•Twenty amino acids had antioxidant activities in soybean oil heated to180°C.•Amino acids with thiol, thioether, or amine groups had higher antioxidant activity.•At 5.5mM, some amino acids showed ...much higher activities than 0.02% TBHQ.•Amino acids with amide, carboxylic acid, imidazole, or phenols had lower activity.•Antioxidant activity increased with increasing hydrophobicity.
The purpose of this study was to evaluate amino acids as natural antioxidants for frying. Twenty amino acids were added to soybean oil heated to 180°C, and the effects of amino acid structure on the antioxidant activity were investigated. Amino acids containing a thiol, a thioether, or an extra amine group such as arginine, cysteine, lysine, methionine, and tryptophan had the strongest antioxidant activities. At 5.5mM, these amino acids had stronger antioxidant activities than 0.02% (1.1mM) tert-butylhydroquinone (TBHQ). A functional group such as an amide, carboxylic acid, imidazole, or phenol appeared to negatively affect amino acid antioxidant activity. Synergism between amino acids and tocopherols was demonstrated, and we found that this synergistic interaction may be mostly responsible for the antioxidant activity that was observed. In a frying study with potato cubes, 5.5mM l-methionine had significantly stronger antioxidant activity than 0.02% TBHQ.
Organogel formation of soybean oil with waxes Hwang, Hong-Sik; Kim, Sanghoon; Singh, Mukti ...
Journal of the American Oil Chemists' Society,
April 2012, Letnik:
89, Številka:
4
Journal Article
Recenzirano
Many waxes including plant waxes and animal waxes were evaluated for the gelation ability toward soybean oil (SBO) and compared with hydrogenated vegetable oils, petroleum waxes and commercial ...non-edible gelling agents to understand factors affecting the gelation ability of a gelator. Sunflower wax (SW) showed the most promising results and all SW samples from three different suppliers could make a gel with concentrations as low as 0.5 wt%. Candelilla wax and rice bran wax also showed good gelation properties, which, however, varied with different suppliers. Gelation ability of a wax is significantly dependant on its purity and detailed composition. A wax ester with longer alkyl chains has significantly better gelation ability toward SBO than that with shorter alkyl chains indicating that the chain length of a component in a wax such as wax ester is an important factor for gelation ability. The SW–SBO organogel showed increased melting point with increased SW content, showing the melting point range from about 47 to 65 °C with 0.5–10 wt% SW. The effects of cooling rate on crystal size and firmness of a gel were investigated. The dependence of firmness on cooling rate was so significant that the desired texture of an organogel could be achieved by controlling the cooling rate in addition to controlling the amount of gelling agent. This research reveals that a small amount of food grade plant waxes including SW may replace a large amount of the hardstock containing trans-fat or saturated fat.
To be able to tailor and optimize the physical properties of oleogels for various food applications, more information is needed to understand how different gelators interact. Therefore, the ...objectives of this study were to evaluate the interactions between binary mixtures of beeswax (BW), candelilla wax (CLW), and sunflower wax (SFW) in pure form as well as in 5% wax oleogels made with soybean oil, in terms of their crystallization and melting properties, crystal morphology, solid fat content, and gel firmness. CLW:BW mixtures had eutectic melting properties, and oleogels from these mixtures with 40:60 to 90:10 CLW:BW were firmer compared to oleogels made with one wax. The main components in SFW and BW appeared to cocrystallize or crystallize at the same temperature, but nonlinear changes in melting point and solid fat content profile of oleogels prepared with the mixed waxes indicated that SFW dominated oleogel formation. In addition, oleogels prepared with mixtures of SFW and BW had lower firmness compared to oleogels prepared with one wax, indicating an incompatibility between the two waxes. The main wax components in SFW and CLW never cocrystallized, and low levels of CLW appeared to prevent SFW from forming a crystalline platelet network. This resulted in low firmness of oleogels made from mixtures of 90:10 to 60:40 SFW:CLW compared to oleogels prepared with one wax. However, the firmest oleogels of all mixtures were made from 10:90 SFW:CLW. Changes in gel firmness and melting properties with mixed wax oleogels were likely to be due to changes observed in the crystal size and morphology. In addition, the firmest gels were shown to result from mixtures that were predicted to have >40% hydrocarbon content, and a high hydrocarbon to wax ester ratio, but minor components such as free fatty acids and fatty alcohols may have also influenced firmness.
Four natural waxes were evaluated as stabilizers in peanut butter. The potential advantage of using natural waxes would be the replacement of current stabilizers such as hydrogenated or tropical ...oils, thereby reducing saturated fats and satisfying clean label requirements. Beeswax (BW), candelilla wax (CLW), rice bran wax (RBW), sunflower wax (SFW), and a commercial peanut butter stabilizer, hydrogenated cottonseed oil (HCO), were added to three natural peanut butter brands at levels ranging from 0.5% to 2.0% (w/w) and tested for accelerated oil release, long‐term stability, firmness, and rheology. At levels ≥0.5%, all waxes improved oil‐binding capacity (OBC). SFW and HCO had the highest OBC, followed by RBW, CLW, and BW. All waxes reduced the amount of oil separation after 6 months at 22 ± 2 °C. HCO followed by SFW reduced oil separation the most, but there were no significant differences between stabilizers at 1–2%. Firmness and yield stress increased with increasing stabilizer level, with SFW increasing firmness the most, followed by HCO, RBW, and CLW, while BW had the lowest effect. The results indicate that the waxes may be feasible replacements for hydrogenated oils as peanut butter stabilizers, but levels would need to be optimized depending on the product characteristics and wax type.
An extract of Salvia officinalis (garden sage) was prepared using supercritical carbon dioxide (SC‐CO₂) extraction, followed by hot water extraction. The resulting extract was enriched in ...polyphenols, including rosmarinic acid (RA), which has shown promising health benefits in animals. The extract contained RA at a concentration of 28.4 mg/g, representing a significant enrichment from the RA content in sage leaves. This extract was incorporated into oil‐in‐water emulsions as a source of lipid antioxidants and compared to emulsions containing pure rosmarinic acid. Both treatments were effective in suppressing lipid oxidation. The extract was evaluated by a trained sensory panel in a tea formulation. While the panel could discriminate among extract‐treated and control samples, panelists demonstrated high acceptability of the sage extract in a tea.
Although studies have shown that spent coffee ground (SCG) extracts have antioxidant activity, no systematic study has been reported under actual storage conditions. The purpose of this study is to ...estimate the feasibility of practical application of SCG extracts as natural antioxidants for soybean oil and fish oil. An ethanol extract (EE), an acetone extract (AE), and polar compounds isolated from oil (PCO) are prepared and their activity is compared to a synthetic antioxidant, butylated hydroxytoluene (BHT). EE shows the strongest radical scavenging activity for 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radicals and the highest total phenolic content (TPC) followed by AE and then PCO. However, during storage of soybean oil and fish oil at 35 and 50 °C, AE has the strongest antioxidant activity as determined by peroxide value, conjugated diene value, p‐anisidine value, and headspace volatile analyses. In soybean oil, 0.25% AE has antioxidant activity that is equal to or better than 0.02% BHT. In fish oil, the antioxidant activity of 0.25% AE is inferior to that of 0.02% BHT. However, increased concentrations of AE show improved antioxidant activity. This study shows that SCG extracts can be practically used as natural antioxidants for vegetable oils and omega‐3 oils.
Practical Application: Due to lack of information about the antioxidant activity of spent coffee ground (SCG) extracts, this study is specifically aimed and designed to provide information on their activity toward soybean oil and fish oil during actual storage. This study shows that 0.25% acetone extract has equal or better protective effects than BHT in soybean oil at 35 and 50 °C. The activity is further improved with increasing concentration. The activity of the acetone extract in fish oil is not as strong as in soybean oil, but higher concentrations further improve the antioxidant activity. In this study, it is clearly demonstrated that the SCG extracts can have practical use as natural antioxidants for vegetable oils and oils with high concentration of omega‐3 fatty acids.
Among spent coffee ground (SCG) extracts, the acetone extract (AE) has the strongest antioxidant activity. In soybean oil, 0.25% AE has antioxidant activity that is equal to or better than 0.02% butylated hydroxytoluene (BHT). This study shows that SCG extracts can be practically used as natural antioxidants for edible oils.
Among spent coffee ground (SCG) extracts, the acetone extract (AE) has the strongest antioxidant activity. In soybean oil, 0.25% AE has antioxidant activity that is equal to or better than 0.02% butylated hydroxytoluene (BHT). This study shows that SCG extracts can be practically used as natural antioxidants for edible oils.
Recently it is reported that some amino acids have strong antioxidant activity in frying oil showing potential as new natural antioxidants. This study attempts to examine some proposed mechanisms and ...to understand a few factors affecting antioxidant activities of amino acids. First, to understand the effect of the two major functional groups in an amino acid, carboxylic acid, and amino groups; β‐alanine and their derivatives are examined. Methyl 3‐aminopropanoate having an ester group (‐COOCH3) in place of the carboxylic acid group (‐COOH) of β‐alanine has stronger activity than β‐alanine, presumably, due to increased lipophilicity. 3‐(Dimethylamino)propionic acid containing a dimethylamino group (‐N(CH3)2) in place of the amino group (‐NH2) of β‐alanine also has slightly increased activity than β‐alanine. In general, antioxidant activity increases with increasing alkyl chain length of an amino acid. However, DL‐2‐aminobutyric acid (C4) and DL‐norleucine (C6) has higher activity than other analogs with a longer alkyl chain. Chelation of metals by an amino acid does not play an important role under the conditions used in this study. Dipeptides do not show stronger activity than the two constituent amino acids alone in soybean oil (SBO).
Practical Application: Amino acids can practically be used as natural antioxidants for frying. Since this finding is very recent, very little is known about the antioxidant activity of amino acids, which must be investigated for the practical application. In this study, the understanding of several factors affecting their activity, which can be used in the practical application is attempted. It is found that, in general, antioxidant activity increases with increasing lipophilicity of an amino acid. Dipeptides do not show stronger activity than the two constituent amino acids alone. Therefore, a single effective amino acid instead of peptides or protein hydrolysates are recommended.
Antioxidant activity of DL‐alanine derivatives with a longer alkyl chain. In general, higher lipophilicity provides higher antioxidant activity. However, DL‐2‐aminobutyric acid (C4) and DL‐norleucine (C6) has higher activity than other analogs with a longer alkyl chain, presumably, due to the combination of their lipophilicity and mobility.
Antioxidant activity of DL‐alanine derivatives with a longer alkyl chain. In general, higher lipophilicity provides higher antioxidant activity. However, DL‐2‐aminobutyric acid (C4) and DL‐norleucine (C6) has higher activity than other analogs with a longer alkyl chain, presumably, due to the combination of their lipophilicity and mobility.
Cold‐pressed hempseed oil (HSO) is known to have many health benefits due to many phytochemicals and high polyunsaturated fatty acids content. In this study, HSO oleogels were prepared with 3%, 5%, ...and 7% natural waxes including sunflower wax (SW), rice bran wax (RBW), beeswax, and candelilla wax to evaluate their potential as solid fat replacements in margarines and spreads. Firmness, cohesiveness, adhesiveness, solid fat content (SFC), crystal structures, and melting properties of these oleogels were evaluated. In general, HSO oleogels except for RBW‐HSO oleogels had lower gel strength and weaker crystal network than the corresponding soybean oil (SBO) oleogels. In contrast, RBW‐HSO oleogels had comparable gel strength to SBO oleogels. After removing polar compounds from HSO, waxes except for RBW provided oleogels with greater firmness, cohesiveness, adhesiveness, and stronger crystal network. Therefore, it was concluded that polar compounds negatively affected the physical properties of wax‐HSO oleogels but not those of RBW‐HSO oleogels. Margarine samples were prepared with SW‐ and RBW‐HSO oleogels, and their firmness, cohesiveness, adhesiveness, and melting properties were examined. The firmness of these margarines indicated that wax‐HSO oleogels may achieve the firmness of commercial spreads with less than 3% wax while the firmness of stick margarines cannot be achieved even with 7% wax. Although the properties of wax‐HSO oleogels should be further improved, they showed potential as solid fat replacements in margarines and spreads.
Previous studies reported that several amino acids had strong antioxidant activity in vegetable oils under frying conditions. In this study, amino acids were converted to their sodium or potassium ...salts, and a heating study was conducted with 5.5 mM amino acid salts in soybean oil (SBO) at 180°C. Sodium salts of amino acids including alanine, phenylalanine, and proline and disodium glutamate had significantly stronger antioxidant activity than the corresponding amino acids, and potassium salts had stronger antioxidant activity than sodium salts. Potassium salts of alanine and phenylalanine more effectively retained tocopherols in SBO than the corresponding amino acids during heating. Phenylalanine potassium salt had stronger antioxidant activity than phenylalanine in other vegetable oils including olive, high oleic soybean, canola, avocado, and corn oils. Phenylalanine potassium salt at 5.5 mM more effectively prevented oil oxidation than tert‐butyl hydroquinone, a synthetic antioxidant, at its legal concentration limit (0.02%) indicating its feasibility as a new antioxidant for frying.
Abstract Sophorolipids (SL) are glycolipids composed of a sophorose head‐group linked to a hydroxy‐fatty acid tail which makes them a potential source of structurally unique biobased hydroxy fatty ...acids. Furthermore, Lesquerella is a native southwestern plant that has been commercially cultivated as a replacement for castor seed oil due to high seed oil concentrations of 14‐hydroxy‐eicosenoic acid (14‐OH‐C20:1 c 11). In this study, SL‐derived hydroxy fatty acids and methyl esters containing 15‐hydroxy‐palmitic acid (15‐OH‐C16), 17‐hydroxy‐stearic acid (17‐OH‐C18), 15‐hydroxy‐palmitic acid methyl ester (15‐OH‐C16ME), 17‐hydroxy‐stearic acid methyl ester (17‐OH‐C18ME), and 13‐hydroxy‐behenic acid methyl ester (13OH‐C22ME) were obtained from the SL produced by two yeast strains. In addition, hydrogenated Lesquerella oil (HLO) was made with ~62% 14‐OH‐eicosanoic (C20) acid (14‐OH‐C20). These materials, along with 12‐hydroxy‐stearic acid (12‐OH‐C18) as a standard for comparison were used to make soybean oil oleogels, and their properties determined. The minimum gelation concentration (MGC) of 12‐OH‐C18 was 1% (wt/wt), while the MGC of 15‐OH‐C16 and 17‐OH‐C18 were 5% and 10%, respectively. The MGC for 15‐OH‐C16ME was 5%, but 17‐OH‐C18ME was unable to form a stable gel at concentrations up to 10%. HLO formed a viscous solution rather than an oleogel, but its crystal morphology underwent a large transformation during storage over a 2.5‐month period, after which it was able to form a stable gel. SL‐based hydroxy fatty acids were able to form oleogels in soybean oil and have the potential to be considered as a new source of low‐molecular weight oleogelators as well as biobased hydroxy fatty acids.
