Comprehensive Profiling of Coconut Oil Varieties: Fatty Acids Composition, Oxidative Stability, Bioactive Properties, and Sensory Attributes

Featured Application

This study highlights the distinct functional properties of selected coconut oil variants (Coco24, Health, Kospa, Vita, and Smetol), guiding their targeted applications. Coconut oil varieties exhibiting the most potent antioxidant and antimicrobial properties (Coco24 and Health) are best suited for nutraceutical or preservative applications. In contrast, those with superior sensory attributes (Vita and Kospa) are more appropriate for premium food formulations. The sample with the most outstanding oxidative stability (Smetol) is recommended for high-temperature processing or lipid systems requiring an extended shelf life. These findings support the evidence-based selection of coconut oil variants tailored to specific industrial applications in the food, health, and cosmetic sectors.

Abstract

Coconut oil is highly regarded for its nutritional and functional attributes, making it an attractive candidate for diverse food and health applications. This study evaluates the fatty acid profile, antioxidant and antimicrobial activities, oxidative stability, and sensory properties of selected coconut oils (Coco24, Health, Kospa, Smetol, and Vita) from the Slovak republic market. Acid values (0.09 ± 0.060–0.42 ± 0.060 mg KOH/g) and peroxide values (0.51 ± 0.058–1.20 ± 0.010 mmol O₂/kg) were within recommended safety limits. Oxidative stability varied significantly (p ˂ 0.05), with Smetol showing the highest induction time (124.5 ± 0.98 h) and Coco24 the lowest (25.8 ± 0.22 h). DPPH antioxidant activity was highest in health (469.2 ± 2.01 mg TEAC/kg) and Coco24 (369.3 ± 1.99 mg TEAC/kg) (TEAC—Trolox equivalent antioxidant capacity). Coco24, Health, and Kospa exhibited the most potent antimicrobial activity against Staphylococcus aureus (2.01 ± 0.001 mm, 1.37 ± 0.021 mm, 1.15 ± 0.010 mm, respectively), Candida glabrata (1.17 ± 0.015 mm, 1.17 ± 0.015 mm, 0.45 ± 0.025 mm, respectively), Candida tropicalis (2.12 ± 0.017 mm, 2.13 ± 0.017 mm, 1.52 ± 0.006 mm, respectively), and Bacillus subtilis (1.29 ± 0.055 mm, 1.35 ± 0.006 mm, 0.31 ± 0.020 mm, respectively). FAME analysis revealed that saturated fatty acids dominated, especially in Smetol (97.6 ± 0.067%), while Coco24 had the highest levels of unsaturated fatty acids. Vita and Kospa received the highest panel ratings for smell, taste, and overall acceptability, indicating superior sensory appeal, whereas Smetol scored the lowest. Correlation analysis showed strong positive relationships between MUFA and PUFA (r = 0.986) and taste and acceptability (r = 0.993), as well as between antioxidant activity and Candida albicans inhibition (r = 0.859). Oxidative stability was negatively correlated with PUFA (r = –0.924). PCA grouped oils high in MUFA/PUFA (Kospa, Vita) with superior sensory scores, while PC2 reflected microbial safety. These differences suggest that Coco24, Health, Vita, and Kospa offer enhanced functional and sensory benefits, whereas Smetol is better suited for applications that prioritize oxidative stability.

1. Introduction

Edible oils are fundamental to human nutrition, serving as significant sources of dietary fatty acids that influence various physiological and biochemical processes in the body [1,2]. Based on their fatty acid composition, edible oils are broadly classified into polyunsaturated (e.g., sunflower oil), monounsaturated (e.g., mustard oil), and saturated fats (e.g., palm and coconut oils) [3]. Coconut oil, derived from the mature kernel of Cocos nucifera L., has captured significant global attention due to its diverse applications in food, health, and industrial sectors [4].

Coconut oil is available in various forms, including copra oil (CO), virgin coconut oil (VCO), and coconut testa oil (CTO), each characterized by its specific extraction and processing methods [4]. Virgin coconut oil (VCO) is typically produced through mechanical or cold pressing without the use of chemicals or heat, allowing for it to retain a higher concentration of bioactive compounds compared to refined or hydrogenated varieties [5,6]. Coconut oil, rich in medium-chain triglycerides, particularly lauric acid, exhibits excellent oxidative and thermal stability, making it suitable for various culinary applications [7]. Additionally, the antioxidant, antimicrobial, and anti-inflammatory properties of coconut oil have further enhanced its popularity [8,9].

As consumers increasingly demand minimally processed foods with health-promoting properties, coconut oil has emerged as a preferred alternative to conventional vegetable oils [8,10]. The edible oil industry is placing greater emphasis on quality attributes such as fatty acid composition, oxidative stability, microbial safety, and sensory appeal to ensure consumer satisfaction, product shelf life, and overall integrity [11,12]. However, despite its widespread consumption across North America, Asia, and Europe [13], few comprehensive studies have compared the various types of coconut oil available in commercial markets, especially those from the Slovakian market.

With the growing global emphasis on food quality and safety, a comprehensive evaluation that integrates biochemical, microbiological, and sensory assessments is essential for informed consumer choices, product standardization, and effective regulatory oversight. In the Slovak republic, the consumption of coconut oil has grown in popularity due to its perceived health benefits. However, specific studies investigating its antioxidant, antimicrobial, and hygienic properties in this context are currently lacking. This study addresses this critical gap by evaluating five coconut oil brands available in the Slovak republic market—Smetol, Coco24, Vita, Kospa, and Health—through analyses of antioxidant activity, physicochemical properties, fatty acid composition, antimicrobial activity against selected microbial strains, and sensory characteristics. Furthermore, by applying principal component analysis (PCA), this study seeks to identify correlations and interrelationships among these variables, offering a nuanced understanding of the key determinants of coconut oil quality.

2. Materials and Methods

2.1. Chemicals

All the chemicals used were of analytical grade and purchased from either Sigma-Aldrich (St. Louis, MO, USA) or CentralChem (Bratislava, Slovakia).

2.2. Material

The samples of coconut oils were purchased from the Slovak republic in 2023. A total of five samples were used: Smetol (cooking coconut fat, fully hydrogenated), Coco24 (refined, non-hydrogenated coconut oil), Vita (organic, virgin coconut oil), Kospa (organic, raw, virgin coconut oil from the first pressing), and Health (organic, extra virgin coconut oil). The detailed characteristics of the samples are as follows: Smetol was purchased in March 2023, Lot No. SMT0323, with declared origin EU (processed in Slovak republic), and a best-before date of 06/2025; Coco24 was purchased in April 2023, Lot No. C24A0423, with declared origin Philippines (refined in Germany), and a best-before date of 08/2025; Vita was purchased in May 2023, Lot No. VITA0523, with declared origin Sri Lanka, and a best-before date of 10/2025; Kospa was purchased in May 2023, Lot No. KSP0523, with declared origin India, and a best-before date of 09/2025; and Health was purchased in June 2023, Lot No. HLT0623, with declared origin Philippines, and a best-before date of 11/2025. All samples were stored under controlled conditions—specifically, in the dark at a low temperature (approximately 4 °C)—to preserve their quality and prevent oxidation before analysis.

2.3. Determination of Oil Quality

2.3.1. Acid Value Determination

Five grams of each oil were mixed with 100 mL of an ethanol–chloroform mixture (1:1, v/v) and gently heated to boiling in a water bath (GFL 1013, Zevenhuizen, The Netherlands). After adding 2–3 drops of phenolphthalein indicator and thorough mixing, the solution was titrated with 0.1 M potassium hydroxide until a colour change from colourless to pink was observed. The free fatty acid content was expressed as the milligrams of potassium hydroxide required to neutralize 1 g of sample. The acid value was calculated using the following equation [14]:

$$\mathrm{Acid} \mathrm{value}={\displaystyle \frac{V\times C\times 56.1}{m}}$$

(1)

where V is the volume of titration KOH solution consumed, in mL; C is the concentration of potassium hydroxide solution, mol/L; m is the mass of the oil, in g; 56.1 is the molar mass of potassium hydroxide, in g/mol.

2.3.2. Peroxide Value Determination

The peroxide concentration in the oil was determined by measuring the iodine released from potassium iodide, following the AOCS official method [15]. A 5 g oil sample was dissolved in a 100 mL mixture of acetic acid and chloroform (3:2). After adding saturated potassium iodide solution and distilled water, the flask was vigorously shaken to release iodine from the chloroform layer. Starch solution served as an indicator, and the mixture was titrated with 0.01 N sodium thiosulfate. The results were expressed in mmol peroxide per kg. The peroxide value was calculated using the formula below:

$$\mathrm{Peroxide} \mathrm{value}={\displaystyle \frac{1000\times M\times \left(a-b\right)\times f}{m}}$$

(2)

where 1000 is the conversion factor; M is the molecular weight of sodium thiosulphate, mol/L; a is the volume of the titrant (sodium thiosulphate solution) used to titrate the sample, mL; b is the volume of the titrant used for the blank run, mL; m is the amount of oil, g; f is the concentration of sodium thiosulphate, g/mol.

2.3.3. Oxidative Stability

A 3.0 g oil sample was tested for oxidative stability using the Metrohm 892 Rancimat apparatus (Metrohm, Herisau, Switzerland) [16]. All tests were conducted at 120 °C with a constant airflow of 20 L/h. Induction times were measured with a precision of 0.005 using the instrument’s software.

2.4. Antioxidant Activity—DPPH Radical Scavenging Activity

Following the method described by [17] the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was employed to evaluate the sample’s free radical scavenging ability. A DPPH solution was prepared by dissolving 0.025 g of DPPH in 100 mL of ethanol. Then, 3.6 mL of this solution was mixed with 0.4 mL of the oil sample. The absorbance was measured at 515 nm using a Jenway 6405 UV/V is spectrophotometer (Keison Products, Essex, UK). Oil in ethanol was used as a blank. The antioxidant capacity of the sample was expressed as milligrams of Trolox equivalent antioxidant capacity per kilogram (mg TEAC/Kg).

2.5. Determination of Fatty Acid Methyl Esters (FAME) Content

A 0.1 g sample of oil was placed into a 40 mL glass vial and mixed with 5 mL of 0. 50 N methanolic NaOH. The mixture was heated at 60 °C for 3 min and then cooled to room temperature. Next, 6 mL of a 14% boron trifluoride methanol complex (BF3) was added, and the mixture was heated again at 60 °C for 3 min before cooling. After cooling, 10 mL of isooctane was added, and the mixture was thoroughly shaken and allowed to settle. The upper layer was collected and passed through sodium sulfate to remove moisture. The esterified oil samples were diluted at a ratio of 1:19 (50 mL FAME to 950 mL n-hexane) before analysis. Fatty acid methyl esters (FAME) were analysed qualitatively and quantitatively using an Agilent 7890B gas chromatograph equipped with a flame ionisation detector (FID). A CombiPAL (Headquarters, Santa Clara, CA, USA) autosampler injected 1 μL of the diluted sample into the system. Separation was achieved using an HP-88 GC capillary column (60 m × 0.25 mm × 0.20 μm). High-purity gases (He, N₂, H₂, and synthetic air, all 5.0 grade) were used throughout the process. The oven temperature programme was as follows: initial temperature 120 °C, held for 1 min; ramp 1: increase at 10 °C/min to 175 °C, hold for 10 min; ramp 2: increase at 5 °C/min to 210 °C, hold for 5 min; final ramp: increase at 5 °C/min to 230 °C, hold for 10 min. The inlet temperature was set to 250 °C, and the detector (FID) temperature to 260 °C. The carrier gas was helium (He) at a constant flow rate of 1 mL/min, with a split ratio of 50:1 and an injection volume of 1 μL. Gases for the FID included hydrogen at 40 mL/min, synthetic air at 450 mL/min, and N2 as a makeup gas at 25 mL/min. Data acquisition and processing were performed with Agilent OpenLab ChemStation software (LTS 01.11). Calibration utilised a 37-component Supelco standard mix, which includes certified reference materials (CRM) from TraceCERT and Supelco USA. Analysis was performed using an Agilent 5977 A MSD (Headquarters, Santa Clara, CA, USA). Confirmation was based on retention time match, characteristic mass spectral ions for each FAME, and data processing through Agilent OpenLab ChemStation [18].

2.6. Antimicrobial Activity Determination

Antimicrobial activity was assessed using the disc diffusion method adapted for oil samples, as described below. The experiment included nine microbial strains: three yeasts (Candida albicans CCM 8186, Candida glabrata CCM 818, Candida tropicalis CCM 8184), three Gram-negative bacteria (Haemophilus influenzae CCM 4454, Yersinia enterocolitica CCM 5671, Salmonella enterica subs. enterica CCM 3807), and three Gram-positive bacteria (Staphylococcus aureus CCM 2461, Clostridium perfringens CCM 4991, Bacillus subtilis CCM 2010). All strains were obtained from the Czech Collection of Microorganisms. Before testing, bacterial and yeast suspensions were cultured in nutrient broth (Imuna, Bratislava, Slovak Republic) at 37 °C for 24 h. A 0.1 mL aliquot of each microorganism suspension, standardised to 10⁵ CFU/mL, was spread onto Mueller-Hinton Agar plates (Oxoid, Leicestershire, UK). Sterile 6 mm filter paper discs were impregnated with 15 µL of the test oil and placed on the inoculated agar. Plates were pre-incubated at 4 °C for 2 h and incubated aerobically at 37 °C for 24 h. Inhibition zone diameters were measured in millimetres after incubation. All tests were conducted in triplicate [19].

2.7. Sensory Characteristic Determination

A sensory panel of 50 evaluators, comprising 25 women and 25 men aged 25 to 65, assessed the organoleptic properties (taste, aroma, aftertaste, overall appearance, and overall acceptability) of the coconut oil samples. Participants were voluntarily recruited from the general population and screened for allergies or dietary restrictions related to coconut products. All participants provided informed consent before participating, and the study adhered to the ethical guidelines approved by the relevant institutional ethics committee (Ethics for Employees of the Slovak University of Agriculture in Nitra, effective from 10 January 2022, and Code of Ethics for Students of the Slovak University of Agriculture in Nitra, effective from 2 December 2021). The evaluation utilized a 9-point hedonic scale, where 9 indicated “like very much” and 1 signified “dislike very much”. The panel was partly trained through a brief orientation session to familiarize them with the evaluation criteria and scale. Samples were presented in identical, coded containers to maintain blinding. The order of presentation was randomized for each panellist to reduce bias. Each sample was served at room temperature (approximately 22–23 °C), with a standard portion size of 5 g per sample. Between samples, panellists were instructed to cleanse their palates with lukewarm water and unsalted wheat rolls. Sensory sessions were conducted under controlled conditions, including neutral lighting and minimal ambient odours, to prevent influencing the evaluations.

2.8. Statistical Analysis

All measurements were performed in triplicate, and the results are presented as means with standard deviation. Using RStudio software, R 3.6.0+ the experimental data were subjected to Shapiro–Wilk (normality test), Bartlett (homogeneity of variance test) and Durbin-Watson (independence of errors test) tests. All analyses were conducted with a significance level of 5% (α = 0.05). PCA (principal component analysis) plots and 2D maps of qualitative features were also created using statistical evaluation with RStudio. Before PCA, the data were pre-treated by auto-scaling (mean-centred and scaled to unit variance) to ensure all variables contributed equally to the model.

3. Results

3.1. Oxidative Stability of the Oil Sample

Measured parameters, including acid value (expressed in mg KOH/g), peroxide value (in mmol O₂/kg), and oxidative stability induction time (hours) for various coconut oil samples (Coco24, Health, Kospa, Smetol, and Vita) are listed in

Table 1. Acid number (mg KOH/g), Peroxide number (mmol O₂/kg), and Oxidative stability (h) of different coconut oil (Coco24, Health, Kospa, Smetol, and Vita) samples.

Sample	Acid Number (mg KOH/g)	Peroxide Number (mmol O2/kg)	Oxidative Stability (h)
Coco24	0.340 ± 0.017 b	1.20 ± 0.010 a	25.8 ± 0.22 d
Health	0.087 ± 0.006 d	0.51 ± 0.006 d	54.6 ± 1.28 c
Kospa	0.418 ± 0.006 a	0.57 ± 0.015 d	59.1 ± 0.90 c
Smetol	0.203 ± 0.013 c	1.11 ± 0.015 b	124.5 ± 0.98 a
Vita	0.213 ± 0.006 c	0.64 ± 0.046 c	72.2 ± 0.57 b
Shapiro–Wilk	0.0866	0.1679	0.3017
Bartlett Test	0.4452	0.0921	0.3775
Durbin-Watson	0.3663	0.3164	0.1038
Box–Cox (λ)	–	–	–
Tukey′s HSD test	Yes	Yes	Yes
Kruskal–Wallis test	No	No	No

Results represent the mean ± standard deviation (n = 3). For Shapiro–Wilk (normality test), Bartlett (test of homogeneity of variances) and Durbin–Watson (test of independence of errors), results represent the p-value. The results of the Box–Cox transformation represent the lambda “λ” (ranging from −2.0 to +2.0) value used to adjust the data, making it more closely align with a normal distribution or homoscedasticity. Lowercase letters (^a,b,c,d indicate differences (p < 0.05) between coconut oil samples using Kruskal–Wallis non-parametric analysis or Tukey’s HSD (honestly significant differences) parametric analysis.

. Coco24 showed the highest peroxide value and the lowest oxidative stability, while Kospa had the highest acid number (p < 0.05). Health displayed the lowest acid and peroxide values with moderate stability (p < 0.05). Smetol exhibited the highest oxidative stability despite a high peroxide level. Vita and Smetol had similar acid values, with Vita demonstrating good overall stability.

3.2. DPPH Radical Scavenging Activity

DPPH radical scavenging activity of coconut oil samples is presented in Figure 1.

The DPPH results show that Health had the highest antioxidant activity (469.2 mg TEAC/kg), followed by Coco24 and Vita. Kospa and Smetol had the lowest antioxidant capacities, with values of 155 and 100.1 mg TEAC/kg, respectively (p < 0.05). However, it is essential to note that the results of the DPPH assay should be interpreted with caution, as they may not represent the complete antioxidant profile, particularly in oils where lipophilic antioxidants play a significant role. Future studies employing assays that target both hydrophilic and lipophilic antioxidants, such as the ORAC or FRAP assays, could provide a more comprehensive understanding of the antioxidant capacity of the samples.

3.3. Antimicrobial Activity

The capacity to suppress microbial growth (

Table 2. Antibacterial activity of different coconut oil (Coco24, Health, Kospa, Smetol, and Vita) samples.

Sample				Bacteria
	Bacillus subtilis CCM 2010	Staphylococcus aureus CCM 2461	Clostridium perfringens CCM 4991	Salmonella enterica CCM 3807	Haemophilus influenzae CCM 4454	Yersinia enterocolitica CCM 5671
Coco24	1.29 ± 0.055 a	2.01 ± 0.010 a	1.01 ± 0.006 d	0.08 ± 0.006 e	1.02 ± 0.006 b	1.03 ± 0.015 c
Health	1.35 ± 0.006 a	1.37 ± 0.021 b	0.24 ± 0.012 a	0.67 ± 0.021 d	1.10 ± 0.021 a	1.08 ± 0.030 c
Kospa	0.31 ± 0.020 b	1.15 ± 0.010 d	0.08 ± 0.006 e	1.51 ± 0.012 a	0.57 ± 0.010 d	1.90 ± 0.017 a
Smetol	0.08 ± 0.006 c	1.28 ± 0.061 c	0.14 ± 0.006 c	1.05 ± 0.055 c	0.42 ± 0.012 e	0.81 ± 0.027 d
Vita	0.32 ± 0.010 b	1.09 ± 0.015 d	0.16 ± 0.006 b	1.13 ± 0.010 b	0.66 ± 0.010 c	1.16 ± 0.017 b
Shapiro–Wilk	<0.0001	0.0997	0.0232	0.0828	0.7535	0.5678
Bartlett Test	<0.0001	0.0718	0.8077	0.0409	0.5876	0.8769
Durbin-Watson	0.9914	0.0276	0.9615	0.3101	0.2444	0.7296
Box–Cox (λ)	−0.2626	−2.00	0.5454	0.6666	--	--
Tukey’s HSD test	No	Yes	No	Yes	Yes	Yes
Kruskal–Wallis test	Yes	No	Yes	No	No	No

Results represent the mean ± standard deviation (n = 3). For Shapiro–Wilk (normality test), Bartlett (test of homogeneity of variances) and Durbin–Watson (test of independence of errors), results represent the p-value. The results of the Box–Cox transformation represent the lambda “λ” (ranging from −2.0 to +2.0) value used to adjust the data, making it more closely align with a normal distribution and/or homoscedasticity. Lowercase letters (^a,b,c,d,e) indicate differences (p < 0.05) between coconut oil samples using Kruskal–Wallis non-parametric analysis or Tukey’s HSD (honestly significant differences) parametric analysis.

and

Table 3. Antifungal activity of different coconut oil (Coco24, Health, Kospa, Smetol, and Vita) samples.

Sample		Fungi
	Candida albicans CCM 8186	Candida glabrata CCM 8185	Candida tropicalis CCM 8184
Coco24	0.56 ± 0.035 c	1.17 ± 0.015 b	2.13 ± 0.017 c
Health	1.02 ± 0.006 a	1.53 ± 0.046 a	3.67 ± 0.012 a
Kospa	0.52 ± 0.010 c	0.45 ± 0.025 d	1.52 ± 0.006 d
Smetol	0.27 ± 0.067 d	0.67 ± 0.027 c	0.87 ± 0.059 e
Vita	0.66 ± 0.015 b	0.64 ± 0.032 c	2.81 ± 0.127 b
Shapiro–Wilk	0.1434	0.9158	0.0330
Bartlett Test	0.0306	0.7405	0.0031
Durbin-Watson	0.1753	0.2341	0.3186
Box–Cox (λ)	0.5454	--	0.5454
Tukey’s HSD test	No	Yes	No
Kruskal–Wallis test	Yes	No	Yes

Results represent the mean ± standard deviation (n = 3). For Shapiro–Wilk (normality test), Bartlett (test of homogeneity of variances) and Durbin-Watson (test of independence of errors), results represent the p-value. The results of the Box–Cox transformation represent the lambda “λ” (ranging from −2.0 to +2.0) value used to adjust the data, making it more closely align with a normal distribution and/or homoscedasticity. Lowercase letters (^a,b,c,d,e) indicate differences (p < 0.05) between coconut oil samples using Kruskal–Wallis non-parametric analysis or Tukey’s HSD (honestly significant differences) parametric analysis.

) was examined in multiple coconut oil brands (Coco24, Health, Kospa, Smetol, Vita). The sample Health showed the most vigorous overall antimicrobial activity, especially against yeast (p < 0.05). Coco24 was also effective, mainly against bacteria. Kospa was most active against Salmonella enterica and Yersinia enterocolitica. Smetol exhibited the weakest activity, while Vita demonstrated moderate bacterial inhibition, accompanied by a vigorous antifungal activity, particularly against Candida tropicalis.

3.4. Fatty Acid Methyl Ester (FAME) Profile of Oil Samples

Table 4. Fatty acids (%) composition of different coconut oil (Coco24, Health, Kospa, Smetol, and Vita) samples.

Sample	C6:0	C8:0	C10:0	C12:0	C14:0	C16:0	C18:0	C18:1trans n-9	C18:1cis n-9	C18:2cis n-6	C20:0	PUFA	MUFA	SFA
Coco24	0.533 ± 0.015 d	7.12 ± 0.015 d	5.72 ± 0.015 d	46.50 ± 0.25 b	19.40 ± 0.20 a	9.57 ± 0.07 b	2.76 ± 0.17 b	0 ± 0	6.45 ± 0.116 a	1.61 ± 0.021 a	0.030 ± 0.010 c	1.63 ± 0.006 a	6.46 ± 0.098 a	91.70 ± 0.159 c
Health	0.640 ± 0.01 c	8.15 ± 0.07 c	6.38 ± 0.006 a	50.21 ± 0.02 a	18.54 ± 0.02 a	7.86 ± 0.01155 c	2.99 ± 0.02 b	0 ± 0	4.46 ± 0.021 b	0.73 ± 0.015 b	0.073 ± 0.006 b	0.73 ± 0.012 c	4.35 ± 0.095 b	94.94 ± 0.155 b
Kospa	0.677 ± 0.0058 a	9.00 ± 0.10 a	6.30 ± 0.011 b	49.99 ± 0.16 a	19.22 ± 0.27 a	7.09 ± 0.0693 d	2.85 ± 0.04 b	0 ± 0	4.37 ± 0.017 b	0.78 ± 0.006 b	0.063 ± 0.006 b	0.77 ± 0.015 b	4.34 ± 0.046 b	94.8 ± 0.015 b
Smetol	0.470 ± 0.01 e	6.53 ± 0.01 e	5.38 ± 0.0153 e	43.75 ± 1.44 c	18.59 ± 0.06 a	10.53 ± 0.29 a	10.70 ± 0.17 a	0.837 ± 0.015 a	1.24 ± 0.130 c	0.13 ± 0.020 c	0.137 ± 0.006 a	0.15 ± 0.006 d	2.19 ± 0.067 c	97.6 ± 0.067 a
Vita	0.687 ± 0.0058 a	8.66 ± 0.03 b	6.03 ± 0.015 c	49.23 ± 0.267 a	18.66 ± 1.71 a	7.45 ± 0.04 d	2.96 ± 0.02 b	0 ± 0	4.37 ± 0.021 b	0.75 ± 0.030 b	0.063 ± 0.012 b	0.72 ± 0.006 c	4.37 ± 0.021 b	94.64 ± 0.202 b
Shapiro–Wilk	0.7238	0.3915	0.1779	0.0055	0.0008	0.0073	0.0084	<0.0001	0.0740	0.8988	0.3199	0.2297	0.3861	0.8996
Bartlett Test	0.6899	0.0492	0.7909	<0.0001	<0.0001	0.0058	0.0072	<0.0001	0.0280	0.4696	0.8025	0.5534	0.4264	0.1074
Durbin-Watson	0.7798	0.3607	0.6279	0.1614	0.4143	0.0113	0.5564	0.0186	0.4677	0.8078	0.9741	0.8516	0.8051	0.6005
Box–Cox (λ)	–	0.6667	–	2.00	2.00	−2.00	−2.00	1.3535	1.3535	–	–	–	–	–
Tukey’s HSD test	Yes	Yes	Yes	No	No	No	No	No	No	Yes	Yes	Yes	Yes	Yes
Kruskal–Wallis test	No	No	No	Yes	Yes	Yes	Yes	Yes	Yes	No	No	No	No	No

Results represent the mean ± standard deviation (n = 3). C6:0 (caproic acid), C8:0 (caprylic acid), C10:0 (capric acid), C12:0 (lauric acid), C14:0 (myristic acid), C16:0 (palmitic acid), C18:0 (stearic acid), C18:1transn9 (elaidic acid, trans oleic acid), C18:1cis n-9 (oleic acid, cis oleic acid), C18:2cis n-6 (linoleic acid), and C20:0 (arachidic acid) are specific fatty acids, while PUFA are polyunsaturated fatty acids, MUFA are monounsaturated fatty acids, and SFA are saturated fatty acids. For Shapiro–Wilk (normality test), Bartlett (test of homogeneity of variances), and Durbin–Watson (test of independence of errors), results represent the p-value. The results of the Box–Cox transformation represent the lambda “λ” (ranging from −2.0 to +2.0) value used to adjust the data, making it more closely align with a normal distribution and/or homoscedasticity. Lowercase letters (^a,b,c,d,e) indicate differences (p < 0.05) between coconut oil samples using Kruskal–Wallis non-parametric analysis or Tukey’s HSD (honestly significant differences) parametric analysis.

displays the FAME profiles of coconut oil varieties: Coco24, Health, Kospa, Smetol, and Vita. The Smetol sample had the highest saturated fatty acid (SFA) content and the lowest levels of MUFA and PUFA, along with a notable amount of trans fat (C18:1 trans). Coco24 exhibited the highest levels of PUFA and MUFA, with moderate levels of SFA (p < 0.05). Health, Kospa, and Vita showed similar profiles, rich in medium-chain saturated fats (C8:0–C12:0), with Health having slightly more C12:0 and Kospa containing the highest C8:0. Vita displayed a balanced profile, characterised by relatively high SFA and moderate UFA.

3.5. Sensory Analysis of Coconut Samples

Sensory outcome of the coconut oil samples is depicted in Figure 2. Vita consistently received the highest scores across all sensory parameters, indicating a strong overall preference. Kospa was favourably rated, particularly for aroma and taste (p < 0.05). Coco24 achieved moderate scores across most parameters, but was slightly lower in aftertaste. Smetol and Health received the lowest ratings, especially for overall acceptability and aftertaste, indicating they were the least preferred.

3.6. Variable Interrelationships

Interdependencies among fatty acid profiles (C12:0–C18:0, SFA/MUFA/PUFA), quality indices (DPPH, acidity, peroxides, stability), microbial inhibition (S. aureus, C. perfringens, S. enterica, C. albicans), and sensory attributes were analysed across five coconut oils (Coco24, Health, Kospa, Smetol, Vita) and are presented in

Table 5. Linear correlations among coconut oil varieties (Coco24, Health, Kospa, Smetol and Vita) for fatty acid composition (C12:0, C16:0, C18:0, PUFA, MUFA, SFA), quality parameters (DPPH, peroxide number, and oxidative stability), antimicrobial activity (Staphylococcus aureus, Clostridium perfringens, Salmonella enterica, and Candida albicans), and sensory results (smell, taste, aftertaste, and overall acceptability).

Correlations	DPPH	Peroxide Number	Oxidative Stability	S. aureus	C. perfringens	S. enterica	C. albicans	C12:0	C16:0	C18:0	PUFA	MUFA	Smell	Taste	Aftertaste
Oxidative Stability	−0.707	0.122
Staphylococcus aureus	0.505	0.674	−0.587
C. perfringens	0.496	0.647	−0.658	0.972
S. enterica	−0.697	−0.563	0.53	−0.924	−0.906
C. albicans	0.859	−0.648	−0.541	0.021	0.022	−0.251
C12:0	0.436	−0.875	−0.535	−0.302	−0.25	0.247	0.766
C16:0	−0.194	0.902	0.403	0.503	0.403	−0.477	−0.566	−0.92
C18:0	−0.609	0.502	0.893	−0.177	−0.29	0.177	−0.669	−0.817	0.753
PUFA	0.577	0.248	−0.924	0.791	0.872	−0.695	0.261	0.207	−0.087	−0.705
MUFA	0.627	0.094	−0.963	0.694	0.79	−0.627	0.379	0.353	−0.238	−0.808	0.986
SFA	−0.594	−0.147	0.942	−0.712	−0.814	0.64	−0.324	−0.299	0.195	0.777	−0.99	−0.994
Smell	−0.132	−0.392	−0.4	−0.265	−0.069	0.349	0.064	0.555	−0.711	−0.659	0.333	0.424
Taste	0.277	−0.799	−0.502	−0.377	−0.236	0.319	0.592	0.905	−0.958	−0.836	0.242	0.393	0.813
Aftertaste	−0.459	−0.556	−0.087	−0.567	−0.478	0.767	−0.12	0.533	−0.727	−0.375	−0.075	0.005	0.767	0.645
Overall acceptability	0.201	−0.751	−0.461	−0.395	−0.236	0.344	0.513	0.855	−0.933	−0.804	0.232	0.378	0.867	0.993	0.668

Values in bold indicate very strong (p-value < 0.001), strong (p-value < 0.01) or moderate (p-value < 0.05) correlation between dependent variables.3.7 Principal component analysis (PCA).

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3.7. Principal Component Analysis (PCA)

Principal component patterns (PC1, PC2, PC3) with their eigenvalues and the proportion of variance explained for chemical compounds across coconut oil varieties (Coco24, Health, Kospa, Smetol, Vita) are shown in

Table 6. PC pattern for the first (PC 1), second (PC 2), and third (PC 3) components (dimension), eigenvalues, and the variance explained among compounds for coconut oil varieties (Coco24, Health, Kospa, Smetol, and Vita).

Features	PC 1	PC 2	PC 3
DPPH	0.5850	0.4580	−0.6472
Acid number	0.2205	0.0732	0.9460
Peroxide number	−0.5050	0.7597	0.3132
Oxidative stability	−0.8689	−0.4500	−0.0550
Staphylococcus aureus	0.1456	0.9804	0.0564
Clostridium perfringens	0.2729	0.9482	0.1265
Salmonella enterica	−0.1596	−0.9410	0.2858
Candida albicans	0.6592	−0.0499	−0.7183
C12.0	0.8163	−0.4480	−0.2062
C14.0	0.2254	0.2546	0.4765
C16.0	−0.7599	0.6299	0.0216
C18.0	−0.9955	−0.0250	0.0062
PUFA	0.6896	0.6881	0.2135
MUFA	0.7971	0.5783	0.1540
SFA	−0.7688	−0.6049	−0.1918
Overall appearance	0.5124	−0.1234	−0.2847
Smell	0.7011	−0.3747	0.4776
Taste	0.8590	−0.5011	−0.0286
Aftertaste	0.3849	−0.6866	0.5965
Overall acceptability	0.8354	−0.5124	0.0347
Eigen values	8.28	6.72	3.07
Variance, %	41.41	33.60	15.37

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In Figure 3, a variable factor map for the main fatty acid, quality parameters, antimicrobial activity, and sensory attributes is shown; individual scores plot (PC1 vs. PC2) for each variety; clustered variable map (PC1: 41.4%, PC2: 33.6%); and biplot illustrating varietal contributions.

4. Discussion

4.1. Oxidative Stability of the Oil Samples

Oxidative stability is a key indicator of the quality of fats and oils. Autoxidation begins when oxygen reacts with unsaturated fatty acids to form hydroperoxides, which subsequently decompose into secondary compounds such as alcohols and carbonyls, and can further oxidize into carboxylic acids [20,21]. During storage, lipids undergo degradation through hydrolysis and oxidation, resulting in the formation of oxygen-containing polymers and volatile compounds [22]. Parameters such as acid value (AV) and peroxide value (PV) are used to assess the oxidation of lipids, and the results are presented in Table 1.

The AV of the coconut oils differed significantly (p < 0.05), ranging from 0.087 mg KOH/g in Health to 0.418 mg KOH/g in Kospa. Health, an extra virgin oil, undergoes minimal processing, preserving antioxidants and bioactive compounds that mitigate lipid oxidation, which may explain its lowest observed acid value [22,23]. Vita exhibited a moderate acid value, likely due to its natural antioxidants. In contrast, the complete hydrogenation of Smetol, yielding fully saturated fatty acids, rendered it less susceptible to oxidation. Coco24 and Kospa exhibited the highest acid values, possibly due to their relatively higher levels of unsaturated fatty acids. All oil samples in this study showed lower AV compared to coconut oils obtained by expeller, traditional, commercial, or cold-press extraction methods [24]. While it is notable that unsaturated fats have remarkable health benefits, they are highly prone to lipid oxidation, which may account for this observed outcome [25]. Free fatty acids are formed during the breakdown of triglycerides, and the AV serves as an indicator of oil rancidity, with higher values reflecting greater oil degradation [26]. The AV also indicates the formation of acidic compounds during hydrocarbon oxidation [22]. The oils examined in this study can be considered safe for consumption, as their AV were below the Codex Alimentarius permissible limit of 0.6 mg KOH/g for oils [27,28]. The AV of all the samples in this study were within the acceptable limit of 4 mg KOH/g for cold-pressed oils [14]. To minimize oxidation and preserve quality, oils should be stored in tightly sealed opaque containers under cool, dry, and dark conditions.

The PV is a widely used index for assessing the oxidative quality of oils and fats, reflecting their degree of oxidation and susceptibility to rancidity [20,27]. The PV varied significantly (p < 0.05) among the oil samples, with Health recording the lowest value (0.513 mmol O₂/kg). This outcome suggests minimal primary oxidation and better preservation of quality, possibly due to the high antioxidant activity of the oil samples. Collectively, Health, Kospa, and Vita had low PV (<0.7 mmol O₂/kg), indicating minimal primary oxidation. In contrast, Coco24 and Smetol had the highest PVs, inferring greater hydroperoxide formation and more pronounced lipid oxidation. The higher PV of Coco24 may be attributed to its greater degree of unsaturation or oxidation induced by processing and storage conditions, including heat, air exposure, or the presence of contaminants. Notably, oils high in unsaturated fatty acids, particularly polyunsaturated fatty acids (PUFAs), are significantly more susceptible to oxidation [29]. Highly saturated fats are generally more resistant to oxidation. The elevated PV in Smetol may result from incomplete hydrogenation, leaving residual unsaturated bonds susceptible to oxidation. The PV observed in this study was higher than that reported by [30], as well as the 0.26 mEq/kg reported for centrifuged high-quality coconut oil [31] and the 0.35 mEq/kg reported for cold-pressed oil [32]. However, the PV of our samples was considerably lower than that of coconut oils obtained by expeller or traditional extraction methods [24]. These discrepancies may result from differences in agroecological zones, coconut varieties, storage conditions, extraction methods, and analytical techniques [33]. The PVs of all samples were below the recommended limit of 20 mmol O₂/kg for cold-pressed oils, indicating acceptable oxidative stability [15]. Fresh oils typically exhibit PVs below 10 mmol O₂/kg, whereas rancid oils exceed 30 mmol O₂/kg, with values approaching 100 mmol O₂/kg even being linked to food poisoning [34]. PVs ranging from 1 to 5 meq/kg indicate low oxidation levels, reflecting high oxidative stability and minimal lipid degradation [18]. Based on this classification, the oils in this study are considered fresh.

The oil samples showed significant differences (p < 0.05) in oxidative stability, with Smetol displaying the highest value (124.5 ± 0.98 h), likely due to its hydrogenation process, which saturates fatty acids and reduces their susceptibility to oxidation. Smetol’s oxidative stability exceeded that of Vita by 72.4%, Kospa by 110.7%, Health by 128.2%, and Coco24 by 382.6%. The high oxidative stability of Vita and Kospa may be attributed to their unrefined, virgin nature, which preserves natural antioxidants such as polyphenols and tocopherols that inhibit oxidation [35]. Coco24 (25.8 ± 0.22 h) exhibited the lowest stability, likely due to its higher content of unsaturated fatty acids and decreased antioxidants resulting from refining, which is consistent with its PV [25]. Despite their high antioxidant activity, Coco24 and Health showed the lowest oxidative stability. This may be due to antioxidant degradation, where reactions with metal ions or oxygen produce reactive species that act as pro-oxidants. Exposure to heat (120 °C) during stability testing probably accelerated this degradation, disrupting the balance with other protective compounds, weakening defences, and promoting pro-oxidant effects. To maintain quality, oils should be properly processed and stored, with regular monitoring of oxidation markers. Further research is necessary to understand the stability of coconut oil in the Slovak republic market.

4.2. DPPH Radical Scavenging Activity

Antioxidant activity is a key indicator used to evaluate the quality of vegetable oils [34]. Antioxidants, especially polyphenols (like gallic, ferulic and p-coumaric acid, quercetin and catechin) found in the coconut oil, act as potent antioxidants by interacting with free radicals to prevent oxidative damage [36,37]. As depicted in Figure 1, the DPPH radical scavenging activity varied notably among the oils from different coconut varieties (p < 0.05). The samples showed marked variations in antioxidant capacity. Among them, Health showed the highest DPPH scavenging activity (469.2 mg TEAC/kg), which was 1.3, 1.5, 3.0, and 4.7 times higher than Coco24, Vita, Kospa, and Smetol, respectively, reflecting its richer antioxidant content and superior radical-quenching ability. This pattern suggests that minimally processed, phenolic-rich oil (mainly gallic, ferulic, and p-coumaric acids, quercetin, and catechin), including Health and Coco24, exhibits more potent antioxidant activity, which improves storage stability compared to heavily processed or hydrogenated oils [22]. Hydrogenation typically removes most natural antioxidants, reducing radical-quenching ability and likely leading to the low DPPH scavenging activity observed in Smetol. The DPPH values obtained for Smetol and Coco24 were higher than those of cold-pressed coconut oil investigated by [33]. Among the samples in this study, these two oils also had higher DPPH radical scavenging activity than oil samples from the Iraqi market [38]. The free radical scavenging ability of cold-pressed oils is largely due to their high levels of alpha-tocopherol and polyphenols [33]. Processing methods have a significant impact on the levels of phytosterols and phenolics in coconut oils, leading to variations in antioxidant activity. Cold pressing, low-temperature, and water-free extraction preserve polyphenols, whereas high heat, prolonged kneading, and chemical refining degrade them [33]. According to [33], hot-pressed coconut oils show greater DPPH scavenging activity than cold-pressed oils, whereas cold-pressed oils exhibit higher activity than commercially heat-treated oils [39]. Extraction at 75 °C, particularly with the Soxhlet method, can lead to partial fat oxidation, altering the fatty acid profile and thereby reducing oil quality [31]. These findings highlight the critical influence of extraction methods and temperatures on the antioxidant activity and oxidative stability of coconut oil.

4.3. Antimicrobial Activity

The coconut oil samples exhibited significantly different inhibitory activities (p < 0.05) across the nine tested microorganisms (Table 2 and Table 3), underscoring the role of compositional variations. Gram-positive strains, including Bacillus subtilis, Staphylococcus aureus, and Clostridium perfringens, were more susceptible to coconut oil treatment than Gram-negative strains. This observation may be due to the absence of an outer membrane in Gram-positive bacteria, which affects how the oil interacts with their thick peptidoglycan layer, contributing to their relative resistance [40]. Staphylococcus aureus exhibited the most significant average susceptibility, with inhibition zones ranging from 1.09 mm (Vita) to 2.01 mm (Coco24), while Clostridium perfringens showed the lowest overall inhibition, suggesting species-specific membrane tolerance [41]. Health demonstrated the highest inhibition against Bacillus subtilis (1.35 mm) and Clostridium perfringens (0.24 mm). This aligns with its higher lauric acid content (46–50%) [42], a fatty acid known for its potent activity against Gram-positive bacteria. Lauric acid integrates into phospholipid bilayers, disrupting membrane integrity. The lipophilic compounds in oil can penetrate and disrupt the peptidoglycan layer, damaging the cell membrane and causing leakage of intracellular contents, ultimately leading to cell death [43,44]. Monolaurin, the monoglyceride form of lauric acid, exhibits strong antimicrobial activity by disrupting cell membranes, inhibiting virulence factor expression, biofilm formation, and key bacterial signalling pathways in Gram-positive bacteria [45,46]. It has been shown to inhibit Staphylococcus aureus and Bacillus cereus with zones of inhibition of 13.75 and 10.44 mm, respectively [47]. Additionally, 2-monolaurin from coconut oil has also been reported to inhibit the growth of S. aureus [48]. Smetol showed the weakest inhibition, particularly against Bacillus subtilis (0.08 mm), likely due to its higher content of long-chain fatty acids, such as stearic acid (10.7%), which have minimal antimicrobial activity [49].

Gram-negative bacteria, including Salmonella enterica, Haemophilus influenzae, and Yersinia enterocolitica, showed low susceptibility, likely due to their lipopolysaccharide-rich outer membranes, which act as barriers to hydrophobic antimicrobials [50]. However, Kospa demonstrated significant inhibition (p < 0.05) against S. enterica (1.51 mm) and Y. enterocolitica (1.90 mm), possibly because of its higher levels of caprylic and capric acids. Medium-chain fatty acids (MCFAs) have shorter hydrophobic tails and lower pKa values, enabling them to remain protonated and more readily penetrate the outer membranes of Gram-negative bacteria under mild acidic conditions [41,49]. Health and Coco24 also showed modest inhibition against H. influenzae (1.10 mm and 1.02 mm, respectively). Monoglycerides of caproic and caprylic acids, such as monocaprin, have been shown to exhibit potent bactericidal activity against Gram-negative pathogens, including Campylobacter jejuni and Salmonella spp. [50,51]. Smetol exhibited the lowest inhibitory activity across all Gram-negative strains, highlighting a potential drawback of hydrogenation on antimicrobial potential [52,53].

Candida species showed the highest overall susceptibility, particularly Candida tropicalis and C. glabrata. Health had the greatest inhibition zones, with 3.67 mm for C. tropicalis, while Vita showed potent inhibition against C. tropicalis (2.81 mm) (p < 0.05). This confirms the yeast-targeting efficacy of oils rich in lauric and capric acids [50,54]. Medium-chain fatty acids (MCFAs) disrupt fungal plasma membranes by integrating into the lipid bilayer, increasing permeability, and triggering osmotic imbalance and cytoplasmic disintegration [55,56]. Smetol consistently showed the least antifungal activity (0.27 mm) against C. albicans, a result attributable to its lower MCFA concentration and higher content of inactive long-chain fatty acids, such as palmitic (C16:0) and stearic (C18:0), which are ineffective against both bacterial and fungal membranes [49]. According to [57], monolaurin in virgin coconut oil inhibited the growth of C. albicans at a 25% concentration within two days, highlighting its antifungal efficacy. Monolaurin reportedly inhibited C. albicans with an MIC value of 2.49 mmol/mL [49]. Coco24 showed moderate efficacy against most yeasts, ranking second only to Health in inhibiting C. glabrata. Its unrefined nature may, therefore, suggest the preservation of bioactive compounds, including phenolics, tocopherols, and partial glycerides, which could synergize with MCFAs to enhance antifungal activity [53]. The antimicrobial potency of Health may be attributed to its low AV (0.087 mg KOH/g) and high antioxidant activity (469 mg TEAC/kg), indicating minimal oxidation and preservation of bioactive lipids. The observed antifungal effects of these oils highlight their potential for protecting consumers against possible fungal infections [51]. Overall, the antimicrobial properties of coconut oil present opportunities for its use as a natural preservative and functional ingredient, with implications for food safety, shelf-life extension, and the development of clean-label products.

4.4. Fatty Acid Methyl Ester (FAME) Profile of Oil Samples

As shown in Table 4, the saturated fatty acid (SFA) content of the oils ranged from 91.70% in Coco24 to 97.60% in Smetol. The high SFA content in Smetol was expected, as it is a fully hydrogenated oil. In contrast, Coco24 exhibited the lowest SFA content among the samples, likely due to its non-hydrogenated and refined nature. Notably, no significant differences (p > 0.05) in SFA content were observed among Health, Kospa, and Vita oil samples. SFAs, particularly long-chain ones, may increase the risk of cardiovascular diseases [58]. However, coconut oil is widely used in the food industry because of its high SFA content, oxidative and thermal stability, and suitability for high-temperature processes such as baking and frying [59,60].

Among the individual SFAs, lauric acid (C12:0) (43.75% to 50.21%) and myristic acid (C14:0) (18.54% to 19.40%) were the most abundant. This aligns with reports that lauric and myristic acids are the primary SFAs in coconut oil [30]. The myristic acid (C14:0) content across all oils analysed in this study showed no significant differences (p < 0.05), while Smetol and Coco24 differed significantly (p < 0.05) from other samples in lauric acid content. The values for these two SFAs agree with previous reports for virgin coconut oils by [30,61]. Lauric acid is recognized for its antimicrobial, antiviral, and anti-inflammatory effects [42]. Therefore, its presence in substantial quantities may confer these bioactivities. Medium-chain triglyceride (MCT) oils mainly consist of caprylic (C8:0) and capric (C10:0) fatty acids [30]. The presence of these SFAs varied considerably, with Kospa, Vita, and Health oils exhibiting the highest levels, possibly due to minimal processing, which preserves the natural medium-chain fatty acid profile of virgin coconut oil. MCTs, such as caprylic and capric acids, are efficiently metabolised by the liver, producing ketones that may have therapeutic benefits for conditions like Alzheimer’s and Parkinson’s diseases [62,63]. Levels of palmitic acid (C16:0), stearic acid (C18:0), and arachidic acid (C20:0) were significantly higher (p < 0.05) in Smetol, likely due to hydrogenation. Most Western diets are notably characterised by high saturated fats, particularly palmitic acid (C16:0) and stearic acid (C18:0) [64]. Palmitic and stearic acids, known for their cholesterol-raising properties, are commonly used in interesterification to enhance the texture and stability of foods. This highlights the need for further research into their metabolic effects [65]. Overall, the content of individual SFAs aligns well with the Codex standard [66]. Unsaturated fatty acids (UFAs), especially polyunsaturated fatty acids (PUFAs), are associated with a reduced risk of cardiovascular disease and type 2 diabetes, particularly when they replace saturated fatty acids (SFAs). Epidemiological and clinical studies show that plant-derived UFAs improve atherogenic lipid and lipoprotein profiles [67,68]. In this study, PUFA and MUFA contents were highest in Coco24 (1.627% and 6.46%) and lowest in Smetol (0.147% and 2.19%), reflecting the preservation of unsaturated fatty acids in the non-hydrogenated Coco24 and their depletion through complete hydrogenation in Smetol. Health, Kospa, and Vita displayed comparable MUFA levels (4.34–4.37%), while the PUFA content did not differ significantly (p > 0.05) between Vita and Health, consistent with their similar virgin processing methods. Coco24 contained the highest levels of oleic acid (C18:1 cis n-9, 6.45%) and linoleic acid (C18:2 cis n-6, 1.61%), whereas Smetol had the lowest (1.24% and 0.13%, respectively), highlighting the impact of hydrogenation. Oleic acid content was similar in Health, Kospa, and Vita (4.37% to 4.46%), and linoleic acid did not differ significantly (p > 0.05) between Vita and Health. The trans fatty acid C18:1 trans n-9 was only detected in Smetol (0.837 ± 0.015%), likely due to hydrogenation, which promotes the formation of elaidic acid. These differences have significant nutritional implications, as higher intakes of MUFA and PUFA, notably oleic and linoleic acids, are linked to improved lipid profiles and a lower risk of cardiovascular disease. Conversely, hydrogenation reduces these beneficial fatty acids and may increase the proportion of less desirable saturated fats.

4.5. Sensory Characteristic of Coconut Samples

As shown in Figure 2, the smell scores for the oil samples in this study varied significantly (p < 0.05). Panellists rated Vita oil (9.0) and Kospa (8.0) as the most pleasant in terms of smell and taste, while Smetol received the lowest score (3.0). This outcome may be attributed to the minimally processed nature of Vita and Kospa, which enables them to retain the natural volatile aroma compounds of fresh coconut [66], resulting in a strong, sweet coconut taste and aroma. The hydrogenation process likely removed most of the natural coconut aroma compounds from Smetol, resulting in a bland or waxy scent that panellists found less appealing. Additionally, the high peroxide values observed in Smetol and Coco24 likely contributed to their lower taste and aroma scores, as increased oxidation is associated with low sensory quality. Lipid oxidation is known to produce off-flavours and lead to overall quality degradation [32]. Panellists rated the aftertaste of Coco24, Smetol, and Health poorly (2.0), while Vita and Kospa scored higher (3.0 and 4.0). The unpleasant aftertaste may result from oxidation by-products and free fatty acids. Overall, appearance scores varied, with Vita rated highest (8.0), followed by Health and Coco24 (6.0), and Kospa and Smetol (5.0). In terms of overall acceptability, Vita and Kospa scored highest for taste, likely due to their pleasant aroma and flavour, consistent with the strong positive correlation between these sensory parameters. Minimally processed, virgin coconut oils, such as Vita and Kospa, exhibited superior sensory qualities compared to more processed or oxidized samples. The retention of natural aroma compounds and lower oxidation levels were key factors contributing to enhanced aroma, taste, and overall acceptability, underscoring the role of processing methods and oxidative stability in determining the quality of coconut oil.

4.6. Variable Interrelationships

Linear correlations between fatty acid composition, quality parameters, antimicrobial activity, and sensory outcomes for the coconut oil varieties are presented in Table 5. Strong positive correlations (r > 0.70) were observed for DPPH (antioxidant activity), which was highly correlated with Candida albicans (r = 0.859), indicating a potential link between antioxidant levels and fungal susceptibility. Concerning the fatty acid profile, PUFA showed a positive correlation with oxidative stability (r = 0.872) and overall acceptability (r = 0.855). MUFA displayed strong positive correlations with overall acceptability (r = 0.986) and taste (r = 0.813). Overall acceptability was positively correlated with taste (r = 0.993), smell (r = 0.867), MUFA, and PUFA. Conversely, strong negative correlations (r < −0.70) were found for oxidative stability, which was negatively correlated with Salmonella enterica (r = −0.906), Clostridium perfringens (r = −0.872), and Candida albicans (r = −0.648). Regarding microbial interactions, Salmonella enterica showed a strong negative correlation with Clostridium perfringens (r = −0.924), indicating possible microbial antagonism. Candida albicans showed strong negative correlations with C16:0 (r = −0.92) and C18:0 (r = −0.817). SFA exhibited negative correlations with taste (r = −0.836) and overall acceptability (r = −0.804).

4.7. Principal Component Analysis (PCA)

The principal component (PC) patterns for the first (PC1), second (PC2), and third (PC3) components, along with their eigenvalues and variance, are explained. Principal component analysis (PCA) identified two principal components, making the PCA plot highly representative and providing a strong summary of the data. These two components accounted for 75.1% of the variation in the twenty original variables (41.4% for PC1 and 33.6% for PC2, Table 6), leaving 15.4% of the variation explained by the third component (PC3). As a result, the first plane (PC1 vs. PC2) explains a significant proportion of the data variability.

Based on the data shown in Table 6, the first principal component (PC1) differentiates samples with elevated levels of unsaturated fats (MUFA and PUFA) and favourable sensory scores, characterised by a higher proportion of saturated fatty acids (notably C16:0 and C18:0) and enhanced oxidative resistance. This axis essentially contrasts sensory appeal with chemical resilience. In contrast, PC2 appears to be primarily influenced by microbial indicators; higher values on this component are associated with the presence of Gram-positive bacteria and increased oxidation, whereas lower scores tend to correspond with the detection of Salmonella. This suggests a dimension related to microbiological safety. PC3, on the other hand, captures more subtle distinctions, particularly in aroma and residual taste, which seem to be linked to acid levels. This component may accentuate delicate flavour aspects or early signs of degradation. Figure 3b,d presents a PCA biplot, a graphical representation used to visualize the relationships between variables (fatty acid composition, quality parameters, antimicrobial activity, and sensory results) and samples (grouped as Coco24, Health, Kospa, Smetol, and Vita). Kospa and Vita samples demonstrated the best sensory performance (taste, smell, acceptability), whilst Smetol, although chemically stable and saturated, was potentially less appealing sensorially. Health presented a balanced product with moderate values across most attributes. Coco24 exhibited a strong chemical profile, but possibly with a higher microbial presence. Figure 3b reveals distinct clustering patterns among the sample groups (Coco24, Health, Kospa, Smetol, and Vita), indicating differential responses or characteristics, particularly between Smetol and the other clusters. Vita appears to be intermediate, potentially sharing features with multiple groups.

Additionally, the PCA (Figure 3a,c) reveals two dominant dimensions: the first (PC1) separates samples based on sensory-chemical stability, with high MUFA/PUFA and acceptability scores on one side (e.g., Kospa and Vita) and high SFA and oxidative stability on the other (e.g., Smetol). The second dimension (PC2) reflects microbial safety, distinguishing samples with Gram-positive contamination (Coco24) from those with lower microbial risks or different pathogens (Kospa, Vita, and Health).

5. Conclusions

Comparative analysis of coconut oil samples reveals significant (p < 0.05) differences in antioxidant properties, antimicrobial activity, fatty acid composition, oxidative stability, and sensory qualities, which are affected by oil variety and processing methods. The findings emphasise the importance of selecting suitable processing techniques to preserve bioactive compounds and maintain desirable functional and sensory properties. Coconut oil, with its proven antimicrobial and antioxidant properties, shows potential for use in both food and pharmaceutical applications. The oils were found to meet safety standards, supporting their suitability for consumption and incorporation into food products such as functional spreads, bakery items, and nutritional supplements. Future research should focus on validating the bioactivity of these oils in vivo and investigating the effects of storage and packaging on their shelf life and stability.