Effects of Sesame Oil Addition to Soybean Oil During Frying on the Lipid Oxidative Stability and Antioxidants Contents of the Fried Products During Storage in the Dark

ABSTRACT: Effects of sesame oil addition to soybean oil during frying on the lipid oxidative stability and antioxidants contents of fried products during storage in the dark were studied. Flour dough pieces (2 cm × 2 cm × 0.1 cm) were fried at 160 °C for 1 min in sesame oil-added soybean oil. Concentrations of sesame oil in the frying oil were 0%, 10%, and 20% by volume. Fried products were put into a glass bottle, and the bottles were tightly sealed and stored at 60 °C in the dark for 18 d. Lipid oxidation of fried products was determined by fatty acid composition changes and conjugated dienoic acid (CDA) and p -anisidine (PA) values. Tocopherols and lignan compounds in the fried products were determined by high-performance liquid chromatography. Relative content of linolenic acid decreased, and CDA and PA values increased during storage of the fried products in the dark. Fatty acid composition change and CDA and PA values during storage were lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil. The results clearly showed that addition of roasted sesame oil to soybean oil at 10% and 20% during frying decreased the lipid oxidation of fried products during storage in the dark for 18 d by extension of induction period and decrease in decomposition of oxidized lipids. Fried products contained 134 to 267 ppm tocopherols and 0 to 148 ppm lignans before storage; however, their contents decreased during storage in the dark. Lignan compounds were more stable than tocopherols, and the rate of tocopherols degradation was lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil, which could be because of protection of tocopherols from degradation by lignan compounds.     

Potato Chip Quality and Frying Oil Stability of High Oleic Acid Soybean Oil

High oleic soybean (HOSBO) and low linolenic acid soybean (LLSBO) oils were evaluated individually and in a 1:1 blend along with cottonseed oil (CSO) to determine frying oil stabilities and the flavor quality and stability of potato chips. Potato chips were fried in the oils for a total of 25 h. Potato chips and oils were sampled periodically for sensory data, gas chromatographic volatile compounds, free fatty acids, and total polar compounds. Total polar compounds levels decreased with increasing amounts of oleic acid. The LLSBO had the highest overall increase (17.3%) in total polar compounds from 0 to 25 h of frying. Flavor evaluations of fresh and aged (0, 1, 3, 5, and 7 wk at 25 °C) potato chips showed differences between potato chips fried in different oil types. Potato chips fried in either LLSBO or in the 1:1 blend had significantly higher intensities of deep fried flavor than the chips fried in HOSBO. Potato chips fried in HOSBO, which had 2% linolenic acid and 1.3% linoleic acid, had significantly higher fishy flavor intensity than chips fried in the other oils. The presence of linoleic acid at a level lower than the amount of linolenic acid probably allowed for the fishy flavors from the degradation of linolenic acid in HOSBO to become more apparent than if the linoleic acid level was higher than linolenic acid. Hexanal was significantly higher in potato chips fried in LLSBO than in the chips fried in the other oils, indicating low oxidative stability during storage. Blending HOSBO with LLSBO in a 1:1 ratio not only improved flavor quality of chips compared with those fried in HOSBO, but also improved oil fry life and oxidative stability of chips compared with LLSBO.     

Whey Improves Oxidative Stability of Soybean Oil

Whey powder and Maillard reaction products (MRP) produced from whey suppressed the formation of hydroperoxides and thiobarbituric acid-reactive substances, and lowered oxygen uptake in the model system. The antioxidant activity of whey was dependent on concentration and preheating treatment. Unheated whey and whey heated for at 24 hr were most effective in retarding lipid oxidation. Whey solutions of 16% were most effective antioxidants followed by 10% and 3% solutions. As MRP indicators increased antioxidant activity increased. Whey may be useful as an antioxidant in some processed foods.     

芝麻油中掺加大豆油鉴别方法的研究

利用气相色谱法分析和确定香油中脂肪酸组成的分布特征,以此建立一种快速鉴别香油是否掺加大豆油的分析方法。研究结果表明,测量假芝麻油样品中C18∶1n9c和C18∶3n3两种特征脂肪酸含量,使用二元一次方程可以计算假芝麻油中大豆油的含量,芝麻油约为90%时,最大计算误差为8.16%,其结果为(实测值±7.36) g/100 g;芝麻油约为70%时,最大计算误差为15.55%,其结果为(实测值±10.84) g/100 g;芝麻油约为50%时,最大计算误差为30.35%,其结果为(实测值±15.00) g/100 g。这个计算方法是可行的,可以用来鉴别芝麻油中是否掺加大豆油,并计算出掺假芝麻油中大豆油的含量。     

High-Temperature Natural Antioxidant Improves Soy Oil for Frying

ABSTRACT:  The objectives of this study were to determine the frying stability of soybean oil (SBO) treated with a natural citric acid-based antioxidant, EPT-OILShield™ able to withstand high temperatures and to establish the oxidative stability of food fried in the treated oil. Soybean oil with 0.05% and 0.5% EPT-OILShield and an untreated control SBO were used for intermittent batch frying of tortilla chips at 180 °C for up to 65 h. Oil frying stability was measured by free fatty acids (FFA) and total polar compounds (TPC). Chips were aged for up to 4 mo at 25 °C and evaluated for rancid flavor by a 15-member, trained, experienced analytical sensory panel and for hexanal content as an indicator of oxidation. Oil with 0.05% EPT-OILShield had significantly less FFA and TPC than the control. The effect of EPT-OILShield was apparently retained in aged chips because hexanal levels were significantly lower in chips fried in oil with 0.05% EPT-OILShield than in chips fried in the control. Tortilla chips fried in the control were rancid after 2 mo at 25 °C at sampling times evaluated from 25 to 65 h; however, chips fried in oil with 0.05% EPT-OILShield and used for 65 h were described as only slightly rancid after 4 mo. Gamma tocopherol levels were significantly higher in the chips fried in the oil with 0.05% EPT-OILShield than in the control, helping to inhibit oxidation in the tortilla chips during storage.     

Microwave Heating Affects Composition and Oxidative Stability of Sesame (Sesamum indicum) Oil

The effects of microwave heating on antioxidative components and lipid quality of sesame seeds were studied. Amounts of antioxidative components were 576, 18, and 8 mg/kg oil for γ-, δ-, and α-tocopherols; 6,824, 5,642, and 54 mg/kg oil for sesamin, sesamolin, and sesamol, respectively. During microwave treatments, concentrations of tocopherols, sesamin and sesamolin gradually decreased, and ca. 20% of these dominant components was lost after 30 min heating. However, microwave treatments for 16 to 20 min, which would be optimal to prepare sesame oil with better quality, still retained over 85% of the antioxidative components (with few exceptions) and caused no significant chemical changes in lipids.     

低场核磁共振技术检测大豆煎炸油品质的研究

煎炸食品一直受到消费者的喜爱,煎炸食品的质量与煎炸油的品质息息相关。传统评价煎炸油品质的理化方法检验费时、操作繁琐、易接触有毒试剂,不能实现在线检测。低场核磁共振技术(LF-NMR)是一种快速、准确、无损的检测方法。以大豆油和添加抗氧化剂大豆油为原料、薯条为煎炸食品,对大豆煎炸油进行理化指标及低场核磁检测。通过研究LF-NMR检测参数S_(21)及t_(2w)与煎炸时间、酸价、羰基价、极性组分含量的相关性,发现S_(21)与2种大豆煎炸油的上述指标均呈正相关、t_(2w)与之均呈负相关,且相关性良好,相关系数在0.905 8~0.994之间。说明利用低场核磁共振技术检测的S_(21)和t_(2w)可以有效地反映大豆煎炸油品质的变化,且不受抗氧化剂的影响。     

3种食用油在薯条煎炸过程中的品质变化

以大豆油、葵花籽油、棕榈油为研究对象,探讨在(180±5)℃条件下煎炸薯条,每天连续煎炸4h,共煎炸5d后各食用油理化指标的变化。结果表明:随着煎炸时间延长,3种食用油的色泽加深、黏度增加;酸价(AV)显著增加,但未超过国家标准;碘价(IV)则随着煎炸过程进行而逐步降低;过氧化值(POV)在煎炸过程中均先上升后下降,其中大豆油和葵花籽油的POV呈波动性;煎炸3d后,大豆油、葵花籽油的羰基值(CV)超过或非常接近国家标准50meq O2/kg,煎炸4d后,两种油的极性化合物(TPM)含量超过国家标准;整个煎炸过程中棕榈油的CV和TPM含量均低于大豆油和葵花籽油。     

Effects of Bleaching on the Properties of Roasted Sesame Oil

ABSTRACT: Improvement in quality of roasted sesame oil was studied. Roasted sesame oil was bleached at 70 °C, 85 °C, or 100 °C for 20 min with acid-activated clay at 0.5%, 1.0%, or 3.0% (w/w) and then centrifuging at 12096 × g at 4 °C for 10 min. The color of the roasted sesame oil became lighter and the viscosity of oil decreased by bleaching. Bleaching caused a significant increase in the smoke point of the oil, from 170 °C to a range of 183 °C to 191 °C. Bleaching increased palmitic acid and decreased linoleic acid contents of roasted sesame oil. Bleaching decreased free fatty acid (FFA) and conjugated dienoic acid (CDA) contents and carbonyl values (CV) of roasted sesame oil. The more the acid clay was used, the lower were the FFA and CDA contents and CV of the oil. Amount of acid clay in bleaching of roasted sesame oil had higher effects on the color, viscosity, smoke point, FFA and CDA contents, and CV of roasted sesame oil than the bleaching temperature. Bleaching did not show a significant effect on tocopherol contents of the sesame oil. Bleaching tended to decrease sesamolin contents and increase sesamol contents in the roasted sesame oil. As the amount of acid clay and the bleaching temperature increased, the contents of sesamin and sesamolin in the oil decreased while sesamol contents increased.     

茶油深层煎炸稳定性的研究

以棕榈油作对照,采用精炼茶油进行深层煎炸。测定煎炸用以及薯条中的油脂在煎炸过程中的主要化学指标,即酸值、过氧化值、羰基价、碘价、皂化值、K值及极性化合物含量等的变化;分析煎炸用茶油的挥发性成分的变化;评价薯条的感官品质。试验结果表明:连续煎炸30h(120批次),茶油及棕榈油的酸值、过氧化值、羰基价、极性化合物含量和K值均逐渐升高,碘价和皂化值则逐渐降低;总挥发物含量逐渐增加,而一些小分子质量挥发物呈先升后降的趋势;用新鲜油煎炸的薯条的总体得分较高;除过氧化值外,薯条中茶油的其它测定指标的变化滞后于煎炸用油的变化。对照国标GB7102,24h时除茶油中的羰基价超标外,其它指标至30h时仍处于规定限值范围。茶油的深层煎炸寿命为24h(96批次)。用茶油煎炸的薯条易被消费者接受。     

煎炸油在薯片煎炸过程中的品质变化

以煎炸油为研究对象,以薯片为煎炸原料,研究煎炸油煎炸过程中理化指标变化及各指标间的相关性。结果表明:在煎炸过程中,煎炸油的折光指数、色泽、酸值、羰基值和极性值均随时间的延长而增大;过氧化值随着煎炸时间延长先增大后逐渐减小;碘值随时间的延长而降低;比重、黏度、皂化值在煎炸过程中的变化无明显规律。酸值、羰基值、极性值、色泽和折光指数彼此之间有极显著的正相关性,且相关系数均大于0.9;煎炸油极性值的变化可通过色泽和酸值进行预测。     

The Dielectric Property of Soybean Oil in Deep-Fat Frying and the Effect of Frequency

ABSTRACT: :
Suitability of the dielectric constant for real time and continuous evaluation of frying oil was investigated. Measurements of the dielectric capacitance, in the frequency range 1 kHz to 100 kHz, were made on soybean oil heated at several temperatures (180, 200, 220, and 240 °C) for a few d. Frequency dependence was also measured between 50 Hz and 30 MHz. The dielectric constant of the soybean oil increased with increase in the heating time, and was well correlated with acid value, density, and relative viscosity. Our equipment for measuring capacitance would be available for real time and continuous evaluation of frying oil quality in the food industry.     

油炸过程中茶多酚对油脂品质的影响

研究茶多酚在油炸过程中对油脂品质的影响.通过测定油脂的理化指标、脂肪酸组成以及挥发性风味成分,评价茶多酚对油脂品质的影响,并进一步测定油脂的总酚含量和油脂热力学性质,分析茶多酚的作用机理.结果表明,与空白对照相比,茶多酚对煎炸油理化品质的下降有显著抑制作用.同时,茶多酚能够抑制煎炸油中不饱和脂肪酸的降解以及反式脂肪酸的...     

芝麻香油风味成分

芝麻香油的风味成分是吡嗪、呋喃、噻唑、噻吩、吡咯,以及醇、醛、酮、酸、酯类等化合物.用葡萄糖、半胱氨酸、精氨酸和水解芝麻蛋白,在145℃温度下加热40 min,可以产生接近焙炒芝麻的风味,香气中的主要物质是2-乙基-5-甲基吡嗪、乙酰呋喃、2-乙酰噻唑、5-乙基-4-甲基噻唑.这些香气成分沸点低,因此芝麻香油不适于煎炸,而且生产芝麻香油温度过高,会引起诸多营养物质劣变,将影响芝麻的资源利用.机榨、低温压榨和水酶法制取的芝麻油,油品用途广,并能综合开发蛋白质、维生素和芝麻木酚素等营养成分.     

浓香大豆油的开发及其氧化稳定性的研究

建立一种新型浓香大豆油(ASO)的生产方法。采用超临界萃取技术对焙烤后的大豆进行提取。通过感官评定对大豆焙烤工艺进行评估：在温度170℃条件下烘烤30min 时,焙烤出的大豆具有浓郁的香味。ASO 的萃取率随着大豆粉粒度的增加而提高,大豆粉的粒度为40～60 目时最佳。采用正交试验设计法对ASO 的萃取参数进行研究：萃取率随着温度的升高,先增大后减小,最佳萃取温度为50℃;萃取率随着压力的增大,先增大后减小,最佳萃取压力为25MPa;萃取率随着时间延长逐渐趋于最大值,确定萃取时间为2.5h。通过对氧化诱导期(IP 值)和抗氧化保护系数(Pf 值)的分析,探讨ASO 的氧化稳定性：ASO 和市售大豆油的IP 值分别为8.93、9.47,其他植物油均大于16;向ASO 中添加0.04% 的BHT、PG 分别能使其IP 值从8.93 提高到12.08、18.55,Pf 值分别达到1.353 和2.077,PG 对ASO 的抗氧化效果要明显优于BHT;在ASO 中单独添加0.01% 柠檬酸能使其Pf 值达到2.25,显示较强的抗氧化能力,复合添加0.01% 柠檬酸和0.04% PG 使其Pf 值达到4.14,显示很强的抗氧化能力。     

芝麻及芝麻油中主要抗氧化物质的研究进展

芝麻及芝麻油都含有抗氧化物质,其中起着抗氧化作用的主要是酚类物质.主要介绍芝麻及芝麻油中的主要抗氧化物质、生理功能和它们的提取方法.     

黑豆黑芝麻复合饮料的研制

为开发一款营养健康的谷物复合饮料,以黑豆、黑芝麻为主要原料,通过单因素实验、正交试验,以感官评价为指标以获得产品的最佳配方和工艺,并对产品进行理化和微生物检测.结果表明:黑豆豆浆预制工艺为黑豆浸泡时间为8h,黑豆煮制25min后,按黑豆:水=1:9打浆;黑芝麻浆预制工艺为黑芝麻:水=1:5打浆;该饮料的最佳配方为:黑豆...     

Enhancing Antioxidant Activity of Sesamol at Frying Temperature by Addition of Additives through Reducing Volatility*

Additives were evaluated to investigate their effects on volatility of sesamol at frying temperature with the hypothesis that the interaction between an additive and sesamol would reduce sesamol volatility. Twenty‐two additive : sesamol combinations were examined by thermogravimetric analysis (TGA) under nitrogen in neat form and in soybean oil. The results indicate that these additives could bind to or interact with sesamol and consequently reduced its volatility. ¹H NMR study provided evidence for hydrogen bonding between sesamol and a hydroxyl group, an amino group, and ether groups. Subsequent heating tests were conducted to investigate the effect of the reduced volatility of sesamol on antioxidant activity in soybean oil at 180 °C. Oxidation of soybean oil was monitored with gel permeation chromatography for formation of polymerized triacylglycerols and with ¹H NMR for loss of olefinic and bisallylic protons. Sesamol retained in soybean oil during the heating process was determined by high‐performance liquid chromatography. A strong correlation between the retained sesamol and the antioxidant activity was observed. The mixture of 830 ppm sesamol and mono‐/diglycerides, polysorbate 20 or l ‐carnosine showed much improved antioxidant activity compared to sesamol itself and slightly better antioxidant activity than 200 ppm tert‐butylhydroquinone. It is believed that this method can also be used for many other antioxidants for which volatility is a problem.     

去皮脱脂芝麻粕粉的功能性质

芝麻经过去皮、脱脂处理后，测定了其粕粉的一些功能性质。发现它的凝胶性和乳化能力分别优于大豆粕粉和花生粕粉，吸水吸油能力与大豆粕粉差不多，发泡能力和稳定性在酸性ｐＨ时比碱性ｐＨ强，此外它的溶解性和粘性都很好。因此去皮脱脂芝麻粕粉可望用于诸如冰淇淋、冷冻甜食、香肠、烘焙食品和糖果等。     

深度油炸对食用油中反式亚油酸含量的影响

选用我国消费最普遍的压榨大豆油和三级浸提大豆油为试验材料,研究不同大豆油经反复油炸对反式亚油酸含量的影响及其含量随油炸次数增加的变化规律。试验分为2组,反复油炸40次,每炸5次采集1次油样,每组测定3个重复。薯条油炸温度为180～185℃,油炸时间为32 h。试验结果表明,压榨大豆油和三级浸提大豆油中总反式亚油酸含量分别为0.18 g/100 g和0.08 g/100 g,前者极显著高于后者(P=0.001),9-cis,12-trans C18:2和9-trans,12-cis C18:2是2种大豆油中主要的反式亚油酸。深度油炸极显著提高大豆油中反式亚油酸含量(P=0.000),在反复油炸40次后,压榨大豆油和三级浸提大豆油中总反式亚油酸含量分别为1.11 g/100 g和0.68 g/100 g,且前者极显著高于后者(P=0.008)。压榨油反式亚油酸经油炸增加幅度高于三级浸提大豆油。