Abstract
Peach palm (Bactris gasipaes Kunth) is an amazonian fruit in which its peel has been appointed as a carotenoid-rich byproduct with biological properties. For analytical purposes, carotenoids are frequently extracted by non-green (use of toxic organic solvents) and time-consuming methods, which can affect the quality (carotenoid profile) and safety of extracts for direct food applications. We investigated herein the effect of different extraction methods on the individual carotenoid profile of extracts of peach palm peels by HPLC-DAD. Carotenoid extractions were carried out by maceration in mortar with pestle (with acetone or ethanol), magnetic stirring, shaker and ultrasound-assisted extraction (UAE) using ethanol. UAE provided the highest carotenoid contents (67 mg/100 g), followed by maceration with acetone and ethanol (63 and 52 mg/100 g, respectively), while the lowest contents were observed for the magnetic stirring and shaker extractions (44 mg/100 g), being (all-E)-β-carotene and a Z-isomer of γ-carotene accounted 54–73% of the carotenoid composition. HPLC-DAD data showed the same carotenoid profile regardless the extraction method, yet the percentage of Z-isomers of β-carotene was higher for the shaking (18%), UAE (17%) and magnetic stirring (15%) than for both maceration methods (7 and 8%, with acetone and ethanol, respectively). Thus, the tested extraction methods affected the total carotenoid contents, whereas the chromatographic profile did not change. Furthermore, a carotenoid-rich extract was effectively obtained by using ethanol associated with ultrasound technique (less time-consuming) instead of toxic and non-safe solvents.
Keywords: Amazonian fruit, Amazon, Bioactive compounds, Food byproduct, β-Carotene
1. Introduction
Carotenoids are natural pigments biosynthesized by plants, bacteria, algae, fungi and some arthropods, such as hemipterans (aphids, adelgids, phylloxerids) [1]. As humans do not synthesize carotenoids, they need to intake such compounds by means a carotenoid-rich diet based on green leaves, fruits and vegetables [2]. The literature reports more than 750 naturally occurred carotenoids with different chemical structures, properties and colors, especially yellow, orange and red, yet colorless carotenoids can be found frequently, such as phytoene and phytofluen [3,4]. Carotenoids have been extensively investigated by science and industry due to their biological properties on human health, such as provitamin A and antioxidant activities [5].
Native people and animals from tropical regions, such as the Amazonia, eat different fruits found just in those places, which arise the interest to know the contribution of the intake of nutrients and bioactive compounds from these fruits [6]. Previous reports showed that some of these fruits contain high contents of bioactive compounds with potential to be used as functional compounds in human and animal diets [7]. Despite previous studies, these fruits have not been extensively studied/exploited by science and industry. For example, peach palm fruit (Bactris gasipaes), which is commonly consumed in the Amazonia after cooked with salty water, it is important to native people due to its proximate composition and promising bioactive compounds profile. Peach palm fruits show high levels of carbohydrate (72% of starch) and variable contents of oil (from 8 to 36%) [[8], [9], [10]]. Furthermore, high content of carotenoids was reported in both pulp (3 mg/100 g fresh weight, fw) and peel (33 mg/100 g fw) of the fruit [11]. The carotenoid profile of peach palm fruits, mainly composed by β-carotene and its Z-isomers, indicates the high potential for increasing the intake of provitamin A carotenoids with antioxidant properties [12,13]. According to our research group, the peel of peach palm fruits are carotenoid-rich byproducts generated during the fruit processing [11], but it is usually discarded without proper attention and underexploited by science or food, cosmetic and pharmaceutical industries.
Developing an appropriate method to extract carotenoids from plants is one of the most important steps to obtain high-quality compounds aiming to use them by both analytical (high-purity standard) and industrial purposes. Taking into account the carotenoid instability facing to the processing settings, such as exposure to oxygen, light and high temperature, the extraction method should not affect or should minimally affect the profile and contents of carotenoids [14]. Several methods have been reported in the literature to extract carotenoids, from conventional (maceration, shaker and magnetic stirring) to emergent technologies, such as ultrasound [15,16]. These methods may be characterized by distinct experimental conditions, such as specific extraction steps and use of different solvents, which might affect the qualitative and quantitative composition of carotenoids, even for the same raw material.
Therefore, we extracted herein carotenoids from peels of peach palm fruits by four methods, namely maceration in mortar with pestle, shaker, magnetic stirring and ultrasound-assisted extraction (UAE) to investigate the effect of each method on the carotenoid profiles and contents. The peels of peach palm fruits (a byproduct) was used as raw material due to its very high carotenoid contents [11]. In addition, ethanol was chosen in this study as acetone replacement, since ethanol is a green solvent, recognized as GRAS (Generally Recognized as Safe) for food application, selective (low to medium polarity), cheaper than acetone, and easy-to-buy as Brazilian Federal Agencies do not strictly limit ethanol sales and use due to its high-safety; which not happen for acetone.
2. Material and methods
2.1. Chemicals
Methyl tert-butyl ether (MTBE) and methanol, both of chromatographic grade, (all-E)-β-carotene and (all-E)-lutein were acquired from Sigma-Aldrich Co. LLC (St. Louis, USA). Acetone, ethanol, potassium hydroxide (KOH), diethyl ether and petroleum ether, all of analytical grade, were purchased from ACS Reagentes (Rio de Janeiro, Brazil).
2.2. Peach palm fruits
Peach palm fruits (Bactris gasipaes) (2 kg) (Fig. 1) were purchased in the “Ver-o-Peso” Market-Place located in Belém, Pará State, Brazil (01°27′21″S latitude and 48°30′16″W longitude). Only ripe (orange-colored peel) and morphological perfect fruits were selected to carry out this study. The selected fruits were washed with tap water followed by immersion in sanitizing solution (sodium hypochlorite 100 ppm) for 10 min, followed by cooking in a pressure cooker, following the traditional way to process peach palm fruits in the Amazonia. Then, the peels were manually separated from the fruits, freeze-dried and ground to obtain a flour. The freeze-dried sample was stored at −20 °C and protected from light until the experiments. The access to the selected fruits was registered in the Brazilian National System for the Management of Genetic Heritage and Associated Traditional Knowledge (SisGen, ACC7773).
Fig. 1.
(a) Orange peach palm fruits, (b) cooked peels and (c) freeze-dried peels. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)
2.3. Extraction of carotenoids by different methods
The carotenoids from peels of peach palm fruits were extracted by maceration in mortar with pestle using acetone as control experiment and with ethanol by maceration in mortar with pestle, magnetic stirring, shaker, and ultrasound using ethanol.
2.3.1. Maceration extraction using acetone (control experiment)
The total carotenoid contents were determined in the freeze-dried samples according to the most used method described by Rodriguez-Amaya [17]. Data obtained from this analytical procedure were considered as control, since it is the most used procedure in the literature to extract carotenoids exhaustively from fruit samples. Briefly, 1 g of freeze-dried samples were macerated with acetone, using Celite in a mortar with pestle, followed by vacuum filtration and re-extractions until colorless. The filtrate was partitioned in separating funnel using petroleum ether/diethyl ether (1:1, v/v) and washed with distilled water. The extract was evaporated to dryness under vacuum (<35 °C) and the dried residue was solubilized in petroleum ether for the total carotenoid determination.
2.3.2. Maceration extraction using ethanol
Maceration extraction in mortar with pestle was carried out according to the procedure described by Rodriguez-Amaya [17], but replacing acetone by ethanol, and the ethanolic extract was not partitioned in separating funnel. Briefly, the freeze-dried samples (1 g) were macerated using Celite and ethanol, followed by vacuum filtration. The residue was used to re-extract carotenoids. These steps were repeated until the orange pigment from the samples were completely removed. Liquid fractions were combined to obtain only one extract for the total carotenoid determination.
2.3.3. Shaker and magnetic stirring extraction
The freeze-dried samples (1 g) were added to erlenmeyers containing ethanol (1:7, w/v) and the system was closed with parafilm® and aluminum foil to avoid solvent loss and light exposure. The flasks were placed in an orbital shaker (MA 140 ⁄CFT Marconi, São Paulo, Brazil) in the following conditions: 115 rpm, 25 °C (room temperature) during 80 min [11].
The magnetic stirring extraction was carried out at the same conditions of shaker extraction (1:7, w/v; 25 °C and 80 min) replacing the shaking in the orbital shaker by a magnetic stirrer (XH-CU, Global Trade Technology, Jaboticabal, São Paulo, Brazil).
In both procedures, the ethanolic extracts were filtered in quantitative filter papers and the volume of the extracts were adjusted before the measurement of total carotenoids.
2.3.4. Ultrasound-assisted extraction (UAE)
Carotenoids were extracted from the freeze-dried samples according to the method previously developed by our research group for peach palm fruit pulps [16]. Briefly, a falcon tube containing 0,5 g of sample and 5 mL of ethanol (1:10, w/v) was placed in an ultrasound bath (Eco-Sonics, Q3.0 L model, 25 KHz, Sao Paulo, Brazil) at 25 °C during 5 min. The extraction procedure was repeated 10 times to extract exhaustively the carotenoids from the sample. The ethanolic extracts were filtered in quantitative filter papers and the lliquid fractions were combined to obtain only one extract.
2.4. Determination of total carotenoids
The total carotenoid contents were determined by spectrophotometry, at λ = 450 nm, using the specific absorption coefficient of β-carotene in petroleum ether (2592) (control experiment) or ethanol (2620) (alternative methods) [17]. The contents (n = 3) were expressed as mg/100 g dry weight, dw (moisture content = 4.07%).
2.5. Carotenoid composition by HPLC-DAD
The carotenoid extracts obtained after all the different methods were saponified using KOH 10% in methanol for 16 h (overnight). The saponified samples were partitioned in separating funnel using petroleum ether/ethyl ether (1:1, v/v), followed by vacuum drying (<38 °C). The dried extracts were solubilized in methanol (MeOH)/methyl tert-butyl ether (MTBE) at the proportion 70:30 (v/v) and filtered (0.22 μm) before the injection (20 μL) into the HPLC system [18].
HPLC system (Shimadzu, Prominece UFLC model) equipped with a binary pump (LC-20 AD), degasser (DGU-20A3), automatic injector (SILL-20AHT) and diode array detector (DAD/SPD-M20A) was used. The carotenoids were separated on a C30 YMC column (5 μm, 250 mm × 4.6 mm) at 29 °C using methanol/MTBE as mobile phase at flow rate of 0.9 mL/min. The linear gradient was as follows: from 95:5 to 70:30 in 30 min, followed by 50:50 in 20 min. The chromatograms were acquired at 450 nm and all the spectra recorded from 200 to 600 nm [18]. The carotenoids were identified according to the following combined data: elution order on C30 column, UV–visible spectrum features [λmax, spectral fine structure (%III/II), peak cis intensity (%AB/AII)], and co-chromatography with authentic standards. Previous data from our research group and literature, by HPLC-DAD coupled to mass spectrometry, were considered to the assignment of the carotenoid peaks [[11], [12], [13]].
The contents of carotenoids were determined by external five-point analytical curves (n = 3) of β-carotene (2.5–80 μg/mL, R2 = 0.99). The results were expressed as mg/100 g dw. Vitamin A equivalent value was calculated according to the NAS-IOM [19] conversion factor, in which 12 μg of dietary (all-E)-β-carotene correspond to 1 μg of retinol activity equivalent (RAE), and the theoretical activity used was 100% for (all-E)-β-carotene.
2.6. Statistical analysis
All determinations were carried out at least three times, and the data were reported as mean ± standard deviation. The data were submitted to Analysis of Variance (ANOVA) followed by Tukey's test (p ≤ 0.05) using the Past Software.
3. Results and discussion
3.1. Total carotenoid contents for all the extraction procedures
To protect carotenoids from light degradation, all the extraction procedures and analyses were carried out under indirect light incidence (penumbra) and all glassware were wrapped with aluminum foil. Table 1 shows the total carotenoid contents (TCC) in the freeze-dried samples obtained by means of the different methods.
Table 1.
Total carotenoid contents (mg/100 g, dry weight, dw) for the peel of peach palm fruits obtained by the different extraction procedures.
| Method | Total carotenoid contents (mg/100 g, dry weight) |
|---|---|
| Maceration (acetone) - control | 40.65 ± 10.13b |
| Maceration (ethanol) | 46.76 ± 0.21b |
| Magnetic stirring (ethanol) | 42.34 ± 0.29b |
| Shaker (ethanol) | 13.83 ± 0.89c |
| Ultrasound-assisted extraction (ethanol) | 69.88 ± 0.60a |
Maceration using acetone is the conventional analytical method (control) described by Rodriguez-Amaya [17]. Magnetic stirring, shaker and ultrasound were carried out with ethanol as alternative replacement for acetone. Means with different superscript letters in the column are statistically different (p < 0.05).
Maceration with ethanol and magnetic stirring showed TCC values statistically equals to the control method (maceration with acetone). These data demonstrate the great potential use of magnetic stirring to extract carotenoids due to its advantages compared to maceration method. For example, maceration method exposures the target compounds to oxygen and light for a long period, while the stirring method present low runtime protocol. Furthermore, magnetic stirring is carried out without Celite, vacuum filtration and maceration to break up plant tissue. These variables can generate great variation in the data since they are not easily controlled.
The shaker method showed the lowest TCC values. This method showed TCC up to 5 and 3 times lower than UAE and the other methods used in this study, respectively. Nevertheless, the carotenoid contents for the shaker extraction using ethanol (13.83 mg/100 g dw) was close to the value reported by Matos et al. [11] (15 mg/100 g dw), yet they used a combination of ethyl acetate and acetone. It indicates that the use of ethanol, a low-cost and high-safe solvent, can be feasible to obtain extraction yield similar to the methods that employ toxic and expensive solvents.
Unlike shaker method, UAE showed the highest TCC, corroborating with previous reports [20,21]. Waves from ultrasound cause mechanical vibration of the liquid (solvent), which form bubbles. Bubbles formed can grow to a critical size thus violently collapse, phenomenon known as acoustic cavitation. Acoustic cavitation causes several physical effects on the raw material, such as increasing of temperature and pressure. As consequence, this phenomenon can break down plant tissue increasing the mass‐transfer rate of bioactive compounds from sample to solvent [20].
Indeed, UAE can be used to extract carotenoids efficiently from both pulp and peel of peach palm fruits. Monteiro et al. [16] extracted carotenoids from pulps of orange peach palm fruits using UAE with ethanol as solvent, and reported total carotenoid values varying from 8 to 10 mg/100 g. We extracted herein almost 5 times more carotenoids from the peels of peach palm fruits (69.88 mg/100 g dw). High contents of carotenoids were reported in peel (33 mg/100 g fw) of the fruit, while the pulp showed lower value (3 mg/100 g fresh weight, fw) [11], which justify the difference between the studies even using the same solvent and extraction method. On the other hand, Ordóñez-Santos et al. [15] extracted high amounts of carotenoids from peels of peach palm fruits using UAE and sunflower oil as solvent (109.82–163.01 mg/100g dw), which are higher than the values reported in the present study (69.88 mg/100 g dw). Despite the great UAE-ethanol performance, UAE-ethanol process should be improved to further increase the extraction of carotenoids from the peels of peach palm fruits.
3.2. Carotenoid composition, by HPLC-DAD, for all the extraction procedures
Regarding carotenoid composition of the peels of peach palm fruits, the used HPLC-DAD method allowed the tentative identification and quantification of ten (10) compounds (Fig. 2). The qualitative profiles of carotenoids were equal independently of the extraction method used, yet the contents of the compounds was different. Z-γ-Carotene (isomer 2) was the main compound in the extracts obtained by UAE, shaker and magnetic stirring, while both maceration methods (with acetone and ethanol) showed all-E-β-carotene as main compound.
Fig. 2.
HPLC-DAD chromatogram of carotenoid extracts of the peels of peach palm fruits obtained by the different extraction procedures. Table 2 shows the characterization of each peak. Maceration C. means the extraction carried out with acetone (Control).
Table 2 shows the carotenoid tentative identification for the peel extracts of peach palm fruit. Peak 1 was positively identified as (all-E)-lutein by means of coelution with authentic standard. This carotenoid belongs to xanthophyll class and it is associated with several beneficial health effects, such as eye health [12,22]. The peaks 2, 4 and 5 were identified as β-carotene isomers, being the (all-E)-β-carotene (peak 4) positively confirmed by coelution with authentic standard and the Z-isomers were assigned due to the observed hypsochromic shift at the λmax, the cis-peak increase (%AB/AII) and their known chromatographic behavior [12]. β-Carotene, which has the highest provitamin A activity among the provitamin A carotenoids, was already reported as the major carotenoid in peels [11] and pulps [12,13] of peach palm fruits, as it is also commonly found as major carotenoid in a wide range of vegetables and fruits [12,23]. Peak 3 was assigned as (all-E)-α-carotene as it is known to have the same chromophore as lutein and, therefore, the same UV/visible absorption spectrum [12,24]. In addition, (all-E)-α-carotene was already positively identified in pulps of peach palm fruits [12].
Table 2.
Carotenoids identified in the peel extract of peach palm fruits by HPLC-DAD.
| Peaka | Carotenoidb | Time (min)c | λmax (nm)d | %III/II | %AB/AII |
|---|---|---|---|---|---|
| 1 | (all-E)-Lutein | 12.6 | 267, 420, 444, 472 | 62 | 0 |
| 2 | 13Z-β-Carotene | 26.5 | 339,420, 443, 467 | 33 | 37 |
| 3 | (all-E)-α-Carotene | 28.9 | 267, 420, 444, 472 | 50 | 0 |
| 4 | (all-E)-β-Carotene | 32.8 | 273, 432, 451, 478 | 33 | 0 |
| 5 | 9Z-β-Carotene | 34.6 | 273, 347, 420, 448, 472 | 16 | 9 |
| 6 | 13Z-δ-Carotene | 38.1 | 280, 349, 433, 454, 482 | 34 | 37 |
| 7 | (all-E)-δ-Carotene | 42.1 | 280, 432, 455, 484 | 44 | 0 |
| 8 | Z-γ-Carotene (isomer 1) | 47.9 | 282, 345, 430, 457, 487 | 47 | n.c |
| 9 | (all-E)-γ-Carotene | 48.7 | 282, 436, 461, 490 | 54 | 0 |
| 10 | Z-γ-Carotene (isomer 2) | 49.4 | 282, 436, 460, 490 | 55 | n.c |
Peaks 6 and 7 were identified as 13Z-δ-carotene and (all-E)-δ-carotene, respectively, which are monocyclic carotenoids containing just one δ-ionone ring due to lycopene cyclization [1]. De Rosso and Mercadante [12] and Chisté et al. [13] reported spectral features, such as λmax (349, 433, 454, 482) and spectral fine structure (%III/II = 34) similar to the data of Table 2 regarding peak 6 (13Z-δ-carotene). Peak 7 ((all-E)-δ-carotene) showed similar spectral features to those previously reported for δ-carotene identified in peels [11] and cooked pulps [13] of peach palm fruits.
Peak 9 was assigned as (all-E)-γ-carotene as this compound was previously identified for peach palm fruits [[11], [12], [13]], and the spectral features described by them corroborate with our data (Table 2). The peaks 8 and 10 were identified as Z-γ-carotene (isomer 1) and Z-γ-carotene (isomer 2), respectively. Both compounds are Z-isomers of γ-carotene and they showed expected hypsochromic shift (≈4 nm) in the λmax in relation to their E-isomer (461 nm), as previously reported [12,13,25].
In this study, regardless the extraction method, the carotenoid profiles in the extracts of peels of peach palm fruits remained the same, yet their individual content varied (Table 3).
Table 3.
Carotenoid profile of extracts obtained by different extraction techniques.
| Carotenoid |
Carotenoid contents (mg/100 g, dry weight) |
||||
|---|---|---|---|---|---|
| Maceration (acetone) | Maceration | Shaker | Magnetic stirring | Ultrasound | |
| (all-E)-Lutein | 0.01 ± 0.01b | 0.02 ± 0.01b | 1.27 ± 0.01a | 0.59 ± 0.06ab | 1.19 ± 0.55a |
| 13Z-β-Carotene | 0.37 ± 0.10a | 0.82 ± 0.22a | 2.34 ± 0.68a | 1.72 ± 0.49a | 2.89 ± 1.84a |
| (all-E)-α-carotene | 1.19 ± 0.01a | 0.83 ± 0.73a | 0.03 ± 0.03a | 0.31 ± 0.24a | 0.61 ± 0.30a |
| (all-E)-β-Carotene | 25.12 ± 0.70a | 19.62 ± 5.42a | 10.12 ± 0.26b | 10.64 ± 1.97b | 14.78 ± 4.37ab |
| 9Z-β-Carotene | 3.76 ± 0.03a | 3.62 ± 1.77a | 5.51 ± 0.47a | 4.96 ± 0.86a | 8.37 ± 5.82a |
| 13Z-δ-Carotene | 6.14 ± 0.29a | 1.02 ± 0.45b | 0.50 ± 0.40b | 0.70 ± 0.31b | 0.67 ± 0.14b |
| (all-E)-δ-Carotene | 0.02 ± 0.01b | 4.25 ± 1.81a | 6.04 ± 0.57a | 5.27 ± 0.30a | 9.03 ± 4.43a |
| Z-γ-Carotene (isomer 1) | 0.73 ± 0.01a | 1.16 ± 0.74a | 0.92 ± 0.03a | 1.24 ± 0.09a | 1.15 ± 1.62a |
| (all-E)-γ-Carotene | 4.04 ± 0.70a | 3.20 ± 2.06a | 4.20 ± 0.89a | 4.47 ± 0.43a | 6.80 ± 2.51a |
| Z-γ-Carotene (isomer 2) | 21.12 ± 1.27a | 17.22 ± 4.62a | 13.50 ± 0.70a | 13.71 ± 4.01a | 21.18 ± 8.46a |
| Total sum | 62.52 ± 7.18a | 51.79 ± 7.18b | 44.48 ± 4.36b | 43.66 ± 4.58b | 66.7 ± 7.33a |
| Vitamin A equivalent value (μg RAE/g) | 38.22 ± 2.15a | 31.58 ± 1.48b | 25.47 ± 1.04b | 25.14 ± 2.06b | 38.13 ± 2.21a |
Carotenoids were quantified as β-carotene equivalents. Means with different lowercase letters (a, b, c) within a line were significantly different (p < 0.05). RAE: retinol activity equivalent.
The contents of (all-E)-lutein were statistically equal for the shaker, magnetic stirring and ultrasound methods, and its contents were higher than the values found by the maceration methods, independently of the solvent (acetone or ethanol), which indicated low efficiency of the maceration procedure on (all-E)-lutein extraction.
The content of the major carotenoid in peach palm fruit, (all-E)-β-carotene, varied as well. Maceration provided the highest content of this compound, in which the content of (all-E)-β-carotene was almost 2 times higher than shaker, magnetic stirring and UAE. Furthermore, UAE showed values of (all-E)-β-carotene statistically equal to the shaker, magnetic stirring and maceration with ethanol.
The extract obtained from maceration with acetone showed 13Z-δ-carotene contents (6.14 mg/100 g) about 6 times higher than in maceration with ethanol (1.02 mg/100 g). On the other hand, UAE showed (all-E)-δ-carotene contents almost 2 times higher than any other method evaluated in this report. Data from Table 3 shows that the type of solvent can affect the formation (increasing or decreasing) of both isomers, 13Z-δ-carotene and (all-E)-δ-carotene. Although the extraction methods are different, the content of the other compounds were not affected by the method. For example, the process time is one of the variables widely different among the evaluated methods. Extraction procedures with long process time will expose the compounds to light, oxygen and temperature increase, which may induce carotenoid isomerization [26]. Importantly, as the conjugated double-bonds of carotenoids are more susceptible to isomerization during temperature increase [14], the formation of β, δ and γ isomers in this study can be also related to the thermal treatment applied in the peach palm fruits (traditional cooking).
Comparison with scientific literature for the individual carotenoids identified in this study and different extraction procedures is still limited as very few studies were carried out with extraction of carotenoids from peels of peach palm fruits. Matos et al. [11] reported lower contents of β-carotene (7.3 mg/100 g) and δ-carotene (1.7 mg/100 g) in fresh peels of peach palm fruits extracted by shaker agitation in an ethyl acetate/acetone (30:70, v/v) solution, considering that the fruit peel showed 15 mg/100 g (wet basis) as the sum of all the identified carotenoids. As cooked peels of peach palm fruits are reported to contain 4.5–4.7% of moisture [27], the sum of all the identified carotenoids reported by Matos et al. [11] can be converted to 15.7 mg/100 g (dry basis). In our study, ethanol and shaker agitation were about 3 times more efficient (44 mg/100 g, dry basis), but such difference can be also attributed to the use of different fruits from different producers, seasons and areas of harvesting. Interestingly, these same authors reported similar contents of γ-carotene (4 mg/100 g), even considering the result in wet basis or dry basis, which suggests future studies to monitor the formation and stability of γ-carotene in peach palm fruits. In a study with dried biomass from pulp of peach palm fruits, Mesquita et al. [28] compared the conventional method do extract carotenoids (maceration with acetone) with an UAE using ethanol-based solutions of ionic liquids and reported almost 2-times higher efficiency to the alternative method without noticing alterations in the individual profile of carotenoid, except for the their contents.
Fig. 3 shows a summary view of the isomers identified in each extract. E-isomers showed similar percentage to all extracts (48–54%), in which maceration with ethanol showed the highest value of E-isomer. The Z-isomers of β-carotene were detected especially in the extracts obtained by shaker (17%), UAE (16%) and magnetic stirring (15%), while maceration with ethanol and maceration showed values of 6 and 8%, respectively. Z-isomers of γ-carotene was not affected by the extraction methods (values ranging from 32 to 35%), while Z-isomers of δ-carotene represent approximately 10% of the carotenoids recovered from the sample using maceration with acetone, while the percentage of this compounds for the other methods was <2%.
Fig. 3.
Total E and Z carotenoids in the extracts obtained from peels of peach palm fruits by means of different methods. Data expressed as relative percentage.
As a general remark, we can highlight that the ethanolic extract obtained by UAE showed high content of provitamin A carotenoids. UAE associated with ethanol showed the same performance of the conventional method applied to extract carotenoids exhaustively from food samples (maceration with acetone). Furthermore, the peach palm fruit peel is a byproduct that could be used as raw material to obtain carotenoid-rich extracts by using emerging technologies, such as ultrasound. Certainly, the process evaluated in this report should be even more improved to achieve yield as high as extraction processes that use oil and organic solvents.
4. Conclusion
The qualitative carotenoid profile of peach palm peels was the same for all the extraction methods, yet the content of the identified carotenoids was different. Ultrasound-assisted extraction using ethanol as solvent showed carotenoid content statistically equal to the traditional procedure (maceration with acetone). In this sense, the conventional analytical method using toxic organic solvent could be replaced by a method using GRAS solvent and low-operational time, which will avoid prolonged contact of carotenoids with degrading factors, such as oxygen and incidence of light. In addition, extraction by magnetic stirring using ethanol is a method with potential use to obtain carotenoids from peels of peach palm fruits due to its low operational and technical costs. The carotenoid-rich ethanolic extract obtained from peels of peach palm fruits by means of ultrasound and magnetic stirring showed potential to be used by food and pharmaceutical industries. The method with high extraction efficiency and low negative effect on the profile of carotenoids can be used in other studies to promote the recovery of rich-carotenoids byproducts from Amazonian fruits. Furthermore, the method can be applied to obtain high-purity standard and natural antioxidant and pigments, which may be used by food, pharmaceutical and cosmetics industries.
Author contribution statement
Jhonathan Vinícius Menezes Silva: Performed the experiments; Analyzed and interpreted the data; Wrote the paper. Alberdan Silva Santos; Gustavo Araújo Pereira: Analyzed and interpreted the data; wrote the paper. Renan Campos Chisté: Conceived and designed the experiments; Analyzed and interpreted the data; Contributed reagents, materials, analysis tools or data; Wrote the paper.
Funding statement
The authors acknowledge Fundação Amazônia de Amparo a Estudos e Pesquisas (FAPESPA, Brazil, Project 2017/52,864 - ICAAF Nº 013/2018), Superintendência do Desenvolvimento da Amazônia (SUDAM, Process 59004.000739/2022-48) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil, Project 408181/2021-4) for the financial support.
Data availability statement
Data included in article/supplementary material/referenced in article.
Additional information
No additional information is available for this paper.
Declaration of competing interest
The authors declare no conflicts of interest. Renan Campos Chisté is part of the Editorial Advisory Board of Heliyon journal (Food Science and Nutrition section).
References
- 1.Rodriguez-Concepcion M., Avalos J., Bonet M.L., Boronat A., Gomez-Gomez L., Hornero-Mendez D., Limon M.C., Meléndez-Martínez A.J., Olmedilla-Alonso B., Palou A., Ribot J., Rodrigo M.J., Zacarias L., Zhu C. A global perspective on carotenoids: metabolism, biotechnology, and benefits for nutrition and health. Prog. Lipid Res. 2018;70:62–93. doi: 10.1016/j.plipres.2018.04.004. [DOI] [PubMed] [Google Scholar]
- 2.Berman J., Zorrilla-López U., Farré G., Zhu C., Sandmann G., Twyman R.M., Carpell T., christou P. Nutritionally important carotenoids as consumer products. Phytochemistry Rev. 2014;14(5):727–743. doi: 10.1007/s11101-014-9373-1. [DOI] [Google Scholar]
- 3.Britton G., Liaaen-Jensen S., Pfander H. Birkhäuser Basel; 2004. Carotenoids – Handbook; p. 647. [DOI] [Google Scholar]
- 4.Meléndez-Martinez A.J., Mappelli-Brahm P., Benítez-Gonzáles A., Stinco C.M. A comprehensive review on the colorless carotenoids phytoene and phytofluene. Arch. Biochem. Biophys. 2015;572:188–200. doi: 10.1016/j.abb.2015.01.003. [DOI] [PubMed] [Google Scholar]
- 5.Costa G.A., Mercadante A.Z. In vitro bioaccessibility of free and esterified carotenoids in cajá frozen pulp-based beverages. J. Food Compos. Anal. 2017;68:53–59. doi: 10.1016/j.jfca.2017.02.012. [DOI] [Google Scholar]
- 6.Peixoto-Araujo N.M., Arruda H.S., Marques D.R.P., Oliveira W.Q., Pereira G.A., Pastore G.M. Functional and nutritional properties of selected Amazon fruits: a review. Food Res. Int. 2021;147 doi: 10.1016/j.foodres.2021.110520. [DOI] [PubMed] [Google Scholar]
- 7.Murillo E., Giuffrida D., Menchaca D., Dugo P., Torre G., Meléndez-Martinez A.J., Mondello L. Native carotenoids composition of some tropical fruits. Food Chem. 2012;140:825–836. doi: 10.1016/j.foodchem.2012.11.014. [DOI] [PubMed] [Google Scholar]
- 8.Oliveira A. N. de, Oliveira L. A. de, Andrade J.S., Chagas-Júnior A.F. Produção de amilase por rizóbios, usando farinha de pupunha como substrato. Ciên. Tecnol. Aliment., Campinas. 2007;27(1):61–66. doi: 10.1590/S0101-20612007000100011. [DOI] [Google Scholar]
- 9.Carvalho A.V., Beckman J.C., Maciel R.A.E.A., Farias J.T. Physical and chemical characteristics of peach palm fruits in the state of Pará. Rev. Bras. Frutic. 2013;35:763–768. doi: 10.1590/S0100-29452013000300013. [DOI] [Google Scholar]
- 10.Pires M.B., Amante E.R., Lucia de Oliveira Petkowicz C., Esmerino E.A., Manoel da Cruz Rodrigues A., Meller da Silva L.H. Impact of extraction methods and genotypes on the properties of starch from peach palm (Bactris gasipaes Kunth) fruits. LWT. 2021;150 doi: 10.1016/j.lwt.2021.111983. [DOI] [Google Scholar]
- 11.Matos K.A.N., Lima D.P., Barbosa A.P.P., Mercadante A.Z., Chisté R.C. Peels of tucumã (Astrocaryum vulgare) and peach palm (Bactris gasipaes) are by-products classified as very high carotenoid sources. Food Chem. 2019;272:216–221. doi: 10.1016/j.foodchem.2018.08.053. [DOI] [PubMed] [Google Scholar]
- 12.De Rosso V.V., Mercadante A.Z. Identification and quantification of carotenoids, by HPLC-PDA-MS/MS, from Amazonian fruits. J. Agric. Food Chem. 2007;55:5062–5072. doi: 10.1021/jf0705421. [DOI] [PubMed] [Google Scholar]
- 13.Chisté R.C., Costa E.L.N., Monteiro S.F., Mercadante A.Z. Carotenoid and phenolic compound profiles, by HPLC-DAD-MS/MS, of orange and yellow peach palm fruits (Bactris gasipaes) from Amazonia. J. Food Compos. Anal. 2021;99:1–8. doi: 10.1016/j.jfca.2021.103873. [DOI] [Google Scholar]
- 14.Rodriguez-Amaya D.B. Change in carotenoid during processing and storage of foods. Arch. Latinoam. Nutr. 1999;49:385–475. [PubMed] [Google Scholar]
- 15.Ordóñez-Santos L.E., Pinzón-Zarate L.X., González-Salcedo L.O. Optimization of ultrasonic-assisted extraction of total carotenoids from peach palm fruit (Bactris gasipaes) by-products with sunflower oil using response surface methodology. Ultrason. Sonochem. 2015;27:560–566. doi: 10.1016/j.ultsonch.2015.04.010. [DOI] [PubMed] [Google Scholar]
- 16.Monteiro S.F., Costa E.L.N., Ferreira R.S.B., Chisté R.C. Simultaneous extraction of carotenoids and phenolic compounds from pulps of orange and yellow peach palm fruits (Bactris gasipaes) by ultrasound-assisted extraction. Food Sci. Technol., Campinas. 2022;42 doi: 10.1590/fst.34021. [DOI] [Google Scholar]
- 17.Rodriguez-Amaya D.B. ILSI Human Nutrition Institute. One Thomas Circle; NW, Washington DC, 20005-5802: 2001. A Guide to Carotenoid Analysis in Foods. 64. [Google Scholar]
- 18.Chisté R.C., Mercadante A.Z. Identificação e quantificação, por HPLC-DAD-MS/MS, de carotenoides e compostos fenólicos do fruto amazônico Caryocar villosum. J. Agric. Food Chem. 2012;60:5884–5892. doi: 10.1021/jf301904f. [DOI] [PubMed] [Google Scholar]
- 19.NAS-IOM . National Academy Press; WA: 2001. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, 17 Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc; p. 92. [PubMed] [Google Scholar]
- 20.Goula A.M., Ververi M., Adamopoulou A., Kaderides K. Green ultrasound-assisted extraction of carotenoids from pomegranate wastes using vegetable oils. Ultrason. Sonochem. 2017;34:821–830. doi: 10.1016/j.ultsonch.2016.07.022. [DOI] [PubMed] [Google Scholar]
- 21.Chutia H., Mahanta C.L. Green ultrasound and microwave extraction of carotenoids from passion fruit peel using vegetable oils as a solvent: optimization, comparison, kinetics, and thermodynamic studies. Innovative Food Sci. Emerging Technol. 2021;67 doi: 10.1016/j.ifset.2020.102547. [DOI] [Google Scholar]
- 22.Semba R.D., Dagnelie G. Are lutein and zeaxanthin conditionally essential nutrients for eye health? Med. Hypotheses. 2003;61:465–472. doi: 10.1016/S0306-9877(03)00198-1. [DOI] [PubMed] [Google Scholar]
- 23.Bertram J.S. Dietary carotenoids, connexins and cancer: what is the connection? Biochem. Soc. Trans. 2004;32(6):985–989. doi: 10.1042/BST0320985. [DOI] [PubMed] [Google Scholar]
- 24.Siqueira F.C., Leitão D.S.T.C., Mercadante A.Z., Chisté R.C., Lopes A.S. Profile of phenolic compounds and carotenoids of Arrabidaea chica leaves and the in vitro singlet oxygen quenching capacity of their hydrophilic extract. Food Res. Int. 2019;126 doi: 10.1016/j.foodres.2019.108597. [DOI] [PubMed] [Google Scholar]
- 25.Cândido T.L.N., Silva M.R., Agostini-Costa T.S. Bioactive compounds and antioxidant capacity of buriti (Mauritia flexuosa.f.) from the Cerrado and Amazon biomes. Food Chem. 2015;177:313–319. doi: 10.1016/j.foodchem.2015.01.041. [DOI] [PubMed] [Google Scholar]
- 26.Rodrigues-Amaya D.B., Kimura M., Amaya-Farfan J. 2. ed. Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis; Brasília: 2008. Fontes brasileiras de carotenoides: tabela brasileira de composição de carotenoides em alimentos. [Google Scholar]
- 27.Silva J.V.M., Macedo G.P., Moura J.S., Chisté R.C. Julio Onésio Ferreira Melo. 2022. Efeito do cozimento sobre as propriedades nutricionais, compostos bioativos e na capacidade antioxidante da polpa e da casca dos frutos de pupunha (Bactris gasipaes) pp. 214–233. Ciências Agrárias: o avanço da ciência no Brasil - Volume 5. 1st ed: Editora Científica Digital. 5. [DOI] [Google Scholar]
- 28.Mesquita L.M.S., Ventura S.P.M., Braga A.R.C., Pisani L.P., Dias A.C.R.V., De Rosso V.V. Ionic liquid-high performance extractive approach to recover carotenoids from Bactris gasipaes fruits. Green Chem. 2019;21(9):2380–2391. doi: 10.1039/c8gc03283a. [DOI] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Data included in article/supplementary material/referenced in article.