Effects of frying oil composition on potato chip stability

Potato chips were fried in six canola (low-erucic acid rape-seed) oils under pilot-plant process settings that represented commercial conditions. Oil samples included an unmodified canola oil and oils with fatty acid compositions modified by mutation breeding or hydrogenation. Chips were fried for a 2-d, 18-h cycle for each oil. Chips and oil were sampled periodically for sensory, gas-chromatographic volatiles and chemical analyses. Unmodified canola oil produced chips with lower flavor stability and oxidative stability than the other oils. The hydrogenated oil imparted a typical hydrogenation flavor to the chips that slightly affected overall quality. the modified canola oil (IMC 129) with the highest oleic acid level (78%) had the lowest content of total polar compounds and the lowest total volatile compounds at most of the storage times; however, the sensory quality of the potato chip was only fair. The potato chip with the best flavor stability was fried in a modified/blended oil (IMC 01-4.5/129) with 68% oleic acid, 20% linoleic acid and 3% linolenic acid.     

Viscosities of fatty acids, triglycerides, and their binary mixtures

Viscosity data have been obtained as a function of temperature for seven fatty acids (pelargonic, capric, lauric, myristic, palmitic, stearic, and oleic) and four triglycerides (tricaprilin, tripalmitin, tristearin, and triolein) and their binary mixtures at temperatures from above their melting points to 90°C. The viscosity measurements were performed by using Cannon Fenske glass capillary kinematic viscometers. Modified versions of the Andrade equation were used to correlate the kinematic viscosities of pure fatty acids and pure triglycerides. The MacAllister method was used for their binary mixtures. The correlation constants are valuable for designing or evaluating chemical process equipment, such as heat exchangers, reactors, distillation columns, and process piping.     

Chemical and physical analyses and sensory evaluation of six deep-frying oils

The performance of three high-oleic canola oils with different levels of linolenic acid [low-linolenic canola (LLC), medium-linolenic canola (MLC), and high-linolenic canola (HLC)], a medium-high-oleic sunflower oil, a commercial palm olein and a commercial, partially hydrogenated canola oil, was monitored by chemical and physical analyses and sensory evaluation during two 80-h deep-frying trials with potato chips. Linolenic acid content was a critical factor in the deep-frying performance of the high-oleic canola oils and was inversely related to both the sensory ranking of the food fried in the oils and the oxidative stability of the oils (as measured by color index, free fatty acid content, and total polar compounds). LLC and sunflower oil were ranked the best of the six oils in sensory evaluation, although LLC performed significantly better than sunflower oil in color index, free fatty acid content, and total polar compounds. MLC was as good as palm olein in sensory evaluation, but was better than palm olein in oxidative stability. Partially hydrogenated canola oil received the lowest scores in sensory evaluation. High-oleic canola oil (Monola) with 2.5% linolenic acid was found to be very well suited for deep frying.     

Novel Paper Sizing Agents Based on Renewables. Part 6: Sizing Properties of Maleated High Oleic Sunflower Oil

Abstract

The sizing efficiency of maleated high oleic sunflower oil (MSOHO), a green reactive sizing agent, was studied in various sizing tests. MSOHO can be applied in the papermaking process according to protocols that are commonly used for the currently popular alkenyl succinic anhydride (ASA) sizing. While an adequate degree of sizing was reached with pure MSOHO, blends of MSOHO and fatty acid anhydride (FAA), another green sizing agent, gave even better results, coming close to the efficiency of pure ASA. Although both pure sizing agents - FAA as well as MSOHO - lack some efficiency when compared to ASA, blending those two sizing agents at an optimum ratio closes this gap with respect to ASA. This synergism was not caused by simply decreasing the viscosity of MSOHO. Blends of ASA-MSOHO and ASA-MSOHO-FAA were proposed for full-scale mill trials.     

Fuel properties of biodiesel produced from the crude fish oil from the soapstock of marine fish

The soapstock of a mixture of marine fish was used as the raw material to produce the biodiesel in this study. The soapstock was collected from discarded fish products. Crude fish oil was squeezed from the soapstock of the fish and refined by a series of processes. The refined fish oil was transesterified to produce biodiesel. The fuel properties of the biodiesel were analyzed. The experimental results showed that oleic acid (C18:1) and palmitic acid (C16:0) were the two major components of the marine fish-oil biodiesel. The biodiesel from the mixed marine fish oil contained a significantly greater amount of polyunsaturated fatty acids than did the biodiesel from waste cooking oil. In addition, the marine fish-oil biodiesel contained as high as 37.07 wt.% saturated fatty acids and 37.3 wt.% long chain fatty acids in the range between C20 and C22. Moreover, the marine fish-oil biodiesel appeared to have a larger acid number, a greater increase in the rate of peroxidization with the increase in the time that it was stored, greater kinematic viscosity, higher heating value, higher cetane index, more carbon residue, and a lower peroxide value, flash point, and distillation temperature than those of waste cooking-oil biodiesel.     

Effect of fatty acid positional distribution and triacylglycerol composition on lipid by-products formation during heat treatment: II. Trans isomers

This study examined the effect of the fatty acid positional distribution and of the triacylglycerol (TG) composition on heat-induced trans isomerization of linoleic and linolenic acids. For this, we synthesized diacid TG molecules that were acylated only with linoleic acid (L) or with linolenic acid (Ln) along with palmitic acid (P). The fatty acid of interest was positioned either in the central position (PLP and PLnP, respectively) or in one of the two outer positions (PPL and PPLn, respectively). Monoacid TG, i.e., trilinolein and trilinolenin, were also synthesized and mixed with tripalmitin in a 1:2 ratio. This model TG was also compared to another TG model, which consisted of a canola oil and its randomized counterpart whose fatty acid positional distribution and TG composition were determined by means of high-performance liquid chromatography. After heating, the content of trans isomers was determined by gas-liquid chromatography with a polar capillary column. In model TG, polyunsaturated fatty acids in monoacid TG (LLL and LnLnLn) exhibited the highest degree of isomerization, compared to diacid TG, and this effect was greatest at 220°C. At this temperature, an effect of the TG structure was observed only with linolenic acid. In that situation, 18:3n-3 acylated in the central position of the TG molecule (PLnP) displayed the highest sensitivity to trans geometrical isomerization. Although to a lesser extent, the same trends as for the pure TG model were observed with the canola oil model with regard to the influence of the fatty acid positional distribution and TG molecular species.     

Effect of fatty acid positional distribution and triacylglycerol composition on lipid by-products formation during heat treatment: II. Trans isomers

This study examined the effect of the fatty acid positional distribution and of the triacylglycerol (TG) composition on heat-induced trans isomerization of linoleic and linolenic acids. For this, we synthesized diacid TG molecules that were acylated only with linoleic acid (L) or with linolenic acid (Ln) along with palmitic acid (P). The fatty acid of interest was positioned either in the central position (PLP and PLnP, respectively) or in one of the two outer positions (PPL and PPLn, respectively). Monoacid TG, i.e., trilinolein and trilinolenin, were also synthesized and mixed with tripalmitin in a 1:2 ratio. This model TG was also compared to another TG model, which consisted of a canola oil and its randomized counterpart whose fatty acid positional distribution and TG composition were determined by means of high-performance liquid chromatography. After heating, the content of trans isomers was determined by gas-liquid chromatography with a polar capillary column. In model TG, polyunsaturated fatty acids in monoacid TG (LLL and LnLnLn) exhibited the highest degree of isomerization, compared to diacid TG, and this effect was greatest at 220°C. At this temperature, an effect of the TG structure was observed only with linolenic acid. In that situation, 18:3n-3 acylated in the central position of the TG molecule (PLnP) displayed the highest sensitivity to trans geometrical isomerization. Although to a lesser extent, the same trends as for the pure TG model were observed with the canola oil model with regard to the influence of the fatty acid positional distribution and TG molecular species.     

Oil content and fatty acid composition of commercially important Turkish fish species

The oil content and fatty acid composition of commercially important Turkish fish species (anchovy,Engraulis encrasicholus; freshwater rainbow trout,Salmo gairdneri; and cultured salmon,S. salar) were determined. Palmitic (16∶0), palmitoleic (16∶1), oleic (18∶1), and docosahexaenoic (22∶6) acids were the most abundant fatty acids in all species. Eicosapentaenoic acid (20∶5) was twice as high in the anchovy oil as in the rainbow trout and salmon oils. Significant quantities of linoleic acid (18∶2) and docosahexaenoic acids (22∶6) were found in both rainbow trout and salmon samples. The individual fatty acid data obtained from rainbow trout and salmon were similar to each other. All three fish species contain high levels of n-3 polyunsaturated fatty acids and would be suitable for inclusion in the formulation of low-fat highly unsaturated diets.     

Genomic Regions Governing the Biosynthesis of Unsaturated Fatty Acids in Recombinant Inbred Lines of Soybean Raised across Multiple Growing Years

The ratio of oleic acid to the combined value of linoleic and α-linolenic acids determines the oxidative stability, and the ratio of linoleic acid to α-linolenic acid is the key to the nutritional value of soybean oil. The present study was conducted to identify genomic regions associated with oleic, linoleic, and α-linolenic acids in recombinant inbred lines (RIL), developed from LSb1 × NRC7, across 5 cropping years. These RIL were genotyped using 105 polymorphic SSR markers across soybean genome and analyzed for fatty acid composition. SSR markers, namely, Satt245 (LGp M), Satt556 (LGpB2), Sat_042 (LGp C1), Staga002 (LGp D1b), Satt684 (LGp A1), and AI856415 (LGpD1b) showed significant (P < 0.05) association with oleic acid for all the 5 years, though this association was weak in the years when the growing temperature during active seed formation stage was high. Quantitative trait loci (QTL) linked to Satt684 (LGp A1), Satt556 (LGp B2), Sat_042 (LGp C1), and AI856415 (LGp D1b) showed pleiotropic influence on the levels of unsaturated fatty acids. Complementation of favorable QTL from LSb1 and NRC7 generated 60% oleic acid and less than 4% α-linolenic acid RIL, stable across 5 cropping years. New SSR markers, namely, Satt245, AI856415, and Staga002 identified to be associated with different unsaturated fatty acids may be useful in improving the efficiency of marker-assisted breeding for enhancing the monounsaturated to polyunsaturated fatty acids ratio of soybean oil.     

Predicting temperature-dependence viscosity of vegetable oils from fatty acid composition

The viscosities of 12 vegetable oils were experimentally determined as a function of temperature (5 to 95°C) by means of a temperature-controlled rheometer. Viscosities of the oil samples decreased exponentially with temperature. Of the three models [modified Williams-Landel-Ferry (WLF), power law and Arrhenius] that were used to describe the effects of temperature on viscosity, the modified WLF model gave the best fit. The amounts of monounsaturated FA or polyunsaturated fatty acids (PUFA) highly correlated (R ²>0.82) with the viscosities of the oil samples whereas and the amounts of saturated or unsaturated FA. An exponential equation was therefore used to relate the viscosity of these vegetable oil samples to the amounts of monounsaturated FA or PUFA. The models developed are valuable for designing or evaluating systems and equipment that are involved in the storage, handling, and processing of vegetable oils.     

Effect of fatty acid positional distribution and triacylglycerol composition on lipid by-products formation during heat treatment: I. polymer formation

Effects of the fatty acid positional distribution and of the triacylglycerol (TG) composition on polymerization of TG during heat treatment were studied. Diacid TG molecules, acylated only with linoleic acid or linolenic acid along with palmitic acid, and positioned either in the central position (PLP and PLnP, respectively) or in one of the two outer positions (PPL and PPLn, respectively) were synthesized. Monoacid TG, i.e., trilinolein and trilinolenin, were also synthesized and mixed with tripalmitin in a 1:2 ratio. These model TG were also compared to TG models that consisted of a canola oil and its randomized counterpart, whose fatty acid positional distribution and TG composition were determined by means of high-performance liquid chromatography (HPLC). After heating, the polymer content and composition were evaluated by HPLC-size exclusion chromatography. Both pure TG and the canola oil models showed that acylation of polyunsaturated acids in the central position was protective against polymerization, although the effect was mainly observed with linolenic acid. The synthetic-TG study showed that the monoacid TG species exhibited higher sensitivity toward polymerization than the diacid species. The slight differences in the TG species between both canola oils did not allow observation of such a relationship with regard to TG composition.     

Effect of fatty acid positional distribution and triacylglycerol composition on lipid by-products formation during heat treatment: I. Polymer formation

Effects of the fatty acid positional distribution and of the triacylglycerol (TG) composition on polymerization of TG during heat treatment were studied. Diacid TG molecules, acylated only with linoleic acid or linolenic acid along with palmitic acid, and positioned either in the central position (PLP and PLnP, respectively) or in one of the two outer positions (PPL and PPLn, respectively) were synthesized. Monoacid TG, i.e., trilinolein and trilinolenin, were also synthesized and mixed with tripalmitin in a 1:2 ratio. These model TG were also compared to TG models that consisted of a canola oil and its randomized counterpart, whose fatty acid positional distribution and TG composition were determined by means of high-performance liquid chromatography (HPLC). After heating, the polymer content and composition were evaluated by HPLC-size exclusion chromatography. Both pure TG and the canola oil models showed that acylation of polyunsaturated acids in the central position was protective against polymerization, although the effect was mainly observed with linolenic acid. The synthetic-TG study showed that the monoacid TG species exhibited higher sensitivity toward polymerization than the diacid species. The slight differences in the TG species between both canola oils did not allow observation of such a relationship with regard to TG composition.     

Fatty acid composition, extraction, fractionation, and stabilization of bullfrog (Rana catesbeiana) oil

The oil extracted from the fat-storage organ (fat body) of the bullfrog (Rana catesbeiana) was characterized for its fatty acid composition. The main fatty acids were palmitic (18.1%), stearic (4.1%), myristic (2.7%), oleic (31.7%), and linoleic (12.9%) acids. Long-chain polyunsaturated fatty acids were also present in significant amounts, i.e., eicosapentaenoic (1.5%) and docosahexaenoic (4.7%), and were probably derived from the fish meal content of the diet. A partially fractionated oil was extracted from the homogenized and frozen fat body with an oleic acid content of 43.2%. The natural alkaloid boldine, added at 0.5 mg/g oil level, improved the oxidative stability by a factor ranging from 1.7 to 2.4, as assessed by the Oil Stability Index method between 90 and 110°C. The stabilization effect of boldine was higher than that of naringenin, morin, and quercitin and for the synthetic antioxidant butylated hydroxytoluene at the same concentration level.     

Quantification of Nonanal and Oleic Acid Formed During the Ozonolysis of Vegetable Oil Free Fatty Acids or Fatty Acid Methyl Esters

The ozonolysis of unsaturated lipids is a process that has been used to generate aldehydes, acids, alcohols, and other biobased chemical intermediates. Reported here is a method that can be used to measure the formation of nonanal and oleic acid during the ozonolysis of unsaturated vegetable oil fatty acids or their methyl esters to indicate the extent of the ozonolysis reaction. Derivatization was performed using boron trifluoride in methanol solution to transform nonanal and oleic acid into nonanal dimethyl acetal and oleic acid methyl ester, respectively. Undecanal and 10‐heptadecenoic acid were used as internal standards and separation was performed using gas chromatography coupled with a flame ionization detector. The method was validated by performing a standard addition procedure in which nonanal or oleic acid standards were spiked into samples collected during the ozonolysis of oleic acid or canola oil fatty acid methyl ester (FAME). Linear regression results indicated that the measured nonanal and oleic acid are in good agreement with the actual amounts of nonanal and oleic acid added to the sample with at least 98 % recovery. The application of the method was demonstrated by the successful measurement of nonanal and oleic acid formed throughout the ozonolysis process for high oleic canola oil FAME.     

Fatty acid composition and its relationship with physicochemical properties of pecan (Carya illinoensis) oil

The composition and physicochemical properties of pecan (Carya illinoensis) kernels and oils from different native trees of the central region of Mexico were investigated. The main compositional characteristic of the kernel was the high lipid content (70–79% w/w on dry basis) with elevated concentration of oleic acid (55–75% w/w). The results confirmed the relationship in the biosynthesis of linoleic and linolenic acids from oleic acid existing in oilseeds. Our results indicate that in pecans such relationship is a function of pecan tree age. The proportion of oleic, linoleic, and linolenic fatty acids determined the oxidative stability, viscosity, and melting/crystallization behavior of pecan oil. In general, these properties in pecan oils were similar or superior to extra-virgin olive oil and unrefined sesame oil. Although all native pecan oils studied showed a significant concentration of oleic acid, a particular group of native Mexican pecan trees produces an oil with a fatty acid composition with the nutritional appeal that consumers demand nowadays (i.e., very high oleic acid, 60–75%), with excellent natural oxidative stability (i.e., induction time for oxidation between 8.5 and 10.8 h), and substantially higher concentrations of α-, γ-, and δ-tocopherol than in pecan varieties previously reported in the literature.     

Stepwise peroxidation of canola and olive oils: A kinetic study

Kinetics of change in the concentration of lipid hydroperoxides (LOOH) and carbonyls (LCO) were simultaneously investigated during peroxidation of canola and olive oils at 90°C. Depending essentially on the fatty acid compositions, the canola and olive oils exhibited one-step and two-step, respectively, multiphase peroxidations before attaining the typical termination phase. Higher and lower rates of the LOOH formation and decomposition, respectively, in the second than in the first step of the canola oil peroxidation were attributed to the dominant peroxidation of linolenic acid in the first step, and the added peroxidation of oleic and linoleic acids in the second step. The kinetics of change in [LCO], which was affected by the potency of constituting antioxidative compounds, indicated that the canola oil would be safe to use till the end of the first peroxidation step whereas the olive oil should be discarded at its induction period.     

Commercialization of high oleic canola oils

High oleic canola oils were developed through plant breeding in the 1980's as a trans fat solution. More than 25 years after its initial launch, high oleic canola oils include a series of products with fatty acid profiles tailored for both foodservice and food processing. High oleic canola oil has taken most of the market for trait enhanced oils while other specialty oils have either seen significant market share reduction or failure. High oleic canola oils with 23%–27% linoleic acid are ideal for fried foods, while those with less than 20% are most suitable in the manufacture of shelf stable foods. In addition to improved nutrition, the next generation of high oleic canola oils will significantly reduce packaging costs.     

Chemical changes in the lipids of canola and flax seeds during storage

The changes in acid value (AV), peroxide value (PV), anisidine value (AnV), tocopherols and fatty acid composition in crushed flax, canola seeds or commercial poultry feed during a 60-day storage period in room temperature (RT) or cold room (CR) were examined. Storage at RT or CR increased AV, PV and AnV of flax and canola seeds. Regardless of storage condition, a 50% reduction in the content of tocopherols was observed in flax, canola and commercial feed samples at day-30 of storage. The changes in the content of polyunsaturated fatty acids were negligible during storage. These results may have implication in the storage and handling of animal feeds containing n-3-polyunsaturated fatty acid-rich oil seeds.     

Partition Coefficients and Solubility of Urea-Fractionated Fatty Acid Ethyl Esters from Fish Oil in Supercritical CO2

Solubilities and K-values of urea-fractionated fish oil fatty acid ethyl esters, prepared from sandeel oil, have been measured in supercritical carbon dioxide experimentally. The measurements were performed at the temperatures of 313.2 and 343.2 K in the pressure range of 8 to 26 MPa. Experimental temperatures, pressures, and densities of the equilibrium phases are tabulated. The K-values of the ethyl esters of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and oleic acid of the urea-fractionated mixture are compared with previously published experimental binary and multicomponent data on the same mixture before performing the urea-fractionation. K-value data of this type are essential to conceive proper equipment design for separation of the various polyunsaturated ω-3 fatty acids present in fish oil as esters.     

Effect of fatty acid positional distribution and triacylglycerol composition on lipid by-products formation during heat treatment: III—Cyclic fatty acid monomers study

The influence of isomeric triacylglycerols (TG) containing 18:3n-3 and 18:2n-6 on the formation of cyclic fatty acid monomers (CFAM) after heat treatment was assessed. Diacid TG, containing linoleic acid (L) or linolenic acid (α-Ln) along with palmitic acid (P), and positioned either in the central position (PLP and PLnP, respectively), or in one of the two outer positions (PPL and PPLn, respectively) were synthesized. Monoacid TG of trilinolein and trilinolenin mixed with tripalmitin were also prepared. The CFAM formed after heating were analyzed after total hydrogenation. The results obtained with the model TG were compared to another model consisting of a canola oil and its randomized counterpart. In diacid TG, the location of α-Ln in the central position of the TG molecule (PLnP) greatly enhanced the formation of the CFAM upon heating at temperatures below 240°C. On the other hand, 18:3n-3 in monoacid TG (LnLnLn) was highly resistant to CFAM formation within the same range of temperatures (180–220°C). The TG structure, more than the TG composition, seemed to explain the differences in the CFAM formation between the original canola oil and its interesterified counterpart. Like α-Ln, 18:2n-6 was more prone to cyclization when attached at the central position of the model TG. Conversely, the influence of the TG composition on the cyclization rate was less important for L than for α-Ln. It was concluded that positioning the C18 polyunsaturated fatty acid in the central position of TG rendered the oils much more sensitive to the cyclization reaction upon heat treatment.