid content

2. Materials and methods 2.1.Raw materials Pink guava puree of Beaumont variety, product of Sime Darby Beverages Sdn. Bhd., Malaysia, was collected from the super market. The brix content of the collected puree was around 8.6 o ±0.1. 2.2. Carrier agent Carrier agents are widely used as an alternative way to increase the glass transition temperature of powder in order to reduce the stickiness and hygroscopicity of the final product (Truong et al., 2005). Maltodextrin with DE 10 was chosen due to its better nutrient binding properties that permit liquids to be transformed into free-flowing powder without altering or covering the flavor (Tonon et al., 2011). 2.3. Sample preparation The pink guava puree was stored at -20oC and defrosted overnight at 4°C before sample preparation and afterward mixed with distilled water and sugar until reaching total soluble solid content of 10.0±0.1 0 brix. Initial experiments were conducted to get optimum ratio and found that puree(v): water(v): sugar(wt.) (1:2.33:0.27) provided better appearance and throughput. Then the mixture was blended for 10 seconds and filtered with 250μm sized sieve. Maltodextrin was added to the juice directly in a concentration of 10%, 15% and 20% (w/v) and homogenized at 5000 rpm for 8 minutes (Carrillo-Navas et al., 2011) by using Homogenizer (Wise Mix HG-15A). Then the total soluble solid content was measured before spray drying and 300 ml sample was taken to spray dry in every case (Fig. 1).

75

76


2.4. Spray drying A laboratory plant spray dryer, Lab Plant SD-05 (West Yorkshire, UK) was used to conduct the spray drying using co-current flow, with a 0.5 mm diameter nozzle and main spray chamber 215 mm×500 mm long. The drying conditions were selected as feed flow rate of 350 mL/h, pressure of 2.0 bars, drying air flow rate was 50 m³/hr and feed temperature of 25°C. Three inlet temperatures of 150, 160, and 170°C were studied based on literature and initial experiments. After setting at each temperature, the sample was spray dried, collected the powder produced and cooled it down in desiccator and stored at 4°C in dark for further analysis.

Fig. 1.Process flow chart for the development of pink guava powder.

2.5. Analysis of powder 2.5.1. Moisture content The moisture content analysis was conducted according to the method of AOAC, 1990. One gram of sample was taken and dried in an oven at 70°C until constant weight and triplicated the analysis and calculated as; Moisture content

Wt. of water loss u 100 Wt. of powder sample

(1)

2.5.2. Bulk and tapped density Bulk density was determined according to Sahin-Nadeem et al., (2013) method. Two grams powder was taken into 10 mL graduated cylinder (keep on plane level) and recorded the volume changes. Bulk density of the powder was estimated as the ratio of mass of the sample to it’s volume. The tapped density of the samples was determined by placing 2 g of powder in a 10 ml graduated cylinder and calculating the volume after the sample was smoothly dropped 120 times on top of a rubber mat from a height of 15 cm (Ozdikicierler et al., 2014). Tappeddensity

Mass of powder Volume after tapping

(2)

2.5.3. Flowability The flowability of the powders was evaluated in terms of the Carr index (CI) and Hausner ratio (HR), (Jinapong et al., 2008). Both CI and HR were calculated from the bulk and tapped densities of the powders as follows:

77


CI

HR

Tapped density - Bulk density u100 Tappeddensity

(3)

Tappeddensity Bulk density

(4)

The flowability chart (Table 1) ranges the values of the Carr index and Hausner ratio in terms of the flow property that indicates the quality of the powder. The Carr Index ranges the excellent and good quality powder at 010% and 11-15% respectively whereas the Hausner ratio ranges 1.00-1.11 and 1.12-1.18 accordingly. Based on the quality of powder, the range which is from excellent to passable is acceptable and others refer to the lower quality of the powder. Table 1. Specification for Carr index and Hausner ratio (Lebrun et al., 2012). Flowability

Carr Index (CI), %

Hausner Ratio (HR)

Excellent

0-10

1.00-1.11

Good

11-15

1.12-1.18

Fair

16-20

1.19-1.25

Passable

21-25

1.26-1.34

Poor

26-31

1.35-1.45

Very poor

32-37

1.46-1.59

Very, very poor

>38

>1.60

2.5.4. Color analysis The powder color was determined by using a color reader (CR-10; Konica Minolta Sensing Ltd., Japan). In order to obtain the L*(lightness), a*(green/red), and b*(blue/yellow) value, the lens of the color reader was placed on the powder. Triplicate samples were analyzed and mean value was reported (Tze et al., 2012). 2.5.5. Particles size distribution The size of powder particles was determined by using a laser light diffraction instrument, Mastersizer 2000 (Malvern Instruments, Malvern, U.K.) (Tze et al., 2012). The particle size was found as mean diameter, which is usually used to characterize a particle. Triplicate samples were analyzed and the average value was reported. 2.5.6. Powder yield The spray drying yield was estimated at the relationship between the mass of the final product and the mass of the feed mixtureand calculatedas (León-Martínez et al., 2010): Y

(W2 W1 ) X wb (W2 W1 ) u100 FvTs

(5)

where Y is powder yield (%), Xwb is the moisture content (wb), Fv is the feed volume, Ts is the total solid content, and W1 and W2 are the weight of the powder bottle before and after spray drying, accordingly.

78


2.6. Statistical analysis All the measurements were conducted in triplicate and evaluated as mean value with standard deviations by analysis of variance (ANOVA) using SAS System 9.3 for Windows 7 (SAS Institute Inc., Cary, NC, USA). The diagrams of average value and error bars were generated by using Microsoft excel version of 2010. 3. Results and discussion 3.1. Moisture content The higher the inlet air temperature and MD concentration, the lower the moisture content of the spray-dried pink guava powder as shown in Fig. 2(a). At higher inlet air temperatures, there was a significant changes found on moisture content due to the higher temperature gradient between the atomized feed and the drying air, causing rapid water vaporization with greater rate of heat transfer, ultimately leads to generate powders with lower moisture content (Kha et al., 2010). Oppositely, higher MD concentrations showed a sound effect to down the moisture trend of spray-dried powder owing tothe fact that the addition of MD that increased the total solids of the feed and reduced the amount of water vaporization (Shrestha et al., 2007). (a)

(b)

(c)

Fig. 2. (a) Moisture content, (b) Mean particle size, (c) Powder yield, of pink guava powders with different concentration of MD, in different inlet air temperature.

3.2. Particles size distribution Higher inlet temperatures generally led to the production of larger particles, which is associated to the higher swelling affected by higher temperatures (Fig. 2(b)). Higher drying temperature causes rapid drying and lower shrinkage, resulting in quick development of particle structure that leads to higher particle size. At lower inlet temperature, the particle becomes more shrinkage and produces smaller diameter (Nijdam and Langrish, 2006). Oppositely, different concentrations of MD at constant temperature increased the mean diameters of the powders produced on the whole except for 15% MD concentration where mean particle diameters dropped. However, the increment of mean diameter of particle is due to the higher feed viscosity, which increased with MD concentration, creates greater droplets and consequentially forms larger particles during spray drying (Masters, 1979). 3.3. Powder yield Analyzing Fig. 2(c), it can be observed that both MD concentrations and inlet temperatures have significant effect on the product yield especially higher MD concentrations that led to higher production up to 15% MD where the increasing inlet air temperature showed random effect, maximum yield (55%) has been found for 20% MD at

79


170°C and 52% yield for 15% MD at 160°C.However, the increasing in MD concentrations in pink guava juice significantly increased the process yield. This is similar with the results of Shrestha et al., (2007). On the whole, the product yield of the samples decreased, when inlet air temperature was increased from 150°C to 170°C. Such decrease may be happened due to the sticking of the pink guava droplets on the hot surface area of the spray drying chamber (Sahin-Nadeem et al., 2013). 3.4. Bulk density and tapped density The bulk density and tapped density both are significant characteristics of the powder product owing to its functional and cost-effective reasons. In this study, bulk density of the pink guava powders reduced with increasing inlet temperature, varied from 342-449.33 kg/m³ (Fig. 3(a)).In general, higher inlet air temperatures result in powders with lower density, which is due to the higher drying temperature that causes faster particle drying with less droplet shrinkage giving lower powder density (Fazaeli et al., 2012). The bulk density increased with the increasing of MD concentrations except for 15% MD concentration that showed maximum values. Bae and Lee (2008) showed similar result which was recognized to increase in the total solid content of the feed solution. According to Fig. 3(b), there was quite similar effect on tapped density as bulk density with different MD concentrations at increasing inlet temperatures. (a)

(c)

(b)

(d)

Fig. 3. (a) Bulk density, (b) Tapped density, (c) Hausner ratio and (d) Carr index of pink guava powders with various MD concentrations in different inlet temperature.

3.5. Flowability According to standard value of the Carr index and the Hausner ratio, to detect good flowability, the compressibility index must be within 15% and the Hausner ratio within 1.18 as shown in Table 1. It is observed that from Fig. 3(c) and 3(d), both HR & CI values increased with the increasing of temperature and MD concentration.

80


In case of the 15% MD samples showed lower HR and CI values that indicated good flowability. There is a possibility that for lower particle size and higher bulk density that led to good flowability. 3.6. Color analysis of powder It is observed from Table 2; the lightness of the powders was considerably affected by MD concentration when powders were produced at inlet temperatures up to 160°C. On the other hand, higher inlet temperature produced lighter product than lower inlet temperature. Higher degree of lightness of spray-dried powder at higher inlet temperature indicates that the pigments have been lost due to oxidation (Sousa et al., 2008). Highest value of a*/b* (0.369), lowest value of hue angle (69.7) and lowest chroma (23.3) were obtained with 10% MD at 150°C while others showed reduction in case of a*/b* value and rise in terms of hue angle and chroma with different MD concentrations at different inlet temperatures. Due to higher MD level and higher inlet temperature, thermal degradation and rapid oxidation could be occurred that resulted in low a*/b* value and high hue angle led to lower color which is similar findings with (Kha et al., 2010). Table 2. Color properties of pink guava powder. Maltodextrin

Temperature (°C)

L* (lightness)

c* (chroma)

h* (hue angle)

a*/b*

150

74.9 ± 0.5

23.3 ± 0.61

69.7 ± 0.25

0.369 ± 0.0030

160

75.5 ± 0.36

23.9 ± 0.26

70.7 ± 0.20

0.349 ± 0.0060

170

75.5 ± 0.26

24.4 ± 0.25

71.9 ± 0.37

0.327 ± 0.0064

150

76.6 ± 0.43

23.5 ± 0.28

71.4 ± 0.36

0.336 ± 0.0062

160

76.9 ± 0.20

23.9 ± 0.26

72.2 ± 0.25

0.320 ± 0.0061

170

76.7 ± 0.26

24.7 ± 0.17

73.5 ± 0.20

0.295 ± 0.0025

150

77.8 ± 0.40

24.1 ± 0.17

73.8 ± 0.15

0.290 ± 0.0028

160

78.1 ± 0.45

24.5 ± 0.55

74.9 ± 0.66

0.270 ± 0.0080

170

77.8 ± 0.20

25.2 ± 0.28

76.5 ± 0.32

0.240 ± 0.0060

10%

15%

20%

4. Conclusions The research work was carried out to assess the selected physical attributes of spray-dried pink guava powder with the addition of different concentrations of MD at several inlet temperatures to preserve unique physical characteristics of the final product. The results showed that inlet temperatures and MD concentrations both have significant influence on the powder properties atP< 0.01. Overall, at the inlet temperature of 150°C and MD concentration of 15%, the spray-dried powders have better properties/ quality; reasonably lower moisture content, higher yield, better bulk density with good flowability and moderate color properties over others. These physical properties of the powders are very significant to ensure the production of better quality final product. Further investigation is required to analyze some chemical compounds of the final powder to preserve the best quality, and on the storage effects towards the quality properties to enhance the shelf life of the product. 5. Acknowledgement This work was supported by the Ministry of Education Malaysia, under Fundamental Research Grant Scheme (Project no: 03-02-13-1296FR)


References AOAC International, 1990. Official Methods of Analysis of AOAC. AOAC International, Gaithersberg, MD. Bae, E.K., Lee, S.J., 2008. Microencapsulation of Avocado Oil by Spray Drying using Whey Protein and Maltodextrin. Journal of Microencapsulation 25, 549-560. Cano-Chauca, M., Stringheta, P.C., Ramos, A.M., Cad-Vidal, J., 2005. Effect of the Carriers on the Microstructure of Mango Powder Obtained by Spray Drying and Its Functional Characterization. Innovative Food Science and Emerging Technologies 6,420–428. Carrillo-Navas, H., González-Rodea, D.A., Cruz-Olivares, J., Barrera-Pichardo, J.F., Román-Guerrero, A., Pérez-Alonso, C., 2011. Storage Stability and Physicochemical Properties of Passion Fruit Juice Microcapsules by Spray-drying. RevistaMexicana de IngenieríaQuímica 10(3), 421-430. Fazaeli, M., Emam-Djomeh, Z., Ashtari, A.K., Omid, M., 2012. Effect of Spray Drying Conditions and Feed Composition on the Physical Properties of Black Mulberry Juice Powder, Food and Bioproducts Processing 90, 667–675. Jinapong, N., Suphantharika, M., Jamnong, P., 2008. Production of Instant Soymilk Powders by Ultrafiltration, Spray Drying and Fluidized Bed Agglomeration. Journal of Food Engineering 84(2), 194-205. Kha, T.C., Nguyen, M.N., Roach, P.D., 2010. Effects of Spray Drying Conditions on the Physicochemical and Antioxidant Properties of the Gac (Momordicacochinchinensis) Fruit Aril Powder. Journal of Food Engineering 98, 385–392. León-Martínez, F.M., Méndez-Lagunas, L.L., Rodríguez-Ramírez, J., 2010. Spray Drying of Nopal Mucilage (Opuntiaficus-indica): Effects on Powder Properties and Characterization. Carbohydrate Polymers 81, 864–870. Mahendran, T., 2010.Physico-chemical Properties and Sensory Characteristics of Dehydrated Guava Concentrate: Effect of Drying Method and Maltodextrin Concentration.. Tropical Agricultural Research and Extension 13(2), 48-54. Masters, K., 1979. Spray-air Contact (Mixing and Flow), in “Spray Drying Handbook”. In: Masters, K. (Ed.). Halsted Press, New York, pp. 286– 290. Nijdam, J.J.,Langrish, T.A.J., 2006. The Effect of Surface Composition on the Functional Properties of Milk Powders. Journal of Food Engineering77, 919–925. Ozdikicierler, O., Dirim, S.N., Pazir, F., 2014. The Effects of Spray Drying Process Parameters on the Characteristic Process Indices and Rheological Powder Properties of Microencapsulated Plant (Gypsophila) Extract Powder. Powder Technology 253, 474–480. Patil, V., Chauhan, A.K., Singh, R.P., 2014. Optimization of the Spray-drying Process for Developing Guava Powder using Response Surface Methodology. Powder Technolology 253, 230–236. Sahin-Nadeem, H.,Dinçer, C., Torun, M., Topuz, A., Özdemir, F., 2013. Influence of Inlet Air Temperature and Carrier Material on the Production of Instant Soluble Sage (Salvia Fruticosa Miller) by Spray Drying. LWT - Food Science and Technology 52, 31-38. Shrestha, A.K., Ua-arak, T., Adhikari, B.R., Howes, T., Bhandari, B.R., 2007. Glass Transition Behavior of Spray Dried Orange Juice Powder Measures by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT). International Journal of Food Properties 10, 661–673. Sime Darby Beverages Sdn. Bhd, (2011). Retrieved January, 2013. http://www.simedarbyplantation.com/ Sime_Darby_ Beverages_Sdn_Bhd.aspx Sousa, A.S.D., Borges, S.V., Magalhaes, N.F., Ricardo, H.V., Azavedo,A.D., 2008. Spray Dried Tomato Powder: Reconstitution Properties and Color. Brazilian Archives of Biology and Technology 51(4), 807–817. Thuaytong,W., Anprung, P., 2011. Bioactive Compounds and Prebiotic Activity in Thailand-Grown Red and White Guava Fruit (Psidiumguajava L.). Food Science and Technology International 17(3), 205-212. Tonon, V.R., Brabet, C.,Hubinger, M., 2011. Spray Drying of Acai Juice: Effect of Inlet Temperature and Type of Carrier Agent. Journal of Food Processing and Preservation 5, 691-700. Torres, L.M., Cruz, G.E.E., Calderas, F., Laredo, R.F.G., Olivares, G.S., Infante, J.A.G., Guzmán, N.E.R., Ramírez, J.R., 2013. Microencapsulation by Spray Drying of Gallic Acid with Nopal mucilage (OpuntiaFicusIndica). Food Science and Technology 50, 642–650. Tze, N.L., Han, C.P., Yusof, Y.A., Ling, C.N., Talib, R.A., Taip, F.S., Aziz, M.G., 2012. Physicochemical and Nutritional Properties of Spraydried Pitaya Fruit Powder as Natural Colorant. Food Science and Biotechnology 21(3), 675-682. Truong, V., Bhandari, B.R.,Howes, T. 2005. Moisture and Glass Optimization of Co-current Spray DryingProcess of Sugar Rich Foods: Transition Temperature Profile During Drying. Journal of Food Engineering 71, 55–65.

Accepted for oral presentation in CAFEi2014 (December 1-3, 2014 – Kuala Lumpur, Malaysia) as paper 163.

81