scholarly journals Effects of thermal treatment on the characteristics quality of some Ghanaian vegetable oils (palm, coconut and groundnut)

Author(s):  
Robert A Ngala ◽  
Evans Owusu Ameyaw ◽  
Dorice Berkoh ◽  
John Barimah ◽  
Simon Koffie

Abstract Introduction: Vegetable oils contain natural antioxidants and other properties reported to impart anti-diabetic properties when consumed, in animal study. In humans however, these oils are subjected to high temperatures during cooking before consumption. High temperature tends to affect the characteristic quality and potential to impart on health benefits such as antidiabetic properties. The objective of this work was to determine the characteristics quality of vegetable oils after thermal treatment that equates to temperatures oils are subjected to during food processing/cooking.Methodology: Three portions of 200g of each fresh unrefined red palm oil, coconut oil and groundnut oils in three conical flasks T1, T2 and T3 were heated to room temperature 28oC (T1) to 100o C in boiling water (T2) and to 200o C in electric cooker oven (T3) for 10 minutes. Acid, iodine, peroxide, saponification, unsaponification values of the oils, Phytoconstituents (Flavanoids, polyphenols saponins etc) and antioxidant (Vitamin A&C) and DPPH (1,1-Diphenyl-2-Picrylhydrazyl) Radical Scavenging Activity were then determined after cooling to room temperature. Results: Coconut oil heated to 200˚C had the least Acid value of 2.89±0.135 whiles Palm oil heated to 100 ˚C had the highest value of 19.57±0.165. There were no peroxides formed in Coconut and Palm oils at 28 ˚C as well as Palm oil at 100 ˚C. However, peroxides were highest in Coconut oil at 200˚C with value of 15.28±2.315. Saponification value of groundnut oil at 28 ˚C was the least at 89.52 ± 2.18 and 296.57±1.045 the highest in coconut oil at 200 ˚C. Heating however increased the unsaponifiable matter in all the vegetable oils used. Total antioxidant capacity was not significantly changed across the temperature treatment. Total phenolic content was not significantly changed for palm oil but was significantly increased at 100C for coconut and groundnut oilsConclusion: The quality of the oils in terms of acid value, iodine vale, peroxide value and saponification value, total antioxidant and phenolic content were retained after one heat treatment. This implies the quality of the oils are maintained after a single heating. The oils may still retain antidiabetic property when consumed after processing.

2021 ◽  
Author(s):  
Evans Owusu ◽  
Dorice A Berkoh ◽  
Simone Koffie ◽  
John Barimah ◽  
Robert A Ngala

Abstract Introduction: Vegetable oils contain natural antioxidants and other properties reported to impart anti-diabetic properties when consumed, in animal study. In humans however, these oils are subjected to high temperatures during cooking before consumption. High temperature tends to affect the characteristic quality and potential to impart on health benefits such as antidiabetic properties. The objective of this work was to determine the characteristics quality of vegetable oils after thermal treatment that equates to temperatures oils are subjected to during food processing/cooking. Methodology: Three portions of 200g of each fresh unrefined red palm oil, coconut oil and groundnut oils in three conical flasks T1, T2 and T3 were heated to room temperature 28oC (T1) to 100o C in boiling water (T2) and to 200o C in electric cooker oven (T3) for 10 minutes. Acid, iodine, peroxide, saponification, unsaponification values of the oils were then determined after cooling to room temperature. Results; Coconut oil heated to 200˚C had the least Acid value of 2.89±0.135 whiles Palm oil heated to 100 ˚C had the highest value of 19.57±0.165. There were no peroxides formed in Coconut and Palm oils at 28 ˚C as well as Palm oil at 100 ˚C. However, peroxides were highest in Coconut oil at 200˚C with value of 15.28±2.315. Saponification value of groundnut oil at 28 ˚C was the least at 89.52 ± 2.18 and 296.57±1.045 the highest in coconut oil at 200 ˚C. Heating however increased the unsaponifiable matter in all the vegetable oils used.Conclusion: The quality of the oils in terms of acid value, iodine vale, peroxide value and saponification value were retained after one heat treatment. This implies the quality of the oils are maintained during food processing.


EKUILIBIUM ◽  
2014 ◽  
Vol 13 (2) ◽  
Author(s):  
Endah Retno Dyartanti

<p>Abstract: Transparent soap is a opaque one having clear structure. This soap has high<br />transparency level. Transparent soap is produced by saponification of oil or fat with NaOH<br />solution at 60-70<br />C. This research aims study the effect of composition of coconut oil and palm<br />oil (100:0; 90:10; 80:20; 70:30; 60:40 g/g) mixture on the quality of transparent soap. The free<br />fatty acid (FFA) level of coconut oil was 0.8% and that of palm oil was 1.07%. In this work, there<br />were 3 processes separately, namely saponification reaction, transparent structure forming, and<br />curing. Saponification reaction was done by reacting stearic acid in fatty acid phase and NaOH<br />at 60-70<br />o<br />o<br />C. Stearic acid was melted with heating until melted and some oil was added. After<br />obtaining homogeneous mixture between stearic acid an oil, then NaOH 30% solution was<br />added. The forming of transparent structure was conducted by adding propylene, glycol,<br />glycerin, sugar solution and ethanol 70% into saponification product. To produce soap color and<br />aroma, the colorant and fragrance were added. Then, the soap was casted and cured for 24<br />hours by storing it at room temperature. The result of transparent soap analysis for coconut oil<br />compositions of 100%, 90%, 80%, 70%, and 60%, it was obtained that the water level were<br />18.36%, 18.24%, 18.66%, 18.66%, and 18.56%, respectively. The free alkali contained in<br />transparent soaps were 0.078%, 0.078%, 0.0796%, 0.0804%, and 0.0796%. The yields were<br />62.78%, 62.25%, 62.49%, 60.88%, 59.79%, and the pH of transparent soap was 9. The best<br />composition of coconut oil and palm oil mixture was 90:10 while the ratio of coconut oil and<br />palm oil mixture composition resulting the highest yield was 100:0.<br />Keywords: Transparent soap, Saponification, Coconut oil, Palm oil</p>


2020 ◽  
Vol 55 (4) ◽  
pp. 301-310
Author(s):  
MSH Khan ◽  
KMYK Sikdar ◽  
N Saqueeb ◽  
MH Hossain ◽  
F Ahmed ◽  
...  

Palm oil is an edible vegetable oil, extracted from the fruit of the Elaeis guineensis which is used for frying foods in most of the restaurants and confectionaries as well as for cosmetic preparations in industries. As the quality of palm oil in Bangladesh is deteriorating day by day, ten brands (S-1 to S-10) of commercially available palm oils were collected from different local markets, their physicochemical properties were tested and compared with the standard parameters stated by Bangladesh Standards and Testing Institution (BSTI). Results revealed that the acid value, free fatty acid value and relative density of all the palm oils (S-1 to S-10) were within the range of BSTI standard. However, the saponification value, peroxide value, iodine value, insoluble impurities and moisture content were much higher than the ranges of BSTI standard in all the samples. Moreover, lead content was higher than the standard value (>0.1 ppm) in brands S-1, S-4 and S-10. In addition, Copper and Iron contents were higher than the BSTI standards (0.1 and 1.5 ppm) in all the tested samples, whereas Cadmium content was below than the standard level (1.0 ppm). Bangladesh J. Sci. Ind. Res.55(4), 301-310, 2020


Author(s):  
G. V. Pavan Kumar ◽  
N. V. V. S. S. Lakshmi ◽  
Ch. Deena ◽  
V. Chandra Sekhar ◽  
N. Mehar Nikhitha ◽  
...  

Aim: The study sought to assess the quality of coconut oil extracted from fresh copra milk by Traditional fermentation(FWCE) and from dry copra balls by continuous processing using expellers(TDCE,DMCE) method with respect to moisture content (MC), free fatty acid (FFA) content, Acid value (AV) and Saponification value in comparison with Food safety and standards authority of India. Methodology: Three samples of coconut oil were taken from major processing centers in east Godavari district (AMP, SML, KRG) for quality determination. Similarly three samples of coconut oil were prepared from fresh grated coconut milk in the Medicinal chemistry laboratory at Korangi College of pharmacy and three samples were prepared from dry coconut cups. Replicate titer values of each of the nine (09) oil samples obtained were compared with brand double refined oil and the averages were taken into consideration. The AOAC and AOCS methods were used in the analyses and the results compared with Standards provided by Food safety and standards authority of India, Coconut Development Board, Kochi. Results: The results showed that 50% of the total fermented oil sample had high moisture content than standard and expected to undergo oxidative rancidity. According to the standards, 100% of the oil samples had free fatty acids and acid value within acceptable range indicating no signs of rancidity. Conclusion: There was a significant difference in saponification value, free fatty acid profile and moisture content of Traditional fermented (FWCE) and dry copra balls by continuous processing expellers (TDCE, DMCE) method. The ANOVA (P<0.05) showed that there were significant differences in the MC, FFA, AV of oils produced among the processing centers and that produced in laboratory. The processes involved in all the extraction centers vary and might have accounted for that. The results indicate that the coconut oils produced in both the cases meet the standards however new technologies in processing should be adopted to improve the quality to meet the standards.


2019 ◽  
Author(s):  
Chem Int

The physicochemical properties of six imported and one locally produced edible vegetable oils (soybean oil, sunflower oil, sunlit oil, hayat oil, avena oil, USA vegetable oil and Niger oil) purchased from Bahir Dar city, Ethiopia, were examined for their compositional quality. All the oil samples were characterized for specific gravity, moisture content, color, relative viscosity, refractive indices, ash content, peroxide value, saponification value, smoke point, acid value, free fatty acid value and trace metals contents using established methods. The result clearly indicates that some of the oil samples exhibited unacceptable value when compared with physicochemical parameters recommended by the Codex Alimentations Commission of FAO/WHO and the specification of Ethiopian standards. The contents of nickel (Ni), copper (Cu) and iron (Fe) in seven samples were determined using ICP-OES and their concentrations were found in the range of 1.8-20.4, 45.8-82.2 and 136.04-445.0 mg/kg, respectively.


Author(s):  
Pankaj Kumar Kannaujia ◽  
Sakharam Kale ◽  
Ajinath Dukare ◽  
Vijay Singh Meena ◽  
Prerna Nath ◽  
...  

Background: Present study, aimed to assess effect of organic and inorganic crop mulching on physical, physiological and biochemical quality of fresh cowpea beans.Methods: Cowpea (cv. Kashi Kanchan bush-type) was grown during two consecutive seasons from April 2018 to July 2019 under four different mulching treatments. Mulching treatments included no mulch; wheat straw mulch (organic mulch); black mulch and silver mulch. Black and silver mulches were made of 25 microns LDPE sheet. Cowpea was grown as per standard agronomic practices and physical, biochemical and postharvest quality parameters of beans were evaluated.Result: Results indicated that bean length (28.7cm) was highest under silver mulch whereas bean thickness (9.10mm), width (9.29mm) and 100 bean weight (1094.5g) were highest under organic mulch. Likewise, protein content (28.63%), total phenolic content (17.0µg GAE/100g) and total antioxidant activity (46.84µmol trolox equiv./100g) were found highest in beans produced under organic mulch. Overall results demonstrated that crop mulching could be used for enhancing the antioxidants, phenolic content of cowpea beans.


2018 ◽  
Vol 4 ◽  
pp. 40-50 ◽  
Author(s):  
Enyoh Christian Ebere ◽  
Verla Andrew Wirnkor ◽  
Enyoh Emmanuel Chinedu ◽  
Verla Evelyn Ngozi

Over 70 % inhabitants of Imo state pend on palm oil for their cooking, frying etc. The study reviews available data on palm oil quality produced locally in Imo state with a view of providing up-to-date information and identify research gaps that could have health consequences on consumers. Peer reviewed scientific articles were reviewed and a meta-analysis of four different scientific research databases, PubMed, Web of Science, Google Scholar and Directory for Open-Access Journals was conducted. The result showed that palm oil produced locally in Imo state has average of pH (4.73), acid value (28.3 mg/KOH), FFA (14.15 mg/KOH), smoke point (115°C), iodine value (1.68 wijj’s), saponification value (197.07 mgKOH/g), ester value (168.77), moisture content (0.44 %), density (0.89 g/ml), SG (0.91), peroxide value (17.75 mEq./kg), refractive index (1.46oBx) and viscocity (60.04 cps). Overall palm oil is highly degraded and of poor quality since major quality indicators are not within Nigerian Industrial Standard and Standard Organization of Nigeria. Also, there is a dearth of information/data available on quality of palm oil produced locally in Imo state especially on its microbial status. Food scientist should look in that direction to enhance proper understanding of the quality of palm oil.


Jurnal Kimia ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 117
Author(s):  
N. M. Suaniti ◽  
M. Manurung ◽  
O. Ratnayani ◽  
A.A. I.S.J. Dewi

Spoilage of coconut oil is indicated by rancidity caused by the oxidation and hydrolysis reactions. One of the efforts that can be carried out to inhibit the rancidity is by adding a natural antioxidant, such as carrot (Daucus carrota L) powder, into the coconut oil. This research aimed to find out the effect of the addition of carrot powder into the coconut oil on some parameters namely iodine number, peroxide number, FFA level, acid value and water content. The coconut oil was prepared by heating technique followed by the addition of carrot powder in the ratio of coconut oil:carrot of 100:1, 100:2, 100:3, 100:4, 100:5, and coconut oil:BHT (Butyl Hydroxy Toluene) of 100:1 as the positive control. The results were then compared to the Indonesian National Standard of SNI 01-2902-1992. It was found that the coconut oil added with carrot powder in the ratio of 100:4 showed the best quality with iodine number of 8.4092 ± 0.5761g iodine/100g, peroxide number of 3.2363 ± 1.9168mg O2/100g, Free Fatty Acid level (FFA) of 0.1676 ± 0.0037 %, acid value of 0.4656 ± 0.0119mg KOH/g and water content of 0.1038 ± 0.0068 %. The characterization using FTIR (Fourier-transform infrared spectroscopy) of such quality of coconut oil indicated some functional groups of OH, CH, CH3, C=O, CºC aliphatic and C=C aliphatic were contained.


Buletin Palma ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
STEIVIE KAROUW ◽  
CHANDRA INDRAWANTO

<p>Abstrak</p><p>Proses penggorengan akan menyebabkan perubahan mutu minyak akibat reaksi hidrolisis, oksidasi dan proses termal. Penelitian ini bertujuan untuk mengetahui perubahan mutu  minyak kelapa dan minyak sawit selama penggorengan. Minyak kelapa dan minyak sawit masing-masing digunakan untuk menggoreng kentang pada suhu 170°C selama 15 menit. Minyak tersebut digunakan untuk 3 kali penggorengan. Pada akhir penggorengan dilakukan pengambilan sampel minyak untuk dievaluasi kadar air, kadar asam lemak bebas, bilangan peroksida dan bilangan TBA (Tiobarbituric acid). Hasil penelitian menunjukkan bahwa sebelum penggorengan minyak kelapa dan minyak sawit memiliki kadar air yang hampir sama, tetapi kadar asam lemak bebas, angka peroksida dan TBA minyak kelapa lebih rendah dibanding minyak sawit. Selama penggorengan minyak kelapa dan minyak sawit menunjukkan pola perubahan kadar air yang hampir sama. Pada 1 kali dan 2 kali penggorengan kadar asam lemak bebas, angka peroksida dan angka TBA minyak kelapa dan minyak sawit cenderung berfluktuasi. Pada 3 kali penggorengan minyak kelapa memiliki kadar asam lemak bebas,  angka  peroksida  dan  angka  TBA  yang  lebih  rendah  dibandingkan  minyak  sawit.  Hasil  yang  diperoleh menunjukkan   bahwa   minyak   kelapa  lebih   stabil   terhadap   reaksi   oksidasi   dibanding   minyak   sawit   selama penggorengan.</p><p> </p><p>Pattern of Coconut Oil and Palm Oil Quality During Frying</p><p>ABSTRACT</p><p> </p><p>Frying was a process which affected the quality of oil due to hydrolysis, oxidation and thermal reactions. The aim of the research was to study the quality pattern of coconut oil and palm oil quality during frying. The oils were utilized to fry french fries at 170°C for 15 minutes and then used in frying process for 3 times. Samples of oil were taken at the end of each frying period and analyzed for its moisture, free fatty acid, peroxide and TBA (tiobarbituric acid) values. The results showed that, coconut oil and palm oil having similary moisture content before and during frying. Otherwise free fatty acid, peroxide and TBA values at coconut oil lower then palm oil. During 1 and 2 times of frying period these two oils showed fluctuation in free fatty acid, peroxide and TBA values. During 3 times of frying, coconut oil contained free fatty acid, peroxide and TBA value lower than palm oi. Thus, we consider that coconut oil was more stable to oxidation compared to palm oil during frying</p>


2018 ◽  
Vol 10 (37) ◽  
pp. 4535-4542 ◽  
Author(s):  
Rafaela Silva Lamarca ◽  
Renato Camargo Matos ◽  
Maria Auxiliadora Costa Matos

The concentration of phenolic acids in vegetable oils is an important criterion for the assessment of the quality of oils with regard to their freshness, the maintenance of their properties, their storage and their influence on human nutrition and health.


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