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。     

添加迷迭香提取物对油茶籽油储藏稳定性的影响

以添加迷迭香提取物的油茶籽油为研究对象,通过Schaal烘箱法在(62±1)℃条件下,储藏0,6,12,18,24天。通过测定样品的过氧化值、酸价、p-茴香胺值、全过氧化值。比较样品的储藏稳定性。结果表明:随着加热时间的延长,油茶籽油的过氧化值、酸价和全过氧化值呈现增大的趋势,p-茴香胺值快速增加;添加迷迭香提取物的油茶籽油在加热过程中表现出较低的过氧化值、酸价、p-茴香胺值和全过氧化值改变,说明迷迭香提取物具有较高的抗氧化性,在抑制油脂氧化方面有着明显的作用。     

烘烤预处理油菜籽的储藏方式对压榨菜籽油品质的影响研究

以烘烤预处理油菜籽为原料,将其分别进行真空包装与编织袋包装。然后进行为期42 d的真空和常压室温储藏,每隔6 d对两种储藏方式的油菜籽进行低温压榨制油,并测定压榨菜籽油的质量指标,动态监测不同储藏方式对压榨菜籽油品质的影响。结果表明:两种储藏条件下压榨菜籽油的酸价、过氧化值和茴香胺值均随储藏时间延长而升高,DPPH自由基清除能力、铁离子还原能力、氧化诱导期均随储藏时间延长而逐渐降低,且真空包装储藏的变化趋势更小,而脂肪酸组成和含量均未发生显著变化;储藏42 d后,真空包装储藏保留了原料中85. 29%的植物甾醇含量、78. 44%的Canolol含量和77. 28%的多酚含量。相对于常压室温储藏,真空包装储藏方式下压榨菜籽油的理化指标变化更小,营养成分损失率更低,抗氧化活性更高。因此,真空包装储藏能够很好地保持烘烤预处理油菜籽的制油品质,可以成为一种绿色的油菜籽储藏方法。     

微波预处理亚麻籽对其压榨饼生氰糖苷含量及压榨油品质的影响

优化了微波预处理亚麻籽降低其压榨饼生氰糖苷含量的条件,并比较了甘肃亚麻籽在最佳微波条件下微波前后压榨油的品质变化,同时对比了另外五个不同品种亚麻籽在最佳微波条件下其压榨饼生氰糖苷含量在微波前后的变化。结果表明:最佳微波条件为功率700 W,时间6 min,亚麻籽水分17%。在此微波条件下,甘肃亚麻籽压榨饼生氰糖苷含量降低至(4.18±0.23)mg/kg,其压榨油的酸价显著升高,过氧化值显著降低,黄色值、红色值均微弱增加。脂肪酸组成、甾醇含量没有显著性变化,总酚含量是直接压榨亚麻籽油的1.42倍;另外五个不同品种亚麻籽仅哈尔滨亚麻籽压榨饼中生氰糖苷的含量为(15.40±0.47)mg/kg,其余四个品种的压榨饼生氰糖苷含量均在5 mg/kg以下。     

不同方式提取调和油的热稳定性研究

为研究不同方式提取调和油的烹饪稳定性,分别测定水酶法调和油、溶剂浸提调和油在150、200℃温度条件下加热不同时间的理化性质。结果表明:加热前后,水酶法调和油的色泽较浅,且其酸价、过氧化值、p-茴香胺值始终低于溶剂法调和油,水酶法调和油的氧化稳定性优于溶剂法调和油。随着加热温度的升高,加热时间的延长,两种调和油的裂变程度均增加,酸价及p-茴香胺值升高,色泽加深,过氧化值出现先上升后下降的波动趋势,单不饱和脂肪酸(C18∶1)、多不饱和脂肪酸(C18∶2)呈下降趋势,饱和脂肪酸(C16∶0)含量升高,但在加热1h前,各项指标变化不大。     

化学和物理精炼工艺对葡萄籽油氧化劣变品质的影响

为了研究化学和物理精炼工艺对葡萄籽油氧化裂变品质的影响,分别采用化学和物理工艺精炼葡萄籽原油,探讨反式脂肪酸的变化规律,以及不同精炼阶段油脂的酸价、过氧化值、p-茴香胺值和VE含量变化。结果表明:葡萄籽油经化学精炼酸价降至(0.20±0.016)mg KOH/g,葡萄籽油的过氧化值和p-茴香胺值降低,反式脂肪酸质量分数增加至(0.36±0.001 4)%,VE损失了37%~43%。对葡萄籽原油进行物理精炼,240℃条件下真空脱酸6 h,酸价降至(0.19±0.029)mg KOH/g,过氧化值降低、p-茴香胺值升高,反式脂肪酸质量分数增至(0.91±0.001 3)%,VE损失了50.69%。比较得知,物理精炼过程相对于化学精炼对葡萄籽油品质的影响较大。     

微波预处理紫苏籽对其油脂品质及抗氧化特性的影响

对紫苏籽采用微波预处理技术,并低温压榨制油。测定分析其理化、营养及抗氧化指标,以考察微波处理对紫苏油品质的影响。结果表明:微波预处理显著增加了油的酸价、过氧化值,降低了油的水分及挥发物含量,使油脂色泽变深;紫苏油含有丰富的α-亚麻酸,且微波预处理不影响油的脂肪酸组成(P0.05);微波预处理可提高紫苏油中维生素E及植物甾醇含量,有效改善油脂的抗氧化能力。黄酮物质的热不稳定性使其在微波后含量少量降低。     

微波预处理对毛茶油品质影响

采用微波技术对油茶籽进行预处理,探讨微波作用条件对茶油提取率和毛茶油品质影响。结果表明,微波预处理可增大提油率,缩短预处理时间,茶籽水分含量很快达到平衡;但毛茶油过氧化值、酸价均有一定程度上升,色泽也有所加深。     

油莎豆油的高温煎炸稳定性

以油莎豆油为研究对象,以大豆油为对照,选择过氧化值、p-茴香胺值、共轭二烯含量、共轭三烯含量为评价指标,考察高温煎炸条件下油莎豆油的稳定性,同时通过傅里叶变换红外光谱表征高温煎炸后油莎豆油结构的变化。结果表明：通过比较煎炸次数与过氧化值的关系,油莎豆油的煎炸稳定性略优于大豆油;两种油脂的p-茴香胺值均随煎炸次数增加而增大,大豆油的p-茴香胺值高于油莎豆油,大豆油与油莎豆油的p-茴香胺值与煎炸次数呈明显的相关性,相关系数分别为0982 8和0.988 2;随煎炸次数增加,大豆油中共轭二烯、共轭三烯含量均高于油莎豆油,因此油莎豆油的煎炸稳定性高于大豆油。红外光谱结果表明高温煎炸破坏了两种油脂的不饱和脂肪酸结构。     

水酶法提取大豆油与其他不同种大豆油品质差异研究

通过对大豆油的感官指标、理化指标及部分功能性成分的比较,研究不同种大豆油(水酶法提取大豆油、一级大豆油、三级大豆油、压榨大豆油、溶剂浸提大豆油)的品质差异。结果表明,水酶法大豆油的外观品质介于一级油与三级油之间;色泽处于二级油与三级油之间,折光率最高,密度处于一级油和三级油之间;水分及挥发物的含量和p-茴香值最高,碘价最低,酸价、过氧化值介于一级油和二级油之间;水酶法大豆油的亚麻酸未检出,其饱和脂肪酸含量最低,总不饱和脂肪酸含量最高,磷脂含量介于一级大豆油和三级大豆油之间。     

Influence of Microwave Treatment of Rapeseed on Minor Components Content and Oxidative Stability of Oil

Rapeseeds were adjusted to moisture contents of 9, 11, 13, and 15 % and treated with microwaves under 800 W for 0, 1, 2, 3, 4, 5, 6, and 7 min at a frequency of 2,450 MHz and oil was extracted with a press to investigate possibility of enhancing oil extraction yield by press, minor component content, and oxidative stability of the pressed oil. The results indicated that microwave pretreatment of rapeseed could increase the oil extraction yield, and both microwave time and initial moisture content of rapeseed had significant effects on the oil extraction yield (p?<?0.001). Total tocopherol content in the oil extracted by press first increased and then decreased depending on the period of microwave radiation (p?<?0.001), and the initial moisture content had no significant effect on the tocopherol content (p?>?0.05). Phytosterol and polyphenol contents increased with increasing microwave time and with decreasing initial moisture content of rapeseeds (p?<?0.001). An F test revealed there were significant interactions between the effects of microwave time and initial moisture content on both polyphenol content and oil extraction yield. The oxidative stability of oil were improved with increasing microwave time and decreasing initial moisture content (p?<?0.001), and there were significant positive correlations with total polyphenol and phytosterol contents. Therefore, it is advisable to treat rapeseeds with low initial moisture content by microwaves prior to oil extraction by press because it results in a relatively good oil extraction yield by cold press, with a high amount of phenolic, tocopherol, and phytosterol. Microwave pretreatment had a positive effect on oxidative oil stability in comparison to the untreated oil.     

Effect of pretreatment with microwaves on oxidative stability and nutraceuticals content of oil from rapeseed

Demand for oil extracted by cold press, such as rapeseed oil, is increasing, but oil extraction yield, and nutraceuticals content are lower for cold pressed oil, compared with oil extracted by solvent. In this study, rapeseed was treated with microwaves, to investigate the possibility of enhancing oil extraction yield, oxidative stability and nutraceuticals content. Rapeseed was pretreated with microwaves for two different times (2 min and 4 min) and oil was then extracted with a press. To compare the results, oil was also extracted from untreated rapeseed by solvent and press. Results showed that solvent-extracted oil had the highest phytosterol content. Microwave pretreatment of rapeseed can increase the oil extraction yield (by 10%), phytosterols (by 15%) and tocopherols (by 55%) of the oil extracted by press. Oil extracted from untreated rapeseed by press had the lowest oxidative stability (1 h); this was increased to 8 h by pretreatment of rapeseed with microwaves. Therefore, from the obtained results, it is advisable to treat rapeseed with microwaves before extraction by oil press, because it gives a relatively good recovery of oil, with a high amount of nutraceuticals, and can produce oil with a longer shelf life and enhanced value.     

小米糠液压榨油工艺的研究

本实验以小米糠为原料,采用液压榨取的方法制取小米糠油,以小米糠的饼残油为考察指标,研究不同的原料水分、压榨时间、压榨温度对小米糠饼残油的影响。得到最佳工艺条件:在原料水分8%、压榨温度50℃、压榨时间1 h的条件下,小米糠饼残油低至11.68%;精炼后的小米糠油的酸价、过氧化值分别降为0.27 mgKOH/kg、0.22 mmol/kg,符合食用油的标准。     

Effect of supercritical CO2 extraction process parameters on oil yield and pigment content from by‐product hemp cake

This research gives an insight into the possibility of exploiting the one of the food industry's by‐products – pressed hemp cake. The complete recovery of oil from pressed hemp cake was achieved. Residual oil that remained in cake after pressing was extracted with supercritical CO₂ by applying different process parameters. Optimal extraction conditions were determined using response surface methodology. Total pigment contents of the oils obtained were determined. Extraction pressure had the most significant influence on yield and pigment content of extracted hemp cake oil. Depending on the pressure, the chlorophyll a content ranged from 101.11 to 378.28 mg kg^?1 and chlorophyll b from 65.14 to 189.78 mg kg^?1, while total carotene content was in the range from 33.58 to 132.67 mg kg^?1. The remaining oil in pressed hemp cake after supercritical CO₂ extraction was determined to be 0.56 ± 0.08% and the defatted cake was rich in proteins and fibre.     

加工工艺对菜籽油主要挥发性风味成分的影响

采用固相微萃取（Solid Phase Microextraction,SPME）方法顶空萃取富集预榨菜籽毛油、浸出菜籽毛油、一级菜籽油、冷榨菜籽油和脱皮冷榨菜籽油中的挥发性成分,经气相色谱-质谱联用仪（Gas Chromatography-Mass Spectrometry,GC-MS）检测和初步分析发现,硫甙降解产物、氧化挥发物（醛、醇、烃、酮等）、杂环类物质是构成菜籽油的主要挥发性风味成分;2-甲代-1-丙烯基-氰、5-己腈、1-丁烯基-异硫氰酸酯、苯基丙氰、2-苯基乙基异硫氰酸酯是主要硫甙降解产物;反2-反4-庚二烯醛、反2-反4-癸二烯醛、4-羟基-3,5-二甲氧基苯甲醛、壬醛等醛类物质是氧化挥发物中的主要成分。加工工艺对菜籽油风味影响显著,经高温蒸炒、压榨获得的预榨毛油中杂环类物质种类和相对含量明显高于其它菜籽油。毛油经脱胶、脱酸、脱色、脱臭、脱水等处理后,一级油中产生的醛、醇、酮、烃等氧化挥发物种类增多,相对含量提高;在一级油中未检测到硫甙降解产物。     

不同品质油茶籽压榨制油工艺的对比研究

采用双螺旋压榨、单螺旋压榨和液压压榨3种压榨工艺对不同品质油茶籽进行压榨制油,并对压榨油的常规指标及微营养成分进行分析对比。结果表明:优质油茶籽经液压压榨制得的压榨油品质明显优于其他两种压榨工艺;普通品质油茶籽经液压压榨制得的压榨油质量稍优;品质较差油茶籽分别采用3种压榨工艺制得的压榨油品质相当;3种压榨工艺中,压榨饼残油最低的是双螺旋压榨,其次是单螺旋压榨,最高的是液压压榨。     

芝麻品种和制油工艺对芝麻油品质的影响

对以黑、白芝麻为原料,采用水代法、螺旋压榨法、液压压榨法工艺所得芝麻油的理化指标、脂肪酸组成、芝麻油中VE、芝麻素、芝麻酚含量和氧化稳定性进行了测定。结果显示:水代法所得芝麻油的酸值(KOH)和磷脂含量最低,而水分及挥发物含量最高;所有芝麻油样品均含有丰富的抗氧化成分芝麻素、芝麻酚和VE;所有芝麻油样品的脂肪酸组成接近,其中油酸和亚油酸含量高达83.4%;白芝麻油氧化稳定性明显优于黑芝麻油,水代法所得芝麻油氧化稳定性最好,液压压榨芝麻油次之,螺旋压榨芝麻油最差。     

隔膜压滤机在棕榈油干法分提中的应用

隔膜压滤机用于棕榈油分提过程的固液分离,在过滤完成后,通过压缩介质(水或空气等)依靠隔膜对滤饼压榨、挤干.采用隔膜压滤机,棕榈硬脂硬度提高、棕榈液油得率增加,分离效果好.过滤过程应用自动化控制,操作方便、产品质量稳定.     

响应面优化冷榨法制取山桐子油工艺的研究

以山桐子为原料,考察了不同冷榨压力、转速、冷榨温度和水分含量对出油率的影响。通过单因素和响应面优化分析得出最佳冷榨工艺条件为:冷榨压力3.75MPa,转速36.5r/min,冷榨温度77.5℃,水分含量9%,此时出油率为26.61%。最后将冷榨后山桐子油的脂肪酸组成进行分析并与其它油脂进行比较,结果显示山桐子油亚油酸含量明显高于茶籽油、花生油和橄榄油。     

微波预处理对芝麻油中芝麻木酚素含量及油脂品质的影响

为了确定高芝麻酚芝麻油的最适微波预处理条件,将芝麻水分含量调节为5个梯度,在不同微波预处理时间下制得芝麻油样品,对其芝麻木酚素含量、酸值、茴香胺值、氧化诱导时间、脂肪酸组成、生育酚含量、有害物质（多环芳烃和杂环胺）含量及感官品质进行了分析,探究芝麻水分含量和微波预处理时间对芝麻油中芝麻木酚素含量及油脂品质的影响。结果表明：微波预处理时间6 min、芝麻水分含量7%条件下制得的芝麻油芝麻酚含量较高,芝麻油酸值符合国家标准限定要求,氧化稳定性较强,有害物质杂环胺和多环芳烃含量处于适当的可控水平,同时兼顾了芝麻油的固有风味,消费者的喜爱度较高。综上,高芝麻酚芝麻油的最适微波预处理条件为微波预处理时间6 min,芝麻水分含量7%。