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Influence of extraction methods and temperature on hemp seed oil stability: A comprehensive quality assessment
(2025-06-01)
Senphan, Theeraphol
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Mungmueang, Natthaphong
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Sriket, Chodsana
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Sriket, Pornpimol
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Sinthusamran, Sirima
Hemp seed oil's increasing popularity demands a comprehensive understanding of the impact of processing on its quality and stability. This study investigated the effects of extraction methods (hydraulic pressing, Bligh and Dyer method, and Soxhlet extraction) combined with storage temperatures (45 °C and 55 °C) on oil characteristics over 60 days. The oil extraction processes were conducted using standard protocols, followed by storage under controlled conditions. Analysis encompassed color changes, oxidation indicators (peroxide value, p-anisidine value, TBARS), free fatty acids, moisture content, and Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy for molecular-level changes. Hydraulic press extraction demonstrated superior stability with minimal linoleic acid reduction (0.75 %) compared to Bligh and Dyer method (1.43 %) at 55 °C (p < 0.05) and Soxhlet extraction method (1.09 %). Higher storage temperature (55 °C) accelerated quality degradation significantly faster than 45 °C (p < 0.05), affecting oxidation markers and sensory attributes. Color darkening intensified at elevated temperatures, particularly in Bligh and Dyer extracted oils. ATR-FTIR spectroscopy analysis revealed significant changes in characteristic bands (2923.78 and 2854.07 cm⁻¹), with hydraulic press-extracted oils showing better stability in peak intensities at 45 °C compared to other methods at 55 °C (p < 0.05). While most fatty acids remained stable, polyunsaturated fatty acids showed temperature and extraction-dependent degradation. These findings highlight the critical role of extraction method selection and temperature control in preserving hemp seed oil quality, suggesting hydraulic pressing as the preferred commercial extraction method. Implementation of appropriate storage conditions and the potential incorporation of natural antioxidants could further enhance oil stability.
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Effect of Pd particle size on activity and cis-trans selectivity in partial hydrogenation of soybean oil-derived FAMEs over Pd/SiO2 catalysts
(2020-06-15)
Numwong, Natthida
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Prabnasak, Panisa
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Prayoonpunratn, Patsakol
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Triphatthanaphong, Pholawat
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Thunyaratchatanon, Chachchaya
Partial hydrogenation of soybean oil-derived fatty acid methyl esters (FAMEs) was performed to improve oxidative stability of biodiesel. The reaction was tested in a semi-batch reactor at 100 °C, 0.4 MPa. The effect of Pd particle size on activity and cis-trans selectivity was investigated over SiO<inf>2</inf>- and MCM-41-supported Pd catalysts, with different Pd loadings (0.5 and 1 wt.%). For Pd/SiO<inf>2</inf> catalysts with relatively large Pd particle sizes (6.1–7.8 nm), the adsorption of polyunsaturated C18:2 and C18:3 FAMEs was promoted on the flat metal surface, providing 2- to 3-fold higher turnover frequency (TOF) compared with Pd/MCM-41 catalysts. In contrast, the Pd/MCM-41 catalysts with relatively small Pd particle sizes (2.7–4.0 nm), showed higher selectivity towards the desired monounsaturated C18:1 FAMEs due to lower affinity of isolated double bond (presented in C18:1) on the Pd surface. In addition, selectivity towards the desired cis-C18:1 FAMEs was found to be highly sensitive to Pd particle size. The 0.5Pd/MCM-41 catalyst with small Pd particle size (2.7 nm), provided high cis-C18:1 selectivity, resulting in a biodiesel with better cold flow property compared with the trans-isomers. With partial hydrogenation over the prepared Pd catalysts, biodiesel with significantly improved oxidative stability (>10 h) could be obtained.
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Physicochemical properties and oxidative stability of oils from samrong (Sterculia foetida) seed
(2018-12-01)
Chanyawiwatkul, J.
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Supapavnich, S.
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Takeungwongtrakul, S.
Samrong seed kernel consisted of 5.91 ± 0.12% moisture, 2.80 ± 0.17% ash, 46.09 ±0.44% oil, 11.68 ±0.16% protein and 33.52 ±0.07% carbohydrate. The crude oil was extracted from samrong seed kernel using cold hexane as solvent. The oil from samrong seed kernel contained 27.32% saturated fatty acid (SFA), 5.30% monounsaturated fatty acid (MUFA) and 55.95% poly-unsaturated fatty acid (PUFA). Gamma-linolenic acid (47.80%) was the dominant fatty acid, followed by palmitic acid (16.49%) and steric acid (10.45%). The physicochemical properties including color, viscosity, tocopherol content, total phenolic content, acid value, free fatty acid, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and ρ-anisidine value of kernel oil were determined. When kernel oil was stored at 30°C for 48 days, the oxidative stability of kernel oil was also examined. The kernel oil had the increase in PV and TBARS within the first 36 days of storage (P < 0.05). Subsequently, a decrease in PV and TBARS were noticeable up to day 48 (P < 0.05). Oil from samrong seed kernel showed high quality and oxidative stability during storage. Thus, samrong seed kernel could be used as a potential source of edible oil for use in the food industrial.
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Influence of Mg modifier on cis-trans selectivity in partial hydrogenation of biodiesel using different metal types
(2016-06-25)
Thunyaratchatanon, Chachchaya
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Jitjamnong, Jakkapong
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Luengnaruemitchai, Apanee
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Numwong, Natthida
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Chollacoop, Nuwong
The catalytic performance of Pd, Pt, and Ni supported on catalysts was investigated for partial hydrogenation of soybean methyl esters, in terms of FAME composition and biodiesel properties, especially oxidative stability and cold flow properties. The effect of Mg modifier over SiO-supported catalysts on cis-trans selectivity of polyunsaturated FAMEs was also examined. The catalytic testing was performed under reaction conditions of 4 bar hydrogen pressure and 80-120 °C. Hydrogenation activity was presented by turnover frequency (TOF) of diunsaturated fatty acid (C18:2) within 4 h of the reaction time. The highest TOF was obtained over Pd catalysts, while the lowest TOF was obtained from Ni catalysts. At high reaction temperature conditions showed a large amount of cis-monounsaturated fatty acid (cis-C18:1); however, it exhibited a large amount of trans-monounsaturated fatty acid (trans-C18:1) which has a negative impact on biodiesel properties. The XPS revealed that the introduction of Mg leads to a strong metal-support interaction caused by electron transfer from the support to the metal, which decreased trans-C18:1 formation and presented the higher oxidative stability than the catalysts without Mg modifier.
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Effects of Ya-nang leaves (Tiliacora triandra) powder on properties and oxidative stability of tilapia emulsion sausage during storage
(2015-01-01)
Sriket, P.
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Sriket, C.
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Nalinanon, S.
Effect of Ya-nang leaves (Tiliacora triandra) powder (YLP) (0.5-2.0%) on qualities and lipid oxidation of tilapia emulsion sausages during 21 days of refrigerated storage was investigated. Control sample had lower fiber content than samples added with YLP (p<0.05) at day 0 of storage. YLP treated samples (1.0-2.0%) revealed lower L* value but higher b* and ΔE* values, compared to the control samples (p<0.05). With the addition of YLP, peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) value in the sausages were retarded effectively, compared to control sample (p<0.05), especially when the YLP at high contents were used. Addition of YLP were also effective in retarding the formation of fishy odor in the samples, compared to control sample (p<0.05). Samples treated with YLP had higher hardness and springiness, compared with control sample during storage (p<0.05). YLP had no detrimental effect on the sensory attributes of sausages. This study pointed out that YLP can be utilized in sausages to enhance quality.

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