New insights into the oil from the seeds of Cerrado passion fruit (Passiflora cincinnata): physicochemical characterization and stability during storage

Plant material and oil extraction

The passion fruit seeds (P. cincinnata) used to carry out the experiments were obtained from ripe fruits of uniform size and without injuries, collected from Cerrado, in the town of Grão Mogol, located in the state of north of the Minas Gerais, Brazil (coordinates: 16°33’27”S, longitude 42°53’38”W, and altitude 829 m). The procedure described below was carried out according to the processes used for extraction in local communities where the collection and sustainable management of passion fruit are common practices.

The fruits were sanitized in a chlorinated solution of 50 mg·L^-1 for 15 min. After that, the fruits were de-pulped through a pulper (Bonina - NB 30, Brazil) to separate the seeds. Subsequently, the samples were washed under running water and dried naturally in the sun for 2 days (27 ± 2 °C). It is important to emphasize that the local producers had already established the practice of drying, observing whether the seeds were properly dried and suitable for the next steps. After drying, the material was packed in a low-density polyethylene plastic bag until oil extraction.

For oil extraction, seeds were crushed with a knife mill (MF32150, Scott Tech, Brazil) and then cold-pressed in a helical-type mechanical press (“Expeller”) (MPE-100 TI, Ecirtec, Brazil) with an extraction capacity of 200 mL of oil/min. After extraction, coarse particles were removed by sedimentation for 12 h and the oil was filtered through a filter press (FPE-25/10 PI, Ecirtec, Brazil). The oil was inerted with gaseous nitrogen, packed in hermetically sealed bottles of 250 mL and stored (7 ± 1 °C) until use.

Oil quality parameters

The iodine value (Tg 1-64 method), saponification index (Cd 3-25 method), moisture and volatile matter (Ca 2b-38 method), and color (Cc 13e-92 method) were determined according to the Official Methods of the American Oil Chemist’s Society (AOCS, 2009AOCS. 2009. Official methods and recommended practices of the American Oil Chemists’ Society. 6th ed., Urbana, IL: USA.).

Statistical analysis

All results are presented as a mean value ± standard deviation (n=3). The storage stability experiments were carried out in a completely randomized design in a 2 x 6 factorial design (two storage conditions: with and without exposure to light, and six analysis times: 0, 45, 90, 135, 180, and 225 days). Analysis of variance (ANOVA) followed by the Tukey test was performed at the statistically significant level p <0.05 for comparison of means. Flow curve data were subjected to linear regression analysis. The statistical analyses were carried out using the SAS University Edition software (SAS Institute Inc, USA).

Quality characteristics

The quality parameters of CPFO are shown in Table 1. According to the iodine index, P. cincinnata oil was classified as a semi-drying oil, that is, it undergoes mild alteration when placed in a thin layer and exposed to the atmosphere, similar to other edible oils (Delvar et al., 2019DelvarA, CaroP, CaroY, SingASC, ThomasR, RaynaudC. 2019. Semi‐Siccative Oils and Bioactive Fractions Isolated from Reunion Island Fruit Co‐Product: Two Case Studies. Eur. J. Lipid Sci. Technol.121. 10.1002/ejlt.201800391.). The iodine index of P. cincinnata oil was comparable to that found in P. edulis seed (136 g·100g^-1) (Delvar et al., 2019DelvarA, CaroP, CaroY, SingASC, ThomasR, RaynaudC. 2019. Semi‐Siccative Oils and Bioactive Fractions Isolated from Reunion Island Fruit Co‐Product: Two Case Studies. Eur. J. Lipid Sci. Technol.121. 10.1002/ejlt.201800391.). Furthermore, the value found in this work was in line with the range reported for other oils, such as soy (124–139 g·100g^-1), and sunflower (118–141 g∙100g^-1) (FAO, 2019FAO. 2019. Codex standard for named vegetable oils. World Health Organization, Food and Ag-riculture Organization of the United Nations, Rome: Italy. Codex Stan 210-1999 (Revised in 2001, 2003, 2009, 2017 and 2019).). These differences are associated with the composition of FA since the iodine value is related to the amount of unsaturation present in the oil. Thus, the greater the number of unsaturation, the greater the iodine value.

The saponification value for P. cincinnata (Table 1) was close to those found by Souza et al. (2022SouzaML, DouradoD, LôboIP, PiresVC, AraújoSNO, RebouçasJS, CostaAM, FernandesCP, TavaresNM, PereiraNP, FormigaFR. 2022. Wild Passiflora (Passiflora spp.) seed oils and their nanoemulsions induce proliferation in HaCaT keratinocytes cells. J. Drug Deliv. Sci. Technol.67, 102803. 10.1016/j.jddst.2021.102803.) for P. setacea (191.01 mg KOH∙g^-1) and P. alata (194.3 mg KOH∙g^-1) seed oils. According to the Codex Alimentarius (FAO, 2019), the saponification values are 185–197, 188–194, and 187–194 mg KOH∙g^-1 for flaxseed, grape seed, and sunflower oils, respectively, which have degrees of unsaturation similar to that of CPFO. These values for saponification index indicate the average molecular weight of the fatty acids present in the oil. Therefore, this result suggests that CPFO has predominantly long-chain fatty acids.

For moisture and volatile matter, CPFO showed lower levels (Table 1) compared to that reported by Wilhelm et al. (2014WilhelmAE, AntoniassiR, Faria-MachadoAF, BizzoHR, ReisSLR, CenciSA. 2014. Diferentes taxas de alimentação de prensa do tipo expeller na eficiência de extração e na qualidade do óleo de semente de maracujá. Cienc. Rural44, 1312–1318. 10.1590/0103-8478cr20131001), whose value was 0.11%. This difference may be because the residue from different passion fruits has, even in small amounts, other components in addition to the seeds, like pulp fragments, which can affect the moisture content. Moreover, this amount of water may be related to the extraction process involving pressing, wherein some small amounts of unbound water could be transferred to the oil samples (Wilhelm et al., 2014WilhelmAE, AntoniassiR, Faria-MachadoAF, BizzoHR, ReisSLR, CenciSA. 2014. Diferentes taxas de alimentação de prensa do tipo expeller na eficiência de extração e na qualidade do óleo de semente de maracujá. Cienc. Rural44, 1312–1318. 10.1590/0103-8478cr20131001). In addition, the volatile matter obtained in this study complies with the standards established by Codex Alimentarius (FAO, 2019FAO. 2019. Codex standard for named vegetable oils. World Health Organization, Food and Ag-riculture Organization of the United Nations, Rome: Italy. Codex Stan 210-1999 (Revised in 2001, 2003, 2009, 2017 and 2019).) for cold-pressed oils, giving values which are in line with the recommended maximum limit (0.2%).

The color parameters demonstrated shades for the yellow (Y) and red (R) colors. As seen in Table 1, CPFO showed a more intense yellow shade than chia seed oil (20–50) but was within the red shade attributed to the same oil (2–5) (Imran et al., 2016ImranM, NadeemM, ManzoorMF, JavedA, AliZ, AkhtarMN, AliM, HussainY. 2016. Fatty acids characterization, oxidative perspectives and consumer acceptability of oil extracted from pre-treated chia (Salvia hispanica L.) seeds. Lipids Health Dis.15, 162. 10.1186/s12944-016-0329-x.). According to Borges et al. (2022BorgesLA, SoutoRNB, NascimentoALA, SoaresJF, PaivaCL, BrandiIV, LimaJP. 2022. Chemical characterization of baru oil and its by-product from the northwest region of Minas Gerais, Brazil. Grasas Aceites73, e460. 10.3989/gya.0447211.), carotenoids are the main constituents associated with the yellow/red color in oils. Thus, the intense yellow color and the red nuances of CPFO can be associated with the presence of these compounds.

Fatty acids profile

CPFO mainly contained polyunsaturated fatty acids (PUFA), followed by saturated fatty acids (SFA) and a considerable amount of monounsaturated fatty acids (MUFA) (Table 2). Regarding the unsaturated fraction, the majority are linoleic and oleic acids. The significant content of PUFA may contribute to lipid oxidation due to the presence of double bonds that affect oil stability. Compared to other studies, Reis et al. (2023ReisCC, FreitasSP, LorentinoCMA, FagundesTSF, MattaVM, SantosALS, MoreiraDL, KunigamiCN, JungEP, RibeiroLO. 2023. Bioproducts from Passiflora cincinnata Seeds: The Brazilian Caatinga Passion Fruit. Foods12, 2525. 10.3390/foods12132525.) found higher levels of linoleic acid (78.34%) and lower levels of oleic acid (8.43%) in P. cincinnata oil obtained from the Caatinga biome, Brazil. In addition, the FA profile is close to those obtained for other passion fruit species (Takam et al., 2019TakamPN, DjikengFT, KuateD, KengneAPN, TsafackHD, MakamwéI, ObenJE. 2019. Passiflora edulis seed oil from west Cameroon: Chemical characterization and assessment of its hypolipidemic effect in high-fat diet–induced rats. Food Sci. Nutr. 7, 3751–3758. 10.1002/fsn3.1234.; Santana et al., 2015SantanaFC, ShinagawaFB, AraujoES, CostaAM, Mancini-FilhoJ. 2015. Chemical Composition and Antioxidant Capacity of Brazilian Passiflora Seed Oils. J. Food Sci.80, C2647–C2654. 10.1111/1750-3841.13102.). Cultivar type, edaphoclimatic conditions, maturation degree, oil processing, analysis protocol, and other factors might affect FA biosynthesis. Comparing the FA profile determined by Codex Alimentarius with other vegetable oils, it is noted that soy and corn oils have lower linoleic acid contents (48–59 and 34–65.6%, respectively) and higher oleic contents (17–30 and 20–42.2%, respectively) (FAO, 2019FAO. 2019. Codex standard for named vegetable oils. World Health Organization, Food and Ag-riculture Organization of the United Nations, Rome: Italy. Codex Stan 210-1999 (Revised in 2001, 2003, 2009, 2017 and 2019).).

As seen in Table 2, the main SFAs present in CPFO were palmitic and stearic. Similarities were verified in the palmitic acid contents regarding P. cincinnata (10.20%), P. edulis (9.40%) and P. alata (11.17–11.50%) oils, as well as in the stearic acid contents, which were slightly lower, at 2.90, 2.50 and 2.47–2.57%, respectively, for the mentioned species (Delvar et al., 2019DelvarA, CaroP, CaroY, SingASC, ThomasR, RaynaudC. 2019. Semi‐Siccative Oils and Bioactive Fractions Isolated from Reunion Island Fruit Co‐Product: Two Case Studies. Eur. J. Lipid Sci. Technol.121. 10.1002/ejlt.201800391.; Lopes et al., 2010LopesRM, SevilhaAC, FaleiroFG, SilvaDB, VieiraRF, Agostini-CostaTS. 2010. Estudo comparativo do perfil de ácidos graxos em semente de Passifloras nativas do Cerrado brasileiro. Rev. Bras. Frutic.32, 498–506. 10.1590/S0100-29452010005000065.; Pereira et al., 2017PereiraMG, HamerskiF, AndradeEF, ScheerAP, CorazzaML. 2017. Assessment of subcritical propane, ultrasound-assisted and Soxhlet extraction of oil from sweet passion fruit (Passiflora alata Curtis) seeds. J. Supercrit. Fluids128, 338–348. 10.1016/j.supflu.2017.03.021.). It is important to note that oils with SFA have improved stability, as these compounds make products less susceptible to oxidation processes because these FAs are more resistant to thermal degradation.

The PUFA/SFA ratio is used to evaluate the nutritional quality of oils and fats. It hypothesizes that PUFA in the diet can decrease low-density lipoprotein cholesterol (LDL-c) and lower levels of serum cholesterol; whereas SFA contributes to high levels of serum cholesterol. According to the Department of Health and Social Security of England (DHSS, 1994Department of Health and Social Security (DHSS). 1994. Diet and cardiovascular disease. London, EN: DHSS.), a PUFA/SFA ratio higher than 0.45 is a desirable index. Hence, the PUFA/SFA ratio of CPFO (Table 2) was consistent with the recommended value. Therefore, the composition of P. cincinnata oil may present benefits in the prevention of metabolic diseases.

Rheological behavior

The rheological evaluation is crucial to determine the flow behavior of liquid foods. In the oil and fat industry, knowing the rheological properties of oils is particularly valuable for sizing equipment such as heat exchangers, reactors, extraction columns, and extractors (Valeri and Meirelles, 2007ValeriD, MeirellesAJA. 1997. Viscosities of fatty acids, triglycerides, and their binary mixtures. J. Am. Oil Chem. Soc.74, 1221–1226. 10.1007/s11746-997-0048-6.). To this end, the rheological behavior of CPFO was evaluated, and its flow curve (Figure 1) demonstrated a linear relationship between shear stress and shear rate (R² = 0.999), which classifies it as a Newtonian fluid. Furthermore, no hysteresis area was observed between the flow curves (ascent, descent, and ascent), indicating the absence of thixotropy, which is expected of the behavior of oils.

Figure 1 Flow curve of Cerrado Passion Fruit Oil at 25 °C in a shear rate range from 1 to 200 s^-1. Mean value ± standard deviation (n=3). 

The viscosity of CPFO was 32.99 ± 2.75 mPa∙s. This value is different from that of other edible oils with comparable linoleic acid content, such as melon seed oil (90.75 mPa∙s) (Mallek-Ayadi et al., 2019Mallek-AyadiS, BahloulN, KechaouN. 2019. Cucumis melo L. seeds as a promising source of oil naturally rich in biologically active substances: compositional characteristics, phenolic compounds and thermal properties. Grasas Aceites70, e284. 10.3989/gya.0215181.) and safflower seed oil (42.97 mPa∙s) (Aydeniz et al., 2013AydenizB, GüneşerO, YilmazE. 2013. Physico-chemical, Sensory and Aromatic Properties of Cold Press Produced Safflower Oil. J. Am. Oil Chem. Soc.91, 99–110. 10.1007/s11746-013-2355-4.) at 25 °C. This difference can be attributed to the higher proportion of linoleic acid and lower concentrations of monounsaturated and saturated long-chain fatty acids in passion fruit seed oil. The presence of double bonds in the fatty acid chain induces torsion, preventing the tight packing of the molecules, resulting in a less rigid and more flexible structure with higher fluidity (Kim et al., 2010KimJ, KimDN, LeeSH, YooS-H, LeeS. 2010. Correlation of fatty acid composition of vegetable oils with rheological behaviour and oil uptake. Food Chem.118, 398–402. 10.1016/j.foodchem.2009.05.011.).

The lower viscosity of CPFO, compared to other edible oils, offers several advantages. First, it results in cost savings for the implementation and maintenance of a flowline, as a lower viscosity leads to a reduced pressure drop. This, in turn, requires less robust equipment and lowers the energy input needed for the oil to flow.

Photostability

Acidity and peroxide indexes

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CPFO was evaluated for light stability. One of the parameters evaluated was the acidity value, which indicates the presence of free fatty acids resulting from the hydrolysis of triacylglycerols in the oil, either by temperature, moisture, or enzymes (Almeida et al., 2019AlmeidaDT, VianaTV, CostaMM, SilvaCS, FeitosaS.2019. Effects of different storage conditions on the oxidative stability of crude and refined palm oil, olein and stearin (Elaeis guineensis). Food Sci. Technol.39, 211–217. 10.1590/fst.43317; Chen et al., 2019ChenM-H, BergmanCJ, McClungAM. 2019. Hydrolytic rancidity and its association with phenolics in rice bran. Food Chem.285, 485–491. 10.1016/j.foodchem.2019.01.139.). The acidity value increased over time in both stored oils, with and without exposure to light (Figure 2). At 225 days, higher acidity values were found for samples stored away from light (1.84 mg KOH∙g^-1) and for those exposed to light (3.09 mg KOH∙g^-1). No significant difference was observed (p > 0.05) in the acidity value when comparing samples stored without light exposure for the duration of 90 to 180 days (Figure 2). However, significant differences (p < 0.05) in acidity values were observed for samples exposed to light in the same period. Significant differences (p < 0.05) were also detected between the two storage conditions from 135 days until the end of the experiment. The acidity values for the oil exposed to light (1.94–3.09 mg KOH∙g^-1) were statistically higher than the values for the oil protected from light (1.65–1.84 mg KOH∙g^-1).

Figure 2 Acidity value changes in Cerrado Passion Fruit Oil samples during 225 days of storage with (♦) and without (●) exposure to light. Values are taken in triplicate and expressed as Mean. Different lowercase letters among timepoints for the same treatment and uppercase letters among treatments for the same time point indicate significant differences according to Tukey’s test (p < 0.05). 

Exposing oils to light can lead to issues of oxidative rancidity (Ayu et al., 2016AyuDF, AndarwulanN, HariyadiP, PurnomoEH. 2016. Effect of tocopherols, tocotrienols, β-carotene, and chlorophyll on the photo-oxidative stability of red palm oil. Food Sci. Biotechnol.25, 401–407. 10.1007/s10068-016-0055-1.). However, in this study, it was observed that exposure of the oil samples to light also led to an increase in the acidity value, which measures the level of hydrolytic rancidity compared to samples that were not exposed to light. Possibly, the aluminum sheets used to protect the oil from light exposure acted as thermal insulators. Their mirrored surface reduced the absorption of heat transmitted by light, creating a barrier that impeded the transfer of heat from the environment to the samples. However, unprotected samples may have absorbed light heat, increasing their temperature and promoting the activity of lipase enzymes (Chen et al., 2019ChenM-H, BergmanCJ, McClungAM. 2019. Hydrolytic rancidity and its association with phenolics in rice bran. Food Chem.285, 485–491. 10.1016/j.foodchem.2019.01.139.), which were possibly liberated from the matrix after the extraction process from seeds. Despite the variations observed in the acidity value between the different treatments at all evaluated times, all of them comply with the maximum acidity value recommended by the Codex Alimentarius (FAO, 2019FAO. 2019. Codex standard for named vegetable oils. World Health Organization, Food and Ag-riculture Organization of the United Nations, Rome: Italy. Codex Stan 210-1999 (Revised in 2001, 2003, 2009, 2017 and 2019).), which is 4.0 mg KOH∙g^-1 for cold-pressed and unrefined vegetable oils.

The peroxide index (Figure 3) indicates the presence of primary products of oxidative rancidity in lipids. This process requires the presence of triacylglycerols or free fatty acids with unsaturation in the product. In treatment without exposure to light, the peroxide index increased over time, ranging from 6.67 to 19.14 meqO₂∙kg^-1. On the other hand, the light-exposed treatment started at the same initial value but rapidly increased to 240.50 meqO₂∙kg^-1 by the second analysis time (Figure 3). According to the Codex Alimentarius (FAO, 2019FAO. 2019. Codex standard for named vegetable oils. World Health Organization, Food and Ag-riculture Organization of the United Nations, Rome: Italy. Codex Stan 210-1999 (Revised in 2001, 2003, 2009, 2017 and 2019).), the recommended maximum peroxide index is 15 meqO₂∙kg^-1. Therefore, oil samples not exposed to light can be safely consumed for up to 135 days of storage (12.52 meqO₂∙kg^-1). Likewise, the consumption of CPFO stored away from light is not recommended since its peroxide content became very high in just 90 days. Due to this, the decision was made to discontinue the peroxide analysis for this treatment.

Figure 3 Peroxide index of Cerrado Passion Fruit Oil samples stored for 225 days with (♦) and without (●) light exposure. Values are taken in triplicate and expressed as Mean. Different lowercase letters among timepoints for the same treatment and uppercase letters among treatments for the same timepoint indicate significant differences according to Tukey’s test (p < 0.05). 

Over a period of 90 days, CPFO, when exposed to both artificial and natural light, exhibited high levels of peroxides (240.50 meqO₂∙kg^-1). This increase in peroxides is attributed to the photo-oxidation process which occurs in the presence of light and catalysts like photosensors or photosensitizers, such as chlorophylls and pheophytins, commonly found in vegetable oils (Ayu et al., 2016AyuDF, AndarwulanN, HariyadiP, PurnomoEH. 2016. Effect of tocopherols, tocotrienols, β-carotene, and chlorophyll on the photo-oxidative stability of red palm oil. Food Sci. Biotechnol.25, 401–407. 10.1007/s10068-016-0055-1.). During this process, reactive oxygen species, such as triplets and singlets, are formed, initiating the degradation of lipids. The oxidation process generates free radicals that combine with oxygen molecules, leading to the formation of peroxides and hydroperoxides. These compounds can further decompose due to interactions with free radicals and external factors, giving rise to volatile compounds responsible for rancid flavors and odors (Gorji et al., 2016GorjiSG, SmythHE, SharmaM, FitzgeraldM. 2016. Lipid oxidation in mayonnaise and the role of natural antioxidants: A review. Trends Food Sci. Technol.56, 88–102. 10.1016/j.tifs.2016.08.002.).

Samples that were not exposed to light also experienced oxidative rancidity. The occurrence of this process is more likely when there is a higher number of PUFA. In this case, oxidative rancidity may have been triggered by pro-oxidants such as free fatty acids, higher ambient temperature, and endogenous enzymes like lipoxygenase, or the presence of oxygen (Almeida et al., 2019AlmeidaDT, VianaTV, CostaMM, SilvaCS, FeitosaS.2019. Effects of different storage conditions on the oxidative stability of crude and refined palm oil, olein and stearin (Elaeis guineensis). Food Sci. Technol.39, 211–217. 10.1590/fst.43317).

Based on the evaluation of the peroxide index, it becomes evident that the most effective method for storing CPFO is by protecting it from light sources. This precautionary measure helps to prevent photo-oxidation processes and slows down other forms of oxidation. It is crucial to protect the oil's content of PUFA, as their reduction could lead to a loss in oil bioactivity and the development of undesirable aroma and flavor compounds (Lee et al., 2015LeeSY, FuSY, ChongGH. 2015. Ultrasound‐assisted extraction kinetics, fatty acid profile, total phenolic content and antioxidant activity of green solvents’ extracted passion fruit oil. Int. J. Food Sci. Technol.50, 1831–1838. 10.1111/ijfs.12844.). According to the analyses performed, it is recommended to consume CPFO within 135 days of storage without the addition of antioxidants. When adhering to this recommendation, the quality of the oil and beneficial properties can be preserved for an extended period.

Color

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The color variations in the samples are shown in Figure 4A and B. The whiteness index (WI) increased during the storage period for both treatments, and the most significant difference between the treatments was observed on day 225, with light-exposed samples being lighter than the non-exposed ones. The chroma of the treatments remained consistently low, with values close to zero. These values fluctuate with time and show statistical differences. Specifically, the samples protected from light exhibited significantly higher values (indicating more intense colors) compared to the samples exposed to light, starting on day 90 (p < 0.05).

Figure 4 Color parameters of Cerrado Passion Fruit Oil samples stored for 225 days with (♦) and without (●) exposure to light: Whiteness index (A) and Chroma (B). Values are taken in triplicate and expressed as Mean. Different lowercase letters among timepoints for the same treatment and uppercase letters among treatments for the same time point indicate significant differences according to Tukey’s test (p < 0.05) 

The increase in the WI might be attributed to the consumption of the pigment β-carotene, which is commonly present in this type of product. This component possibly acted as an antioxidant photoprotector in light-exposed samples. β-carotene contains numerous conjugated double bonds that absorb light energy, thereby limiting the capture of excessive energy by UFA and the formation of hydroperoxides (Ayu et al., 2016AyuDF, AndarwulanN, HariyadiP, PurnomoEH. 2016. Effect of tocopherols, tocotrienols, β-carotene, and chlorophyll on the photo-oxidative stability of red palm oil. Food Sci. Biotechnol.25, 401–407. 10.1007/s10068-016-0055-1.). Additionally, chlorophyll may have catalyzed the photo-oxidation reactions in the oil, as suggested by Ayu et al. (2016AyuDF, AndarwulanN, HariyadiP, PurnomoEH. 2016. Effect of tocopherols, tocotrienols, β-carotene, and chlorophyll on the photo-oxidative stability of red palm oil. Food Sci. Biotechnol.25, 401–407. 10.1007/s10068-016-0055-1.). Investigating the presence of chlorophyll in CPFO is a prospective goal for future studies. Even in treatments not exposed to light, which experienced oxidative rancidity possibly induced by heat and/or enzymes, β-carotene may have acted as an antioxidant by scavenging free radicals and singlet oxygen, according to Almeida et al. (2019AlmeidaDT, VianaTV, CostaMM, SilvaCS, FeitosaS.2019. Effects of different storage conditions on the oxidative stability of crude and refined palm oil, olein and stearin (Elaeis guineensis). Food Sci. Technol.39, 211–217. 10.1590/fst.43317). Consequently, the oil maintained a lighter appearance over time.

The low chroma indices result from the low values of the coordinates a* and b*, indicating an opaque coloration of CPFO. These values are close to the axis, where color intensity is reduced. Lee et al. (2015LeeSY, FuSY, ChongGH. 2015. Ultrasound‐assisted extraction kinetics, fatty acid profile, total phenolic content and antioxidant activity of green solvents’ extracted passion fruit oil. Int. J. Food Sci. Technol.50, 1831–1838. 10.1111/ijfs.12844.) proposed a grayer color intensity for passion fruit oil with chroma values ranging from 12.07 to 15.09, which are higher than those found in the current study. Therefore, CPFO typically exhibits a predominantly grayish color with limited color intensity. However, it is known to be rich in carotenoid pigments, such as β-carotene. Over time, these pigments may degrade due to oxidative reactions, leading to a lighter appearance. Thus, it is essential to store this oil protected from light and preferably under refrigeration to preserve its quality.