Addition Of Synthetic Antioxidants Research Articles

Appropriate analysis on properties of various compositions on fluids with and without additives for liquid insulation in power system transformer applications

Transformer is a well-known power system apparatus utilized in conjunction with solid insulations such as paper and press board, as well as liquid insulations like mineral oil, a petroleum-based fluid. Despite the notable drawbacks associated with mineral oil, such as limited resources for future generations and its non-eco-friendly nature, its usage remains ubiquitous. There is a growing imperative to explore alternative fluids that surpass mineral oil in terms of environmental impact and performance. Amidst the global shift towards green energy, this study focuses on vegetable seed oils such as corn oil, soybean oil, mustard oil, and rice bran oil as potential substitutes. The research evaluates these oils based on key transformer properties including breakdown voltage, water content, interfacial tension, viscosity, acidity, flash point, and fire point. Interestingly, rice bran oil and soybean oil exhibit promising characteristics that suggest they could effectively replace petroleum-based fluids in transformers. Furthermore, the study extends to blending mineral oil with vegetable seed oils in various compositions, incorporating natural and synthetic antioxidant additives ranging from 0 to 1%. Comparative analyses between samples with and without additives reveal that the inclusion of 1% propyl gallate yields outstanding performance improvements. For instance, a blend comprising 25 ml of mineral oil and 25 ml of soybean oil, supplemented with 1% propyl gallate, demonstrates 90% higher effectiveness compared to other blends and additives tested. Moreover, the research employs statistical regression analysis to establish relationships between different parameter variables, providing deeper insights into the performance and compatibility of these blended oils in transformer applications. This comprehensive investigation underscores the potential of vegetable seed oils as viable alternatives to mineral oil, contributing to the advancement of eco-friendly solutions in power systems.

Mutation accumulation under UV radiation and chemical mutagen for meliorated biodiesel production using B. amyloliquefaciens (MF 510169)

The cost-effective production of biodiesel is a major concern to address the issues related to climate change and energy security for protecting the economy of both non-developed and under-developed countries. The use of synergistically mutated bacteria for biodiesel production is an emerging and advantageous impendent. In the present investigation, B. amyloliquefaciens (MF 510169) strain has been mutated firstly with UV-C (254 nm for 320 S) which produces 3.93 % oil. Thus, the mutated strain is explored for chemical mutagen; ethyl methane sulphonate (EMS) at a concentration of 20 µg/ mL adduces the highest oil i.e. 6.43 % to produce the highest quantity of biodiesel. Synergistically mutated strain’s lipids are extracted and transesterified using sulphuric acid (1.5 %) under optimal reaction conditions yielding 75 % fatty acid methyl esters (FAME’s). Produced biodiesel is physico-chemically characterized using different spectroscopic techniques. The as-synthesized biodiesel fuel properties are nearly 75 % matched with ASTM International Standards. The model synergistic mutated strain is stable in terms of lipid production for up to 40 days. The recycling pattern of agro-waste substrate imparts best performance for up to three revisions consistently. The antioxidant stability of the as-synthesized biodiesel tested up to 25 days confirms moderate stability upon the addition of synthetic antioxidants. Overall, the synergistically mutated strain’s fatty acids are modulated well fashion as compared to wild type strain.

The employment for high-density polyethylene active packages (HDPAP) bottles containing Coriandrum sativum (Corainder) essential oil in the improvement of the oxidative stability of sunflower oil

ABSTRACT In this research, the effect of high-density polyethylene active packaging (HDPAP) bottles containing Coriandrum sativum essential oil (CSEO) on the oxidation stability and sensory attributes of sunflower oil (SFO) during the accelerated storage was investigated. The migration test showed that the CSEO could migrate from the package to SFO. In the accelerated storage procedure at 65°C, the increase in the levels of acid value (AV), peroxide value (PV), p-anisidine value (AnV), thiobarbituric acid reactive substances (TBARS), conjugated dienes (K232) and conjugated trienes (K268) of SFO samples was significantly inhibited after the sunflower oil packaged by the HAPAP containing CSEO at 6000 ppm (p < .05), which showed that the HDPAP bottle containing CSEO could delay the oxidation of SFO. Therefore, the results demonstrated that employment of HDPAP bottles containing CSEO at 6000 ppm could be applied as a good replacement for the direct addition of synthetic antioxidants to the SFO.

Comparative study of the antioxidant capability of EDTA and Irganox

Oxidative stress makes it difficult to preserve food and negatively affect the applicability of polymeric packaging. It is typically caused by an excess of free radicals, and it is dangerous to human health, resulting in the onset and development of diseases. The antioxidant ability and activity of ethylenediaminetetraacetic acid (EDTA) and Irganox (Irg) as synthetic antioxidant additives were studied. Three different antioxidant mechanisms were considered and compared by calculating bond dissociation enthalpy (BDE), ionization potential (IP), proton dissociation enthalpy (PDE), proton affinity (PA), and electron transfer enthalpy (ETE) values. Two density functional theory (DFT) methods were used, M05-2X and M06-2X with the 6–311++G(2d,2p) basis set in gas phase. Both additives can be used to protect pre-processed food products and polymeric packaging from oxidative stress related material deterioration. By comparing the two studied compounds, it was found that EDTA has a higher antioxidant potential than Irganox. To the best of our knowledge several studies have been carried out to understand the antioxidant potential of various natural and synthetic species, but EDTA and Irganox were not compared and investigated before. These additives can be used to protect pre-processed food products and polymeric packaging and prevent material deterioration caused by oxidative stress.

Pectin from Fruit- and Berry-Juice Production by-Products: Determination of Physicochemical, Antioxidant and Rheological Properties.

Plums (Prunus domestica); red currants (Ribes rubrum); black currants (Ribes nigrum); gooseberries (Ribes uva-crispa); sour cherries (Prunus cerasus); pumpkins (Cuccurbita spp.) are sources for valuable fruit- and berry-juice and cider production. This process leaves a large number of by-products (BP) in the form of pomace, which accounts for up to 80% of the raw material. This by-product represents a rich source of biologically active compounds, especially in the form of different pectic polysaccharides. The pectin extracted from commercial fruits such as citric fruits and apples has high medicinal properties, can be used as edible films and coatings, and is also useful in texture improvement and gel production in the food industry. However, many under-utilized fruits have received little attention regarding the extraction and characterization of their high/value pectin from their by-products. Moreover, the commercial extraction process involving strong acids and high temperature to obtain high-purity pectin leads to the loss of many bioactive components, and these lost components are often compensated for by the addition of synthetic antioxidants and colorants. The aim of the research is to extract pectin from juice production by-products with hot-water extraction using weak organic (0.1 N) citric acid, thus minimizing the impact on the environment. The yield of pectin (PY = 4.47-17.8% DM), galacturonic acid content (47.22-83.57 g 100-1), ash content (1.42-2.88 g 100 g-1), degree of esterification (DE = 45.16-64.06%), methoxyl content (ME = 4.27-8.13%), the total content of phenolic compounds (TPC = 2.076-4.668 µg mg-1, GAE) and the antiradical scavenging activity of the pectin samples (DPPH method (0.56-37.29%)) were determined. Free and total phenolic acids were quantified by saponification using high-pressure liquid chromatography (HPLC). The pectin contained phenolic acids-benzoic (0.25-0.92 µg mg-1), gallic (0.14-0.57 µg mg-1), coumaric (0.04 µg mg-1), and caffeic (0.03 µg mg-1). The pectin extracts from by-products showed glucose and galactose (3.89-21.72 g 100 g-1) as the main neutral sugar monosaccharides. Pectin analysis was performed using FT-IR, and the rheological properties of the pectin gels were determined. The quality of the obtained pectin from the fruit and berry by-products in terms of their high biological activity and high content of glucuronic acids indicated that the products have the potential to be used as natural ingredients in various food products and in pharmaceutical products.

Spectroscopic determination of the synergistic effect of natural antioxidants in Bio-Transformer oils

Considering the eventual depletion of fossil fuels from which mineral oil transformer fluids are derived in addition to the environmental footprint associated with the use of the latter, vegetable oils are increasingly becoming formidable alternatives both as environmentally benign lubricants and as dielectric fluids. However, their lower oxidative stability and higher viscosity compared to traditional mineral oils are their main shortfalls. To address the lower oxidative stability problem, addition of synthetic antioxidants to vegetable oil transformer fluids has been found technically feasible, but given that these natural esters already have organo-soluble antioxidants, information about the concentrations of these phytochemicals is essential for a systematic approach to boosting oxidative stability. The presence of some of these in natural esters can lead to a synergy in antioxidation processes. In this paper, we have used Ultraviolet–Visible Spectroscopy and Infrared Spectroscopy to demonstrate the occurrence of natural antioxidants, alfa-tocopherol and beta-carotene, in concentrations sufficient to offer a synergistic effect in samples of transformer fluids from a producer. One major role of beta-carotene is quenching of reactive singlet oxygen species in the oxidation reaction chain when a photosensitizer is present. Therefore, our findings in this paper is a useful guide to planning a cost-effective means of producing a quality transformer fluid where the cost involved in mitigating photoinduced degradation of oil is a problem. Accordingly, the findings shed light on the quality of bio-oils used by the producer of the transformer fluids used in this study.

Oxidative stability of chicken burgers using organic coffee husk extract

The antioxidant capacity of organic coffee husk extract (Coffee arabica L.) added to chicken burgers was evaluated. Two formulations were prepared: with addition of the extract (100 and 200 ppm CAE/kg), in addition to control formulations without the addition of antioxidant, and with the addition of synthetic antioxidant. The products were characterized by physical and chemical analysis and analyzed for oxidative stability during 45 days of storage under freezing. The addition of extract in the proportion of 200 ppm CAE/kg of hamburger revealed efficacy against lipid oxidation equivalent to treatment with a synthetic antioxidant. As for protein oxidation, there was no pro or antioxidant influence in the treatments. The addition of organic coffee husk extract to chicken hamburgers is thus indicated, being considered as a potential natural additive. In addition, the use of coffee husks helps to minimize the lager amounts of agro-industrial by-products generated by the coffee industry.

Eugenol, obtained from the bioassay-guided fractionation of Coriandrum sativum essential oil, displayed antioxidant effect in deep-frying procedure of sunflower oil and improved sensory properties of fried products, Caijiao

ABSTRACT The deep-frying procedure of Caijiao in sunflower oil (SFO) needs natural antioxidants. In the present study, the essential oil of Coriandrum sativum (CSEO) was added into SFO at 0.16 g/kg to prepare SFO sample. During the deep-frying procedure of Caijiao, total polar compounds (TPC), thiobarbituric acid (TBA), conjugated dienes (CD), conjugated trienes (CT), polymers, viscosity and b* were prominently inhibited, together with the obvious reduction of L* (p < 0.01 or p < 0.05). The sensory attributes of Caijiao were also obviously improved (p < 0.01 or p < 0.05). In the meantime, the addition of synthetic antioxidants to SFO, such as TBHQ, BHA and BHT, didn<apos;>t display effective antioxidant effect. After the bioassay-guided fractionation, the antioxidant effect of CSEO was attributed to one of its natural products, eugenol. The research and development of eugenol for effective natural antioxidants is of much importance for the whole food industry.

Curry leaf (Murraya koeneigii) extract as a natural source of antioxidants for enhancing the oxidative and thermal stability of ghee

Ghee is used for making various sweets and dishes in addition to its various culinary purposes. In the course of such preparations, ghee is subjected to different degrees of heat treatment which on combining with air can undergo considerable physico-chemical changes. The high temperature cooking process creates a series of complex chemical reactions in ghee which affects the sensory and the functional properties of foods as well as the ghee used. This leads to adverse health effects on consumers. One of the best ways to protect ghee from autooxidation and thermal oxidation is by the incorporation of antioxidants during their processing. Addition of synthetic antioxidants is restricted in several countries. Scientific investigations have also found that the use of synthetic antioxidants in foods may harm the liver and lead to the development of cancer. The aim of the present study was to check the effect of curry leaves (Murraya koeneigii) extract on the thermal stability of ghee. Based on the peroxide and thiobarbituric acid (TBA) value determinations, it was observed that quality of ghee samples added with 1 % CLE during frying was significantly higher than that of control (ghee without antioxidant) and ghee added with 0.02 % BHA (a synthetic antioxidant). At 15 minutes of frying (180°C), the peroxide value was 3.615±0.24, 1.04±0.10 and1.07±0.02 mM O2/kg fat for the control, BHA added and CLE added ghee respectively and this increased to 8.23±0.23, 6.47±0.21 and 4.0±0.01 mM O2/kg fat after 60 minutes of frying, respectively. Findings suggested that CLE could be used as a source of natural antioxidants for imparting thermal stability to ghee during frying.

Potential application of supercritical extract of pomegranate peel as bio‐antioxidant for biodiesel

AbstractThe performance of the pomegranate peel extract against the synthetic antioxidant additives on the oxidation stability of commercial biodiesel B100 derived from soybean was evaluated. The experimental extraction was conducted under 200 bar, 35, 45, and 55°C, and 0.0, 2.5, and 5.0 mL of ethanol as co‐solvent. Due to the rich in squalene and α‐tocopherol composition, all extracts presented high antioxidant capacity, 16.70 to 1.68 μg mL−1. In the oxidation stability tests, the addition of 1000 ppm of the supercritical extracts of pomegranate peel to biodiesel resulted in the increment of the induction time of pure biodiesel by up to 1.83. In contrast, the biodiesel added at 1000 ppm with commercial antioxidants increased the times up to 1.58 and 1.79, respectively for butylated hydroxyanisole and butylated hydroxytoluene. Biodiesel added with supercritical extract of pomegranate peel, obtained under 35°C and with 5.0 mL of ethanol, presented higher efficiency in the prevention of the oxidative process and was in accordance with norm European Standard EN 14214. The findings revealed that the extract is a promising natural antioxidant for biodiesel, that, besides being eco‐friendly, is an additive that can substitute commercial synthetic antioxidants, extending biodiesel stability.

Ultraviolet induced random mutagenesis in Bacillus amyloliquefaciens (MF 510169) for improving biodiesel production

The present study aims to mutate Bacillus amyloliquefaciens (MF 510169) randomly for improving lipid accumulation towards green and efficient transformation of bacterial oil into biodiesel. The cellular lipid content of wild type Bacillus strain is improved by exposing the strain to ultraviolet light at 254 nm (UV-C) and 365 nm (UV-A) wavelengths for different time intervals from 20 to 380 s. A remarkable increase in lipid content is noted with increase in cell dry weight when exposed to UV-C with 320 s exposure time. The accumulated lipids are extracted and transesterified through acid catalyst (H2SO4, 1.52%) by various means for biodiesel production. The chemical profiling of thus obtained biodiesel has been done by employing various spectroscopic techniques. The physical and chemical properties of thus transesterified biodiesel are well-matching 86–90% with International ASTM standards. The antioxidant stability of produced biodiesel tested with an addition of synthetic antioxidants remains stable for 25 d.

Black locust flowers as a natural source of antioxidants: Sustainable production of high-quality oil from plum by-product and its incorporation in the moisturizing cream

This study presents a challenge in terms of the development of cleaner technologies and sustainable development. The main effort was invested in the improvement of oxidative stability of plum seed oil using an eco-friendly and easy-to-use procedure (maceration). The fixed oil of plum seeds is composed of unsaturated fatty acids that are very sensitive to oxidative processes, but the addition of antioxidants can solve this problem. Since the obtained oil was further applied for the preparation of topical formulation, the aim was to avoid the use of toxic solvents and the process of their evaporation during the extraction of antioxidants from plant material. The way to overcome this problem was to directly use oil for the extraction of non-polar antioxidants from black locust flowers. The reason of use this plant material was due to its pleasant odor and high content of antioxidants. The maceration was carried out at the different temperatures (25, 40, and 60 °C) and the liquid-to-solid ratio of 10 mL/g for 48 h. After the extraction, the reducing capacity of the fixed oils was determined using a standard spectrophotometric method with Folin-Ciocalteu reagent. The extraction process was described using two kinetic models, Ponomaryov and non-stationary diffusion models. The optimal extraction time and temperature were 16 h and 60 °C, respectively, for the extraction of antioxidants. Thus obtained oil with improved stability was incorporated in the moisturizing cream to develop an innovative topical formulation that can be used against the harmful effects of the environmental factors. During the oil stabilization, the addition of synthetic antioxidants was omitted so that the application of natural antioxidants was favored. This was acceptable from an ecological point of view because in this way the planting of black locust trees will be intensified and thus the carbon dioxide emissions will be reduced. • The fixed oil of plum seeds was obtained from the industrial by-product. • The plum seed oil was enriched with antioxidants from black locust flowers. • A sustainable procedure was proposed for the improvement of oil stability. • The innovative moisturizing cream with fixed oil of plum seeds was designed.

Ethanol extracts of mango seeds added to the diet of pigs increases antioxidant capacity of processed pork.

Synthetic antioxidants (e.g.butylhydroxytoluene, BHT) are routinely used for to restrict oxidative processes of meat products, but they are implicated as harmful to the health of humans. Therefore natural alternatives, such as plant antioxidants, have been sought as replacements. Plant antioxidants when added to the diet can be incorporated into meat and reduce the need for the addition of synthetic antioxidants during processing. The objective of this study was to evaluate the effects of ethanol extracts of mango seeds (EEMS) in the diet of pigs on qualitative parameters and total antioxidant capacity of mortadella produced from these animals. Thirty-two pigs with an average 60 days of age were distributed among four treatments: control=no antioxidant; BHT=200ppm BHT; EEMS200=200ppm of EEMS and EEMS400=400ppm of EEMS. At 145 days of age the animals were slaughtered and loin was removed for the preparation of mortadella, which was analyzed during 90 days of storage at 4°C. A higher content of polyphenolic compounds and, total antioxidant capacity in mortadellas processed with meat of animals which consumed the EEMS400 ration after 60 and 90 days of storage was observed. EEMS polyphenolic antioxidants incorporated into pork through the diet results in an increase of total antioxidant capacity in the processed product.

Black bone syndrome in broilers fed ethanolic extract of mango seeds

This study aimed to evaluate the incidence of black bone syndrome (BBS) in broiler chickens fed with ethanolic extract of mango seed (EEMS). A total of 504 one-day-old male broilers were used in a completely randomised design assigned with 7 experimental diets and 6 replicates of 12 broilers per experimental plot. The experimental diets consisted of: diet without addition of synthetic antioxidant; diet with addition of synthetic antioxidant (200 ppm); and 5 levels of EEMS: 200 ppm, 400 ppm, 600 ppm, 800 ppm, and 1,000 ppm. Two methods of cooking (roasted and boiled) were used to prepare thigh samples. According to the results, the diets did not significantly influence the performance of the broilers. BBS incidence was higher in broilers fed a diet without antioxidants and was reduced with EEMS dietary inclusion, with the lowest incidence occurring with the inclusion of 1,000 ppm. The synthetic antioxidant butylated hydroxytoluene in the diet promoted a significantly higher BBS incidence than that obtained with 800 and 1,000 ppm EEMS and did not differ from the other diets. Of the cooking methods, a higher BBS incidence was observed for the boiled method. For the meat coloration and bone parameters, there were no significant interactions between the factors, diets and cooking methods. There was a linear reduction in the darkening score and linear increase in the luminosity (L∗) of the meat with increasing EEMS in the diet. With regard to the cooking method, the boiled thighs had lower luminosity (L∗), higher parameter a∗, and lower parameter b∗ values because of more pronounced meat darkening. The roasted bones were less heavy, dense, and flexible. A negative correlation was observed between the degree of darkening of the meat that characterizes the BBS with the luminosity (L∗) and intensity of yellow. We concluded that the addition of EEMS contributes to a reduced darkening of meat that characterises the BBS and recommend the dietary inclusion of 1,000-ppm EEMS.

Comparison of Synthetic and Plant Extract Antioxidant Additives on Biodiesel Stability

Oxidation stability is a critical parameter on biodiesel quality. Relates to The Indonesian Government policy to increase the percentage of biodiesel in diesel fuel blends, it is necessary to improve biodiesel quality so the diesel blends can meet the specification. This research focus on the effects of antioxidant additive to biodiesel quality, especially on oxidation stability characteristics, represented by Acid value, kinematic viscosity and induction period. Three additives used on this study were synthetic antioxidant additives tert-Butylhydroquinone (TBHQ), Propyl Gallate (PG) and a natural based antioxidant from Mango leaves extract prepared at LEMIGAS laboratory. Palm Oil based biodiesel is added with these three additives. A sample which is biodiesel without any additive was used for reference. All samples stored at an open glass tin for 12 weeks period. The Acid value, kinematic viscosity and induction period were measured for each 2 weeks. The result shows that additive TBHQ gives better performance in terms of Acid value, where sample containing TBHQ increase only 2.86% compare to PG and mango leaves extract that increase 11.43% and 22.22% respectively during 12 weeks storage. In terms of kinematic viscosity, these three additives shows similar result where the increasing of viscosity isn’t significant during test period. From the oxidation stability which is measured by induction period, PG additive show the lowest decreasing with only 1.96% lower from its initial value compare to TBHQ and mango leaves extract which decrease 5.03% and 18.76% respectively. From the result we conclude that the synthetic additives give better performance on biodiesel oxidation stability that the natural based additive.

Effects of The Dietary Supplementation of Layer Diets with Natural and Synthetic Antioxidant Additives on Yolk Lipid Peroxidation and Fatty Acid Composition of Eggs Stored at Different Temperatures and Duration

ABSTRACT In this study, the effects of the supplementation of natural and synthetic antioxidant additives in layer diets on egg weight loss, yolk lipid peroxidation (TBARS values) and fatty acid composition of eggs stored at different temperatures and duration were evaluated. In total, 112 48- weeks-old Bovans White layers were randomly allotted to four dietary treatments with four replicates of seven birds each. The treatments consisted of a control diet, containing no additives, and diets with the inclusion of 200 mg synthetic vitamin E/kg, 1000 mg thyme extract/kg and 1000 mg rosemary extract/kg. Dietary treatments did not influence (p>0.05) relative weight loss of eggs stored for 14, 28, and 56 days, except for those from rosemary-fed hens stored at room temperature on d 42, which were significantly lighter than the eggs from vitamin E- and thyme-fed hens (p 0.05) of dietary treatment on yolk TBARS values were detected in refrigerated eggs. The inclusion of the synthetic and both natural antioxidants in layer diets significantly reduced stearic acid (C18: 0) level in the egg yolk. In addition, only natural antioxidants significantly increased yolk levels of palmitoleic acid (C16: 1) and vaccenic acid (C18: 1n7). The results of the present study showed that adequate storage temperature was more effective in improving egg shelf life than feeding layers synthetic or natural antioxidant additives. However, the positive effects of the evaluated natural antioxidants on yolk fatty acid composition suggest their supplementation to layer diets may provide health benefits to the consumer.

Stabilization of Rice Bran in Broiler Feed with Natural and Synthetic Antioxidants and Heat Treatment

The objective of this study was to evaluate different strategies for the oxidative stabilization of rice bran (RB) in the diet of broiler chickens using natural antioxidant additives, synthetic antioxidant additives and heat treatment on performance, breast meat quality and liver fat content and the nutrient digestibility coefficients. Furthermore, the study aimed to evaluate the effects of heat treatment and antioxidants, antioxidant additive treatments, without antioxidants, natural, and synthetic, and to three heat treatments, without heat, dry-heat and moist-heat, after the rice bran was stored for 90 days and then incorporated into the experimental diets. 1080 broilers were arranged in a 3 x 3-factorial randomized design with 10 replicates per treatments. The wet heat treatment of the meal resulted in a higher daily feed intake and body weight at 28 days and better feed conversion than did the meal without heat treatment. No significant interactions were observed between the tested factors on the apparent digestibility of dry matter and ether extract as well as the values of apparent metabolizable energy and apparent metabolizable energy corrected for nitrogen. However, there was significant interaction between the tested factors on the nitrogen retention coefficient; the natural antioxidant and dry heat-treated meal combination presented a lower crude protein digestibility coefficient than those without heat treatment. In conclusion, thermal treatment of this bran proved to be more effective as demonstrated by the performance responses of the birds. Broiler chickens reared up to 28 days of age consuming diets containing 6.5% RB stabilized by heat treatment showed better performance, and the use of antioxidants was not necessary.

The Effectiveness of Natural and Synthetic Antioxidant Additives on the Oxidation Stability of Biodiesel Synthesized from Fresh and Waste Sunflower Oilesized from fresh and waste sunflower oil

Biodiesel fuel is the realistic fuel for the future due to its environmental, economic and energetic benefits. However, the degradation and instability during biodiesel storage and application present the major disadvantages and hence a modern scientific challenge. The aim of this study was to choose optimal parameters for biodiesel synthesis from fresh and waste sunflower cooking oil and to investigate the possibilities of increasing its resistance towards oxidative degradation. Various physico-chemical characteristics essential for the quality estimation of the resulting biodiesel products were compared before testing the effectiveness of natural and synthetic antioxidants. Butylated hydroxytoluene (BHT), carvacrol and α-tocopherol were added to the biodiesel in different concentrations in order to determine their efficiency during the Schaal oven test. Results proved that both, fresh and waste oil can be valuable sources for the synthesis of biodiesel that meets European and American quality standards. Among the antioxidants, BHT was the most efficient one in both types of biodiesel and its usage would be recommended at the concentration of 1000 ppm. The findings present a cost-effective and environmentally friendly source for biodiesel production with improved properties - considerably enhanced resistance to oxidative degradation, where synthetic antioxidants are given the priority. DOI: http://dx.doi.org/10.17807/orbital.v10i7.1174

Experimental and quantum chemical investigations on the oxidative stability of sesame oil base stock with synthetic antioxidant additives

AbstractDepleting resources and increasing environmental pollution caused by the petroleum products made researchers to think about its biodegradable counterparts. Vegetable oils due to its characteristics such as availability, renewability, eco‐friendliness, and biodegradability are progressively encouraged as a replacement for mineral oils in lubricant industry, while enhancement of few properties like the oxidative stability aids in the efficient use of them as the base stock. A generous amount of unsaturation in vegetable oils decreases oxidative stability and improves the pour point. Hence, a compromise between these two properties (pour point and oxidative stability) is critical in vegetable oil‐based lubricant. In this regard, sesame oil (SESO) possesses high pour point, and presence of natural antioxidants in it imparts superior oxidative stability than any other vegetable oils with a higher level of unsaturation. The addition of certain synthetic antioxidants to the SESO helps in the further improvisation of its oxidative stability to suit it for lubricant purpose. In the present work, the oxidative stability of SESO blended with octyl gallate (OG), salicyl hydroxamic acid, 2,5‐di‐tert‐butyl hydroquinone (DTBHQ), and tertbutyl hydroquinone (TBHQ) are assessed using hot oil oxidation test (HOOT) and differential scanning calorimetry (DSC, ASTM E2009‐08). The results are further compared with commercially available mineral oil‐based lubricant, SAE20W40. HOOT results show that a blend of SESO + 1.5%DTBHQ + 0.5%OG possesses higher oxidative stability than other antioxidant blends with SESO. In addition, from the DSC results, it is observed that the oxidative onset temperature (OOT) for abovementioned combination (268.10°C) shows an increase of 46.6% than the value of neat SESO (182.79°C) and is nearer to SAE20W40 (277.38°C). Fourier‐transform infrared spectroscopy results show that SESO + 1.5%DTBHQ + 0.5%OG combination subjected to HOOT hampers oxidation and hence increases the oxidative stability. The tribological properties of neat and antioxidant added SESO are studied using a four‐ball tester. Quantum chemical studies are also performed for antioxidant molecules on the basis of bond dissociation energies, ionisation potential, and HOMO‐LUMO energy gap to identify the dominant antioxidant mechanisms.

The effect of addition of Nigella sativa L. oil on the quality and shelf life of pork patties

The aim of the study was to determine the effect of the addition of different levels of Nigella sativa L. oil to minced pork on the quality and shelf life of pork patties. During the studies lipid oxidation, fatty acids profile, color as well as a total number of aerobic bacteria of raw pork patties stored under refrigeration conditions in the period of 8 days were determinated. Furthermore, sensory evaluation of roasted patties were performed. Results showed that the addition of Nigella sativa L. oil to pork has an impact on the properties of patties. The radical scavering activity of Nigella sativa L. oil was also indicated. It can be concluded that there is the potential of using Nigella sativa L. oil in the development of functional pork products with favorable volatile compounds and beneficial for people fatty acids profile. Practical applications Synthetic antioxidants have been used to prevent lipid oxidation in meat. However, the addition of synthetic antioxidants to food products has been restricted because of possible of health risks and toxicity. Therefore, there is an increasing interest in the addition of natural antioxidants to prevent oxidative processes in meat products. The study presents the effect of Nigella sativa L. on quality changes of pork patties under refrigerated conditions. The work has shown the positive effect of Nigella sativa L. oil on fatty acids profile in raw pork patties and volatile compounds profile in roasted pork patties. Samples with the addition of oil characterized up to 60% slower oxidative process of lipids than control samples; simultaneously without a negative changes of sensory properties.