Variability in Fatty Acid Composition, Oxidative Status, and Vitamin E Content of Commercial Roasted Peanuts

Abstract

This study evaluated the oil quality of roasted peanut samples collected from different Turkish producers (M–T7) by analyzing oil yield, acidity, peroxide index, vitamin E content, oleic/linoleic acid ratio, fatty acid composition, and multivariate relationships using principal component analysis (PCA). Oil yields varied from 47.81% to 57.64%, reflecting differences in raw materials and processing efficiency. Acidity values (0.13–0.61 mg KOH g⁻¹) and peroxide indices (0.15–7.19 meq O₂ kg⁻¹) indicated generally good oil quality, although some samples showed early oxidative or hydrolytic degradation. Vitamin E content ranged widely (0–166.50 mg 100 g⁻¹ oil), highlighting variability in antioxidant capacity and its inverse relationship with oxidation. Oleic/linoleic acid ratios ranged from 1.78 to 20.99, allowing discrimination between conventional and high-oleic profiles, with higher ratios associated with improved oxidative stability. Fatty acid analysis confirmed oleic and linoleic acids as the dominant components, with marked inter-sample variability. PCA revealed that sample dispersion was mainly driven by fatty acid composition, oxidation indices, and antioxidant content, reflecting heterogeneous genetic origins and processing conditions. These findings demonstrate substantial quality variability among commercial roasted peanut products and underline the importance of systematic quality assessment for industrial applications.

Keywords

• Roasted peanuts
• Oil quality
• Fatty acids
• Variability
• PCA

Variability in fatty acid composition, oxidative status, and vitamin E content of commercial roasted Peanuts

Abstract

This study evaluated the oil quality of roasted peanut samples collected from different Turkish producers (M–T7) by analyzing oil yield, acidity, peroxide index, vitamin E content, oleic/linoleic acid ratio, fatty acid composition, and multivariate relationships using principal component analysis (PCA). Oil yields varied from 47.81% to 57.64%, reflecting differences in raw materials and processing efficiency. Acidity values (0.13-0.61 mg KOH g⁻¹) and peroxide indices (0.15-7.19 meq O₂ kg⁻¹) indicated generally good oil quality, although some samples showed early oxidative or hydrolytic degradation. Vitamin E content ranged widely (0-166.50 mg 100 g⁻¹ oil), highlighting variability in antioxidant capacity and its inverse relationship with oxidation. Oleic/linoleic acid ratios ranged from 1.78 to 20.99, allowing discrimination between conventional and high-oleic profiles, with higher ratios associated with improved oxidative stability. Fatty acid analysis confirmed oleic and linoleic acids as the dominant components, with marked inter-sample variability. PCA revealed that sample dispersion was mainly driven by fatty acid composition, oxidation indices, and antioxidant content, reflecting heterogeneous genetic origins and processing conditions. These findings demonstrate substantial quality variability among commercial roasted peanut products and underline the importance of systematic quality assessment for industrial applications.

Keywords

• Roasted peanuts
• Oil quality
• Fatty acids
• Variability
• PCA

Thanks

I want specially to thanks Mrs. Emine Koşucu for her advisory during the execution of this work.

References

1. Food and Agriculture Organization Statistics Database (2025) Peanut (groundnut) production by country. Food and Agriculture Organization of the United Nations Statistics Division, Rome, Italy.
2. Sutrisno AP, Khoiroh ID,Natasya ZAP, Muh. SD (2025) The role of peanuts: nutritional, bioactive, food technology and novel. Acad Lett 1: 88-97.
3. Lusas, EW (1979) Food uses of peanut protein. J Am Oil Chem Soc 56:425–430. https://doi.org/10.1007/BF02671530
4. Çiftçi S., SUNA G. (2022) Functional components of peanuts (Arachis Hypogaea L.) and health benefits. Fut Foods 5: 100140. https://doi.org/10.1016/j.fufo.2022.100140
5. Ortiz C, Martirosyan D (2024) Bioactive compounds in peanuts (Arachis hypogaea L.): A review of their anti-inflammatory and antioxidant effects. Agri Food Bioac Comp 1:1-18. https://doi.org/10.31989/afbc.v1i12.1525.
6. Bhat E, Sajjad N, Manzoor I, Rasool A (2019) Bioactive compounds in peanuts and banana. Biochem. Anal, Biochem 8:38. https://doi.org/10.35248/2161-1009.19.8.382
7. Kamalaja T, Prashanthi M, Rajeswari K (2018) Evaluation of antioxidant activity and bioactive compounds on domestic cooking method. Inter J Curr Microbio App Sc 7:4090-4097. https://doi.org/10.20546/ijcmas.2018.708.425.
8. Janila P, Nigam SN, Pandey MK, Nagesh P and Varshney RK (2013) Groundnut improvement: use of genetic and genomic tools. Front Plant Sci 4:23. https://doi.org/10.3389/fpls.2013.00023

9. Young CT, Heinis JJ (1989). Manufactured peanut products and confections. In: Lusas EW, Erickson DR, Nip WK (ed). Food Uses of Whole Oil and Protein Seeds. American Oil Chemists' Society, Champaign, IL., pp 177–190.
10. Singh U, Singh, B (1992) Tropical grain legumes as important human foods. Econ Bot 46:310–321. https://doi.org/10.1007/BF02866630
11. Clemente, TE and Cahoon, EB (2009) Soybean Oil Genetic Approaches for Modification of Functionality and Total Content. Plant Phy 151:1030-1040.
12. Davis JP, Price KM, Dean LL, Sweigart DS, Cottonaro JM, Sanders TH (2016) Peanut oil stability and physical properties across a range of industrially relevant oleic acid/linoleic acid ratios. Peanut Science 43: p.1-11. https://doi.org/10.3146/0095-3679-43.1.1l’m
13. Zhang D, Li X, Cao Y, Wang C, Xue Y (2020) Effect of roasting on the chemical components of peanut oil. LWT-Food Sci Technol 125:1-9. https://doi.org/10.1016/j.lwt.2020.109249
14. Elias MC, Ziegler V, Romano CM, Alves GH, Paraginski RT, Oliveira M de (2016) Physicochemical properties and enzymatic bean grains dried at different temperatures and stored for 225 days. Semina: Ciências Agrárias 37:1295–1306.
15. Li X, Qin W, Chen L (2018) Impact of storage conditions on peanut oil quality and shelf life. Food Control 84:432-437. https://doi.org/10.1016/j.foodcont.2017.08.026
16. Fat Determination in Foods (1998) method no 160. Nordic Committee on Food Analysis Publ., Oslo, Norway.
17. International Standard for Determination of Acid Value and Acidity in Animal and Vegetable Fats and Oils (2017) ISO 660. International Organization for Standardization, Geneva, Switzerland.
18. International Standard for Determination of Peroxide Value-Iodometric (Visual) Endpoint Determination in Animal and Vegetable Fats and Oils (2017) ISO 3960. International Organization for Standardization, Geneva, Switzerland.
19. Internal Standard Operating Procedure for Determination of Vitamins A, D₂, D₃ and E in Food and Feed by HPLC-DAD SOP 40 Rev 00 (n d). KKMM Authorized Food Control Laboratory, Turkey.
20. Bligh EG, Dyer WJ (1959) A rapid method of total lipid extraction and purification. Can J Biochem Physiol 37:911-917. https://doi.org/10.1139/o59-099
21. Carrín ME., Carelli AA (2010) Peanut oil: Compositional data. Eur J Lip Sci Tech 112:697–707. https://doi.org/10.1002/ejlt.200900176
22. Okereke GO, Banigo EOI (2021) Proximate Composition of Some Selected Legumes and Quality Attributes of Oils Extracted from Soybean, Oil Bean and Groundnut Seeds. Asian Food Sci J 20:49-60.
23. Maguire LS, O’Sullivan SM, Galvin K, O’Connor TP, O’Brien NM (2004) Fatty acid profile, tocopherol, squalene and phytosterol content of walnuts, almonds, peanuts, hazelnuts and the macadamia nut. Int J Food Sci Nut 55:171–178.
24. Zhang J, Wang T, Zhang F., Li Y, Liu Y, Wang G, Wang X (2021). Genetic diversity of nuts traits and fatty acids of pecan (Carya illinoinensis) germplasm resources. https://doi.org/10.21203/rs.3.rs-1133010/v1
25. Alasalvar C, Amaral JS, Shahidi F (2006) Functional lipid characteristics of Turkish Tombul hazelnut (Corylus avellana L). J Agric Food Chem 54:10177-10183.
26. Li W, Yoo E, Lee S, Sung J, Noh HJ, Hwang SJ, Desta KT, Lee G-A (2022) Seed Weight and Genotype Influence the Total Oil Content and Fatty Acid Composition of Peanut Seeds. Foods 11:1-13. https://doi.org/10.3390/foods11213463
27. Wang ML, Tonnis BD, Li X, Benke R, Huang E, Tallury S, Puppala N, Peng Z, Wang J (2024) Genotype, environment, and their interaction effects on peanut seed protein, oil, and fatty acid content variability. Agronomy J 116: 1440-1453.
28. Gunstone FD (2003) Vegetable oils in food technology. CRC Press, Boca Raton.
29. O’Brien RD (2004) Fats and oils: formulating and processing for applications. CRC Press, Boca Rato
30. Turan A (2018) Effect of drying methods on nut quality of hazelnuts (Corylus avellana L.). J Food Sci Technol 55:4554-4565. https://doi.org/10.1007/s13197-018-3391-8.
31. Ghirardello D, Contessa C, Valentini N, Zeppa G, Rolle L, Gerbi V, Botta R (2013) Effect of storage conditions on chemical and physical characteristics of hazelnut (Corylus avellana L.). Postharv Bio Tech 81:37–43. https://doi.org/10.1016/j.postharvbio.2013.02.014
32. Pokorný J, Yanishlieva N, Gordon M (2000) Antioxidants in food: practical applications. Woodhead Publ, Cambridge.
33. Groot SPC, van Litsenburg MJ, Kodde J, Hall RD, de Vos RCH, Mumm R (2022) Analyses of metabolic activity in peanuts under hermetic storage at different relative humidity levels. Food Chem 373:1-9. https://doi.org/10.1016/j.foodchem.2021.131020
34. Özçınar AB (2022) Food-grade oil quality of peanut (Arachis hypogaea L). MAS J Appl Sci 7:81-87.
35. Yıldız AY, Karaca H (2021) Comparison of the Oil Quality of Light and Dark Walnuts under Different Storage Conditions. J Oleo Sci 70:615-632. https://doi.org/10.5650/jos.ess20266.
36. Bakkalbaşı E,Yilmaz OM, Javidipour İ, Artik N (2012) Effects of packaging materials, storage conditions and variety on oxidative stability of shelled walnuts. LWT-Food Sci Tech 46:203-209, 2012.
37. Buransompob A, Tang J, Mao R, Swanson Bg (2003) Rancidity of walnuts and almonds affected by short time heat treatments for insect control. J Food Process Preserv 27:445–464. https://doi.org/10.1111/j.1745-4549.2003.tb00529.x.
38. Shin EC, Dean LL, Hendrix KW, Zheng H (2009) Commercial Runner Peanut Cultivars in the United States: Tocopherol Composition. J Agric Food Chem 57:10289-10295.
39. Onat B (2013) Determination of tocopherol composition of some peanut cultivars grown under main-crop conditions in the Çukurova region. Acta Biol Turc 26:45-51.
40. Eltom HAE, Sulieman MA, Hassan AB (2023) Effect of boiling and roasting processing on nutritional quality of two Sudanese peanuts (Arachis hypogaea) cultivars. Legume Sci. 5:1-9. https://doi.org/10.1002/leg3.159
41. Zhang Y, Li Y, Ren X, Gao J, Wang Y, Zhu D (2024) Comparative Study on the Nutritional Quality of Peanut in Saline and Non-Saline Land. Foods 13:1-20. https://doi.org/10.3390/foods13233751
42. de Freitas Floriano R., Radunz LL, Dionell, RG, Ziegler V, de Moraes Vieira M, Hoffmann, JF, Uitdewilligen GS, Ferreira CD (2023) Effect of storage on the quality of peanut grain oil. J of Food Comp Anal 124. https://doi.org/10.1016/j.jfca.2023.105688
43. Asogwa, IS, Onweluzo J C (2010) Effects of processing methods on the chemical composition of flour, moinmoin and akara from Mucunapruriens. J Trop Agri Food Env and Extension 9:200–208.
44. Kim EH, Jung JW, Yu O, Lee Y, Kim MJ, Lee SG, Park, HM, Jo Y, Joo Y, Oh SW (2024) Natural variation in tocopherols, B vitamins, and isoflavones in seeds of 13 Korean conventional soybean varieties. Appl Biol Chem 67. https://doi.org/10.1186/s13765-024-00896-5
45. Lim HJ, Kim DS, Pan JH, Pae SB, Kim HS, Shin EC, Kim JK (2017) Characterization of physicochemical and sensory attributes of a novel high-oleic peanut oil cultivar (Arachis hypogaea ssp fastigiata L). Appl Biol Chem 60:653-657. https://doi:10.1007/s13765-017-0324-6
46. Kornsteiner-Krenn M, Wagner K-H, Elmadfa I (2013) Phytosterol content and fatty acid pattern of ten different nut types. Inter J Vit Nutri Res 83:263–270.
47. Kalantar Ahmadi SA, Daneshian J (2025), Enhancing Soybean (Glycine max L. Merr) Heat Stress Tolerance: Effects of Sowing Date on Seed Yield, Oil Content, and Fatty Acid Composition in Hot Climate Conditions. Food Sci Nutr 13: e4690. https://doi.org/10.1002/fsn3.4690
48. Ergun Z, Zarifıkhosroshahi M (2020) Comparative analysis of oil content and fatty acid composition of peanut (Arachis hypogaea L) varieties from Turkey. Int J Agric Life Sci 4:42-47.
49. Ozdemir S, Kokten K, Cacan E et al (2025) Some Chemical Features and Fatty Acid Compositions of the Seeds of Some Peanut Varieties. Chem Nat Compd 61:1213-1216. https://doi.org/10.1007/s10600-025-04859-0
50. Sebei K, Gnouma A, Herchi W, Sakouhi F, Boukhchina S (2013) Lipids, proteins, phenolic composition, antioxidant and antibacterial activities of seeds of peanuts (Arachis hypogaea l) cultivated in Tunisia. Biol Res 46: 257-263. https://dx.doi.org/10.4067/S0716-97602013000300006
51. Andersen PC, Gorbet DW (2002) Influence of year and planting date onf atty acid chemistry of high oleic acid and normal peanut genotypes. J Agri Food Chem 50:1298–1305.
52. Shin, E-C, Craft B, Pegg R, Phillips RD, Eitenmiller R (2010) Chemometric approach to fatty acid profiles in Runner-type peanut cultivars by principal component analysis (PCA). Food Chem 119:1262-1270. https://doi.org/10.1016/j.foodchem.2009.07.058
53. Jung S, Powell G, Moore K, Abbott A (2000) The high oleate trait in the cultivated peanut [Arachis hypogaea L.]. II. Molecular basis and genetics of the trait. Molecular and General Genetics, 263:806–811.
54. Patel M, Jung S, Moore K, Powell G, Ainsworth C, Abbott A (2004) High oleate peanut mutants result from a MITE insertion into the FAD2 gene. Theoretical App Gen 108:1492–1502.
55. Hammond EG, Duvick D, Wang T, Dodo H, Pittman RN (1997) Survey of the fatty acid composition of peanut (Arachis hypogaea) germplasm and characterization of their epoxy and eicosanoic acids. J Am Oil Chem Soc 74:1235–1239.