**1. Introduction**

110 Mass Transfer in Chemical Engineering Processes

[25] Paixa˜o, A.E.A.; Rocha, S.C.S. Pneumatic drying in diluted phase: Parametric analysis

[26] Baeyens, J.; van Gauwbergen, D.; Vinckier, I. Pneumatic drying: The use of large-scale experimental data in a design procedure. Powder Technology 1995, *83*, 139 - 148. [27] Arlabosse, P.; Chavez, S.; Prevot, C. Drying of municipal sewage sludge: From a

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rotary disk atomizer using a three-dimensional computational fluid dynamic

rotary disc atomizer and pressure nozzle using computational fluid dynamic


The significance of and interest in pungent paprika have been growing over the years due to its high potential to provide a broad spectrum of products with important medicinal and commercial value (Govindarajan & Sathyanarayana, 1991; Guzman et al., 2011; Pruthi, 2003). As a rich source of characteristic phytocompounds, pungent paprika has a notable place in modern food and in pharmaceutical industries (De Marino et al., 2008).

As acknowledged, the principal pungent constituent of pungent paprika is capsaicin, an alkaloid or predominant capsaicinoid, followed by dihydrocapsaicin, nordihydrocapsaicin, homodihydrocapsaicin and homocapsaicin (Davis et al., 2007; Hoffman et al., 1983). Although there are two geometric isomers of capsaicin, only *trans*-capsaicin occurs naturally, and thus the term 'capsaicin' is generically used to refer to the *trans*-geometric isomer. The capsaicin content of pungent paprika ranges from 0.1 to 1%w/w (Barbero et al., 2006; Govindarajan & Sathyanarayana, 1991).

Over the years, capsaicin, a promising molecule with many possible clinical applications, has been comprehensively studied (experimentally, clinically and epidemiologically) owing to its prominent antioxidant, antimicrobial and anti-inflammatory properties (Dorantes et al., 2000; Materska & Peruska, 2005; Reyes-Escogido et al., 2011; Singh & Chittenden, 2008; Xing et al., 2006; Xiu-Ju et al., 2011). Many studies give evidence that capsaicin has been widely used as the potent active ingredient incorporated into a wide range of topical analgesic formulations (Weisshaar et al., 2003, Ying-Yue et al. 2001). Moreover, considerable interest has developed in expanding the usage of capsaicinoids in other forms such as natural product-based food additive, dietary supplements and as constituent in self-defense products (Dorantes et al., 2000; Materska & Perucka, 2005; Nowaczyk et al., 2008; Spicer & Almirall, 2005; Xing et al., 2006). In addition, the recent results showing their possible therapeutic effects in obesity treatment have further increased the importance of capsaicinoids (Ji-Hye et al., 2010).

One of the most common pungent paprika products is pungent capsicum oleoresin (PCO), an organic oily resin derived from the dried ripe fruits of pungent varieties of *Capsicum annuum* L., by means of solid-liquid extraction and subsequent solvent removal (Cvetkov &

Extraction of Oleoresin from Pungent Red Paprika Under Different Conditions 113

single extract. Furthermore, for extraction parameter study at different temperature and time, the extraction was carried out in thermostatic water bath at a temperature of 30, 40, 50,

dynamic extraction time on the analyte of interest was followed during 60, 120, 180 and 300 min, respectively. After extraction for selected time and at maintained temperature, the solvent was removed under vacuum (rotary vacuum evaporator, type Devarot, Slovenia,

(vacuum drier, Heraeus Vacutherm VT 6025, Langenselbold, Germany). Each extraction

Obtained PCOs were cooled in a desiccator and weighed. The steps of drying, cooling and weighing were repeated until the difference between two consecutive weights was smaller than 2 mg. The PCO yield was estimated according to dry matter weight in extracted quantity of red pungent paprika. The extract was transferred into a 100 mL volumetric flask

The capsaicin content in the extracts was determined by reading of the absorbance at 282 nm. Actually, 0.5 mL of 1st dissolution was dissolved and filled up to 10 mL with ethanol and the absorbance was measured. The concentration of capsaicin was estimated from the

Pigments concentration in red pungent paprika extract was calculated using the extinction coefficient of the major pigment capsanthin (1%E460nm= 2300) in acetone (Hornero-Méndez et

The spectrophotometric measurements were carried out on a Varian Cary Scan 50

The statistical analysis and evaluation of the data were performed using STATISTICA 8 (StaSoft, Inc., Tulsa, USA) software. A two-predictors non linear regression model was used to evaluate the individual and interactive effects of two-independent variables, extraction temperature (x1) and dynamic time (x2). The responses measured were PCO yield, capsaicin

The second order model includes linear, quadratic and interactive terms thus, in the responses function (Y)-Eq. 2, xi and xj are predictors; 0 is the intercept; i are linear coefficients; ii are squared coefficients; ij are interaction coefficients and is an error

y=9.64x+0.005 R2=0.9909 (1)

C.

C, atm. pressure). Solvent traces were discharged by drying the sample at 40

procedure was performed in duplicate under the same operating conditions.

**2.4 Determination of capsaicin content in pungent capsicum oleoresin** 

**2.5 Determination of capsanthin content in pungent capsicum oleoresin** 

**2.3 Determination of pungent capsicum oleoresin yield** 

and filled to 100 mL with ethanol (1st dissolution).

standard curve for capsaicin given by the Eq. (1).

where x = μg capsaicin/mL extract and y = absorbance.

spectrophotometer (Switzerland) in 1cm quartz cells, at 25

and major pigment capsanthin present in the PCO.

C, respectively with the exception of 70°C when ethanol was utilized. The effect of

C, 105 mPa

60 and 70

al., 2000).

term.

**2.6 Apparatus**

**2.7 Statistical analysis** 

35

Rafajlovska, 1992; Kense, 1970; Rajaraman et al., 1981). Basically, PCO contains pigments carotenoids predominantly capsanthin (Giovannucci, 2002, Hornero-Méndez et al., 2000; Matsufuji et al., 1998) and not less than eight percent of total capsacinoids. Furthermore, beside the pigments, chemical entities such as flavors, taste agents, vitamins and fatty oil are also present in the PCO components profile (Howard et al., 1994; Vinaz et al., 1992). However, a survey of literature reveals that, generally, the most commonly employed and a preferred method for extraction of compounds present in plant matrices is the conventional solid-liquid extraction using organic solvents. In later studies, these conventional methods were improved, modified or rationalized by varying different operating parameters (Boonkird et al., 2008; Toma et al., 2001; Vinatoru, 2001; Wang & Weller, 2006).

The paprika oleoresins are produced by solvent extraction of dried, ground red pepper fruits, using a solvent-system compatible with the lipophilic/hydrophilic characteristics of the extract sought and subsequent solvent-system removal. The solvents most commonly used for paprika oleoresin extraction are trichloroethylene, ethylacetate, acetone, propan-2 ol, methanol, ethanol and *n*-hexane (Cvetkov & Rafajlovska, 1992; Hornero-Méndez et al., 2000; Kense, 1970).

Although many studies have been published on the development and implementation of the different operating conditions for PCO recovery, little attention seems to have been given to the optimization of the various extraction variables (e.g. the appropriate solvent, temperature, dynamic extraction time, quantity of sample, etc.) nor has a systematic study for the optimization of the method been carried out. Therefore, in a situation, where multiple variables may influence the extraction yield, application of a response surface methodology (RSM) to optimize the extraction condition offers an effective technique for studying and optimizing the process and operating parameters (Acero-Ortega et al., 2005; Giovanni, 1983; Li & Fu, 2005; Montgomery, 2001).

As part of our contribution to the studies on extraction methods for pungent red paprika we have carried out organic solvent extraction procedure under different conditions, resulting in optimized conditions for the matrix compounds from *Capsicum annuum* L. Hence, the principal goals were to study the influence of the solvent type, extraction temperature and dynamic time on pungent red paprika extraction efficiency expressed by PCO yield and capsaicin and capsanthin content in it and to establish mathematical models to predict system responses.
