抗氧化剂对油脂煎炸稳定性的影响研究进展

煎炸过程中,油脂会发生水解、氧化、聚合等一系列化学反应,其中一些反应产物影响着油脂和煎炸食品的安全、健康和保质期。抗氧化剂可以有效抑制油脂的氧化,提高油脂的煎炸稳定性。油脂的煎炸稳定性通常通过测定极性组分、过氧化值、酸价、不饱和脂肪酸以及有害物质的含量等进行评价。结合近年来国内外抗氧化剂应用于油脂的最新研究,系统阐述了抗氧化剂对油脂煎炸稳定性的影响,同时总结了抗氧化剂在油脂煎炸过程中的变化,最后提出抗氧化剂在实际应用中面临的问题,以期为抗氧化剂尤其是天然抗氧化剂在油脂中的应用提供参考。     

油脂的自动氧化和氧化稳定性及检测方法

论述了油脂自动氧化的机理和油脂氧化稳定性的测定原理，并对油脂氧化稳定性的测定方法作了简要介绍。     

油脂氧化及其氧化稳定性测定方法

论述了油脂氧化的机理和油脂氧化稳定性的测定原理,按测定参数的不同对油脂氧化稳定性的常用测定方法进行了分类和介绍,旨在为选用合理的油脂氧化稳定性测定方法和今后开发更新的测定方法提供参考。     

油脂的自动氧和氧化稳定性及检测方法

论述了油脂自动氧化的机理和油脂氧化稳定性的测定原理，并对油脂氧化稳定性的测定方法作了简要介绍。     

提取方法对3种坚果油脂理化性质及氧化稳定性的影响

研究了溶剂法和水酶法提取核桃、扁桃、大扁杏仁等3种坚果油脂的理化性质,气相色谱法分析了坚果油脂的脂肪酸组成,比较了加速氧化过程中3种坚果油脂酸价及过氧化值的变化,采用Rancimat油脂氧化仪测定了不同方法得到油脂的氧化稳定性。结果发现,油脂制备方法对其理化特性和氧化稳定性均有重要影响,其中,3种水酶法提取油脂的透明度、酸价和风味均优于溶剂法,而氧化稳定性均低于溶剂法,但是不同方法提取油脂的折光指数、碘价、皂化价和不皂化物以及脂肪酸组成等理化特性不存在显著差异。在加速氧化实验中,油脂酸价变化不大,而过氧化值和OSI变化较大。3种坚果油脂中,大扁杏仁油最为稳定、扁桃油次之,而核桃油最容易氧化。     

2种方法测定核桃油脂氧化稳定性相关性

为了比较2种不同方法测定核桃油氧化稳定性的效果,分别采用氧化酸败法(Rancimat法)和烘箱法评价核桃油脂氧化稳定性,并进行货架期预测,对测定结果进行相关性分析。结果表明,核桃油的氧化稳定指数(OSI)与其过氧化值、共轭烯烃值、羰基价呈极显著线性负相关(P0.01),相关系数分别为-0.963、-0.941和-0.952;与酸价呈显著线性负相关(P0.05),相关系数为-0.681。进一步研究表明,在核桃油氧化过程中,反应速率常数(k)与活化能(Ea)并非定值,因此通过Rancimat法和烘箱法推算得到的货架期(1 457.00 h和565.72 h)与真实货架期(733.21 h)之间存在显著差异(P0.01)。Rancimat法可以代替烘箱法快速、准确评价核桃油脂氧化稳定性,但利用此法预测核桃油脂货架期误差较大。     

能量棒贮藏过程中美拉德反应对油脂氧化的影响

能量棒富含蛋白质、糖和油脂。为探究能量棒中美拉德反应和油脂氧化之间的相互作用,检测了常温(25℃)贮藏过程中产品色差及过氧化值的变化,在此基础上选取45、65℃2个温度进行加速试验,测定了加速贮藏过程中产品色差、还原糖含量的变化,同时检测能量棒和其提取油脂在相同加速条件下的过氧化值,并对能量棒与对照油脂相比过氧化值的降低量和能量棒还原糖的减少量进行相关性分析。结果表明:能量棒贮藏过程中会发生显著的褐变反应以及一定的油脂氧化。45和65℃2个加速温度一定时间内,过氧化值的降低量与还原糖减少量均呈正相关,相关系数R2分别为0.973和0.967,说明在此条件下,能量棒中美拉德反应对能量棒油脂氧化有显著的抑制作用。而65℃条件下贮存15 d后,油脂过氧化物的积累表现出加速美拉德反应的作用。因此,油脂的氧化和美拉德反应之间的影响是相互制约的。     

油脂氧化稳定性的研究

用Ｒａｎｃｉｍａｔ仪器测定了油脂氧化稳定性。结果表明,温度的高低,脂肪酸不饱和度,抗氧化剂和增效剂的使用,均与油脂氧化稳定性有着密切的关系。     

热重分析法在油脂氧化稳定性研究中的应用

主要介绍了热重分析法在食用油脂氧化稳定性定性分析中的应用,检测了菜籽油、玉米油、调和油3种油脂的氧化分解温度,探讨了升温速率、保护气氛对油脂氧化分解温度的影响;通过油脂的热重分析法等温实验,观察了油脂的氧化诱导时间。实验表明:菜籽油的氧化稳定性优于玉米油和调和油;相同条件下,升温速率越快,氧化分解温度越高;在氮气气氛下,油脂的氧化稳定性更好。热重分析方法采样量少、操作方便、效果明显,可以应用于油脂生产过程的质量监控和抗氧化剂的开发研究。     

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生成。此外,茶多酚显著抑制了油脂中挥发性醛类物质的生成。茶多酚的添加增加了油脂中酚类物质的含量,并且增加了油脂的氧化稳定性,进而对油脂在油炸过程中的品质起到保护作用。研究结果表明茶多酚在食品、化工等行业具有应用于保护煎炸油品质的潜在价值。     

油脂OSI值的研究

研究了油脂ＯＳＩ值与脂肪酸组成的关系及抗氧剂与金属钝化剂对油脂ＯＳＩ值的影响。指出我国高级烹调油ＯＳＩ值大多偏低的主要原因是油脂中含有较高的催化氧化的金属离子，提出了解决ＯＳＩ值偏低的方法。还研究了菜子高级烹调油ＯＳＩ值与温度的关系。     

APPLICATION OF THE OXIDATIVE STABILITY INDEX FOR ASSESSING THE ANTIOXIDANT PROPERTIES OF FLAVONOIDS1

The antioxidant activities of representative flavonoid classes (flavonols, flavones, flavanones, isoflavones and flavanols) relative to dl‐α‐tocopherol were evaluated using the Oxidative Stability Index (OSI) value. At 5 mM concentrations in tocopherol stripped corn oil (TSCO), antioxidant activity was determined as follows: (+) catechin > quercetin > (+,?) taxifolin > dl‐α‐tocopherol > THI (3′, 4′, 7‐trihydroxyisoflavone) > luteolin. Intra‐assay and inter‐assay coefficients of variation were 1.43% and 2.73%. Peroxide Induction (PI) values were utilizéd as a comparison method using compounds and conditions identical to those in OSI experiments. Relative values for OSI and PI of the flavonoids tested showed a 0.98 correlation. This method also revealed differences in antioxidant activity of catechins due to stereochemistry. The OSI offers a simple, reproducible method for the evaluation of flavonoid antioxidant activities in a lipid environment.     

Composition of total sterols (4-desmethyl-sterols) in extravirgin olive oils obtained with different extraction technologies and their influence on the oil oxidative stability

The composition and antioxidant activity of total sterols in extravirgin olive oils obtained with different extraction technologies from olives harvested at two ripening stages, were studied. The antioxidant activity was evaluated with an oxidative stability instrument (OSI), by using a model system (made of a mixture of treated/untreated commercial refined peanut oil) enriched with the total sterol fractions of the extravirgin olive oils. No correlation was found between the OSI time and the extraction technologies, the ripening stages or the actual amount of sterols added. No significant differences were observed in the percent composition of sterols of extravirgin olive oils produced with different technologies during the same harvesting period. The latter, however, had a significant effect on the percent of β-sitosterol and 5-avenasterol in extravirgin olive oils produced with the same technology.     

Stability of Dried Filled Milks

Samples of dried filled milk (DFM) were made with several vegetable fats and compared with dried milk. Several specially prepared vegetble oils, such as Trisun HS-500, hydrogenated cottonseed oil and hydrogenated coconut oil could impart stability to the DFM as high as that imparted by milk fat to conventional dried milk. Stability could be further enhanced by appropriate antioxidant and storage conditions. The simple technique of measuring oxygen consumption by the DFM was as effective as flavor evaluation, gas chromatography of volatiles, or spectroscopy for screening large numbers of samples or as a quality control procedure.     

Enzymatic and Autoxidation of Defatted Peanuts

Ground, blanched, raw, and roasted peanuts with varying oil contents were analyzed for oxidation products. Peroxide values (PV) of blanched, ground raw (BRAW) peanuts, demonstrating enzymatic oxidation, and heat-treated rancid roasted peanuts (RRST), demonstrating autoxidation, exhibited decreases (p ≦ 0.05) with decreasing oil content. The Oxidative Stability Index (OSI) time at 110 °C increased (p < 0.05) with decrease in oil content of raw (BRAW) and roasted (BRST) ground peanuts. A higher OSI indicated more oxidative stability, thereby supporting the hypothesis of higher potential for autoxidation at higher oil contents. In addition, BRST exhibited a shorter OSI than BRAW, indicating slower autoxidation in BRAW. Roasted peanutty odor, burnt odor, and roasted peanutty flavor, rancid/oxidized flavor, and burnt flavor scores of rancid roasted peanuts decreased (p ≦ 0.05) with decreasing oil content.     

不同抗氧化剂对油脂抗氧化性能影响的研究

油脂抗氧化对于保证油脂及富含油脂食品的质量有非常重要的意义。研究了几种单体抗氧化剂及复合抗氧化剂对不同油脂的抗氧化性能。复合抗氧化剂由于各单体之间以及金属离子螯合剂的协同增效作用,使油脂的抗氧化能力较单体抗氧化剂有很大提高,同时采用复合抗氧化剂也是降低使用成本的重要途径之一     

Anti-radical activity and oxidative stability of oils manufactured from flax, sesame and silybum seeds

Comparative analysis of oils, prepared from flax, sesame and silybum seed composition, and adequate oil blends, prepared by mixing flax oil, sesame oil and silybum oil was performed. Antiradical activity was evaluated for the oils, both for their methanol-soluble phase and the fraction insoluble in methanol. DPPH radical scavenging activity expressed in Trolox equivalent antioxidant capacity. Oxidative stability during 6-month store was evaluated by peroxide value and dienic conjugates content. Oils from seed composition show the more high antiradical activity and oxidative stability than adequate oil blends. A significant correlation was found between antiradical activity and gamma-/alpha-tocopherol ratio in oils.     

大花红景天抗氧化作用的研究

在5种食用油脂中添加适量的大花红景天乙醇提取物,通过测定不同时间的油脂POV,研究了大花红景天对食用油脂的抗氧化作用,并对其抗氧化作用机理作了初步的分析.试验结果表明,其对菜籽油、花生油、酥油、大豆油、猪油均有一定的抗氧化作用.     

Effects of antioxidants on peanut oil stability

Several antioxidants including phospholipids (PL), ascorbyl palmitate (AP), rosemary (ROS), tocopherol (TOC) and catechin (CAT) were chosen to study the effects on peanut oil stability. Among these antioxidants, catechin alone and composites of catechin with other antioxidants showed significant increases in oil stability as compared to control oil. A response surface design was used to study the effects of three antioxidant composites on the peanut oil stability. Results showed the OSI (Oxidation Stability Index) values are significantly influenced by CAT (p<0.0001), followed by ROS (p<0.05) and PL (p<0.5). TOC was the least significant (p>0.5) in the increase of OSI value. By considering cost, handling and minimum usage of antioxidants, the OSI value of peanut oil would reach 15–16 h by the addition of 1500 ppm of CAT and a maximum level of either 400 ppm of ROS or PL.     

油脂抗氧化剂TBHQ的应用研究

本文论述油脂自动氧化的机理，氧化程度的衡量，进而引入抗氧化剂的应用。