大豆热损对其油脂品质及组成的影响

旨在为热损大豆的加工提供理论支撑,以不同热损程度的巴西大豆为原料,采用索氏抽提法制备大豆油,分析其酸值、过氧化值、茴香胺值、全氧化值、氧化诱导期、甘油酯和游离脂肪酸组成及含量、磷脂及生育酚组成及含量、色素含量,探明大豆热损对其油脂品质及组成的影响。结果表明：随着大豆热损程度的增加,其油脂的酸值、过氧化值、茴香胺值、全氧化值显著升高(p<0.05),氧化诱导期显著下降(p<0.05),与正常大豆相比,重度热损大豆油脂酸值和全氧化值的增长率分别高达557%、148%;热损导致大豆油水解,甘三酯相对含量降低,甘二酯和游离脂肪酸相对含量上升,以Sn-1,3位水解为主;氧化反应导致多不饱和脂肪酸相对含量显著降低(p<0.05),且热损程度越深变化越明显;热损导致大豆油总磷脂含量下降,磷脂酸相对含量显著上升,生育酚含量降低,重度热损大豆油脂中总生育酚的损失率高达19%;未成熟大豆更易发生热损现象,不同热损程度大豆油脂中的叶绿素、叶黄素及β-胡萝卜素含量具有显著性差异(p<0.05)。综上,大豆热损会导致其油脂组成发生变化,品质降低。     

不同油料作物油脂体氧化稳定性差异的研究

以大豆、花生和葵花籽油脂体为研究对象,比较了3种油料作物油脂体组成间的差异,对储藏过程中不同油脂体的脂肪酸组成、磷脂和生育酚的含量以及过氧化值、硫代巴比妥酸值(TBARS)和酸价的变化进行分析。实验结果表明,随着储藏时间的延长,3种不同油料作物油脂体中的脂肪酸组成、磷脂和生育酚含量均显著降低(P 0. 05);在60℃加速氧化的条件下,储藏第0～6天时,3种不同油脂体的过氧化值均无明显变化(P 0. 05),但在储藏第6～12天时,3种油脂体过氧化值显著增加(P 0. 05),过氧化值由高到低依次为花生油脂体葵花籽油脂体大豆油脂体;随着储藏时间的延长,3种油脂体的TBARS值均保持平稳,但酸价逐渐升高。研究表明,3种不同油脂体的组成和氧化稳定性存在差异,且大豆油脂体的氧化稳定性最好。     

基于微波预处理压榨文冠果油储藏期间的品质研究

利用Schaal烘箱法,研究测定了由微波预处理种仁冷榨制取的文冠果油储藏期间酸价、过氧化值、p-茴香胺值、生育酚含量、脂肪酸组成及含量的变化,评价了微波预处理对油脂氧化稳定性的影响,并对文冠果油理化指标进行了相关性分析。结果表明:文冠果油在储藏期间,过氧化值和K_(232)在前期快速增高,中期趋于平缓,后期又快速增长;酸价、p-茴香胺值及K_(270)则持续增长;生育酚含量与氧化诱导时间在前、后期快速降低,中期降低较缓慢;不饱和脂肪酸与饱和脂肪酸的比值降低;相关性分析表明文冠果油在储藏期间的氧化稳定性与生育酚含量及过氧化值、酸价、p-茴香胺值、K_(232)、K_(270)密切相关。此外,适当的微波预处理有助于增强文冠果油的氧化稳定性。     

贮藏条件对原料葵花籽油脂酸败的影响

以白色葵花籽原料为研究对象,考察温度、包装、避光等不同贮藏方法对原料葵花籽在贮藏过程中过氧化值、酸价、碘价、p- 茴香胺值和TBA 值变化的影响。结果表明：葵花籽原料在贮藏过程中发生了油脂的氧化酸败,表现为过氧化值、酸价、p- 茴香胺值和TBA 值上升,碘价下降。采用低温贮藏和真空避光包装可显著降低葵花籽的氧化酸败、延缓品质劣变,可延长贮藏期。     

高油大豆与低油大豆油脂体组成及其稳定性的研究

为研究高油大豆和低油大豆油脂体组成及乳化稳定性和氧化稳定性差异,本试验分析了高油大豆和低油大豆油脂体基本组成、脂肪酸组成、磷脂组成、生育酚组成,同时比较了高油大豆油脂体与低油大豆油脂体乳化性及乳化稳定性、过氧化值及TBARS值。研究表明,高油大豆油脂体蛋白质含量显著低于低油大豆油脂体(P0.05),而高油大豆油脂体的脂肪含量显著高于低油大豆油脂体(P0.05);高油大豆油脂体的棕榈酸和亚油酸含量显著低于低油大豆油脂体(P0.05),而十七碳酸、油酸、二十碳一烯酸和α-亚麻酸含量显著高于低油大豆油脂体(P0.05),高油大豆油脂体的总不饱和脂肪酸质量分数(83.08±0.05)%显著高于低油大豆油脂体(81.86±0.12)%(P0.05);高油和低油大豆油脂体中脑磷脂、卵磷脂和溶血磷脂酰胆碱含量无显著差异(P0.05);高油大豆油脂体中DL-α-生育酚和γ-生育酚含量显著高于低油大豆油脂体(P0.05);高油大豆油脂体和低油大豆油脂体的乳化性无显著差异(P0.05),而高油大豆油脂体的乳化稳定性显著高于低油大豆油脂体(P0.05);14 d热处理条件下,高油大豆油脂体的过氧化值和TBARS值均高于低油大豆油脂体。上述研究表明,高油大豆和低油大豆的油脂体之间的组成和稳定性都存在差异。     

草鱼片热风干制过程中脂质氧化特性研究

探讨热风干燥过程中青鱼片油脂的变化情况。在青鱼片的不同干燥阶段提取油脂,检测油脂氧化程度,油脂成分及脂肪酸组成的含量变化。在干燥过程中鱼片油脂的过氧化值、羰基价和酸价显著性升高(P<0.05)。随着甘油三酯和磷脂含量的下降,游离脂肪酸含量明显增加,表明在干制过程中油脂在酯酶和磷酸化酶的催化下发生了水解反应。在总油脂和总磷脂中多不饱和脂肪酸,尤其是二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)含量下降。在游离脂肪酸中,除DHA以外的多不饱和脂肪酸含量均显著升高。研究结果表明,青鱼片热风干燥过程中其油脂被氧化,同时发生脂质降解,特别是不饱和脂肪酸被释放为游离态。     

丙醛+正己醛含量评价DHA/ARA粉末油脂氧化情况的可行性研究

采集了DHA粉末油脂、ARA粉末油脂和ALA粉末油脂样本110个,样本涵盖了新鲜、临近货架期、超过货架期的样品,测定其过氧化值、茴香胺值、全氧化值、丙醛和正己醛含量,并将丙醛+正己醛含量与过氧化值、茴香胺值、全氧化值进行了相关性分析。Pearson相关性分析表明,丙醛+正己醛含量与过氧化值、茴香胺值、全氧化值在P0.01水平呈极显著相关,相关性系数分别为0.663、0.869和0.846;非线性拟合结果表明,丙醛+正己醛含量与过氧化值、茴香胺值、全氧化值回归方程的相关系数分别为0.726 4、0.989 0和0.978 4;测定DHA/ARA粉末油脂的挥发性丙醛+正己醛含量,将其作为特征指标可以简便、准确地表征粉末油脂的氧化情况,尤其是后期氧化情况。     

高温加热下芝麻素酚对花生油的抗氧化作用

旨在为芝麻素酚在食品加工中的应用提供参考,以过氧化值和茴香胺值为指标,通过正交实验研究了不同高温加热条件下芝麻素酚对花生油的抗氧化作用,并对比了芝麻素酚与α-生育酚、二丁基羟基甲苯(BHT)、抗坏血酸棕榈酸酯的抗氧化效果及协同增效作用。结果表明：高温加热下花生油会发生显著氧化;在芝麻素酚添加量0.06%、加热温度150℃、加热时间15 h条件下,芝麻素酚对花生油过氧化值和茴香胺值的抑制率最高,且优于抗坏血酸棕榈酸酯、α-生育酚及BHT的抗氧化能力;芝麻素酚与α-生育酚及BHT均具有一定的协同增效作用。综上,芝麻素酚可以作为天然抗氧化剂应用于延缓高温加热油脂的氧化。     

薏米贮藏过程中异味产生的机理

以薏米为原料,研究了薏米贮藏过程中脂肪含量、脂肪酸值、脂肪酸组成、常见氧化指标(过氧化值、茴香胺值、总氧化值、丙二醛含量)和醛类化合物的变化情况,并分析了薏米的异味变化与上述指标的关系。研究结果表明:随着薏米贮藏时间的延长,薏米的脂肪含量和不饱和脂肪酸相对含量均显著降低,脂肪酸值、饱和脂肪酸相对含量、过氧化值、茴香胺值、总氧化值、丙二醛含量均显著增加,醛类的"相对内标含量"也显著增加。薏米贮藏过程中其总氧化值、丙二醛含量和挥发性醛类化合物含量与薏米的异味程度间呈显著正相关(p0.01),不饱和脂肪酸含量与薏米异味程度间呈显著的负相关(p0.01)。说明薏米贮藏过程中异味主要是由于薏米油脂氧化产生的,薏米油脂的二级氧化产物醛类化合物为薏米贮藏过程中产生异味的主要原因。     

后熟期间大豆籽粒油脂组成和品质特征的变化规律

通过测定新收获的国产大豆在后熟期间油脂的粗脂肪含量、酸价、过氧化值和脂肪酸组成来探究后熟期间大豆籽粒中脂肪的变化规律。结果表明：在后熟过程中,大豆的粗脂肪含量呈逐渐上升趋势,度过后熟期则逐渐下降,粗脂肪含量从初始的19.25%升高至21.30%,在30 d达到最大值后缓慢下降;大豆酸价及过氧化值均为上升趋势,且大豆酸价及过氧化值均与大豆油脂肪酸的比值呈负相关;油酸和亚油酸的相对含量呈负相关,亚油酸和亚麻酸的相对含量呈正相关。通过研究发现后熟期间大豆籽粒脂肪含量有了显著升高,对于生产实际有很好的指导作用。     

芝麻林素对煎炸过程中大豆油品质的影响

以添加芝麻林素的精炼大豆油为原料煎炸土豆条,研究芝麻林素对180 ℃煎炸过程中大豆油理化指标包括 脂肪酸组成和VE含量变化的影响。结果表明：芝麻林素对煎炸大豆油的过氧化值、茴香胺值和黏度的增加以及透 光率的降低具有抑制作用,对大豆油酸价影响不明显;且芝麻林素能够延长大豆油的氧化诱导时间,减缓大豆油煎 炸过程中总不饱和脂肪酸含量的降低;芝麻林素还能够延缓（β＋γ）-VE和δ-VE的分解率和总VE的分解率,但对 α-VE的影响不显著。因此,芝麻林素对煎炸大豆油具有一定的抗氧化保护作用,在油脂和食品工业领域具有一定 的开发潜力。     

Comparative Analysis of the Physico-Chemical,Thermal, and Oxidative Properties of Winged Bean and Soybean Oils

To explore possible food applications, the oxidative stability, antioxidants contents (tocopherols and tocotrienols), thermal properties, and solid fat content of winged bean oil were investigated along with soybean oil for comparison. Results showed that winged bean oil was significantly (p < 0.05) resistant to oxidation (27 h) compared to soybean oil (9 h) heated at 110^oC for 32 h, due presumably to the presence of alpha tocotrienol and the high behemic acid content. The high content of tocopherols, 230 mg/100 g in soybean oil did not contribute much to its oxidation stability. At around 25^oC, winged bean oil contained about 15% solid fat content with <1% in soybean oil. Soybean oil, however, had better levels of the omega-3 and omega-6 fatty acids with a ratio of 7.6:1, falling within the range of 5:1 and 10:1 recommended by the Food and Agriculture Organization/World Health Organization, when compared to winged bean oil having a ratio of 34.4:1. The positional fatty acids esterified as stearoyl, palmitoyl, behemoyl or lignoceroyl triacylglycerides species, PSP, PPP, PLB, POB and SSlg+PBP overwhelmed the unsaturated FAs of winged bean oil for free radical reaction and also conferred it high thermal conductivity. The high oxidative stability, solid fat content, and thermal conductivity of winged bean oil coupled with its crystalization characteristics confirmed it to be good material for frying and for making zero-trans-fat margarines and spreads.     

Storage stability of liver oil from two ray (Rhinoptera bonasus and Aetobatus narinari) species from the Gulf of Mexico

The effect of storage time on the quality of liver oil from two commercial rajiform species (Rhinoptera bonasus and Aetobatus narinari) captured in the Gulf of Mexico (State of Campeche coast line) was evaluated. Oil characterisation was conducted by physical (specific gravity, saponification index and water content) and chemical analyses (fatty acid content, carotenes and tocopherols) whilst storage stability (peroxide value, free fatty acids, conjugated dienes, anisidine value and changes in docosahexaenoic acid, DHA and content) was studied for 87 days at 25 °C. Increases (p < 0.05) in free fatty acids, conjugated dienes, peroxide value and anisidine value, and a decrease (p < 0.05) in DHA were observed during the storage time for both oil species as oxidation proceeded. It was concluded that R. bonasus and A. narinari oils lasted for 52 and 66 days under these storage conditions, respectively.     

Comparison of Oxidative Stability among Edible Oils under Continuous Frying Conditions

The stability of camellia oil (saturated fatty acid: monounsaturated fatty acid: polyunsaturated fatty acid = 1:7:1) after frying potatoes was compared with palm oil (saturated fatty acid: monounsaturated fatty acid: polyunsaturated fatty acid = 4:4:1) and peanut oil (saturated fatty acid: monounsaturated fatty acid: polyunsaturated fatty acid = 2:4:4). Oil samples were evaluated for acid value, iodine value, peroxide value, p-anisidine value, total oxidation value, tocopherols content, and fatty acids composition. There was the least change in fatty acid composition in camellia oil among the three edible oils. The α-tocopherol was more vulnerable to heat degradation than γ-tocopherol and δ-tocopherol, and α-tocopherol was completely degraded before the whole frying process was done for palm and peanut oils. The oxidative stabilities of the three edible oils were in the order of camellia oil > palm oil > peanut oil. The oxidative stability was mainly determined by the calculated oxidizability value related to fatty acid composition, and when calculated oxidizability values were similar, the tocopherol contents of edible oils would be a key factor in affecting their oxidative stabilities.     

大豆油抗冻性的影响因素

抗冻性是成品一级大豆油质量指标之一,评价方式为冷冻试验。受油料、原油品质以及加工情况等的影响,有时一级大豆油的抗冻效果会有很大差异。因此,对大豆油抗冻性的影响因素进行了研究。首先,考察了不同精炼工序大豆油的抗冻性;其次,选取5种市售一级大豆油,使其在低温条件下结晶,比较分析结晶成分与非结晶成分的脂肪酸组成以及甘油酯组成差异,并分析其理化指标差异,考察大豆油脂肪酸、甘油酯组成及理化指标对抗冻性的影响;另外,通过反添磷脂与白土探究其对一级大豆油抗冻性的影响。结果表明：不同精炼工序大豆油表现出不同的抗冻性,随着精炼程度的加深,大豆油抗冻性逐渐变差。一级大豆油中饱和脂肪酸、甘一酯、甘二酯含量为影响其抗冻性的重要因素;磷脂会提高一级大豆油的抗冻性,但磷脂含量过高,其抑制油脂结晶的效果降低;大豆油的抗冻性随着白土残余量的增加而降低。     

紫苏提取物对裂壶藻油氧化稳定性的影响

目的：探究紫苏提取物对裂壶藻油氧化稳定性的影响。方法：采用强制氧化法,以过氧化值、丙二醛值、茴香胺值、共轭二烯值作为评价指标,探究不同浓度紫苏提取物、0.04%茶多酚与0.02% TBHQ对裂壶藻油氧化稳定性的影响,采用气相—质谱检测裂壶藻油中脂肪酸成分的变化。结果：强制氧化15 d后,0.10%紫苏提取物组不饱和脂肪酸含量相比空白组提高了16.91%,紫苏提取物可以通过延缓不饱和脂肪酸的氧化分解,起到抗氧化效果,紫苏提取物对裂壶藻油的氧化抑制效果略低于TBHQ,不饱和脂肪酸含量仅减少了5.30%,紫苏提取物添加组相比茶多酚添加组不饱和脂肪酸含量增加了12.93%,抗氧化效果明显高于茶多酚。结论：紫苏提取物能够有效提高裂壶藻油的氧化稳定性,且随着提取物剂量的增加,其延缓氧化效果也更加显著。     

西式快餐条件下煎炸油氧化稳定性及其不饱和脂肪酸氧化动力学研究

为了解煎炸油在煎炸过程中的氧化动力学规律,考察了5种常见煎炸油在西式快餐条件下的氧化稳定性,并对煎炸油中主要不饱和脂肪酸（亚麻酸、亚油酸及油酸）的氧化动力学进行研究。结果表明,煎炸过程中,棕榈油的茴香胺值、全氧化值的生成速率及碘值降低幅度最小,相比其他4种煎炸油具有更好的氧化稳定性。大豆油和菜籽油中亚麻酸的反应规律均同时符合0级和1级反应动力学模型;棕榈油、菜籽油、葵花籽油及稻米油中亚油酸的反应规律均同时符合0级和1级反应动力学模型,大豆油中亚油酸符合1级反应动力学模型;棕榈油、大豆油、菜籽油及葵花籽油中油酸的反应规律均同时符合0级和1级反应动力学模型;模型相应的决定系数R2在0.886~0.987之间,均大于0.85,模型拟合程度均较好。表明所构建煎炸油不饱和脂肪酸氧化动力学模型是可行的。     

不同储存时间和抗氧化剂添加量对鱼油质量影响的研究

通过设定不同的储存时间和抗氧化剂添加量监测鱼油氧化相关指标的动态变化,评估不同储存时间和抗氧化剂添加量对鱼油质量的影响,同时筛选反映鱼油氧化程度的敏感指标,为建立并完善鱼油质量检测体系提供重要依据。结果表明:不同储存时间和抗氧化剂添加量对鱼油的酸值、过氧化值、茴香胺值、硫代巴比妥酸反应物、碘值、脂肪酸组成均有显著影响(P0.05),并且储存时间和抗氧化剂添加量的交互影响显著(P0.05);综合来看,鱼油的储存时间在90 d以内添加30mg/kg乙氧基喹啉即可;若长期保存(90~135 d),添加300 mg/kg乙氧基喹啉最佳。建议将过氧化值、茴香胺值和碘值作为鱼油品质检测的必需指标。     

Frying of potato chips in a blend of canola oil and palm olein: changes in levels of individual fatty acids and tocols

The changes occurring in the levels of nutritionally relevant oil components were assessed during repeated frying of potato chips in a blend of palm olein and canola oil (1:1 w/w). The blend suffered minimal reductions in omega‐3 and omega‐6 polyunsaturated fatty acids. There was no significant difference between the fatty acid composition of the oil extracted from the product and that of the frying medium, in all three cases. The blend also contained a significant amount of tocols which add a nutritional value to the oil. The concentration of the tocols was satisfactorily retained over the period of oil usage, in contrast to the significant loses observed in the case of the individual oils. The blend also performed well when assessed by changes in total polar compounds, free fatty acids, p‐anisidine value. When fried in used oil, the product oil content increased progressively with oil usage time. This study shows that blended frying oils can combine good stability and nutritional quality.     

Improvement of palm oil and sunflower oil blends by enzymatic interestrification

Palm oil (PO) and sunflower oil (SFO) blends with varying proportions were subjected to enzymatic interesterification (EIE) using a 1,3‐specific immobilised lipase. The interesterified blends were evaluated for their slip melting point (SMP), solid fat content (SFC) at 10–40 °C, p‐anisidine value, peroxide value, free fatty acids (FFA), induction period of oxidation at 110 °C (IP110) and composition of fatty acids by gas chromatography. Under EIE treatment, the blends of PO and SFO in different proportions (20:80, 40:60, 50:50, 60:40 and 80:20) had saturated and unsaturated fatty acid content in the range of 37.6–52.0% and 48.0–62.4%, respectively. The blends showed a considerable reduction in their SFC, SMP, peroxide value and oxidative stability at 110 °C, but presented increase in FFA and p‐anisidine value. The optimum condition for minimising the fatty acid in oil was obtained, at 64 °C, using 8.9% enzyme and 3 h reaction time.