Effects of frying on the trans‐fatty acid formation in soybean oils

To evaluate the effects of repeated deep‐frying on the trans‐fatty acid (TFA) formation in soybean oils, simultaneous frying experiments were carried out. French fries were prepared using three different types of soybean oil (pressed soybean oil, PSBO; first‐grade solvent extracted soybean oil, FG‐SESBO; and third‐grade solvent extracted soybean oil, TG‐SESBO). French fries were fried intermittently at 180–185°C for a total frying time of 32 h and at an interval time of 30 min. It was found that the initial amount of total TFAs was 0.29 g/100 g, 0.31 g/100 g, and 0.90 g/100 g in PSBO, TG‐SESBO, and FG‐SESBO, respectively. Before the frying started, the C18:1,t‐9, trans‐linoleic acid (TLA), trans‐linolenic acid (TLNA), and total TFA content of the PSBO and TG‐SESBO were significantly lower than in the FG‐SESBO (p<0.05). However, in the frying oil samples, the final concentration of total TFA in the PSBO, TG‐SESBO, and FG‐SESBO were 1.79 ± 0.17 g/100 g, 1.12 ± 0.10 g/100 g, and 1.70 ± 0.07 g/100 g, which was 6.17‐, 3.61‐, and 1.89‐fold higher that in fresh oil, respectively. The highest increasing slopes of C18:1,t‐9, TLA, TLNA, and total TFA were observed in the PSBO. Practical applications : A high intake of TFAs has been shown to lead to an increased risk of coronary heart disease. Plant oils, particularly soybean oil, have been widely used in the food industry in China. Frying is one of the most common methods to cook food. The formation of TFAs during frying has been shown to be closely related to the temperature and duration of the frying process. However, the effects of frying on the formation of TFAs in different soybean oils have not been well studied. In the present study, we demonstrated that increasing the number of frying cycles can cause an intensive increase in the concentration of TFAs in different types of soybean oil, but especially in PSBO.     

Trans octadecenoic fatty acid (TFA) isomers in German foods and bakery goods

In the present study, 122 food samples from the German food market were analysed for their C18:1 trans fatty acid (TFA) content and profile. A particular focus of the survey were baked and fried foods. TFA analysis was performed by means of silver ion SPE (Ag⁺‐SPE) in combination with high‐resolution GC (HRGC‐FID). Overall, 51 bakery product samples were analysed of which 25 samples were prepacked bakery products purchased from local retail stores and 26 samples of unpacked bakery products purchased from local bakery shops. In addition, 14 French fries samples obtained from small local fast food restaurants as well as from internationally operating fast food chains, 27 potato and tortillas chips, 15 instant soups as well as 15 dry culinary sauces were analysed. The highest amounts of C18:1 TFA isomers were found in deep‐fried bakery products. Prepacked branded cookies and biscuits on the other hand contained only negligible C18:1 TFA amounts. Regarding their C18:1 trans isomer profile most deep‐fried bakery products exhibited a Gaussian‐distributed isomer profile. The analysed prepacked croissants, cookies and biscuits contained predominantly ruminant TFA (TFA) as suggested by the presence of vaccenic acid (C18:1 trans 11), which was the major C18:1 TFA isomer in these products. All non‐bakery samples (n = 71) contained less than 3 g C18:1 TFA per 100 g fat. In conclusion, TFA still occur in considerable amounts in a few German food products, especially in some deep‐fried bakery products (‘Berliner’ type of doughnuts). Practical applications: Trans fatty acids, in particular the trans octadecenoic fatty acid isomers (C18:1), are generally considered from the nutritional point of view as undesirable food components due to their negative health effects. Tremendous efforts have been made by major food processors in order to decrease or even eliminate the presence of TFA in some foodstuffs (e.g. in margarines in European countries). However, some food processors of other food sectors are still applying oils and fats containing partially hydrogenated vegetable oils, whereas others within the same food category have already switched their processing conditions and/or raw materials towards TFA alternatives. Therefore, actual TFA data of foodstuffs determined by means of state‐of‐the‐art analytical procedures (Ag⁺‐SPE in combination with GC‐FID) is necessary to detect areas of further improvement in the food supply chain and to provide data for an update of dietary TFA intake.     

Microencapsulation of Chia Seed Oil by Spray-Drying: Influence of the Antioxidant Addition

Chia seed oil has a high content of polyunsaturated fatty acids, giving it nutritionally beneficial qualities, although determining its high susceptibility to oxidative deterioration. Microencapsulation and natural antioxidants are alternatives to protect this oil during its processing and storage. This work aims to study the physicochemical characteristics and the oxidative stability of chia seed oil microencapsulated with different antioxidants (rosemary extract, blend of rosemary and chamomile extracts, ascorbyl palmitate) by spray-drying using sodium caseinate and lactose as wall material. The microencapsulation efficiency and the moisture content are >97% and <3% d.b., respectively. Scanning electron microscopy shows that the microcapsules are spherical, with diameters ranging between 11.3 and 14.8 µm. At t = 0, the microencapsulated oil recorded a t_i = 12.7 h, seven times greater than that of the bulk-oil. The addition of the antioxidants increases the t_i of the microencapsulated oil. The addition of ascorbyl palmitate maintains the peroxide value under the acceptable limit after 60 d of storage (25 °C, darkness, HR 33%). Thus, microencapsulation by spray drying of chia oil with ascorbyl palmitate addition will be the most appropriate studied system to obtain microparticles with high efficiency and oxidative stability during the processing and storage. Practical Application: This study contributes to investigating the microencapsulation of omega-3 fatty acids n-3 fatty acids (FAs) from a novel oilseed (chia oil), applying different antioxidants, including those from vegetable sources such as rosemary and chamomile extracts, to confer additional protection to microencapsulated oil. Thus, the application of these techniques will enable the delivery of this vegetable oil for the development of functional foods.     

Formation and distribution of oxidized fatty acids during deep‐ and pan‐frying of potatoes

The formation of cis‐9,10‐epoxystearate, trans‐9,10‐epoxystearate, cis‐9,10‐epoxyoleate, cis‐12,13‐epoxyoleate, trans‐9,10‐epoxyoleate, trans‐12,13‐epoxyoleate and the co‐eluting 9‐ and 10‐ketostearates during eight successive pan‐ and deep‐frying sessions of pre‐fried potatoes in five different types of vegetable oils – namely cottonseed oil, sunflower oil, vegetable shortening, palm oil and virgin olive oil – was followed and quantified both in fried oils and in fried potatoes by GC/MS after derivatization to methyl esters. These oxidized fatty acids were present at relatively low concentrations in the fresh oils and pre‐fried potatoes while they increased linearly with frying time, reaching up to 1140.8 µg/g in virgin olive oil (VOO) and 186.9 µg/g in potatoes pan‐fried in VOO after eight pan‐frying sessions, with trans‐9,10‐epoxystearate predominating in all cases. The formation of polymerized triacylglycerols (PTG) was also quantified in frying oils by size exclusion HPLC. Pan‐frying caused higher oxidized fatty acid and PTG formation compared to deep‐frying. Epoxyoleates and PTG concentrations were increased after frying in polyunsaturated oils, while epoxystearate and 9‐ and 10‐ketostearate concentrations were increased after frying in monounsaturated oils. No specific absorption of the oxidized fatty acids by the fried potatoes seems to occur. The dietary intake of oxidized fatty acids and PTG by the consumption of fried potatoes was discussed.     

Characterization of Trimethylolpropane‐Based Biolubricant

The oxidative stability index (OSI) of fatty acid methyl esters (FAME) and trimethylolpropane (TMP) esters or TMPE produced from five vegetable oils (Brassica rapa L., Linum usitatissimum L., Zea mays L., Brassica napus L., Camelina sativa L.) are compared. The highest stability is observed in vegetable oils while the processed products are less stable. The major causes in loss of OSI are attributed to excess FAME in the crude product and the loss of natural antioxidants due to refinement with silica and celite. The low‐temperature flow properties of TMPE produced from four different vegetable oils (B. juncea L., L. usitatissimum L., B. rapa L., and C. sativa L.) are investigated by proton nuclear magnetic resonance (¹H‐NMR). The T2 relaxations of different TMPE are measured to observe how the mobility of oil changed as temperature decreased. Increased oil mobility (represented by T2) is correlated with rising temperature. The Gaussian widths of the singlet in ¹H‐NMR spectra of each oil demonstrated increased molecular mobility as temperature increased. Extrapolation of the relation of T2 signals of these four oils indicates that T2 approached zero between 232 K and 239 K, suggesting the molecular motion leading to a T2 relaxation has largely ceased. Practical Applications: The OSI is determined for four vegetable oils as well as the product FAME and TMPE. The vegetable oils are more stable than their products. The loss of natural antioxidants during purification of FAME and TMPE contributes to the lower OSI compared to vegetable oil. The low‐temperature flow behavior of TMP‐based biolubricants is determined between 238 K and 298 K using T2 relaxation. As temperature decreases, a singlet resonance in ¹H‐NMR spectra attributed to TMP protons broadens until it disappears. The results suggest that the log of the spin‐spin relaxation time is linearly correlated with rising temperature and oil mobility.     

Stabilization of Camelina Oil with Synthetic and Natural Antioxidants

Camelina oil was found to have a much lower Oil Stability Index and higher p-anisidine rates in the oven storage test than either rapeseed or sunflower oils. Stabilization of camelina oil was evaluated with 21 food grade synthetic and natural antioxidants and antioxidant formulations, using both the Oil Stability Index (OSI) and the oven storage test. The Oil Stability Index of camelina oil was able to be increased above that of rapeseed oil with TBHQ and its formulation with citric acid, and above that of sunflower oil with EGC, EGCG, carnosic acid, propyl gallate, rosemary extract with ascorbyl palmitate or with gallic acid. para-Hydroxyphenols were found to be more effective than ortho-hydroxyphenols and monohydroxyphenols had no significant effect on the OSI. Good correlation (R ² = 0.96) was found between the stabilizing effect of ortho-hydroxyphenols and the molarity of the phenyl hydroxyl groups per weight of antioxidant. The oven storage test carried out with six of the evaluated antioxidants indicated that p-anisidine rates of camelina oil stabilized with commercial formulations of TBHQ with citric acid or rosemary extract with ascorbyl palmitate were about the same as that of sunflower oil, an almost 90% rate reduction when compared to camelina oil. Accordingly, camelina oils stabilized with TBHQ/citric acid and rosemary extract/ascorbyl palmitate formulations were more stable than rapeseed and sunflower oils, respectively in terms of OSI induction times and p-anisidine rates.     

Impact of Canolol‐Enriched Extract from Heat‐Treated Canola Meal to Enhance Oil Quality Parameters in Deep‐Frying: a Comparison with Rosemary Extract and TBHQ‐Fortified Oil Systems

Canolol‐enriched extracts obtained from the extraction of fluidized bed treated canola meal with supercritical carbon dioxide were added to high‐oleic canola oil in different concentrations (200, 500 and 750 mg/kg). After 30 h of deep‐fat frying, oils fortified with canolol‐enriched extracts showed a two to three times better frying performance in comparison to the commonly used antioxidants (TBHQ, 200 mg/kg; rosemary extract, 40 and 200 mg/kg) and a control without antioxidants with regards to the formation of di‐ and polymer triacylglycerols, total polar compounds, secondary degradation products (anisidine value) and the iodine value. The canolol‐enriched extracts were also able to slow down the degradation of α‐ and γ‐tocopherol during frying resulting in significant amounts of tocopherols after 30 h of frying in comparison to the other oils. The influence of the canolol‐enriched extracts indicated strongly concentration‐dependent performance. With increasing concentration of the extract, the thermal stability of the fortified oil was improved. The only disadvantage of the addition of the extracts was an increase in the initial acid value, but within the frying time, only oil fortified with 750 mg canolol‐enriched extract/kg reached the limit given in different countries.     

Lipid oxidation inhibiting capacities of blackseed essential oil and rosemary extract

Lipid oxidation is the main deterioration process that occurs in vegetable oils containing lipid molecules with polyunsaturation. The aim of the present study was to investigate the possible effects of blackseed (Nigella sativa L.) essential oil (BEO) and rosemary (Rosmarinus officinalis L.) extract (RE) on stabilization of sunflower oil under accelerated storage conditions. RE was obtained by soxhlet extraction using methanol, whereas BEO was hydrodistilled from the blackseed extract obtained by extraction using petroleum ether (b.p. 40–60°C). The results indicate that both extracts stabilize sunflower oil to a certain extent, the extent being greater with RE than with BEO based on measurements of peroxide value, p‐anisidine value, amount of nonoxidized linoleic acid in saponified oil samples by HPLC‐DAD, concentration of conjugated diene hydroperoxide, and UV light absorption. The oil stabilizing effect of BEO against lipid oxidation, especially at concentrations of 0.06 and 0.1 g/100 g oil was found to increase as the temperature increased, according to principal component analysis results. Based on its strong lipid oxidation inhibiting capacity, RE can be used as a potential natural extract for stabilizing sunflower oil against oxidation. BEO, at carefully selected concentrations, can be suggested as an alternative supplement of plant origin for improving oil stabilization. Practical applications: Sunflower oil is a widely used vegetable oil for cooking and frying, and has a high linoleic acid content of about 40–70%. Here we show that sunflower oil can be stabilized by adding rosemary and blackseed extracts. The treatment can be useful especially in applications which require heating the oil to high temperatures.     

Enhancing Lipid Oxidative Stability of Cooked‐Chilled Lamb Meat through Dietary Rosemary Diterpenes

A dietary rosemary extract (DRE) containing carnosic acid and carnosol at 1:1 (w/w) for enhancing the lipid oxidative stability in cooked‐chilled lamb meat, is evaluated. Three diets for fattening lambs are tested: i) a cereal‐based concentrate (C‐diet); ii) the C‐diet plus 600 mg vitamin E per kg feed (E‐diet); and iii) the C‐diet plus 600 mg rosemary diterpenes per kg feed (R‐diet). Griddled‐chilled lamb patties are kept at 4 °C and lighting for 2 days, simulating catering conditions. Diterpenes have a lower deposition rate than vitamin E in lamb muscle and are completely degraded during cooking. DRE is thus less effective than dietary vitamin E in enhancing the oxidative stability of the patties. After 2‐day storage, the R‐diet shows lower (p < 0.01) peroxide values and thiobarbituric acid reactive substances than the C‐diet, while, in contrast to the E‐diet, it does not inhibit (p > 0.05) the formation of cholesterol oxidation products. The R‐diet increases (p < 0.05) the proportion of polyunsaturated fatty acids and decreases (p < 0.05) the n‐6/n‐3 ratio. These findings suggest antioxidant protection by dietary bioactive compounds beyond the direct radical scavenging activity that is able to stabilize lipids during the meat shelf‐life. Practical Applications: Cooked‐chilled meat lipids strongly oxidize in ready‐to‐eat dishes kept in retailing conditions, which may negatively affect their levels of polyunsaturated fatty acids (PUFA), cholesterol oxidation products (COP), and other lipid oxidation products. Dietary rosemary diterpenes can be used as a clean alternative to feed additives to enhance the oxidative stability of cooked‐chilled meat. Improved health and antioxidant status of the animal might be able to reduce oxidative spoilage during meat shelf‐life. Diterpenes provide lesser antioxidant protection than dietary vitamin E but may improve the PUFA content, with positive implications for the nutritional quality of lamb fat. The use of dietary antioxidants with different properties may contribute to improving the efficacy of animal feeds to improve meat quality.     

Retraction: Are conjugated linoleic acid (CLA) isomers good or bad trans fats?

Even though trans fatty acids (TFAs) are present in natural sources such as foods from ruminant origins, the development of partially hydrogenated vegetable oil contributed to a significant increase in total TFAs consumption in humans. Currently, TFA consumption is considered to be a risk factor for coronary heart diseases. Researchers are now starting to discover that not all TFAs behave in a similar manner, that is, isomer specificity may be found. Among non‐conjugated TFAs, plant originated TFAs (mainly elaidic and linolelaidic acids) are particularly linked to increased risk for coronary heart diseases, while animal originated TFAs (mainly vaccenic acid) are not. Among conjugated TFAs, two major isomers of conjugated linoleic acid (CLA), cis‐9, trans‐11 and trans‐10, cis‐12, show distinctive biological activities. A number of clinical trials of CLA with effects on body composition have been reported, but effects on coronary heart disease risk factors have been inconsistent. Meanwhile, safety concerns regarding CLA, in particular isomer specificity, have also been raised. Thus, it is critical to identify isomer specific effects of TFAs on particular risk factors, to determine their health impact.     

Synergistic effects of rosemary, sage, and citric acid on fatty acid retention of palm olein during deep-fat frying

A study to optimize the use of oleoresin rosemary extract, sage extract, and citric acid in refined, bleached, and deodorized (RBD) palm olein during deep-fat frying of potato chips was performed using response surface methodology. Results showed that the natural antioxidants used in this study retarded oil deterioration, as evidenced by retention of fatty acid profiles. The linoleic to palmitic (C18∶2/C16∶0) ratio was chosen as the parameter for optimizing the use of natural antioxidants in RBD palm olein during deep-fat frying. Linoleic (R ²=0.946) and palmitic (R ²=0.825) acids were found to be the most important dependent variables, giving highest R ² values to various antioxidant treatments after 25 h of frying. All three antioxidants had independent significant (P<0.05) effects on the C18∶2/C16∶0 ratio. In fact, significant effects on the C18∶2/C16∶0 ratio of RBD palm olein were also given by a second-order form. A combination of 0.076% oleoresin rosemary extract, 0.066% sage extract, and 0.037% citric acid produced the optimal retention of the essential fatty acid C18∶2. In addition, a synergistic effect among these antioxidants on the fatty acid ratio of RBD palm olein was found.     

Use of rosemary extract in preventing oxidation during deep-fat frying of potato chips

The effect of using a rosemary extract on the stability of oil used for frying potato chips has been evaluated. Sliced potatoes were fried intermittently in soybean oil containing a natural extract from rosemary. The conditions used for frying were 185°C for 90 s. Two separate experiments, with and without replenishment of oil, were carried out. Oil samples were taken each day, not only from the frying pans but also by extraction with hexane from the chips. Changes in the induction period of the oil samples (Rancimat method) were determined. The induction period decreased as frying progressed. The reduction in the induction period was higher in the oil free of rosemary extract, and the chips were much darker in color. The oil containing the extract showed greater antioxidant activity, and reduced darkening and rancidity of the oil. Potato chips fried in the oil with added rosemary extract were more acceptable than chips fried in oil containing no extract until the last frying. The free radical scavenging activity of rosemary extract in comparison to other natural antioxidants was also determined by the reduction of O₂ ^.- in a hypoxanthine/xanthine oxidase system.     

Overcoming mass‐transfer limitations in partial hydrogenation of soybean oil using metal‐decorated polymeric membranes

The conventional soybean oil hydrogenation process (metal catalyst on solid support particles slurried in oil, H₂ bubbled through the oil) is compared with metal‐decorated integral‐asymmetric polyetherimide (PEI) membranes, as far as changes in temperature and pressure are concerned. Using metal‐decorated polymeric membranes, H₂ is supplied to the catalytic sites by permeation from the membrane substructure. As opposed to the slurry process, metal‐decorated membranes show only slightly increased trans fatty acid (TFA) formation when the temperature is raised (50–90°C) to accelerate the process. This is likely due to the efficient and to some extent self‐regulating H₂ supply directly to the catalytic sites on the membrane skin. The hydrogenation rate and TFA formation of the metal‐decorated membrane process show a minor dependence on pressure. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Efficient stabilization of bulk fish oil rich in long‐chain polyunsaturated fatty acids

The aim of the present study was to systematically investigate the possibilities of stabilizing a bulk oil rich in long‐chain polyunsaturated fatty acids under ambient conditions. Combinations of different antioxidants (α‐, γ‐ and/or δ‐tocopherol, rosmarinic acid and rosemary extract rich in carnosic acid) as well as lecithin and citric acid were systematically investigated. Efficient stabilization was achieved by choosing a combination of tocopherols rich in γ‐ or δ‐tocopherol and low in α‐tocopherol, by including tocopherol‐sparing synergists like ascorbyl palmitate and carnosic acid from rosemary extract and metal‐chelating agents. For carnosic acid, a concentration of 400 mg/kg oil provides sufficient protection; the concentration of the metal chelator should be adapted to the concentration of metal ions present in the oil. As an alternative ingredient with metal‐chelating and tocopherol‐sparing activity, lecithin may be included in the formulation, but its poor solubility in bulk oils limits its use.     

Content of trans,trans‐2,4‐decadienal in deep‐fried and pan‐fried potatoes

Trans,trans‐2,4‐decadienal is a by‐product of frying oil that is also transferred to fried food. This aldehyde has been found and quantified both in frying oils and fumes generated during frying. Furthermore, it has been reported that 2,4‐decadienal has cytotoxic and genotoxic effects and promotes LDL oxidation. In the present work trans,trans‐2,4‐decadienal was detected directly in fried potatoes (french‐fries). Moreover, the influence of frying conditions (deep‐frying, pan‐frying), the oil type (olive oil, sunflower oil, cottonseed oil, palm oil and a vegetable shortening) and the degree of thermal deterioration (eight successive frying sessions without replenishment) on the production of 2,4‐decadienal in oil and potatoes was studied. The isolation of the aldehyde was performed by methanol extraction, while the identification and quantification was performed by RP‐HPLC. The quantity of trans,trans‐2,4‐decadienal produced during successive pan‐frying demonstrated a peak at the third and fourth frying session. The highest concentration of trans,trans‐2,4‐decadienal was detected in potatoes fried in sunflower oil, and the lowest in olive oil. The quantity of trans,trans‐2,4‐decadienal in fried potatoes decreased during successive deep‐frying at the seventh frying session or remained stable, except for cottonseed oil. The quantity of trans,trans‐2,4‐decadienal in fried potatoes was considered to be dependent on the oil used, on the frying process and, to a lesser extent, on the oil deterioration. In all cases tested, the highest concentration of trans,trans‐2,4‐decadienal was detected during deep‐frying. The unsaturation degree of the frying oil was considered to promote the formation of trans,trans‐2,4‐decadienal. Considering the quantity of 2,4‐decadienal found in french‐fries and in the respective frying medium, direct quantification of 2,4‐decadienal is required in order to make an estimation of intake from french‐fries.     

Kinetic study of β‐carotene and lutein degradation in oils during heat treatment

The kinetics of trans‐β‐carotene and trans‐lutein degradation were individually investigated in palm olein and Vegetaline®, at four temperatures ranging from 120 to 180 °C. HPLC‐DAD analysis was carried out to monitor trans and cis carotenoid variations over the heating time at each temperature. In both oils, initial trans‐β‐carotene and trans‐lutein degradation rates increased with temperature. Trans‐lutein was found to degrade at a slower rate than trans‐β‐carotene, suggesting a higher thermal resistance. The isomers identified were 13‐cis‐ and 9‐cis‐β‐carotene, and 13‐cis‐, 9‐cis‐, 13'‐cis‐, and 9'‐cis‐lutein. In spite of the higher number of lutein cis isomers, their total amount was lower than that of β‐carotene cis isomers. Trans and cis carotenoids were involved in degradation reactions at rates that increased with temperature. All degradation rates were generally found to be lower in Vegetaline® than in palm olein. These results were explained by the initial composition of the two oils and especially their peroxide and vitamin E contents.     

Medium‐chain alkyl esters of tyrosol and hydroxytyrosol antioxidants by cuphea oil transesterification

Effective lipophilic antioxidants were prepared by non‐aqueous enzymatic transesterification of plant phenols with cuphea oil. Tyrosol and hydroxytyrosol, abundantly available phenols from olive oil processing byproduct, were found to be predominately acylated with capric acid derived from the triglyceride fraction of the Cuphea germplasm line PSR 23 (Cuphea Viscosissima × C. lanceolata). The reaction was complete within 2 h, with a >97% conversion of either phenol using immobilized Candida antarctica lipase B. The reaction products were good solvents for tyrosol or hydroxytyrosol, suggesting a facile manufacturing route not dependent on use of organic solvents. Phenolic derivatives were assessed for their ability to serve as antioxidants for preventing the oxidation of polyunsaturated fatty acyl groups. The antioxidant capacities of the cuphea‐derived fatty acyl derivatives of tyrosol or hydroxytyrosol were the same as their respective derivatives prepared from decanoic acid. These biobased antioxidants may improve the oxidative stability of sensitive fatty acids in food applications. Practical applications: A new biobased antioxidant was created for the food industry. Foods can contain fats and oils that are susceptible to deterioration during storage, which can limit product quality and shelf‐life. Synthetic antioxidants can slow the spoilage process, although there are limitations to how much can be added to foods. The food industry is interested in using natural ingredients to solve storage stability problems. We found that the oil from the plant Cuphea, cultivated in the upper Midwest region of the US, is very useful for modifying olive oil waste molecules to create antioxidants for use in foods. The developed process would be suitable for commercial production. This research creates a new commercial use for a specialty oil seed crop, expands the market for cuphea oil, and has developed two novel antioxidants to help the food industry improve food quality.     

Properties and antimicrobial activities of starch–sodium alginate composite films incorporated with sodium dehydroacetate or rosemary extract

Antimicrobial films were prepared with oxidized and acetylated corn starch–sodium alginate by incorporating sodium dehydroacetate or rosemary extract. Films incorporated with sodium dehydroacetate ≥ 0.1% or rosemary extract ≥ 0.3% had an anti‐Escherichia coli effect. Aspergillus niger could be effectively inhibited by the incorporation of sodium dehydroacetate ≥ 0.3%. Rosemary extract showed no inhibitory effect on Aspergillus niger. Sodium dehydroacetate and rosemary extract reduced the tensile strength and elongation at break, and increased the water vapor permeability of the films. Sodium dehydroacetate made the films more greenish–yellow with the increase of sodium dehydroacetate concentration. The color of the films became darker and more reddish–yellow as rosemary extract was increased. Fourier transform infrared (FTIR) spectra analysis revealed that sodium dehydroacetate and rosemary extract reduced starch crystallinity. The surface of the films became rougher as a result of an addition of sodium dehydroacetate and rosemary extract. These findings had potential applications in prolonging food shelf life based on different needs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Electron spin resonance spectroscopy for evaluation of early oxidative events in semisolid palm oil

Electron spin resonance (ESR) spectroscopy was applied to study early oxidative events in semisolid palm oil in bulk. Oil was stored at mildly accelerated conditions of 50°C for 7 days and the free radical formation was followed with the addition of spin trap N‐tert‐butyl‐α‐phenyl‐nitrone. Dissolution of the oil samples in isooctane prior to ESR measurements stabilized the ESR signal allowing the changes in relative free radical concentrations during oil storage to be monitored. Formation of lipid hydroperoxides as primary lipid oxidation products was found to correlate with the tendency for the formation of free radicals in the oil during the storage and accordingly, ESR spectroscopy may be used to detect the early events in lipid oxidation in palm oil. However, the interference of added rosemary extract (RE) in ESR analyses was seen as an increased ESR signal while the efficiency of RE as antioxidant in palm oil was confirmed by isothermal DSC. Practical applications : ESR spectroscopy may be used to evaluate early events of oxidation in semisolid oils such as palm fat, which is widely used in food industry.