AUCTORES
Globalize your Research
Research Article | DOI: https://doi.org/10.31579/2637-8914/117
1 Department of Chemical Engineering, University of Port Harcourt, Rivers State.
2 Department of Chemical Engineering, Delta State University of Science & Technology, Ozoro.
*Corresponding Author: Edeh Ifeanyichukwu, Department of Chemical Engineering, University of Port Harcourt, Rivers State.
Citation: Edeh Ifeanyichukwu and Okpo Samson Onoriode (2023), Determining the Physicochemical Properties of Lemongrass oil Extract for Suitability in Various Applications, J. Nutrition and Food Processing, 6(2); DOI:10.31579/2637-8914/117
Copyright: © 2023 Edeh Ifeanyichukwu. This 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.
Received: 27 January 2023 | Accepted: 14 March 2023 | Published: 27 March 2023
Keywords: lemongrass; physicochemical; properties; essential oil; extraction
Essential oil such as lemongrass oil is currently gaining traction globally probably due to the growing concern of the potentially hazardous effect of synthetic spices, gains in consuming organic products, and its medicinal, agricultural, and cosmetics values. For appropriate use of lemongrass oil and its suitability for the intended applications, there is a need to assess its physicochemical properties. In this work, the properties investigated included saponification, acid, free fatty acid, iodine, and peroxide values, respectively, refractive index, viscosity, density, and pH. These were determined mostly according to AOAC (2000). The results obtained were viscosity (211.5 pa.s), saponification value (165.49 mg KOH. g-1), iodine value (84.6 mg/100g of sample), peroxide value (14.2 meq/kg), pH (6.57), acid value (4.488 mg KOH/g), free fatty acid (1.244 % oleic acid), refractive index (1.442), density at 25oC (0.984 g/mL) and specific gravity (0.982). Most of these results are in agreement with prescribed standards, and deviations are attributed predominantly to the difference in the geographical location where the lemongrass was grown. Based on the results, the lemongrass oil is relatively of good quality and preservation status, and is suitable for applications in the food industry, agriculture, cosmetics, beverages and medicine, and bioenergy production.
Lemongrass (Cymbopogon citratus) is typically a tropical perennial plant that produces aromatic oil that is cultivated in tropical and subtropical areas including Africa, India, Malaysia, Sri Lanka, China, Cambodia, and Guatemala. Its aromatic oil is one of the most popular essential oils. These oils are commonly used traditionally for various applications such as food, agriculture, medicine, and cosmetics. Its applications vary in different countries, for instance in Ethiopia, lemongrass has been used as an additive, killing lice and mosquitoes, treatment of hypertension, abortifacient, bronchitis, cold, fever, malaria, hemorrhoids, and toothache (Letebo, 2018; Maryo, et., 2015). In Nigeria, lemongrass is reported to have been used for the treatment of fever, convulsion in children, throat inflammations, stomach upset, skin diseases, ears/eyes infections, pepper soup ingredient, curries, and as a local drink (Okpo and Edeh, 2022).
Based on the foregoing, there is a need to determine the physicochemical properties of lemongrass oil. Such properties include colour, odour, density, specific gravity, refractive index, optical rotation, acid value, iodine value, and saponification value influence indirectly the quality of both essential and fixed (Ibrar, et al., 2011). These properties determine the storage status and suitability of essential oils for various applications such as human consumption (Bamgboye and Adejumo, 2010; Parthiban, et al., 2011). The iodine value may be used to predict the potential of oil to rancid and to determine the level of deterioration of the oil due to enzymatic or chemical oxidation (Dawodu and Omole, 2000). The acid value helps to determine the quality, age, edibility, and suitability of oil for various industrial applications such as paint (Akubugwo, et al., 2008). This value measures the extent of the hydrolysis of the glycerides in the oil by enzymes such as lipase, and physical factors like light and heat (Demian, 1990). The saponification value indicates the average molecular mass of various fatty acids in the oil, and the lower the molecular weight of fatty acids, the lower the saponification value. The viscosity is a measure of the resistance to fluid motion and determines the rheological properties of the essential oils (Kimbonguila, et. al, 2010). The viscosity of vegetable oils increases with the chain length of the fatty acid constituents (Tovar, 2011). The density is used to determine the quality of essential oil and has a direct relationship with the composition of the essential oil (Florido et al., 2013). The refractive index (RI) is used for the identification of compounds, determination of their purity, and for analyzing the ratio of homogeneous binary mixtures of known components leading to ascertaining the quality of essential oils quickly and cheaply. The refractive index of vegetable oils has a relationship with the degree of saturation, as cis/trans double bonds, and can be transformed by the incident light used in the assay (Ospina, et. Al., 2016). The iodine value is the number of grams of iodine absorbed per 100 g of fat or oil and it measures the degree of unsaturation with a high value being indicative of a high degree of unsaturation, and the range for semi-drying of oil is 100-300 (Kagwachie and Anozie, 1995). This value helps to predict the drying properties of oils and suggests if the oil is suitable to be used as a drying agent in the manufacture of oil paints, varnishes, cosmetics, and as cocking oil manufacturing index (Akinhanmi et al., 2008; Adelaja, 2006). The iodine value indicates whether essential oils may rancid, and determines the level of oxidative deterioration of the oil due to enzymatic or chemical oxidation (Dawodu and Omole, 2000). Determining the fatty acid helps to ascertain the degree of degradation of the essential oil. The degradation leads to the production of FFA and increases the acidity of the oil (Tovar, 2011). The peroxide value indicates the extent of lipid oxidation with a high value showing high levels of oxidative rancidity of oil which means the absence or low level of antioxidants (Kyari, 2008).
2.1 Materials
Some amount of lemongrass leaves were freshly harvested at Ozoro, Delta State, Nigeria as indicated with the arrow in Figure 1. Shuniu GG-17 Soxhlet apparatus was used to carry out the essential oil extraction, and the reagents used were of analytical grade. Setra analytical weighing balance BL-410s was used to determine the weights of the materials.
2.2 Sample preparation
The freshly harvested lemongrass leaves were washed and dried for 8h in an oven to reduce their moisture content, and preserved in a sealed bag to prevent exposure to direct sunlight. The dried leaves were cut into 0.5cm which was the optimum particle size that gave the highest yield of essential oil in a previous experiment (Okpo and Edeh, 2022).
Figure 1:A map showing the location of Ozoro where the sample was collected
2.3 Experimental procedures
Extraction of lemongrass oil
The extraction of the lemongrass oil was conducted according to the method described by Okpo and Edeh (2022) using acetone as the organic solvent. 100g of the dried lemongrass leaves sample and 300 mL of acetone were used. The acetone was recovered in a rotary evaporator operated at a speed of 110 rpm, and the lemongrass oil extract was dried to a constant weight in an oven.
Determination of the physicochemical properties
Determining the physicochemical properties of the lemongrass oil extract makes it possible to ascertain its quality and hence, potential applications. The following properties were analysed saponification values (SV), acid value (number),
3.1 Determining the physicochemical properties of lemongrass oil
This was conducted to assess the potential applications of the lemongrass oil extract. The results obtained are presented in Table 1.
Density
The density and specific gravity of the lemongrass oil extract obtained at 25oC were 0.984g/mL and 0.982, respectively. The value of the density is greater than 0.908 and obtained by Tovar et al. (2011) for the distillate and residue streams, respectively at 120oC. The disparity may be attributed to difference in extraction methods, and the geographical location where the lemongrass was grown. The specific gravity of 0.982 is in agreement with the literature value which is less than one (Tovar, et al., 2011).
Viscosity
Properties such as viscosity help to assess the rheological behaviour of essential oil (Santos, 2005). Essentially, the viscosity of essential oil is high because of the presence of a long fatty chain structure. The viscosity of the lemongrass oil extract obtained at 25oC was 211.5 pa.s. Comparing this result with the highest range of 2.430 to 2.491 mPa.s obtained at 60 to 120oC from the residue stream of the short-path-distillation process of lemongrass essential oil recorded by Tovar, et al. (2011), showed that the viscosity of the lemongrass is low. The disparity may be due to the difference in temperature and geographical location where the lemongrass was grown.
pH
The pH obtained was 6.57 as against 5.6 recorded by Abera (2020) showing that the lemongrass oil extract is slightly acidic.
Refractive index
The refractive index obtained was 1.442 which is lower than 1.48900.0002, 1.4870 0.0002, 1.4883 0.0002 obtained by Mieso and Befa (2020) for Lomisar-I, WG-Lomisar-Java and WG-lomisar-UA (upper awash), respectively. The high refractive index shows that the lemongrass oil extract may have a high long fatty acid chain composition (Ibrar and Inyat-Ur-Rahman, 2012).
Iodine value
The iodine value obtained was 84.6 mg/100g of sample and compared to 100-300 mg/100g of sample prescribed for semi-drying of oil (Kagwachie and Anozie, 1995). The value is out of the prescribed range and this shows that the lemongrass oil extract has a low degree of unsaturation.
Acid value
The acid value obtained was 4.488 mg KOH/g and it is slightly above 4.09 mg KOH/g and 4.35 mg KOH/g reported by Mustapha (2018) and Dutta et al., (2014). Although, this value is within the specification of 30 prescribed by the FAO (2015).
Table 1: Physicochemical properties of the lemongrass oil
The difference may be attributed to the geographical location where the lemongrass was grown and the method of extraction (Dao, et al., 2020). Acid value impacts the storage quality of oil, with a higher value indicating lower storage quality (Abera, 2020). Thus, an acid value of 4.888 mg KOH/g obtained in this work, shows that the quality of the lemongrass oil extract will not deteriorate significantly upon storage. Since the acid value is lower than the 10 acceptable limits for edible oil, the lemongrass oil extract can be used in food manufacturing industries as an additive (Sampson, 2005). Saponification value
The saponification value obtained was 165.49 KOH/g as shown in Table 1. This result is higher than 140.25 mg KOH/g and 144.16 reported by Abera (2020) and Dutta et al. (2014), respectively. The disparity could be due to environmental factors or the method of drying Abera (2020). Although the saponification values are out of the range 189-199 prescribed by the FAO (2015), lemongrass has a potential for application in the cosmetic industry for soap and bioenergy production, as the higher saponification values are an indication of high oil content (Dutta et al., 2014; Haque, 2018).
Free fatty acid
Free fatty acid helps to determine the extent of degradation of essential oil. The free fatty acid obtained as shown in Table 1 was 2.244 % of oleic acid. The value is less than 2.36 - 3.50 wt % of oleic acid obtained by Tovar, et al. (2011) in the residue stream, but greater than 0.5 prescribed by the FAO (2015). The result shows that the lemongrass oil extract is of better quality compared to that obtained by Tovar, et al. (2011), but may not be suitable for consumption, as the value is greater than 2.0% required for human consumption (ANVISA, 1999). The high FFA is an indication that the essential oil extract is degrading increasingly and there is losses in its composition. The lemongrass oil extract, although has the potential of being used for bioenergy production may face the challenge of saponification reaction resulting in soaps formation, especially if used for biodiesel production (see Figure 2). The soap may cause more catalysts to be consumed, lower catalyst efficiency, and increase the viscosity of the biodiesel mixture. This gives rise to a low yield of biodiesel, especially if an alkali catalyst is used and difficulty in purification (Saraf, 2007).
Figure 2:Saponification from FF
Peroxide value
The peroxide value of lemongrass oil obtained was 14.2 meq/kg and this result is higher than less than 10 meq/kg required for fresh oil. The high value shows that the oil extract has high oxidative rancidity and low level of antioxidants (Kyari, 2008).
The physicochemical properties of lemongrass oil extract have been assessed. The acid and saponification values of 4.488 mg KOH/g and 165.49 mg KOH.g-1, respectively demonstrate that the oil can be used in the manufacture of cosmetics. The good acid value suggests that the lemongrass oil extract may be used as a food additive. Although the value of the free fatty acid is greater than 0.5, the lemongrass oil can be used for the production of bioenergy such as biodiesel and renewable diesel, preferably using acidic catalysts. These bioenergies can also be effectively produced due to the high free fatty acid with two-stage processes involving esterification before transesterification using acidic and alkaline catalysts, respectively. The pH of 6.57 shows that lemongrass is slightly acidic and can be used for human consumption as it is projected to have some health benefits. The peroxide value of slightly greater than 10 meq/kg showed that the lemongrass oil extract is relatively of good quality and storage status.
Clearly Auctoresonline and particularly Psychology and Mental Health Care Journal is dedicated to improving health care services for individuals and populations. The editorial boards' ability to efficiently recognize and share the global importance of health literacy with a variety of stakeholders. Auctoresonline publishing platform can be used to facilitate of optimal client-based services and should be added to health care professionals' repertoire of evidence-based health care resources.
Journal of Clinical Cardiology and Cardiovascular Intervention The submission and review process was adequate. However I think that the publication total value should have been enlightened in early fases. Thank you for all.
Journal of Women Health Care and Issues By the present mail, I want to say thank to you and tour colleagues for facilitating my published article. Specially thank you for the peer review process, support from the editorial office. I appreciate positively the quality of your journal.
Journal of Clinical Research and Reports I would be very delighted to submit my testimonial regarding the reviewer board and the editorial office. The reviewer board were accurate and helpful regarding any modifications for my manuscript. And the editorial office were very helpful and supportive in contacting and monitoring with any update and offering help. It was my pleasure to contribute with your promising Journal and I am looking forward for more collaboration.
We would like to thank the Journal of Thoracic Disease and Cardiothoracic Surgery because of the services they provided us for our articles. The peer-review process was done in a very excellent time manner, and the opinions of the reviewers helped us to improve our manuscript further. The editorial office had an outstanding correspondence with us and guided us in many ways. During a hard time of the pandemic that is affecting every one of us tremendously, the editorial office helped us make everything easier for publishing scientific work. Hope for a more scientific relationship with your Journal.
The peer-review process which consisted high quality queries on the paper. I did answer six reviewers’ questions and comments before the paper was accepted. The support from the editorial office is excellent.
Journal of Neuroscience and Neurological Surgery. I had the experience of publishing a research article recently. The whole process was simple from submission to publication. The reviewers made specific and valuable recommendations and corrections that improved the quality of my publication. I strongly recommend this Journal.
Dr. Katarzyna Byczkowska My testimonial covering: "The peer review process is quick and effective. The support from the editorial office is very professional and friendly. Quality of the Clinical Cardiology and Cardiovascular Interventions is scientific and publishes ground-breaking research on cardiology that is useful for other professionals in the field.
Thank you most sincerely, with regard to the support you have given in relation to the reviewing process and the processing of my article entitled "Large Cell Neuroendocrine Carcinoma of The Prostate Gland: A Review and Update" for publication in your esteemed Journal, Journal of Cancer Research and Cellular Therapeutics". The editorial team has been very supportive.
Testimony of Journal of Clinical Otorhinolaryngology: work with your Reviews has been a educational and constructive experience. The editorial office were very helpful and supportive. It was a pleasure to contribute to your Journal.
Dr. Bernard Terkimbi Utoo, I am happy to publish my scientific work in Journal of Women Health Care and Issues (JWHCI). The manuscript submission was seamless and peer review process was top notch. I was amazed that 4 reviewers worked on the manuscript which made it a highly technical, standard and excellent quality paper. I appreciate the format and consideration for the APC as well as the speed of publication. It is my pleasure to continue with this scientific relationship with the esteem JWHCI.
This is an acknowledgment for peer reviewers, editorial board of Journal of Clinical Research and Reports. They show a lot of consideration for us as publishers for our research article “Evaluation of the different factors associated with side effects of COVID-19 vaccination on medical students, Mutah university, Al-Karak, Jordan”, in a very professional and easy way. This journal is one of outstanding medical journal.
Dear Hao Jiang, to Journal of Nutrition and Food Processing We greatly appreciate the efficient, professional and rapid processing of our paper by your team. If there is anything else we should do, please do not hesitate to let us know. On behalf of my co-authors, we would like to express our great appreciation to editor and reviewers.
As an author who has recently published in the journal "Brain and Neurological Disorders". I am delighted to provide a testimonial on the peer review process, editorial office support, and the overall quality of the journal. The peer review process at Brain and Neurological Disorders is rigorous and meticulous, ensuring that only high-quality, evidence-based research is published. The reviewers are experts in their fields, and their comments and suggestions were constructive and helped improve the quality of my manuscript. The review process was timely and efficient, with clear communication from the editorial office at each stage. The support from the editorial office was exceptional throughout the entire process. The editorial staff was responsive, professional, and always willing to help. They provided valuable guidance on formatting, structure, and ethical considerations, making the submission process seamless. Moreover, they kept me informed about the status of my manuscript and provided timely updates, which made the process less stressful. The journal Brain and Neurological Disorders is of the highest quality, with a strong focus on publishing cutting-edge research in the field of neurology. The articles published in this journal are well-researched, rigorously peer-reviewed, and written by experts in the field. The journal maintains high standards, ensuring that readers are provided with the most up-to-date and reliable information on brain and neurological disorders. In conclusion, I had a wonderful experience publishing in Brain and Neurological Disorders. The peer review process was thorough, the editorial office provided exceptional support, and the journal's quality is second to none. I would highly recommend this journal to any researcher working in the field of neurology and brain disorders.
Dear Agrippa Hilda, Journal of Neuroscience and Neurological Surgery, Editorial Coordinator, I trust this message finds you well. I want to extend my appreciation for considering my article for publication in your esteemed journal. I am pleased to provide a testimonial regarding the peer review process and the support received from your editorial office. The peer review process for my paper was carried out in a highly professional and thorough manner. The feedback and comments provided by the authors were constructive and very useful in improving the quality of the manuscript. This rigorous assessment process undoubtedly contributes to the high standards maintained by your journal.
International Journal of Clinical Case Reports and Reviews. I strongly recommend to consider submitting your work to this high-quality journal. The support and availability of the Editorial staff is outstanding and the review process was both efficient and rigorous.
Thank you very much for publishing my Research Article titled “Comparing Treatment Outcome Of Allergic Rhinitis Patients After Using Fluticasone Nasal Spray And Nasal Douching" in the Journal of Clinical Otorhinolaryngology. As Medical Professionals we are immensely benefited from study of various informative Articles and Papers published in this high quality Journal. I look forward to enriching my knowledge by regular study of the Journal and contribute my future work in the field of ENT through the Journal for use by the medical fraternity. The support from the Editorial office was excellent and very prompt. I also welcome the comments received from the readers of my Research Article.
Dear Erica Kelsey, Editorial Coordinator of Cancer Research and Cellular Therapeutics Our team is very satisfied with the processing of our paper by your journal. That was fast, efficient, rigorous, but without unnecessary complications. We appreciated the very short time between the submission of the paper and its publication on line on your site.
I am very glad to say that the peer review process is very successful and fast and support from the Editorial Office. Therefore, I would like to continue our scientific relationship for a long time. And I especially thank you for your kindly attention towards my article. Have a good day!
"We recently published an article entitled “Influence of beta-Cyclodextrins upon the Degradation of Carbofuran Derivatives under Alkaline Conditions" in the Journal of “Pesticides and Biofertilizers” to show that the cyclodextrins protect the carbamates increasing their half-life time in the presence of basic conditions This will be very helpful to understand carbofuran behaviour in the analytical, agro-environmental and food areas. We greatly appreciated the interaction with the editor and the editorial team; we were particularly well accompanied during the course of the revision process, since all various steps towards publication were short and without delay".
I would like to express my gratitude towards you process of article review and submission. I found this to be very fair and expedient. Your follow up has been excellent. I have many publications in national and international journal and your process has been one of the best so far. Keep up the great work.
We are grateful for this opportunity to provide a glowing recommendation to the Journal of Psychiatry and Psychotherapy. We found that the editorial team were very supportive, helpful, kept us abreast of timelines and over all very professional in nature. The peer review process was rigorous, efficient and constructive that really enhanced our article submission. The experience with this journal remains one of our best ever and we look forward to providing future submissions in the near future.
I am very pleased to serve as EBM of the journal, I hope many years of my experience in stem cells can help the journal from one way or another. As we know, stem cells hold great potential for regenerative medicine, which are mostly used to promote the repair response of diseased, dysfunctional or injured tissue using stem cells or their derivatives. I think Stem Cell Research and Therapeutics International is a great platform to publish and share the understanding towards the biology and translational or clinical application of stem cells.
I would like to give my testimony in the support I have got by the peer review process and to support the editorial office where they were of asset to support young author like me to be encouraged to publish their work in your respected journal and globalize and share knowledge across the globe. I really give my great gratitude to your journal and the peer review including the editorial office.
I am delighted to publish our manuscript entitled "A Perspective on Cocaine Induced Stroke - Its Mechanisms and Management" in the Journal of Neuroscience and Neurological Surgery. The peer review process, support from the editorial office, and quality of the journal are excellent. The manuscripts published are of high quality and of excellent scientific value. I recommend this journal very much to colleagues.
Dr.Tania Muñoz, My experience as researcher and author of a review article in The Journal Clinical Cardiology and Interventions has been very enriching and stimulating. The editorial team is excellent, performs its work with absolute responsibility and delivery. They are proactive, dynamic and receptive to all proposals. Supporting at all times the vast universe of authors who choose them as an option for publication. The team of review specialists, members of the editorial board, are brilliant professionals, with remarkable performance in medical research and scientific methodology. Together they form a frontline team that consolidates the JCCI as a magnificent option for the publication and review of high-level medical articles and broad collective interest. I am honored to be able to share my review article and open to receive all your comments.
“The peer review process of JPMHC is quick and effective. Authors are benefited by good and professional reviewers with huge experience in the field of psychology and mental health. The support from the editorial office is very professional. People to contact to are friendly and happy to help and assist any query authors might have. Quality of the Journal is scientific and publishes ground-breaking research on mental health that is useful for other professionals in the field”.
Dear editorial department: On behalf of our team, I hereby certify the reliability and superiority of the International Journal of Clinical Case Reports and Reviews in the peer review process, editorial support, and journal quality. Firstly, the peer review process of the International Journal of Clinical Case Reports and Reviews is rigorous, fair, transparent, fast, and of high quality. The editorial department invites experts from relevant fields as anonymous reviewers to review all submitted manuscripts. These experts have rich academic backgrounds and experience, and can accurately evaluate the academic quality, originality, and suitability of manuscripts. The editorial department is committed to ensuring the rigor of the peer review process, while also making every effort to ensure a fast review cycle to meet the needs of authors and the academic community. Secondly, the editorial team of the International Journal of Clinical Case Reports and Reviews is composed of a group of senior scholars and professionals with rich experience and professional knowledge in related fields. The editorial department is committed to assisting authors in improving their manuscripts, ensuring their academic accuracy, clarity, and completeness. Editors actively collaborate with authors, providing useful suggestions and feedback to promote the improvement and development of the manuscript. We believe that the support of the editorial department is one of the key factors in ensuring the quality of the journal. Finally, the International Journal of Clinical Case Reports and Reviews is renowned for its high- quality articles and strict academic standards. The editorial department is committed to publishing innovative and academically valuable research results to promote the development and progress of related fields. The International Journal of Clinical Case Reports and Reviews is reasonably priced and ensures excellent service and quality ratio, allowing authors to obtain high-level academic publishing opportunities in an affordable manner. I hereby solemnly declare that the International Journal of Clinical Case Reports and Reviews has a high level of credibility and superiority in terms of peer review process, editorial support, reasonable fees, and journal quality. Sincerely, Rui Tao.
Clinical Cardiology and Cardiovascular Interventions I testity the covering of the peer review process, support from the editorial office, and quality of the journal.
