富含n-3LC-PUFA调和油的家庭烹饪氧化稳定性研究

通过对DHA和EPA质量分数分别为0.23%、0.45%、0.90%、1.80%的调和油进行家庭炒菜试验的研究,考察了富含n-3长碳链多不饱和脂肪酸(Long chain polyunsaturated fatty acid,LC-PUFA)的调和油的家庭烹饪氧化稳定性。结果表明:炒土豆丝后,上述油样中DHA和EPA的损失分别为1.2%、2.9%、2.4%、1.4%;炒青椒肉片后其损失分别为:3.0%、2.2%、2.4%、4.5%。炒菜前后调和油的各项指标包括羰基价、总氧化值(TOTOX)、硫代巴比妥酸值(TBA)、酸价和聚合物含量与大豆油(对照样1)以及不含DHA和EPA的调和油(对照样2)相比,油样的氧化程度以及油脂品质与两个对照样接近。不同DHA和EPA含量的调和油炒菜之后其多不饱和脂肪酸保留率在95%以上,氧化稳定性和豆油接近,适合家庭烹饪。     

Composition, stability and acceptability of different vegetable oils used for frying peanuts

The purpose of this work was to determine the chemical stability of vegetable oils in the frying process and the consumer acceptance of fried-salted peanuts prepared in different vegetable oils. Fatty acids composition was determined in sunflower, corn, soybean, peanut and olive oils. A chemical study (free fatty acid and p-anisidine values) of these oils at frying temperature (170 °C) was developed during 96 h. Consumer test of fresh products was performed on fried-salted peanuts prepared in the different oils. Peanut oil and virgin olive oil presented oleic acid as predominant fatty acid (44.8% and 64.2%, respectively), making it more resistant to lipid oxidation at frying temperature than the other refined vegetable oils (sunflower, corn and soybean oils). Virgin olive and peanut oils showed less increment of free fatty acids and p-anisidine value than the other oils along the heating essay. In addition, fried-salted peanuts prepared with refined peanut oil showed higher consumer acceptance than those prepared with other vegetable oils such as sunflower, corn, soybean and olive oils. Peanut oil could be used to fry peanuts obtaining products with higher consumer acceptance and shelf-life, thus preventing loss of their sensory and nutritional quality.     

Physicochemical Properties and Volatile Profiles of Cold-Pressed Trichosanthes kirilowii Maxim Seed Oils

The physicochemical properties and volatile profiles of cold-pressed Trichosanthes kirilowii Maxim (T. kirilowii) seed oils from four regions in China were determined in this study. The total oil content and cold-pressed oil yield of the four different sourced seeds were 38.06–44.33% and 15.17–30.97%, respectively. All the cold-pressed oil samples were found to be rich in polyunsaturated fatty acids, with content ranging from 45.41 to 75.32% of the total fatty acids. Punicic, α-eleostearic and catalpic acids were the main conjugated linolenic acid isomers in the cold-pressed T. kirilowii seed oils. The results of melting and crystallization profiles indicated that each oil sample exhibited different transitions steps due to its triacylglycerol composition, crystal structure and total unsaturation. Analysis of volatile profiles showed that 2,4-nonadienal was one of the most important aldehydes in the cold-pressed T. kirilowii seed oils, and less short chain acids (0.20%) but more esters (5.48%) were found in the sample with high content of punicic acid (Hebei sample). Results of oil quality indices indicated that cold-pressed T. kirilowii seed oils were liable to be oxidized, and their stabilities reduced with the increase of acid values. In general, more attention should be paid to improve the oxidative stability of cold-pressed T. kirilowii seed oils in their further application in food industry.     

Frying oils with lower levels of saturated fatty acids induce less heterocyclic amine formation in meat floss (boiled,shredded and fried pork)

Heterocyclic amines (HAs) as potent mutagens are formed in meat floss which is a boiled, shredded and fried traditional meat product. In this study, effects of frying oils (lard, soybean oil and palm oil) on the formation of HAs in meat floss during frying have been investigated. The results showed that the contents of Norharman, Harman, AαC and MeAαC in meat floss that treated with lard and palm oil were higher than soybean oil which contained less saturated fatty acids (P < 0.05). The contents of total HAs in meat floss that treated with palm oil at 150 °C and 180 °C were significantly higher than that treated with soybean oil and lard (P < 0.05). In conclusion, meat floss treated with soybean oil at 120 °C, 150 °C and 180 °C contained lowest levels of HAs and soybean oil could be used as lard substitution to produce healthy meat floss.     

Thermal stability of corn oil flavoured with Thymus capitatus under heating and deep-frying conditions

BACKGROUND: The thermal stability of corn oil flavoured with thyme flowers was determined and compared with that of the original refined corn oil (control). The oxidative stability index (OSI) was measured and samples were exposed to heating (30 min at 150, 180 and 200 °C) and deep‐frying (180 °C). Changes in peroxide value (PV), free fatty acid (FFA) content, specific absorptivity values (K₂₃₂ and K₂₇₀), colour and chlorophyll, carotenoid and total phenol contents were monitored. RESULTS: The OSI and heating results showed that thyme incorporation was effective against thermal oxidation based on the increased induction time observed for the flavoured oil (6.48 vs 4.36 h), which was characterised by lower PV, FFA content, K₂₃₂ and K₂₇₀ than the control oil after heating from 25 to 200 °C, with higher red and yellow colour intensities and chlorophyll, carotenoid and total phenol contents. The deep‐frying test showed the accelerated deterioration of both oils in the presence of French fries. CONCLUSION: Compared with the control oil, the thyme‐flavoured oil showed improved thermal stability after heating. This could be attributed to the presence of thyme pigments and antioxidant compounds allowing extended oil thermal resistance. Copyright © 2011 Society of Chemical Industry     

模拟油罐储藏大豆油氧化稳定性研究

以过氧化值、酸值、p-茴香胺值和氧化稳定性指数(OSI)为评价指标,模拟油罐储藏,通过正交试验探讨了温度、含水量、氮气量、储油罐的表面积/体积关键影响因素,在储藏5个月内对成品大豆油储藏期氧化稳定性的影响.结果表明,在大豆油储藏过程中,温度对油脂的氧化稳定性的影响比较显著,其次是氮气量、含水量和储油罐的表面积/体积.由于受外界环境和自身结构的影响,大豆油氧化是一个复杂的过程,因此,为了控制成品大豆油具有较好的氧化稳定性,成品大豆油应在较低的温度(25℃)、适量的含水量(0.02％～0.05％)、充足的氮气(100％)和较大的表面积/体积条件下储藏.     

Storage stability of butter oils produced from sheep’s non-pasteurized and pasteurized milk

The physical and chemical characteristics and thermal stability of butter oil produced from non-pasteurized and pasteurized sheep’s milk were studied. Thermal stability of samples was estimated by using the accelerated shelf-life testing method. Samples were stored at 60, 70 and 80 °C in the dark and the reaction was monitored by measuring peroxide, thiobarbituric acid and free fatty acid values. The peroxide and thiobarbituric acid values increased as the temperature increased. The increase of acid values of the two samples was not significant. A slight increase in free fatty acid value showed that hydrolytic reactions were not responsible for the deterioration of butter oil samples in thermal stability studies. When compared, butter oil produced from pasteurized sheep’s milk has higher thermal stability than butter oil produced from non-pasteurized sheep’s milk. Although butter oil produced from non-pasteurized milk was not exposed to any heat treatment, the shelf-life of this product was lower than the shelf-life of butter oil produced from pasteurized sheep’s milk. Therefore, heat treatment for pasteurization did not affect the thermal stability of butter oil.     

Impact of Roasting on the Chemical Composition and Oxidative Stability of Perilla Oil

Abstract: The impact of roasting was observed with regard to certain changes in the chemical components and oxidative stability of oil expelled from the roasted perilla seeds. The roasting times were established differently at each roasting temperature of 180, 200, and 220 °C. Trans fatty acids in perilla oil were detected, and the level detected increased as the roasting time increased. Moreover, the roasting of perilla seed led to an increase of 4 tocopherols, α‐, β‐, γ‐, and δ‐tocopherol, as well as phosphorus in the oil. The oxidative stability of the oils obtained after roasting increased during 60 d of storage at 60 °C. The rate of decrease of tocopherol in the oil from unroasted perilla seed was faster than that of the tocopherol in the oils from roasted perilla seeds during storage. Practical Application: The results reported in present research provide useful information that the producers of perilla oil could apply for their processing.     

高温加热对牡丹籽油脂肪酸和理化性质的影响

通过研究牡丹籽油经不同温度（90、120、150、180、210、240 ℃）加热30 min后脂肪酸组成、含量以及 理化性质的变化,探究高温加热对牡丹籽油品质的影响。结果表明：牡丹籽油在高温加热后会生成脂肪酸异构体、 环状脂肪酸以及中、短碳链脂肪酸,且温度越高种类越多。虽然上述高温加热后牡丹籽油各理化指标均符合食用油 标准,但是随着温度的升高,牡丹籽油不饱和脂肪酸含量下降,富含营养价值的α-亚麻酸含量在温度超过180 ℃时 迅速下降。可见,在理化指标上牡丹籽油具有良好的热稳定性,但是从营养角度其不适合用于高于180 ℃的高温煎 炸等烹调方式。     

加热条件下α-生育酚在油脂中的抗氧化活性、损耗及其对油脂全氧化值的影响

以大豆油、棕榈油、茶油和猪油为材料,以α-生育酚为研究对象,采用Rancimat法（110～130?℃）和烘箱法（120～180?℃）研究在加热条件下α-生育酚在油脂中的抗氧化活性、损耗情况及其对油脂全氧化值的影响。Rancimat结果表明：110 ℃条件下,α-生育酚（200～1?000?mg/kg）能显著延长猪油、茶油和棕榈油的氧化诱导期（P＜0.05）,且添加量越大,油脂的氧化诱导期越长,而在大豆油中,α-生育酚则表现出促氧化现象,即添加量越大,大豆油氧化诱导期越短;烘箱实验结果表明：α-生育酚在油脂中的损耗率,与加热温度呈正相关,与其添加量呈负相关;180?℃条件下,α-生育酚（1?000?mg/kg）能有效抑制大豆油、茶油和猪油在加热过程中全氧化值的增长;而在棕榈油中,α-生育酚促进了棕榈油全氧化值的增大,添加量越大,促进作用越强。     

葡萄籽油的添加对改善特种植物油脂货架保质期的研究

保健植物油脂对人体具有较好营养补充,它也具有独特的食品风味。本项目对葡萄籽油的添加改善月见草油、紫苏油、亚麻籽油等保健植物油的氧化稳定性研究。结果表明,葡萄籽油的OSI值较大,保留时间(货架储存期)长,而月见草油、紫苏油、亚麻籽油等氧化稳定性不是很好,通过添加复配氧化剂(0.02%BHT+0.02%VE+0.02%VC)和葡萄籽油对比,找出通过添加葡萄籽油,进而延长油脂的保质期限的有效措施。     

Comparative Growth ofEscherichia coli0157:H7, Spoilage Organisms and Shelf-Life of Shredded Iceberg Lettuce Stored under Modified Atmospheres

The objective of this work was to compare organoleptic and microbiological spoilage with the survival of Escherichia coli 0157:H7 in modified atmosphere (MA) stored shredded lettuce. The rates of growth of E coli 0157:H7, increase in aerobic plate counts (APC g⁻¹), and rates of visual spoilage of shredded lettuce held under air or MA at 13 and 22°C were compared. Samples were inoculated with nalidixic acid-resistant E coli 0157:H7 (ATCC 35150) and placed in a chamber which was continuously flushed with gas mixtures of 0/10/90, 3/0/97, 5/30/65, 20/0/80 (O₂/CO₂/N₂, v/v) and held at 13 or 22°C. APC growth was inhibited in 5/30/65 (O₂/CO₂/N₂) at 13°C compared to all other atmospheres which were not significantly different from each other. The growth rates for both E coli 0157:H7 and APC were greatest in air at 22°C. Carbon dioxide concentration had no significant effect on the growth of E coli 0157:H7 at either temperature. The shelf-life of shredded lettuce, as judged by appearance, was extended in atmospheres containing 30% CO₂ by approximately 300% compared to air. The APC were similar at the time when the shredded lettuce samples were judged unacceptable regardless of shelf-life. However, the extended shelf-life provided by the MA allowed E coli 0157:H7 to grow to higher numbers compared to air-held shredded lettuce.     

苍耳籽油的研究

苍耳是一种很有开发价值的野生油源,苍耳籽仁含油量高达４５．４６％,经气相色他耳籽油中脂肪酸以亚油酸为主,含是为６５．９％,油酸含量为２０．８％,而和脂肪酸含量较低。ＯＳＩ法测定其氧化稳定性,结果显示苍耳籽带壳烘烤后提取的油脂氧化稳定性显著升高。     

French Fries oleuropein content during the successive deep frying in oils enriched with an olive leaf extract

Olive oil, sunflower oil and soybean oil were enriched with an olive (Olea Europaea) leaf extract rich in oleuropein at a supplementation level of 100 mg total phenolics per kg oil. Supplemented oils were used for deep frying of potatoes for eight successive frying sessions without replenishment under domestic frying conditions. Supplemented oils contained oleuropein while deep frying resulted in a gradual decrease in oils oleuropein content. After the eighth successive frying, oleuropein was still detected in oils, its retention being 3.2–12.4%. Deep frying of potatoes in supplemented oils succeeded in preparing French fries containing oleuropein even after eight successive fryings. Contrary to the oil type, the number of frying sessions affected potatoes oleuropein content. Oleuropein intake by consuming French fries deep‐fried in enriched oils was approximately ten times higher in potatoes prepared in the first frying session as compared to the respective intake after the eighth frying.     

Fatty Acid Composition and Oxidative Stability of Cold-pressed Edible Seed Oils

ABSTRACT: This study was conducted to determine the fatty acid (FA) compositions and oxidative stabilities of cold-pressed cranberry, carrot, hemp, and caraway seed oils. The cold-pressed cranberry and hemp seed oils exhibited higher α-linolenic acid (18:3n-3) contents with levels of 22 and 19 g/100 g fatty acids, respectively. Cold-pressed carrot seed oil contained about 82% oleic acid and had the lowest total saturated fatty acids among all tested oils. Cold-pressed caraway seed oil had the greatest oxidative stability with an OSI value of 150 hours. In addition, cold-pressed carrot seed oil had the lightest color while hemp seed oil was the darkest among all the oils tested.     

Stabilization of sunflower oil by pennyroyal (Mentha piperita) extracts during accelerated storage

The aim of this study was to examine the antioxidant activity of pennyroyal (Mentha piperita) extracts of sunflower oil as a replacement for synthetic antioxidant. This study was performed in two stages. In the current study, it was proven that the examined pennyroyal was in all ways similar to Mentha piperita sequence and its blast performance at the National Center for Biotechnology Information (NCBI). The anti-oxidation activities of Mentha piperita extracts were identified using 2,2-diphenyl-1-picrylhydrazyl and total phenolic content. The protective effect of extracts on the stabilization of sunflower oil was tested and compared with tertiary butyl hydroquinone by measuring peroxide values (y₁), p-anisidine (y₂), and rancimat value (y₃) during storage for 4 weeks at 60°C (Schaal test).The results showed that the antioxidant activity of Mentha piperita extracts (500 ppm) was equal with tertiary butyl hydroquinone effect (100 ppm) at 60°C. In the next step, the sunflower oil containing Mentha piperita extracts (500 ppm) and tertiary butyl hydroquinone (100 ppm) as two blocks were tested to determinate the optimum condition of both high temperature (x₁:180–220°C) and time (x₂: 5–15 min) variables on oxidative stability. The optimum conditions were optimized using response surface methodology. The analysis of variance result showed that temperature and time had significant effects on peroxide, p-anisidine, and rancimat values (p < 0.01). The optimal condition for the examined parameters was related to a sunflower oil treatment containing Mentha piperita extracts (500 ppm) at 180°C and 5 min (with the desirability of 92.1%).     

Oil Bodies Extracted from High‐Fat and Low‐Fat Soybeans: Stability and Composition During Storage

Soybeans contain oil bodies (OBs) that encapsulate triacylglycerols (TAGs) with a phospholipid monolayer carrying scattered proteins. In nature, soybean OBs can form natural emulsions in aqueous media and may serve as natural, minimally processed, stable, and pre‐emulsified oil for addition into appropriate food systems. In this study, OBs were obtained by aqueous extraction from the mature seeds of 2 soybean crop cultivars, high‐fat soybean and low‐fat soybeans. The compositions of the extracted OBs were analyzed during storage at room temperature up to 14 d (pH = 7). The oxidative stability of these OBs, stored at 60 °C, was evaluated by measuring the presence of primary (lipid hydroperoxides) and secondary lipid oxidation products (malondialdehyde) by determining the standard peroxide value (PV) and thiobarbituric acid‐reactive substances (TBARS) value. During storage, the contents of unsaturated fatty acids, phospholipids, and tocopherols declined in both OBs, while their mean particle diameters (d₃₂) and ζ‐potentials increased. The changes in PV and TBARS values exhibited a similar trend for both OBs, but the OBs from low‐fat soybeans had significantly lower PV and higher TBARS values than the OBs from high‐fat soybean cultivars (P < 0.05). Overall, the OBs from both soybean cultivars had good stability during storage.     

Deep fat frying of frozen foods in sunflower oil. Fatty acid composition in fryer oil and frozen prefried potatoes

The fatty acid pattern was used to evaluate the alteration of a sunflower oil that had been used 20 times to fry various frozen foods with frequent replenishment (FR) or without replenishment (NR) of the used oil with fresh oil during frying. Furthermore, the fat extracted from potatoes fried in the sunflower oil from fryings 1, 5, 8, 12, 16 and 20 was also analysed by gas–liquid chromatography to compare its fatty acid profile with that of the corresponding fryer oil. The amount of unaltered fatty acids decreased from 96.2 mg per 100 mg oil in the unused sunflower oil to 89.6 mg per 100 mg oil after 20 fryings in the FR oil and to 88.9 mg per 100 mg oil in the NR oil, following a linear adjustment (r > 0.97; p < 0.001). Linoleic acid also decreased while palmitic and oleic acids increased in the bath oil. Fatty acid variations were more pronounced in NR than FR oil for major fatty acids and not only related to the degradation of unsaturated fatty acids but also to the interactions between the bath oil and the fried food fat. Thus the increase in palmitic acid of the fryer oil could be due to migration of this fatty acid from the prefried frozen potatoes as revealed by the composition of the fat extracted from those potatoes. Although the fatty acid variation (eg myristic, palmitic, oleic, trans–cis isomers of linoleic and linoleic acids) was not equivalent in FR or NR fryer oil and in the fat of the potatoes, the changes in total unaltered fatty acids were not significantly different in oil and potatoes. Present data suggest that frequent addition of fresh oil throughout the frying process minimises the fatty acid changes, contributing to the obtainment of fried foods with a healthy fatty acid profile. © 2000 Society of Chemical Industry     

Measurement of emissions from air pollution sources. 4. C1-C27 organic compounds from cooking with seed oils

The emission rates of gas-phase, semivolatile, and particle-phase organic compounds ranging in carbon number from C1 to C27 were measured from institutional-scale food cooking operations that employ seed oils. Two cooking methods and three types of seed oils were examined: vegetables stir-fried in soybean oil, vegetables stir-fried in canola oil, and potatoes deep fried in hydrogenated soybean oil. The emission rates of 99 organic compounds were quantified, and these include n-alkanes, branched alkanes, alkenes, n-alkanoic acids, n-alkenoic acids, carbonyls, aromatics, polycyclic aromatic hydrocarbons (PAH), and lactones. Carbonyls and fatty acids (n-alkanoic and n-alkenoic acids) make up a significant portion of the organic compounds emitted from all three seed oil cooking procedures. The compositional differences in the organic compound emissions between the different cooking operations are consistent with the differences in the organic composition of the various cooking oils used. The distribution of the n-alkanoic acids between the gas and particle phases was found to be in good agreement with gas/particle partitioning theory. The relative importance of emissions from commercial deep frying operations to the total emissions of C16 and C18 n-alkanoic acids in the Los Angeles urban area was estimated using the available information and is estimated to account for approximately 7% of the total primary emissions of these acids. Additional emissions of these n-alkanoic acids from stir-frying and grill frying operations are expected. Estimates also indicate that seed oil cooking may make up a significant fraction of the emissions of lighter n-alkanoic acids such as nonanoic acid.     

Effects of Accelerated Storage on the Quality of Kenaf Seed Oil in Chitosan‐Coated High Methoxyl Pectin‐Alginate Microcapsules

The objective of this research was to study the oxidative stability and antioxidant properties of microencapsulated kenaf (Hibiscus cannabinus L.) seed oil (MKSO) produced by co‐extrusion technology upon accelerated storage. The combination of sodium alginate, high methoxyl pectin, and chitosan were used as shell materials. The oxidative stability of the kenaf seed oil was determined by iodine value, peroxide value, p‐Anisidine value, total oxidation (TOTOX), thiobarbituric acid reactive substances assay, and free fatty acid content. Total phenolic content, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) cation radical‐scavenging assay and 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging assay were used to examine the antioxidant properties of oils. Oxidative stability tests showed that bulk kenaf seed oil (BKSO) was oxidized significantly higher (P < 0.05) than MKSO. The total increment of TOTOX value of BKSO was 165.93% significantly higher (P < 0.05) than MKSO. Co‐extrusion technology has shown to be able to protect kenaf seed oil against lipid oxidation and delay the degradation of natural antioxidants that present in oil during storage.