Pigment content and fatty acid composition of paprika oleoresins obtained by conventional and supercritical carbon dioxide extraction

Abstract

An experiment was conducted to examine the influence of conventional and supercritical extraction of ground paprika (“Aleva N.K.” variety) on the quality of paprika oleoresin. Paprika was extracted using hexane as an organic solvent and supercritical carbon dioxide at 20, 30 and 40 MPa. The extraction yields were 12.8, 10.6, 10.6 and 10.3%, respectively. It was confirmed that the organic solvent was less selective than the supercritical carbon dioxide. The analyses of fatty acid composition showed that oleoresin consisted mostly of linoleic acid. The highest pigment content was found in the conventional oleoresin, 31,476 mg/kg. Among supercritical oleoresins, the richest in pigments was the one obtained at 40 MPa (14,134 mg/kg), 44.9% in comparison with the conventional.

Se realizó un experimento para examinar la influencia de la extracción convencional y supercrítica de páprika molida (de la variedad ‘Aleva N.K.’) en la calidad de la oleorresina de páprika. La páprika fue extraída usando hexano como solvente orgánico y dióxido de carbono supercrítico a 20, 30 y 40 MPa. La extracción dio como resultado 12,8, 10,6 y 10,3%, respectivamente. Se confirmó que el solvente orgánico fue menos selectivo que el dióxido de carbono supercrítico. Los análisis de composición de ácidos grasos mostraron que la oleorresina consistía principalmente en ácido linoleico. El contenido mayor de pigmento se encontró en la oleorresina obtenida por método convencional, 31,476 mg/kg. Entre las oleorresinas obtenidas por el método supercrítico, la más rica en pigmento fue la obtenida a 40 MPa (14,134 mg/kg), 44,9% en comparación con lo obtenido por el método convencional.

Keywords:

• paprika oleoresin
• supercritical fluid extraction
• Soxhlet extraction
• fatty acid composition
• carotenoids
• GC-MS
• HPLC

Palabras clave:

• oleorresina de páprika
• extracción por fluido supercrítico
• extracción Soxhlet
• composición de ácido graso
• carotenoides
• GC-MS
• HPLC

Introduction

Red pepper (Capsicum annuum L.) is one of the most important vegetable cultures in the province of Vojvodina in Serbia. There are a number of foods containing paprika or its compounds. It is especially important because of its high nutritive and biological value (Daood et al., 2002; El-Adawy & Taha, 2001). In recent years, carotenoids have received research interest as potential antioxidants, based on studies which reported that a higher consumption of carotenoids leads to lower risk of cancer and cardiovascular diseases (Di Mascio, Murphy, & Sies, 1991; El-Agamey et al., 2004; Matsufuji, Nakamura, Chino, & Takeda, 1998; Maoka et al., 2001b).

The yellow, orange and red colours of paprika fruit originate from carotenoids and the pigments are synthesised during ripening. They are the most widespread group of pigments – the number of naturally occurring carotenoids continues to rise and has reached about 750 (Britton, Liaaen-Jensen, & Pfander, 2004). More than 25 different pigments have been identified in the fruits of paprika: green chlorophylls, yellow-orange lutein, zeaxanthin, violaxanthin, antheraxanthin, β-cryptoxanthin, β-carotene, etc. The red pigments capsanthin, capsorubin and cryptoxanthin are unique to the Capsicum species. The colour of paprika is determined by the proportion of red to yellow pigments (Hornero-Méndez, de Guevara, & Minguez-Mosquera, 2000; Jarén-Galán & Mínguez-Mosquera, 1999), whereas β-, α-, γ-carotene and β-cryptoxanthin, as provitamins, contribute to its nutritive value. Capsanthin and capsorubin, which comprise 65–80%, contribute the red colour to paprika (Jarén-Galán et al., 1999; Weissenberg, Schaeffler, Menagem, Brazillai, & Levy, 1997).

In the fruits of paprika during ripening, free carotenoids esterification with fatty acids occurs (Biacs, Daood, Pavisa, & Hajdu, 1989; Goda et al., 1996; Mínguez-Mosquera & Hornero-Méndez, 1994; Philip & Chen, 1988), and as a result, carotenoids can be found as free, partially (mono-) and completely (diesters) esterified, with the latter category being predominant (Levy et al., 1995). The pigment content in paprika fruits is dependent on the variety, degree of ripeness, time of harvest, growing and storage conditions (Deli, Matus, & Toth, 1996; Deli, Molnár, Matus, & Tóth, 2001b).

Saturated fatty acids are known to be more stable and solid at room temperature. With an increase in the number of double bonds, the fluidity rises. On the other hand, unsaturated fatty acids are prone to autoxidation, which leads to the generation of free radicals and increasing risk of cancer. However, substituting saturated with unsaturated fats in diet lowers the level of total cholesterol and LDL cholesterol in blood. Also, linoleic (18:2) and α-linolenic (18:3) are essential fatty acids, which play an important role in human nutrition.

Fatty acids are found in the pericarp and the seeds of the pepper (C. annuum L.) fruit. Lauric, myristic, palmitic, oleic and linoleic acids are esterified to the xanthophyll pigments in the mono- and diester form (Breithaupt & Schwack, 2000; Pérez-Gálvez, Garrido-Fernández, Mínguez-Mosquera, Lozano-Ruiz, & Montero-de-Espinosa, 1999b).

HPLC has been the most effective and accurate method for separation, identification and quantification of carotenoids (Maoka, Fijiwara, Hashimoto, & Akimoto, 2001a; Vesper & Nitz, 1997; Weissenberg et al., 1997) and enables detailed research of pigment compound in red pepper (Cserháti, Forgács, Morais, Mota & Ramos, 2000; Cserháti, Forgács, Darwish, Morais, Mota, & Ramos, 2002; Deli, Matus, Molnár, & Toth, 2001a; Deli & Tóth, 1997; Maoka et al., 2001a; Mínguez-Mosquera & Hornero-Méndez, 1993; Rodriguez et al., 1998) and many other fruits and vegetables rich in carotenoid pigments. Quantitative measurement of individual carotenoids by HPLC analysis includes sample preparation, extraction, saponification (or not), HPLC separation, peak identification and quantification. As paprika contains carotenoids esterified with fatty acids, as well as non-esterified (free) carotenoids, fatty acids can be removed by saponification, leaving free pigments in the sample. HPLC analysis of saponified extracts separates free pigments, giving data about the type of pigments present in the sample.

Supercritical fluids are used in the extraction of a wide variety of compounds. Probably the most widely used supercritical fluid is carbon dioxide, because of a number of advantages such as inexpensiveness, nontoxicity, non-flammablity, inertness, non-explosiveness and low critical point (Lang & Wai, 2001; Wang & Weller, 2006). The quality of paprika oleoresins obtained by supercritical extraction depends on the solvent used, the extraction conditions, as well as on the characteristics of the ground pepper. The optimal pressure for paprika oleoresin production should be in the range of 35–50 MPa (Lock & Simándi, 2001). There can be found a number of scientific works in the field of supercritical extraction. Scientists dealt with the influence of extraction conditions (solvent, temperature, time, flow rate of the solvent) to yield and quality of extracts, as well as modelling of the process (Daood et al., 2002; Gnayfeed, Daood, & Illes, 2001; Jarén-Galán et al., 1999; Uquiche, del Valle, & Irtiz, 2004).

The present experiment was designed to investigate the influence of conventional extraction (Soxhlet, with hexane as the organic solvent) and supercritical fluid extraction with carbon dioxide (SFE-CO₂ at four different pressures) on the composition of paprika oleoresins. As there is very little information about the characteristics of Serbian varieties of red pepper (Tepić & Vujičić, 2004; Vračar, Tepić, Vujičić, & Šolaja, 2007), the results of this experiment will give a closer insight into its pigment content and find its place among the oleoresins produced in the world, according to literature data.

Materials and methods

Material

Commercial ground paprika, “Aleva N.K.” variety, harvested in 2005, was obtained from the Aleva a.d. company from Novi Kneževac, the most important producer of ground pepper in Serbia. The mean diameter of the particles was 0.224 mm.

Ground pepper was placed into the thimble in the middle portion of the Soxhlet apparatus, the solvent was then poured in, and the process was continued until complete discoloration of sample was achieved. Soxhlet (Sx) extract of paprika was obtained using technical grade hexane. The solvent was evaporated from extract under vacuum. Supercritical fluid extracts were obtained with commercial carbon-dioxide (Tehno-gas, Novi Sad, Serbia), using a laboratory-scale high-pressure extraction plant (NOVA-Swiss, Effretikon, Switzerland), at 40 °C and pressures of 20 (SF20 extract), 30 (SF30 extract) and 40 (SF40 extract) MPa, with the carbon-dioxide flow rate 3.59 g/min. During the extraction process, the flow of supercritical carbon dioxide was stopped for a short time, to measure the weight of the extract collection container and to determine the extraction curve.

Fatty acid composition

Standards and reagents

A mix of 19 fatty acid methyl esters (FAMEs) including some isomers was supplied by Supelco (Bellefonte, PA), Cat. No. 47801. All other chemicals were reagent grade.

Preparation of fatty acid methyl esters

Oleoresins were directly converted to fatty acid methyl esters (FAMEs) without prior extraction of fat. Approximately 60 mg of sample was put in tube with cup and 2.4 mL of hexane was added to the sample and shaken continuously for 10 s. Then, 0.6 mL of 2M potassium hydroxide solution in methanol was added and shaken for 20 s. Tube was placed in water bath at 70 °C and left to boil for 1 min. After 20 s of shaking, 1.2 mL of 1M HCl was added, gently stirred and the upper hexane phase, containing the FAMEs, was decanted and dissolved in hexane to 5 mL.

Gas chromatography – mass spectrometry analysis

The analysis of FAMEs was performed using a Hewlett-Packard (HP) 5890 gas chromatograph coupled with a HP 5971A mass spectrometer detector. Chromatographic resolution was achieved by the 100 m × 0.25 mm SP-2560 (Supelco) capillary column with a 0.2 μm film thickness of highly polar biscyanopropyl polysiloxane liquid phase. Ultra-pure helium was passed through moisture and oxygen traps and was used as a carrier gas with constant flow rate of 0.59 cm³/min (column head pressure was 210 psi). The following temperature program was used: injector temperature 230 °C, initial temperature 100 °C (held 5 min), temperature increase of 10 °C/min to 240 °C and held at this temperature for 10 min. Total run time was 30 min. The injection was carried out manually and the volume was 1.0 μL (split ratio 1:82). The mass spectrometer was operated in the electron ionisation mode with quadrupole temperature of 180 °C. Data acquisition was carried out in the scan mode (m/z, range 40–400). The instrument was tuned daily by operating software programs (AUTOTUNE) using perfluorotributylamine (PFTBA) calibration substance. Mass spectrometer parameters were adjusted so that the masses 69, 219 and 502 and their respective isotopes met the target mass–intensity criteria.

Identification and quantification of fatty acids

The fatty acids were identified by comparing their mass spectral data with the mass spectral data obtained by analysis of standard FAMEs solution under the same conditions. A commercial database of mass spectra (Wiley, HP, Waldbronn, Germany) was also used.

The response factor, the mean of the five injections of the standard solution for each FAME present in the calibration standard solution was calculated related to palmitic acid as follows:

where, m _o,i is the mass % of FAME_i in the calibration standard solution; A _16:0 is the peak area of 16:0 in the calibration standard solution chromatogram; m _16:0 is the mass % of 16:0 in the calibration standard solution; and A _o,i is the peak area of FAME_i in the calibration standard solution.

The content of each fatty acid (x) expressed by mass percentage (%, w/w) was calculated as follows:

Where, R _i is the response factor for each fatty acid and A _i the peak area of fatty acid methyl ester in the sample solution.

HPLC analysis of carotenoid content

Qualitative and quantitative analysis of samples was performed according to the Morais, Ramos, Cserháti, & Forgacs (2001) modified method. HPLC was performed using a Hewlett-Packard Liquid Chromatograph HP 1090 equipped with Diode Array Detector (DAD). A reversed-phase column (Zorbax SB-C18, 5 μm, 3.0 × 250 mm² i.d.), protected by guard column (Zorbax SB-C18, 5 μm, 4.6 × 12 mm² i.d., Agilent, USA) was used throughout this research. The mixture of two mobile phases A – acetone : water (75 : 25; v/v) and B – acetone : methanol (75 : 25; v/v) was used and the HPLC separations were performed by the following linear gradient: 0–25% B in 10 min, then until 100% B by 35 min, 100% B by 45 min, 0% B by 65 min, post time 15 min. The flow rate of the mobile phase was set at 0.500 mL/min. The oven was operated at room temperature (25 °C). The sample injection volume was 10 μL, and the injection was performed manually. The chromatograms were acquired in the range 460 ± 4 nm by DAD detector; the spectra were recorded in the range of 350–550 nm.

Carotenoid standards capsanthin, capsorubin, β-cryptoxanthin, cantaxanthin, antheraxanthin, zeaxanthin, violaxanthin, β-carotene were obtained from “Carotenature” Switzerland; 8′-β-apo-carotenal was obtained from Fluka. All reagents used were HPLC grade.

Statistics

All analyses were done in three replicates. To check the quality of measurements, standard deviations were calculated. A two-tailed t-test was used to compare the means of related (paired) samples to evaluate, if the proposed supercritical fluid extraction yields results, at the 95% confidence level, similar to the Soxhlet reference extraction method.

Results and discussion

Oleoresin extraction

The extraction curve was obtained by plotting the extraction time (in hours) versus yield of oleoresin (%, w/w) ( Figure 1). All extractions were performed at 40 °C. At 20, 30 and 40 MPa maximum yields of oleoresins were 10.6, 10.6 and 10.3%, respectively, which were less than values obtained by Daood et al. (2002) (11.4–11.5%), and, at the same time, greater than those given by Gnayfeed et al. (2001) and Illés, Daood, Biacs, Gnayfeed, & Mészáros (1999). The maximum yield of oleoresin by soxhlet extraction with hexane was 12.8%.

Figure 1. Extraction curve of ground paprika oil solubility in SC-CO₂ as a function of time at different extraction pressures and 40 °C.

Figura 1. Curva de extracción de la solubilidad en aceite de páprika molida en SC-CO₂ como función del tiempo a diferentes presiones y a 40 °C.

HPLC analysis of extracts

The HPLC analysis of the pigment profile showed that carotenoids in paprika occur as free form and esterified with fatty acids, i.e. mono- and di- esters.

The highest carotenoid content was measured in the extract obtained by conventional extraction (Soxhlet), 31,476 mg/kg of extract. The lowest carotenoid content was in SF20 (4530 mg/kg, i.e. 14.4% in comparison to Soxhlet); in SF40, 44.9% of total carotenoid content was extracted. From data shown in Table 1 and Figure 2, it can be seen that Sx extract was rich in different carotenoids, free and esterified. Supercritical carbon dioxide showed low solubility for free (non-esterified) carotenoids ( Figure 3). In comparison with the β-carotene, diesters eluted at higher, whereas free and monoesters at lower retention times. All supercritical extracts contained no capsorubin, violaxanthin or zeaxanthin. β-cryptoxanthin showed some solubility in SC-CO₂. Capsanthin was present only in extracts SF30 and SF40. Antheraxanthin was detected only in oleoresin extracted at 40 MPa. β-carotene was detected in all extracts, conventional and supercritical, for its high solubility in SC-CO₂, because of its low molecular polarity. As a consequence of temperature and high pressure influence, in SF30 and SF40 oleoresins, all-trans to cis-β-carotene isomerisation occured, being more expressive at higher pressure applied. In supercritical extracts, the free carotenoids content raised by the decrease of extraction pressure. Despite the fact that mono- and di- esters solubility increases by the increase of supercritical carbon-dioxide density, the highest content of carotenoids was measured in the Soxhlet extract ( Table 1). The major pigment was capsanthin (93.5–96.1%). The red fraction comprised 79.1% (for Sx) and 42.5, 61.0 and 69.1% (for SC20, SC30 and SC40, respectively) of the pigmentation in oleoresins. It is noticeable that increased pressure caused the increase in red-to-yellow (R/Y) pigment ratio for free carotenoids, monoesters and total pigments. Nevertheless, the highest R/Y ratio was in Soxhlet extract.

Figure 2. HPLC chromatogram of Soxhlet extract of paprika. Peak identification – 1: capsorubin, 2: violaxanthin, 3: capsanthin, 4: cis-capsanthin, 8: zeaxanthin, 9: antheraxanthin, 14: β-cryptoxanthin, 15: capsorubin monoester, 17, 20: capsanthin monoesters, 26: β-carotene, 28: capsorubin diester, 29, 31, 32, 33, 34: capsanthin diesters.

Figura 2. Cromatograma HPLC de extracto Soxhlet de páprika. Identificación de picos – 1: capsorubina, 2: violaxantina, 3: capsantina, 4: cis-capsantina, 8: zeaxantina, 9: anteraxantina, 14: β-criptoxantina, 15: capsorubina monoéster, 17,20: capsantina monoéster, 26: β-caroteno, 28: capsorubina diéster, 29,31,32,33,34: capsantina diésters.

Figure 3. HPLC chromatogram of SFE-CO₂ extracts of paprika at 20 MPa (SF 20). Peak identification – 14: β-cryptoxanthin, 15: capsorubin monoester, 17, 20: capsanthin monoesters, 26: β-carotene, 31, 32, 33, 34: capsanthin diesters.

Figura 3. Cromatograma HPLC de CO₂ SFE de extractos de páprika a 20 MPa (SF 20). Identificación de picos – 14: β-criptoxantina, 15: capsorubina monoéster, 17,20: capsantina monoéster, 26: β-caroteno, 31,32,33,34: capsantina diésters.

Table 1. Carotenoid composition of conventional and SFE paprika oleoresins.
Tabla 1. Composición de carotenoides en oleorresinas por métodos convencional y SFE.

No	Carotenoid	Colour	Content (mg/kg)
			Sx	SF20	SF30	SF40
Free carotenoids
1	Capsorubin	red	88.6 ± 2.45	nd	nd	nd
2	Violaxanthin	yellow	254 ± 13.6	nd	nd	nd
3	Capsanthin	red	1102 ± 21.8	nd	159 ± 8.49	192 ± 9.64
4	Capsanthin	red	154 ± 8.01	nd	nd	nd
6	n.i.	yellow	77.6 ± 2.32	nd	nd	nd
7	n.i.	yellow	162 ± 10.3	nd	nd	nd
8	Zeaxanthin	yellow	256 ± 17.5	nd	nd	nd
9	Anteraxanthin	yellow	361 ± 12.7	nd	nd	124 ± 5.91
14	β-cryptoxanthin	yellow	345 ± 11.8	102 ± 7.44	219 ± 14.3	232 ± 14.6
26	β-carotene	yellow	3251 ± 285	2240 ± 192	3514 ± 315	2920 ± 234
27	cis-β-carotene	yellow	nd	nd	193 ± 11.7	235 ± 15.0
Total free			6052	2342	4085	3703
Total red pigments			1345	0	159	192
Total yellow pigments			4707	2342	3926	3511
Monoesters
15	Capsorubin	red	1253 ± 43.5	118 ± 6.15	272 ± 18.1	363 ± 25.3
16	Capsanthin	red	nd	nd	nd	nd
17	Capsanthin	red	2949 ± 102	240 ± 15.4	456 ± 29.7	751 ± 50.5
18	Capsanthin	red	nd	nd	279 ± 17.1	530 ± 27.9
19	n.i.	yellow	496 ± 22.0	113 ± 5.64	127 ± 6.49	198 ± 10.5
20	Capsanthin	red	1865 ± 153	181 ± 11.7	576 ± 28.6	816 ± 57.3
21	Capsanthin	red	nd	nd	130 ± 5.82	218 ± 11.8
25	n.i.	yellow	1232 ± 43.4	150 ± 10.1	459 ± 19.8	657 ± 25.6
Total monoesters			7795	802	2299	3533
Total red monoesters			6067	539	1713	2678
Total yellow monoesters			1728	263	586	855
Diesters
28	Capsorubin	red	274 ± 9.78	nd	nd	201 ± 11.6
29	Capsanthin	red	626 ± 20.1	nd	292 ± 15.3	427 ± 19.6
30	Capsorubin	red	nd	nd	nd	nd
31	Capsanthin	red	3088 ± 113	383 ± 12.9	1175 ± 40.4	1614 ± 101
32	Capsanthin	red	5811 ± 138	570 ± 27.6	1968 ± 137	2608 ± 189
32a	Zeaxanthin	yellow	nd	nd	nd	nd
33	Capsanthin	red	5369 ± 113	346 ± 15.8	1274 ± 74.9	1687 ± 101
33a	Zeaxanthin	yellow	nd	nd	nd	nd
34	Capsanthin	red	2461 ± 80.0	86.8 ± 1.94	487 ± 27.4	361 ± 18.3
Total diesters			17,629	1386	5196	6898
Total red diesters			17,629	1386	5196	6898
Total			31,476	4530	11,580	14,134
nd, not detected; n.i., not identified.
All determinations were done in three replicates.

Regarding the results of other researchers, who investigated different Hungarian and Spanish paprika pigments, it could be seen that there are oleoresins with lower carotenoid content than ours, as reported by Daood et al. (2002), Gnayfeed et al. (2001) and Illés et al. (1999). However, according to Mínguez- Mosquera and Pérez-Gálvez (1998) and Jarén-Galán and Mínguez-Mosquera (1999), there are some commercial oleoresins with total carotenoid content greater than 80,000 mg/kg, which is higher from the results of this research. These results show that the main determining factors of the oleoresin quality are fruit variety and the applied extraction method.

GC-MS analysis of fatty acid composition

During the ripening of paprika fruits, esterification of carotenoids with fatty acids occurs, making carotenoids become more liposoluble. The GC-MS fatty acid composition analysis showed that paprika oleoresins consisted mostly of linoleic (18:2), oleic (18:1) and palmitic (16:0) fatty acids, as also reported by El-Adawy and Taha (2001) and Asilbekova (2003). The origin of linoleic acid is mostly from the seeds (Pérez-Gálvez, Garrido-Fernández, Mínguez-Mosquera 1999a; Pérez-Gálvez et al., 1999b). The experiment showed that about 87% of fatty acids in oleoresins were C18, with 18:2 (linoleic) being the predominant ( Table 2). Similar results were published in works of number of authors (Breithaupt & Schwack, 2000; El-Adawy & Taha, 2001; Guil-Guerrero, Martínez-Guirado, del Mar Robelloso-Fuentes, & Carrique-Pérez, 2006; Mínguez-Mosquera & Hornero-Méndez, 1994; Orhan, Eryilmaz, & Bingöl, 2002).

Table 2. Fatty acid composition^a (%) of oleoresins obtained by conventional (Soxhlet) and supercritical fluid extraction.
Tabla 2. Composición^a de ácidos grasos (%) en oleorresinas, obtenidos por extracciones convencional (Soxhlet) y supercrítica.

	Sx	SF20	SF30	SF40
Myristic (14 : 0)	0.46 ± 0.04	0.18 ± 0.02	0.27 ± 0.03	0.28 ± 0.03
Palmitic (16 : 0)	9.66 ± 0.57	9.11 ± 0.71	9.60 ± 0.46	10.14 ± 0.74
Palmitooleic (16 : 1)	0.29 ± 0.02	0.31 ± 0.04	0.29 ± 0.04	0.30 ± 0.05
Stearic (18 : 0)	2.23 ± 0.12	1.90 ± 0.07	1.97 ± 0.12	1.93 ± 0.12
Oleic (18 : 1)	8.20 ± 0.41	8.14 ± 0.76	7.69 ± 0.54	7.92 ± 0.60
Linoleic (18 : 2)	75.70 ± 1.20	78.26 ± 0.95	77.91 ± 0.84	77.20 ± 1.22
Linolenic (18 : 3)	2.93 ± 0.12	1.65 ± 0.14	1.73 ± 0.08	1.71 ± 0.07
Arachidic (20 : 0)	0.29 ± 0.02	0.25 ± 0.03	0.31 ± 0.03	0.31 ± 0.03
Behenic (22 : 0)	0.24 ± 0.02	0.20 ± 0.02	0.21 ± 0.01	0.20 ± 0.02
Total saturated FA	12.88	11.63	12.37	12.86
Total unsaturated FA	87.12	88.37	87.63	87.14
Mono-unsaturated FA	8.49	8.45	7.99	8.22
Poly-unsaturated FA	78.63	79.91	79.65	78.92
Unsaturated : saturated FA	6.76 : 1	7.59 : 1	7.09 : 1	6.77 : 1
^aAll determinations were done in five replicates.
Mean value of coefficient of variation was 7.14.

The high amount of linoleic and α-linolenic essential fatty acids in pepper oleoresin contributes to its nutritive value.

Results were compared using t-test pair values. The t-test shows that there was no significant difference between contents of fatty acids in extracts obtained by conventional and supercritical fluid extractions under different conditions.

Conclusion

Our results show that, during supercritical extraction, the oleoresin yields were in the range of 10.3–10.6%, the share of β-carotene in oleoresins decreased (from 49.4% to 20.7%), while, at the same time, the share of red pigments increased (from 42.5% to 69.1%), showing that pigments isolated at lower pressure consisted for the most part of β-carotene, while pigments isolated at a higher pressure contained greater proportions of capsorubin and capsanthin. Because of remarkable carotenoid and essential fatty acid content, paprika oleoresins can be considered as a very valuable supplement to human nutrition. It should be kept in mind that application of supercritical fluids in oleoresin production leads to products with different qualitative and quantitative composition, depending on the process conditions applied, as well as solvent free extracts.

Acknowledgements

This research is part of the Project No 114-451-01458, which is financially supported by the Provincial Secretariat for Science and Technological Development of Vojvodina.