电子自旋共振波谱法评价花生油氧化稳定性的可行性研究

为探究花生油加速氧化过程中的自由基链式反应,利用电子自旋共振波谱法(ESR)研究花生油的加速氧化过程,结果发现加速氧化过程中产生大量的烷基自由基(R·)以及少量的烷氧基(RO·)和过氧化自由基(ROO·)。对ESR法与Rancimat法(经典油脂氧化稳定性测定方法)进行比较研究,分别利用这两种方法测定添加不同抗氧化剂花生油的氧化稳定性,发现ESR法的滞后时间(Lagtime)和Rancimat法的诱导时间(IP)结果一致,即加入0.02%TBHQ和0.01%柠檬酸(CA)的花生油中自由基生成量最少,滞后时间最长,且诱导时间最长。此外,滞后时间与诱导时间之间具有良好的线性关系,回归方程为[Lagtime]=79.724[IP]-165.630(R2=0.9688)。综上所述,ESR法可预测Rancimat法的结果,也可作为一种评价花生油氧化稳定性的方法。     

花生油氧化稳定性的研究

为了可以更好的研究花生油的氧化稳定性,为花生油的综合开发利用和安全储藏提供一定的依据,本实验以压榨花生油为原料,对其油脂的组成及影响其氧化稳定的主要因素分别进行研究。主要通过气相色谱研究自身脂肪酸组成,通过液相色谱研究自身维生素E含量,通过Rancimat仪测定温度、金属离子、抗氧化剂以及增效剂对氧化诱导时间的影响,通过测定过氧化值研究光照以及食物存在对其氧化稳定的影响。     

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。     

单甘酯稳定的花生酱涂抹性的改善

本文以添加氢化植物油的消费者广泛认可的四季宝品牌花生酱为参照，分析添加单甘酯、单甘酯和花生油的花生酱以及花生酱原浆的涂抹性感官评价以及流变学性质、质构、固体脂肪含量和微观结构，来阐明添加一定量的花生油是否可以改善单甘酯稳定的花生酱的涂抹性及相应的原因。结果表明：花生酱原浆以及单甘酯稳定的花生酱的组织形态和涂抹性的感官评分均显著低于添加氢化植物油的花生酱，而当2.0%花生油加入到单甘酯稳定的花生酱，其感官评分与添加氢化植物油的花生酱接近，表现出良好涂抹性。稳态剪切曲线显示花生油加入降低了单甘酯的花生酱表观黏度，使其在25℃屈服应力从201.79 Pa降至103.70 Pa,32～42℃黏度下降百分比从62.7%降至53.2%。质构分析表明花生油使单甘酯稳定的花生酱的硬度分别从376.19 g降至289.42 g，黏稠度从2050.24 g降至1607.23 g。同时2.0%花生油加入使单甘酯稳定的花生酱的固体脂肪含量降至8.0%以下，上述结果显示添加花生油后的单甘酯稳定的花生酱的理化性质与氢化植物油稳定的花生酱是十分接近的，这可能是其涂抹性改善的原因。此外，微观结构显示花生油的加入使单甘...     

植物油在储存过程中氧化情况的研究

对不同等级的大豆油、菜籽油、花生油、棉籽油在常温储存条件下的过氧化值、碘值、茴香胺值的变化规律进行了研究,并对Rancimat方法推出的货架期与实际储存期进行了对比.结果表明:过氧化值与茴香胺值变化趋势相同;碘值变化不明显;在反映油脂氧化程度时过氧化值较茴香胺值和碘值变化更为灵敏;Rancimat方法外推出的货架期与实际储存期相关性很小.     

Tween对精炼大豆油氧化稳定性的影响

本文采用烘箱法和Rancimat法研究了亲水性乳化剂Tween(如Tween20、Tween60和Tween80)对精炼大豆油氧化稳定性的影响。低温下的烘箱法研究结果表明:对于Tween20,添加0.005%时可以延缓油脂的氧化,添加量增加到0.01%~0.20%时会在一定程度上起到促进氧化的作用;添加Tween60会在一定程度上起到促进氧化的作用;添加Tween80能延缓油脂的氧化,添加量为0.005%时效果最明显。高温下的Rancimat法结果表明:添加0.005%的Tween20具有一定的抗氧化作用,加入0.01%~0.20%Tween20对油脂的氧化稳定性影响不明显。添加Tween60对大豆油的氧化稳定性没有太大影响。添加Tween80能延缓油脂的氧化,加入0.005%Tween80时延缓氧化的效果最好。     

Tween对精炼大豆油氧化稳定性的影

本文采用烘箱法和Rancimat法研究了亲水性乳化剂Tween（如Tween20、Tween60和Tween80）对精炼大豆油氧化稳定性的影响。低温下的烘箱法研究结果表明：对于Tween20,添加0．005％时可以延缓油脂的氧化．添加量增加到0．01％～0．20％时会在一定程度上起到促进氧化的作用;添加Tween60会在一定程度上起到促进氧化的作用：添加Tween80能延缓油脂的氧化,添加量为0．005％时效果最明显。高温下的Rancimat法结果表明：添加0．005％的Tween20具有一定的抗氧化作用,加入0．01％邗．20％Tween20对油脂的氧化稳定性影响不明显。添加Tween60对大豆油的氧化稳定性没有太大影响。添加Tween80能延缓油脂的氧化,加入0．005％Tween80时延缓氧化的效果最好。     

高油酸花生酱的制备及其氧化稳定性研究

文章用高油酸花生制备花生酱,研究花生酱的制备工艺及其氧化稳定性。以感官评分和酸值为指标,研究烘烤时间、烘烤温度、食盐添加量、蔗糖添加量等因素对花生酱品质的影响。正交试验结果表明,高油酸花生酱的最佳制备工艺为烘烤时间30min、烘烤温度140℃、食盐添加量1.3%、蔗糖添加量5.0%。在此条件下制备的高油酸花生酱口感纯正、香味浓郁,感官评分约为92分。氧化稳定试验期内(5个月)的过氧化值、羰基值和酸值等指标变化情况表明,高油酸花生酱的氧化酸败速度比普通花生酱缓慢,具有良好的氧化稳定性。该研究为高油酸花生调味制品的开发提供了理论基础。     

DSC和Rancimat法测定亚麻籽油氧化稳定性研究

采用差示扫描量热仪(DSC)测定压榨亚麻籽油和菜籽油的起始氧化温度,并采用DSC法和油脂氧化稳定性测定仪(Rancimat)法测定两种食用油在不同氧化温度下的诱导氧化时间。实验结果表明:亚麻籽油的起始氧化温度比菜籽油的起始氧化温度低30℃;DSC法和Rancimat法测定的诱导氧化时间均随氧化温度升高而缩短,两种方法在不同氧化温度下的诱导氧化时间有显著的线性相关性;DSC法的诱导氧化时间与氧化温度的相关系数最高,更利于未知温度下诱导氧化时间的推导。在检测方法上,与Rancimat法比较,DSC法用量小,测定时间短,更适于食用油的快速氧化稳定性测定。     

α-亚麻酸及其乙酯的氧化稳定性研究

采用尿素包合法从亚麻油混合脂肪酸及其混合乙酯中制备高纯度α-亚麻酸及其乙酯。通过采用烘箱法与Rancimat法分别测定亚麻油、亚麻油混合脂肪酸、高纯度α-亚麻酸、亚麻油混合脂肪酸乙酯、高纯度α-亚麻酸乙酯的过氧化值和诱导时间来研究其氧化稳定性以及天然抗氧化剂的添加对样品氧化稳定性的影响。研究表明,5种样品的氧化稳定性大不一样;110℃时,添加0.02%的TBHQ可以有降低样品氧化酸败的速度。     

利用有机凝胶因子提高花生酱稳定性的工艺研究

使用紫虫胶作为有机凝胶因子制备稳定型花生酱,并对其工艺条件进行优化。以析油率为指标,紫虫胶添加量、加热温度、加热时间和冷却温度为因素变量,进行响应面优化试验,得到了最优工艺条件,并进行了花生酱感官评鉴。结果表明,紫虫胶添加量为3.2%(w/w)、加热温度为90 ℃、加热时间为40 min、冷却温度为1 ℃时,制得的有机凝胶花生酱最稳定,此时析油率仅1.24%。在最优工艺条件下制备的有机凝胶花生酱与商品花生酱相比,析油率更低,感官品质更好。     

Unhydrogenated Palm Oil as a Stabilizer for Peanut Butter

Response surface methodology was used to investigate the potential of unhydrogenated palm oil (PO), with and without peanut shell flour (PSF), to prevent oil separation in peanut butter. Percent oil separation, texture and color attributes were measured after 0, 1 and 2 wk storage at 15, 25 and 35°C. Computer-generated contour plots indicated that 2.0–2.5% PO should effectively stabilize peanut butter stored at 21–24°C for ≥ 1 year without affecting color. PSF (≥ 0.8%) decreased L value of color by a 5% but did not increase firmness of experimental products containing PO. Samples stabilized with PO were softer than those containing a commercial stabilizer.     

天然抗氧化剂的增效作用及其对花生油抗氧化效果研究

对迷迭香提取物、茶多酚、植酸、VE、抗坏血酸棕榈酸酯在花生油中的抗氧化性能和五种天然抗氧化剂相互之间的增效作用进行了研究。通过Rancimat法测定了添加各种抗氧剂的花生油的诱导时间,根据正交实验结果,各种天然抗氧化剂在组分中的主次因素为迷迭香提取物>茶多酚>植酸>抗坏血酸棕榈酸酯,优化得出天然抗氧化剂的复配配方为迷迭香提取物0.07%、茶多酚0.03%、植酸0.02%、抗坏血酸棕榈酸酯0.02%。此配方对花生油的抗氧化能力优于TBHQ。     

Effect of Peanut Butter Manufacture on Vitamin E

ABSTRACT: The effect of peanut butter manufacture on vitamin E originating from raw peanuts ( Arachis hypogaea L., runner-type) was determined. Tocopherols were quantified by normal-phase high-performance liquid chromatography. No significant differences were observed in tocopherol (T) values between 1998 and 1999 crop raw peanuts or between raw peanuts and peanut butter except for γ-T ( P > 0.05). Oil and stabilizer added to the roasted peanuts during peanut butter processing provided 4% of α-T in the finished peanut butter. Retention of total tocopherols during peanut butter manufacture was 95%. Mean α-T values (mg/100 g) of commercial peanut products ranged from 12.3 (peanut oil) to 4.1 (dry roasted peanuts).     

Functionality of Palm Oil as a Stabilizer in Peanut Butter

ABSTRACT: Studies have shown that palm oil is an effective stabilizer in peanut butter. The objective of our investigation was to better define the role of palm oil as a stabilizer. Peanut butters without and with palm oil added at concentrations of 1.5, 2.0, and 2.5% (w/w of peanuts), and Fix-X™ (hydrogenated rapeseed and cottonseed oils as commercial control) were stored at 0, 21, 30, and 45 °C for 23 wk. Palm oil improved the oil holding capacity (OHC) of peanut butters, but had no effect on their adhesiveness and hardness characteristics. The unstabilized and palm oil-stabilized peanut butters were not as good as the Fix-X™ stabilized peanut butters with regard to their OHC, hardness, and adhesiveness characteristics.     

天然椰子油的组分及其对花生油氧化稳定性的影响

分析了海南高种椰子制备的天然椰子油(VCO)的脂肪酸组成、功能性成分及对花生油氧化稳定性的影响。采用GC-MS测定了VCO的脂肪酸组成、植物甾醇含量,采用HPLC测定了VCO中VE含量,并研究了不同温度下VCO对花生油过氧化值的影响。结果表明,VCO中脂肪酸以月桂酸质量分数最多,达47.36%;植物甾醇含量为420 mg/kg,VE含量为89.8 mg/kg,多酚含量为18 mg/100g油。在40℃和60℃,不同添加量的VCO对花生油过氧化值(POV)均有影响,VCO浓度越大,花生油的POV值越低。     

Droplet Size and Coalescence Stability of Whey Protein Stabilized Milkfat Peanut Oil Emulsions

Droplet diameter and the polydispersity of droplet size tended to decrease with increased proportion of peanut oil. Macromolecular additives affected droplet size. Xanthan gum or sodium carboxymethyl-cellulose (Na-CMC) produced smaller droplets than the controls, but the average diameter was independent of the composition of the dispersed phase. At 50°C the coalescence stability of these emulsions qualitatively correlated with the initial droplet diameter. Xanthan gum and Na-CMC, despite increasing continuous phase viscosity, gave lower stability than controls, primarily the result of flocculation of droplets due to depletion of the highly hydrophilic macromolecule from the intervening region between approaching droplets. At 25°C, stability increased as solid butter oil content of the dispersed phase increased.     

Minimal effects of high-pressure treatment on Salmonella enterica serovar Typhimurium inoculated into peanut butter and peanut products

About 1.2 billion pounds of peanut butter are consumed annually in the United States. In 2008 to 2009, an outbreak involving Salmonella Typhimurium in peanut butter led to a recall of over 3900 products by over 200 companies. More than 700 people became sick, 100 were hospitalized, and 9 people died from this outbreak. This study examines the efficacy of high-pressure processing (HPP) to decrease S. Typhimurium American Type Culture Collection (ATCC) 53647 inoculated into peanut butter and model systems. The viability of S. Typhimurium in peanut butter stored at room temperature was investigated. A culture of S. Typhimurium (6.88 log CFU/g) was inoculated into peanut butter. Following 28 d at 20 °C there was a 1.23-log reduction. Approximately 10(6) to 10(7) CFU/g S. Typhimurium were inoculated into 4 brands of peanut butter, 3 natural peanut butters and peanut flour slurries at 2, 5, and 10% peanut flour protein in peanut oil and in distilled water. All were treated at 600 MPa for 5 min at 45 °C. While significant differences were found between natural peanut butter and peanut protein mixtures, the reduction was <1.0 log. The peanut flour/oil mixtures had a 1.7, 1.6, and 1.0-log reduction from HPP (2, 5, and 10% protein, respectively) whereas peanut flour/water mixtures had a 6.7-log reduction for all protein levels. Oil had a protective effect indicating HPP may not help the microbial safety of water-in-oil food emulsions including peanut butter. Practical Application: There have been multiple outbreaks of foodborne illness involving peanut butter products. This study looks at the potential use of high-pressure processing to reduce the bacteria that may be in peanut butter.     

昆仑雪菊多酚对花生油氧化稳定性的影响

以昆仑雪菊为原料制备昆仑雪菊多酚,采用加速氧化的方法评价其对花生油氧化稳定性的影响。结果表明,昆仑雪菊多酚添加量在700?mg/kg条件下,抗氧化能力同添加200?mg/kg的二丁基羟基甲苯无显著性差异（P＞0.05）,昆仑雪菊多酚添加量同花生油的氧化稳定性呈正相关;昆仑雪菊多酚能够显著提高花生油的1,1-二苯基-2-三硝基苯肼自由基清除能力和铁离子还原能力（P＜0.05）,昆仑雪菊多酚能够有效抑制亚麻酸含量的降低（P＞0.05）。由此可见,昆仑雪菊多酚可作为天然抗氧化剂用于延缓食用油氧化。