scholarly journals Raman Spectroscopy Analysis of Free Fatty Acid in Olive Oil

2019 ◽  
Vol 9 (21) ◽  
pp. 4510
Author(s):  
Jin Qiu ◽  
Hua-Yi Hou ◽  
In-Sang Yang ◽  
Xiang-Bai Chen

Free fatty acid (FFA) is one of the most critical parameters for evaluating the quality of olive oil. In this paper, we present a simple and rapid Raman spectroscopy method for analyzing free fatty acid in olive oil. First, FFA degradation of carotenoids in olive oil is confirmed by analyzing the relative intensity of characteristic vibrational modes and introducing an intensity decrease factor. Second, it is demonstrated that the relative intensity ratio of the two characteristic vibrational modes at 1525 cm−1 and 1655 cm−1 presents a good and rapid analysis of FFA content in olive oil; the relative intensity ratio decreases linearly with FFA content. In addition, resonance Raman scattering of carotenoid is discussed, showing that a green laser should be utilized to study FFA in olive oil.


2018 ◽  
Vol 12 (3) ◽  
Author(s):  
E. Ghanbari Shend ◽  
D. Sivri Ozay ◽  
M . T. Ozkaya ◽  
N. F. Ustunelc

In this study Turkish monocultivar extra virgin olive oil (EVOO) “Sarı Ulak” was extracted by using the Mobile Olive Oil Processing Unit (TEM Oliomio 500-2GV, Italy). Changes in minor and major components and quality characteristics, free fatty acid content, peroxide value and UV absorbance value, were surveyed during a year’s storage period. “Sarı Ulak” olive oil samples were classified as EVOO according to the trade standards of the International Olive Council (IOC) based on free fatty acid, peroxide value, K232 and ΔK values up to the eighth month of the storage period. The results have shown that color values of EVOO changed from green to yellow slowly while UV absorbance values changed during storing. Total polyphenol content of extra virgin olive oil decreased from 205.17 ppm to 144.29 ppm during a year’s storage. Luteolin was the most abundant phenolic compound, and its concentration changed from 184.33 ppm to 115.06 ppm. Apigenin concentration was differed from 2.67 to 1.06 ppm during storing. The initial level of α-tocopherol contents was 184.51 ppm, it decreased to 147 ppm at the end of storage time. After 12 months of storing, about 20 % of α-tocopherol content was destroyed. The amounts of phenolic and tocopherol isomers decreased during storage as expected.



1995 ◽  
Vol 396 ◽  
Author(s):  
Seok-Keun Koh ◽  
Ki-Hwan Kim ◽  
Won-Kook Choi ◽  
Hong-Gui Jang ◽  
Young-Soo Yoon ◽  
...  

AbstractChanges of crystallinity and surface roughness are discussed in terms of the average energy per deposited atom in the partially ionized beam(PIB) deposition. The average energy per deposited atom can be controlled by adjusting the ionization potential, Vi and acceleration potential, Va. The ion beam consists of a Cu ion beam and residual gas ion beam and residual gases as well as Cu particles that were ionized and accelerated to provide the film with energy required for film-growth. The relative contribution of residual gas ions and Cu ions to total average energy per deposited atom was varied with the ionization potential. At fixed ionization potentials of Vi=400 V and Vi=450 V, the average energy per deposited atom was varied in the range of 0 to 120 eV with acceleration potential Va, of 0 to 4 kV. The relative intensity ratio, 1(111)/I(200), of the Cu films increased from 6 to 37 and the root mean square(Rms) surface roughness decreased with an increase in acceleration potential at Vi=400 V. The relative intensity ratio, I(lll)/I(200), of Cu films increased up to Va=2 kV at Vi=2 kV, above which a decrease occurred, and the surface roughness of Cu films increased as a funtion of acceleration potential. The degree of preferred orientation was closely related with the average energy per deposited atom. The change of Rms roughness might be affected by ion flux, particle energy and preferred orientation.



2019 ◽  
Vol 9 (14) ◽  
pp. 2807 ◽  
Author(s):  
Jin Qiu ◽  
Hua-Yi Hou ◽  
Nguyen Thi Huyen ◽  
In-Sang Yang ◽  
Xiang-Bai Chen

Raman spectroscopy has been applied to study unsaturated fatty acid in edible vegetable oils. The relative intensity ratio of characteristic vibrational bands has been investigated as a function of the content of totally unsaturated fatty acid, polyunsaturated fatty acid, and monounsaturated fatty acid. The results suggest the intensity ratio of 1655 cm−1 to 1440 cm−1 or 1265 cm−1 to 1300 cm−1, i.e., a characteristic vibrational band correlated with carbon-carbon double bond in acid chain to a vibrational band not correlated with double bond, could be applied for preliminary analysis of the content of polyunsaturated fatty acid or monounsaturated fatty acid, but cannot be used to analyze the content of total unsaturated fatty acid. Additionally, two-dimensional correlation spectroscopy (2DCOS) has been performed on the content dependent Raman spectra. The 2DCOS result is consistent with that by Raman spectroscopy.



2017 ◽  
Vol 2 (1) ◽  
pp. 56
Author(s):  
Edy Agustian Yazid

<p><em>Fermentation is one of the bioconversion processes to produce anaerobic microbes which are beneficial and can produce enzymes. One of the enzymes that can be produced is lipase. Mixed fruit fermentation is an effort to produce lipase that can be done simply. The purpose of this research is to know the activity of lipase enzyme from mixture of fermented avocado fruit (Persea americana), bananas (Musa paradisiaca) and snakefruit (Salacca zalacca). Lipase enzyme activity is tested by measuring of free fatty acid (FFA) content obtained from olive oil hydrolysis process by lipase enzyme. The results showed the highest activity obtained 17.425 U/ml and the percentage of FFA produced was 12.94%. The highest activity of lipase enzyme was obtained at 45<sup>0</sup>C and pH 6.5. From this research can be concluded that the fermentation of the mixture of avocado, bananas and snakefruit can produce lipase enzyme that has relatively high activity.</em></p><p> </p><strong>Keywords: </strong><em>Fermentation, Lipase, Enzyme Activity, Fruits</em>



2019 ◽  
Author(s):  
Lusi Marlina

IDENTIFIKASI KADAR ASAM LEMAK BEBAS PADA BERBAGAI JENISMINYAK GORENG NABATILusi Marlina1, Imam Ramdan21,2 Teknik Kimia – Politeknik TEDC BandungEmail : [email protected] minyak goreng untuk mengolah makanan sangat banyak dipergunakan oleh masyarakat.Minyak goreng berasal dari bahan baku seperti: kelapa, kelapa sawit, jagung, kedelai, buah zaitun, dan lainlain. Kandungan utama dari minyak goreng secara umum adalah asam lemak yang terdiri dari asam lemakjenuh (saturated fatty acids) misalnya: asam plamitat, asam stearat, dan asam lemak tak jenuh (unsaturatedfatty acids) misalnya: asam oleat (Omega 9) dan asam linoleat (Omega 6). Asam lemak bebas merupakanasam lemak yang tidak terikat sebagai trigliserida yang dapat terbentuk karena adanya reaksi hidrolisis didalam minyak. Asam lemak yang berlebihan di dalam tubuh dapat memicu terjadinya kanker karena bersifatkarsinogen. Penelitian ini bertujuan untuk mengidentifikasi kadar asam lemak bebas pada minyak gorengnabati, dengan menggunakan metode titrasi asam basa. Titrasi asam basa yaitu suatu analisis kuantitatifuntuk menetapkan kadar senyawa-senyawa yang bersifat asam, dengan menggunakan larutan basa sebagaistandar. Analisis fisika meliputi warna, aroma dan massa jenis, sedangkan analisa kimia berdasarkan kadarasam lemak bebas. Hasil dari penelitian diperoleh : kadar asam lemak bebas dari berbagai sampel minyaknabati yang terdiri dari: minyak jagung sebesar 0,22%, minyak sawit sebesar 0,16%, VCO sebesar 0,25%dan minyak zaitun sebesar 0,21%, sedangkan untuk massa jenis minyak yaitu: minyak jagung sebesar1,01gr/ml, minyak sawit sebesar 1,04gr/ml, VCO sebesar 0,97gr/ml, dan minyak zaitun sebesar 0,90gr/ml.Secara umum dapat disimpulkan bahwa minyak goreng nabati yang diteliti tidak melebihi standar SNI 3741-1995 yang ditetapkan sebesar 0,30%.Kata kunci: minyak goreng nabati, asam lemak bebas, hidrolisis, titrasi asam basa.AbstractThe use of cooking oil to proceed food is very common in daily cooking. Vegetable Cooking oil is made ofsubstance like: coconut, pal oil, corn, soybean, sunflower seeds, and others. The prominent content ofcooking oil commonly is fatty acid which consists of saturated fatty acids, as: plamitat acid, stearat acid; andunsaturated fatty acids as: oleat acid (Omega 9) and linoleat acid (Omega 6). Free fatty acid is untied fattyacid as triglyceride that can be formed as a result of hydrolysis reaction in cooking oil. The abundant fattyacid in body can cause cancer because it is carcinogenic. The purpose of the research is to identify free fattyacid levels in vegetable cooking oil, by using alkalimeter method. Alkalimeter is a quantitative analysis todetermine level of acid compounds, using standard alkali solution. Physical analysis includes, smell andweight, meanwhile chemical analysis based on free fatty acid levels. The result of the research is: free fattyacid levels of various vegetable cooking oil samples those are: corn oil about 0,22%, palm fruit oil about0,16%, VCO about 0,25%, and olive oil about 00,21%, whereas for the weights, those are: corn oil about0,01gr/ml, palm fruit oil about 0,04gr/ml, VCO about 0,97gr/ml, and olive oil about 0,90gr/ml. It can generallybe concluded that examined vegetable cooking oil still meet the standard of SNI 3741-1995 that is 0,30%.Keyword: vegetable cooking oil, saturated fatty acid, hydrolysis, alkalimeter.



2019 ◽  
Vol 11 (1) ◽  
pp. 52-58
Author(s):  
Esmael Ghanbari Shendi ◽  
Dilek Sivri Özay ◽  
Mücahit Taha Özkaya ◽  
Nim,eti Feyza Üstünel

Turkish olive cultivar known as “Halhalı” that is locally grown in Mardin (Derik) province, situated in the southeast Anatolia, was used for virgin olive oil (VOO) production. Halhalı olive was processed in the “Mobile Olive Oil Processing Unit” (TEM Oliomio 500-2GV, Italy) designed as the first mobile olive mill in Turkey. Some chemical and physical properties (colour, UV absorbance values, free fatty acid content, peroxide value, phenolic and tocopherol profiles) were determined and monitored during one year of storing in the dark at room temperature once in every three months. Results showed that up to the eighth month of storage, free fatty acid content, peroxide and UV-absorption values (K232 and K232 values) did not exceed the limits reported by International Olive Council (IOC) and olive oils were categorized as Extra Virgin Olive Oil (EVOO). Colour changed from green to yellow and UV absorbance values altered during storage. Total phenol and vitamin E (α- tocopherol) contents decreased by 18% and 16.38%, respectively. Luteolin and apigenin were the most abundant phenolics and their contents decreased up to 22% and 28% during storing, respectively.



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