Hindawi Journal of Lipids Volume 2018, Article ID 1762342, 7 pages https://doi.org/10.1155/2018/1762342 Research Article Free Radical Scavenging Capacity, Carotenoid Content, and NMR Characterization of Blighia sapida Aril Oil Andrea Goldson Barnaby ,1 Jesse Clarke,1,2 Dane Warren,1 and Kailesha Duffus1 1 Te Department of Chemistry, Te University of the West Indies, Mona, Kingston 7, Jamaica 2College of Health Sciences, Medical Technology Department, University of Technology, Kingston 7, Jamaica Correspondence should be addressed to Andrea Goldson Barnaby; [email protected] Received 21 May 2018; Accepted 5 August 2018; Published 13 August 2018 Academic Editor: Cliford A. Lingwood Copyright © 2018 Andrea Goldson Barnaby et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Blighia sapida aril oil is rich in monounsaturated fatty acids but is however currently not utilized industrially. Te oil was characterized utilizing nuclear magnetic resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). A spectrophotometric assay was conducted to determine the free radical scavenging properties and carotenoid content of the oil. 1 Chemical shifs resonating between � 5.30 and 5.32 in the H NMR are indicative of olefnic protons present in ackee aril oil which −1 are due to the presence of oleic acid. A peak at 3006 cm in the FTIR spectra confrms the high levels of monounsaturation. Te oil has a free radical scavenging activity of 48% ± 2.8% and carotenoid content of 21 ± 0.2 ppm. 1. Introduction intoxication. Proper education of the potential toxicity of the fruit is therefore necessary. Te ackee is not the only Blighia sapida Koenig (ackee) (Figure 1) is native to West source of hypoglycin. Hypoglycin has also been isolated Africa. Te immature fruit is toxic and should not be from sycamore maple tree (Acer pseudoplatanus)andhas consumed due to the presence of a nonproteinogenic amino been implicated in atypical myopathy observed in horses acid, hypoglycin A [1]. Mature arilli is however safe for [4]. consumption. In Jamaica, ackee is widely consumed without Te ackee is canned in brine for export to the United any ill efects. Tis is due to the proper harvesting and States of America, Canada, and Europe. A signifcant amount preparationofthefruitforconsumption.Tearilliisamajor of ackee arilli waste is generated from the canning process component of the national dish, ackee, and cod fsh. As the fruit matures, hypoglycin A is translocated to the seeds where which may be considered for use in the production of it is converted to hypoglycin B [2]. Te concentration of ackee aril oil. Mature ackee arilli contains over 50% lipid hypoglycin A decreases from approximately 8000 mg/kg in and is high in oleic acid [5]. Te toxic components of the the immature arilli to 271 mg/kg in the mature fruit. Te fruit are water soluble and therefore would not be present concentration of hypoglycin B in the seeds increases from in lipid extracts of the fruit. Lipids play an important 1629 to 11774 mg/kg [2]. Immature arilli and the seeds of the role in food and nutrition serving as a source of energy, fruit should therefore not be eaten. Te mode of toxicity vitamins, and antioxidants [6]. Carotenoids and vitamin E of hypoglycin is its metabolism to methylenecyclopropyl- in the form of tocopherols or tocotrienol are examples of acetyl-CoA which inhibits fat oxidation [1]. Regrettably there natural antioxidants found in plant oils [7]. Antioxidants arestillreportsofpeoplefallingillfromtheconsumptionof serve a protective role by scavenging free radicals such immature ackees. In Nigeria, there were reports of children as reactive oxygen species that can lead to the damage becoming ill afer the consumption of roasted ackee seeds of cell membranes [8]. Carotenoids are also of commer- and arilli of the fruit [3]. Children who are unaware of cial signifcance due to their application as food colorants the dangers of the fruit have been more prone to ackee [9]. 2 Journal of Lipids where A1 =absorbanceofsampleat517nm A0 = absorbance of control at 517 nm Aril 2.4. Carotenoid Determination. Aspectrophotometricassay Husk was used to determine the carotenoid content of oil samples [7]. Samples (0.5 g) were weighed and transferred to a volu- metric fask and n-hexane added (25 mL). Te absorbance of Seed the solution was measured at 446 nm. [V × 383 × (As − Ab)] Carotenoid content (ppm)= (2) (100 × W) Figure 1: Te ackee fruit where In the present study ackee aril oil was characterized uti- V=volumeusedforanalysis lizing nuclear magnetic resonance and infrared spectroscopy. Te free radical scavenging capacity and carotenoid content 383 = vxtinction coefcient for carotenoids of ackee aril oil were also evaluated. As =sampleabsorbance Ab =blankabsorbance 2. Materials and Methods W = sample weight (g) 2.1. Samples. Ackeearilliwereobtainedfromalocalproces- sor of canned ackee in brine. Arilli were dried to constant 1 13 1 ∘ 2.5. � NMR and � NMR Characterization. HNMR weight (75 C for 1 day, Gallenkamp Laboratory Oven OV- 13 and C NMR characterization of the oil was performed on a 330, England). A composite sample of the dried arilli was ∘ Bruker BioSpin 200 MHz at 200 MHz. Lipid extracts (20 mg) extracted with hexane (26 C, 24 h). Te resulting extract was ∘ were analyzed in deuterated chloroform (CDCl3)at25C, concentrated in vacuo. Samples of commercial coconut oil with tetramethylsilane (TMS) as the internal standard. Te and soybean oil were also evaluated to provide a comparison. chemical shifs reported is in units of parts per million (ppm). ∘ A chemical shif of 1 ppm implies that the magnetic feld 2.2. Acid Value, Free Fatty Acid, pH, and Brix. Te pH of required to produce the signal is 1 millionth less than that the oil samples was measured using a pH meter (Oakton, required for TMS. pH Tutor). Te acid value was determined by titration of aril oil (10 mL) with sodium hydroxide (0.1 M) utilizing phenolphthalein as indicator [10]. Te percentage free fatty 2.6. Fourier Transform Infrared Spectroscopy. ABrukerVec- acid was expressed based on oleic acid, the predominant tor 22 Fourier Transform Infrared (FTIR) Spectrometer ∘ fatty acid present in ackee aril oil [5]. Te Brix (total was utilized to record the infrared spectra of ackee oil samples. Te FTIR spectrum was recorded between 4000 soluble solids) of the oils was determined utilizing a HI96801 −1 ∘ and 500 cm . Te spectrum was obtained by averaging refractometer (Hanna instrument, 0-85% Brix, and 26.4 C). −1 20 scans recorded at a resolution of 2 cm .Spectrawere baseline-corrected. OPUS sofware was used to acquire and 2.3. Te 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) Radical Scav- manipulate the spectral data. enging Assay. Te DPPH assay was performed according to the method of Brand-Williams [11]. To each oil sample (200 mg), ethanol (2 mL, 80%) containing hydrochloric acid 2.7. Data Analysis. Samples were analyzed in duplicate. Te (1%) was added and the resulting mixture reacted with mean of the data and the standard error is reported. the stable DPPH radical. Te reaction mixture consisted of ackee aril oil (0.5 mL), absolute ethanol (3 mL), and DPPH 3. Results and Discussion (0.5 mM, 0.3 mL). Te reaction was allowed to proceed for ∘ 100 min afer which the absorbance was measured at 517 nm 3.1. Acid Value, Free Fatty Acid, pH, and Brix. Te acid value using a spectrophotometer (Termo Scientifc, Genesys 10S). is a frequently investigated parameter in the edible oil indus- A mixture of ethanol (3.3 mL) and oil (0.5 mL) served as the try.Itisameasureofthefreefattyacidcontentoftheoilandis blank. A control solution was prepared by mixing ethanol anindicatorofoilquality[12].Inthepresenceoftheenzyme (3.5 mL) with the DPPH radical solution (0.3 mL). Te data lipase, triglycerides undergo enzymatic hydrolysis to produce obtainedwasusedtocalculatethefreeradicalscavenging freefattyacids[13].Freefattyacidsarehighlysusceptibleto capacity. oxidative rancidity leading to of favor and odors. High acid values indicate oil degradation and inadequate processing or A1 % =[1− ] ∗ 100 (1) storage of oils. Te acid value of ackee aril oil was 1.3% which A0 is within the required limits observed for oils such as coconut Journal of Lipids 3 Table 1: Physicochemical properties of ackee, coconut, and soybean oils. Parameter Coconut Ackee Soybean ∘ ∘ ∘ Brix 66 69 73 pH 3.6 4.5 5.2 Acid value 0.6 1.3 0.03 Free fatty acid (%) 0.2 0.1 0.1 Carotenoid (ppm) 0.34 ± 0.1 21.0 ± 0.2 1.39 ± 0.1 Free radical scavenging activity (%) 28 ± 7. 1 4 8 ± 2.8 100 oil < 6andsoybeanoil< 2.5 [14]. Te oil had a pH of 4.5 3.4. Nuclear Magnetic Resonance (NMR) Spectroscopy. Fatty (Table 1). acids exist primarily as triacylglycerols in oils of plant origin. ∘ TedegreeBrix(Brix) is widely utilized in the food Tey are formed predominantly from the unsaturated fatty and beverage industries for quality control. It represents the acids, oleic acid, linoleic acid, and �-linolenic acid. Ackee aril percentage sucrose or dissolved solids in a particular liquid. ∘ oil and soybean oil consist primarily of the unsaturated fatty Of the oils investigated, the highest Brix was observed in acids oleic acid (C18:1) and linoleic acid (C18:2), respectively, soybean oil (73) followed by ackee oil (69) and coconut oil whereas in coconut oil, lauric acid (C12), a saturated fatty (66). Palm oil and olive oil have been reported as having a ∘ acid, is the predominant fatty acid [5, 20, 21]. NMR spec- Brix in the range of 70–75 [15]. troscopy has been utilized in the characterization of lipids and to detect adulteration [22, 23]. It may also be utilized as an indicator of the level of unsaturation present in the oils 3.2.