scholarly journals Fluorescence Spectroscopy Applied to Monitoring Biodiesel Degradation: Correlation with Acid Value and UV Absorption Analyses

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Maydla dos Santos Vasconcelos ◽  
Wilson Espíndola Passos ◽  
Caroline Honaiser Lescanos ◽  
Ivan Pires de Oliveira ◽  
Magno Aparecido Gonçalves Trindade ◽  
...  

The techniques used to monitor the quality of the biodiesel are intensely discussed in the literature, partly because of the different oil sources and their intrinsic physicochemical characteristics. This study aimed to monitor the thermal degradation of the fatty acid methyl esters of Sesamum indicum L. and Raphanus sativus L. biodiesels (SILB and RSLB, resp.). The results showed that both biodiesels present a high content of unsaturated fatty acids, ∼84% (SILB) and ∼90% (RSLB). The SILB had a high content of polyunsaturated linoleic fatty acid (18  :  2), about 49%, and the oleic monounsaturated (18  :  1), ∼34%. On the other hand, RSLB presented a considerable content of linolenic fatty acid (18  :  3), ∼11%. The biodiesel samples were thermal degraded at 110°C for 48 hours, and acid value, UV absorption, and fluorescence spectroscopy analysis were carried out. The results revealed that both absorption and fluorescence presented a correlation with acid value as a function of degradation time by monitoring absorptions at 232 and 270 nm as well as the emission at 424 nm. Although the obtained correlation is not completely linear, a direct correlation was observed in both cases, revealing that both properties can be potentially used for monitoring the biodiesel degradation.

2021 ◽  
Vol 11 (8) ◽  
pp. 3590
Author(s):  
Endale Amare ◽  
Luca Grigoletto ◽  
Viviana Corich ◽  
Alessio Giacomini ◽  
Anna Lante

Teff and amaranth are gluten-free cereals with significant nutritional and health benefits. However, they are underutilized and known in limited areas of the world. The present study evaluated the fatty acid profile, crude fat, squalene content and lipid quality of seven teff (Eragrostis teff (Zucc.) Trotter) and three amaranth (Amaranthus caudatus L.) varieties from Ethiopia. The fat content ranged from 2.92 to 3.34% (averaging 3.06%) and from 8.28 to 9.21% (averaging 8.6%) for teff and amaranth, respectively. Linoleic, oleic and palmitic acid were predominant in both teff and amaranth, accounting for approximately 89 and 85% of total fatty acid content, respectively. The saturated to unsaturated fatty acids ratio ranged from 0.30 to 0.32 in teff and from 0.38 to 0.40 in amaranth. The parameters used to describe lipid quality, i.e., thrombogenicity and atherogenicity indices, show that teff was superior over amaranth, suggesting a preference for the former for healthy food formulation. The squalene content of white amaranth (486.54 mg/100 g DM) was significantly higher than that of the other two varieties (327.54 and 340.81 mg/100 g DM for red and brown amaranth, respectively). In general, both gluten-free crops should be exploited for their potential as ingredients for the development of novel functional foods.


Author(s):  
Rukmana Rahayu Lestari ◽  
Ratna Ibrahim ◽  
Putut Har Riyadi

ABSTRAK   Proses pengolahan minyak ikan kasar dengan metode steam jacketed di salah satu perusahaan pengolahan hasil perikanan menggunakan bahan baku campuran limbah padat pengalengan ikan Mackerel dengan suhu yang tinggi 90-100 °C menghasilkan produk yang belum memenuhi persyaratan mutu minyak ikan secara nasional. Penelitian ini bertujuan untuk mengetahui pengaruh perbedaan suhu pengolahan minyak ikan kasar ≤ 85 °C dari kepala ikan Mackerel tanpa insang dengan metode steam jacketed sederhana terhadap mutu produknya serta untuk mengetahui suhu dan lama waktu pengolahan yang menghasilkan minyak ikan kasar yang memenuhi persyaratan mutu secara nasional maupun internasional. Materi penelitian berupa kepala ikan Mackerel tanpa insang. Penelitian dilakukan dengan metode eksperimental laboratoris. Percobaan dirancang dengan Rancangan Percobaan Kelompok dengan perlakuan suhu berbeda (85 °C, 75 °C, dan 65 °C). Masing-masing perlakuan diulang tiga kali. Variabel mutu yang diamati adalah asam lemak bebas, bilangan peroksida, bilangan iod, kadar air, rendemen dan nilai sensori, serta uji profil asam lemak untuk produk yang terbaik. Data dianalisis menggunakan ANOVA dan perbedaan diantara perlakuan diuji dengan Uji Tukey. Hasil penelitian menunjukkan bahwa perbedaan suhu pengolahan minyak ikan kasar dari kepala ikan Mackerel tanpa insang dengan metode steam jacketed sederhana memberikan pengaruh berbeda nyata terhadap nilai asam lemak bebas, bilangan peroksida, bilangan iod, dan rendemen, tetapi tidak menyebabkan perbedaan nyata terhadap nilai sensori. Mutu produk terbaik yaitu produk yang diolah pada suhu 65 °C selama 20 menit, produk tersebut mengandung asam lemak omega-3 dan omega-6.   Kata kunci: Kepala ikan Mackerel, Minyak ikan kasar, Steam jacketed sederhana     ABSTRACT  The process of crude fish oil processing using the steam jacketed method in a fish product processing company which uses the raw material of solid mixed waste of canned Mackerel at 90-100 °C result in the products which have not fulfilled the requirement of national fish oil quality. The purpose of this research is to figure out the effect of processing temperature difference in the processing of crude fish oil below or at 85 °C from gill-less Mackerel fish head using the simple steam jacketed method on the quality of the processing products. This research is also intended to figure out the temperature and duration for the processing which produces the crude fish oil to fulfill both national and international quality standard.The research materials were gill-less Mackerel fish heads. The research was conducted using laboratory experimental method. The experiments were designed into Randomized Block Design with difference temperatures (85 °C, 75 °C, and 65 °C). Each of the temperature treatments was made in triplicate. The quality variables to be observed were free fatty acid value, peroxide value, iodine value, moisture content, yield and sensory value. The quality variables which made the best treatment was then tested using the fatty acid profile test for the best crude fish oil product. The data obtained were analyzed using ANOVA, and the difference among the treatments were tested using HSD test.The research result showed that the temperature difference in crude fish oil processing from gill-less Mackerel fish heads using the simple steam jacketed method gave significantly different effect on free fatty acid value, peroxide value, iodine value, and yield. However, did not give significantly different effect on sensory value. The best product quality was obtained from the product which was processed at 65 °C for 20 minutes, the product contains fatty acid omega-3 and omega-6. Keywords: Crude fish oil, Mackerel fish head, Simple steam jacketed method


2021 ◽  
Vol 51 (2) ◽  
pp. 262-270
Author(s):  
I.M. Boldea ◽  
C. Dragomir ◽  
M.A. Gras ◽  
M. Ropotă

The objective of this research was to assess the effects of including oil-rich feedstuffs in diets for lactating goats on the fatty acid (FA) profile of their milk. Thirty-six Murciano-Granadina goats were randomly assigned to three treatment groups, namely a control diet (CTRL), a diet based on whole rapeseed (RS), and a diet based on pumpkin seed cake (PSC). The diets were composed of 1 kg hay (70 % Italian ryegrass, 30% alfalfa) and 1.24 kg concentrate, and were formulated to be isoenergetic and isonitrogenous. Milk yield and its contents of protein, fat and lactose did not differ significantly among the groups. However, including oil-rich feeds in the diet altered the fatty acid profile of the milk significantly, decreasing its saturated fatty acid (SFA) content and increasing its content of unsaturated fatty acids (UFAs). Effects on polyunsaturated fatty acids (PUFAs), conjugated linoleic acid (CLA), and the n-6 to n-3 ratio depended on the source of dietary lipids. The PSC augmented diet increased the relative amount of PUFAs and fatty acid methyl esters (FAME) in milk (+25 %) significantly In comparison with CTRL, whereas the RS diet produced a limited and statistically insignificant increase (+7.5%). The concentration of CLA was higher in milk from does fed the PSC diet, whereas the n-6 to n-3 ratio was lower in milk from does fed RS. These preliminary results form the basis for developing premium dairy products that are enriched in fatty acids that are more favourable for human health.


2017 ◽  
Vol 60 (3) ◽  
pp. 191-198 ◽  
Author(s):  
Ewa Sosin-Bzducha ◽  
Michał Puchała

Abstract. In this experiment we used the meat of 16 Polish Red-and-White and Simmental bulls slaughtered at the age of 24 months. Physicochemical and organoleptic analyses were carried out on meat aged for 2, 7, 14 and 21 days and subjected to heat treatment. In addition, the effect of aging on oxidative stability and fatty acid profile of meat lipids was examined after 21 days of aging. The meat aging process determined all the physicochemical characteristics except for heating loss, as well as most of the sensory properties of meat. During aging, lightening of muscle colour, increased redness and chroma, and improved tenderness were observed. High scores were given for aroma intensity and taste desirability. The highest scores were awarded to meat aged for 7 and 14 days. The evaluation showed that meat tenderness and delicate texture steadily improved until day 14, after which they remained at a similar level or slightly deteriorated after 21 days of aging. Meat from the conserved breed generally had better scores, which could be influenced by better component scores for delicate texture and juiciness, as well as taste intensity. This study revealed no significant effect of breed on the degree of lipid peroxidation expressed as thiobarbituric acid-reactive substances (TBARS). The amount of malondidehyde was higher in meat aged for 21 days than in fresh meat. Aging did have an effect on the fatty acid profile of longissimus dorsi muscle (MLD) intramuscular fat. Wet aging of meat for 21 days was found to alter the content of capric (C10 : 0), palmitoleic (C16 : 1) and stearic acids (C18 : 0).


Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1186 ◽  
Author(s):  
Ibrahim A. A. Mohamed ◽  
Nesma Shalby ◽  
Ali M. A. El-Badri ◽  
Muhammad Hamzah Saleem ◽  
Mohammad Nauman Khan ◽  
...  

Salinity stress is a limiting factor for the growth and yield quality of rapeseed. The potentiality of melatonin (MT; 0, 25, 50, and 100 µM) application as a seed priming agent in mediating K+/Na+ homeostasis and preventing the salinity stress mediated oxidative damage and photosynthetic inhibition was studied in two rapeseed cultivars. We found that 50 µM MT treatment imparted a very prominent impact on growth, metabolism of antioxidants, photosynthesis, osmolytes, secondary metabolites, yield, and fatty acids composition. Days required for appearance of first flower and 50% flowering were decreased by MT application. Exogenous MT treatment effectively decreased the oxidative damage by significantly declining the generation of superoxide and hydrogen peroxide under saline and non-saline conditions, as reflected in lowered lipid peroxidation, heightened membrane stability, and up-regulation of antioxidant enzymes (catalase, superoxide dismutase, and ascorbate peroxidase). Furthermore, MT application enhanced the chlorophyll content, photosynthetic rate, relative water content, K+/Na+ homeostasis, soluble sugars, and proline content. Moreover, MT application obviously improved the oil quality of rapeseed cultivars by reducing glucosinolates, saturated fatty acids (palmitic and arachidic acids), and enhancing unsaturated fatty acids (linolenic and oleic acids except erucic acid were reduced). Yield related-traits such as silique traits, seed yield per plant, 1000 seeds weight, seed oil content, and yield biomass traits were enhanced by MT application. The anatomical analysis of leaf and stem showed that stomatal and xylem vessels traits are associated with sodium chloride tolerance, yield, and seed fatty acid composition. These results suggest the supportive role of MT on the quality and quantity of rapeseed oil yield.


2018 ◽  
Vol 7 (3.32) ◽  
pp. 147
Author(s):  
Enjarlis . ◽  
Sri Handayani ◽  
Yenny Anwar

Cocozone Oil (CCO) is one of the ozonated oils, obtained by the ozonation process of Virgin Coconut Oil (VCO), that can be used as a material for skin care products. The purpose of this study was to determine: (1) the optimum time and ozone dose for CCO synthesis from VCO using ozonation; (2) the changes in physico-chemical properties of the oil; (3) the change in saturated-unsaturated fatty acids content and the existence any new substances in the CCO. The ozonation of VCO was carried out for 25 hours, with monitoring at the intervals of 4, 8, 12, 16, 20 and 25 hours, at a constant temperature (25 °C) with an ozone flow of 0.25 g/hr. From this study it can be concluded that: (1) The optimal time or dose of ozone required for the synthesis of CCO from VCO through the ozonation process was 25 hours or equivalent to 0.0208 gr O3/ml VCO, (2) Physico-chemical characteristics of the CCO produced: resulting acid value (AV) was 2.71 mg/gram i.e. an increase of 630%; the peroxide value (PV) obtained was 238,77 mgrek/kg i.e. increase  of 3,453 %; the Iodine value (IV) was 0 (zero) i.e. a decrease of 100%; and, the viscosity was 13.30 centipoice i.e. it rose 116%; (3) the total content of saturated fatty acid increased by 3.34%  whereas the unsaturated fatty acid decreased by 98.83; and based on the analysis results of 13C and 1H NMR spectra, the resultant CCO contains a new substance, that is aldehydes.  


2018 ◽  
Vol 116 ◽  
pp. 613-622 ◽  
Author(s):  
Parvaneh Esmaeilnejad-Ahranjani ◽  
Mohammad Kazemeini ◽  
Gurvinder Singh ◽  
Ayyoob Arpanaei

2017 ◽  
Vol 7 (17) ◽  
pp. 3659-3675 ◽  
Author(s):  
S. M. Danov ◽  
O. A. Kazantsev ◽  
A. L. Esipovich ◽  
A. S. Belousov ◽  
A. E. Rogozhin ◽  
...  

The present critical review reports the recent progress of the last 15 years in the selective epoxidation of vegetable oils and their derivatives, in particular unsaturated fatty acids (UFAs) and fatty acid methyl esters (FAMEs).


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5203
Author(s):  
Vikas Sharma ◽  
Abul K. Hossain ◽  
Ganesh Duraisamy

The fuel qualities of several biodiesels containing highly saturated, mono, and poly unsaturated fatty acids, as well as their combustion and exhaust emission characteristics, were studied. Six biodiesel samples were divided into two groups based on their fatty acid composition, including group 1 (coconut, castor, and jatropha) and group II (palm, karanja, and waste cooking oil biodiesel). All fuels (in both groups) were tested in a single-cylinder off-road diesel engine. Castor and karanja biodiesel, both rich in mono-unsaturation level, have a high viscosity of about 14.5 and 5.04 mm2/s, respectively. The coconut and palm biodiesels are rich in saturation level with cetane numbers of 62 and 60, respectively. In both groups, highly saturated and poly-unsaturated methyl esters presented better combustion efficiency and less formation of polluted emissions than mono-unsaturation. At full load, coconut and palm biodiesel displayed 38% and 10% advanced start of combustion, respectively, which reduced ignition delay by approximately 10% and 3%, respectively. Mono-unsaturated methyl esters exhibited a higher cylinder pressure and heat release rate, which results in higher NOx gas emissions. The group II biodiesels showed about 10–15% lower exhaust emissions owing to an optimum level of fatty acid composition. Our study concluded that highly saturated and poly-unsaturated fatty acid performed better than mono-unsaturated biodiesels for off-road engine application.


2015 ◽  
Vol 58 (1) ◽  
pp. 40-46
Author(s):  
Muhammad Nadeem ◽  
Rahman Ullah ◽  
Muhammad Imran ◽  
Atta Muhammad Arif

This study investigated the effect of fatty acid modification and cholesterol removal on physico-chemical characteristics of yoghurt and ice cream. Fatty acid profile of milk fat was modified by feeding calcium salts of soybean oil fatty acids to cows and cholesterol was removed by b-cyclodextrin. b-cyclodextrin removed 76% and 60% cholesterol from yoghurt and ice cream. Modification of fatty acid composition did not have a significant effect on a-tocopherol content; while b-cyclodextrin treated milk had substantially lower a-tocopherol content. The concentration of a-tocopherol in control and b-cyclodextrin treated yoghurt was 45.62, 32.73 mg/g and 210.34, 185.56 mg/g for ice cream, respectively. Fatty acid modification and cholesterol removal significantly decreased the overrun in ice cream (P<0.05), with no effect on sensory characteristics of yoghurt and ice cream. These results evidenced that milk with higher content of unsaturated fatty acids and low cholesterol can be used in the formulation of yoghurt and ice cream with improved health benefits and suitable sensory features.


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