烘烤条件对芝麻香油显色反应呈色特征的影响

为了分析芝麻香油烘烤工艺对显色反应的影响,以RGB色彩模式中的R、G、B为评价指标,采用三氯乙酸分别对烘烤温度150~170℃,烘烤时间10~35min的芝麻香油显色,分析显色后1~7min样品的RGB变化。结果显示:伴随着显色反应的进行,样品的绿、蓝值显著下降,而红值有所上升。烘烤温度和烘烤时间会影响红、绿、蓝值,但随着反应时间延长,由烘烤温度和烘烤时间引起的样品颜色差异趋于缩小,故采用三氯乙酸显色反应鉴别芝麻油掺假的方法需要在显色反应进行7min之后再进行。此外,显色反应中的蓝值可以用于对芝麻香油烘烤条件的推测。     

烘烤条件对奇亚籽油理化性质及脂肪酸组成的影响

对奇亚籽进行烘烤、压榨取油,测定不同烘烤条件(温度、时间)下奇亚籽油的理化性质及脂肪酸组成,探讨烘烤温度和时间的影响。结果表明:随着烘烤温度的升高和烘烤时间的延长,奇亚籽油色泽加深,酸价、过氧化值、K_(232)、K_(268)均呈现上升趋势,且180℃烘烤50 min以上较其他条件下显著升高(p0.05);烘烤条件对脂肪酸组成无影响。故烘烤奇亚籽不宜在高温下进行,若采用180℃烘烤时,则时间不应超过50 min。     

烘烤条件对压榨奇亚籽油中苯并[a]芘含量的影响北大核心CSCD

为探索不同烘烤条件下奇亚籽油中苯并[a]芘含量的变化规律,在不同的烘烤温度(60、100、140、180℃)和烘烤时间(10、30、50、70、90 min)下烘烤奇亚籽,采用液压压榨制备奇亚籽油。观察奇亚籽油色泽,并记录其气味。以MIL-101(Cr)为分散式固相萃取材料,采用分散式固相萃取-高效液相色谱-荧光检测器对苯并[a]芘进行定量检测。结果表明:烘烤条件对奇亚籽油的色泽、气味影响较大;随着烘烤温度的升高及烘烤时间的延长,奇亚籽油中苯并[a]芘含量逐渐升高,且烘烤温度越高、烘烤时间越长,苯并[a]芘含量增幅越大。参考GB 2762—2017及欧盟No 835/2011对食用油中苯并[a]芘的限量规定,并结合奇亚籽油的色泽、透明度和气味变化规律,在压榨前烘烤奇亚籽时,烘烤温度不应超过140℃,烘烤时间不应超过50 min。     

芝麻脱皮对芝麻香油自然沉降过程的影响

在芝麻香油精制过程中,自然沉降规律受诸多因素影响,为探索提升芝麻香油精制效率的技术手段,以脱皮和未脱皮芝麻所得芝麻香油为研究对象,通过测定芝麻原油与沉淀物组成,并结合沉降过程中沉淀物含量、磷脂含量、酸值、过氧化值、沉淀物压缩速度的变化规律,考察芝麻脱皮对芝麻香油自然沉降过程的影响。结果表明：相比未脱皮芝麻香油,脱皮芝麻香油在线性沉降阶段的沉降效率高约5百分点;芝麻香油沉淀物的90%以上是粗脂肪,还有少量水分、磷脂、蛋白质、糖形成的胶杂,水和磷脂发生明显聚集;沉淀物的酸值远高于芝麻香油,但过氧化值变化不明显;芝麻香油磷脂含量与沉淀物含量变化呈现相似的趋势,上、下层油中磷脂含量和酸值在线性沉降阶段后差异较小;脱皮芝麻香油沉淀物初始高度远低于未脱皮芝麻香油,且在线性沉降阶段压缩速度快于未脱皮芝麻香油,最终成品油得率高于未脱皮芝麻香油约3百分点。综上,脱皮有利于芝麻香油的自然沉降以及获得更高的得率。     

脱皮对芝麻香油以及蛋白品质的影响

分别以带皮、碱法脱皮、酶法脱皮芝麻为原料,制作芝麻香油和芝麻蛋白,对香油的指标和蛋白的功能特性进行测定,确定脱皮对芝麻香油和芝麻蛋白品质的影响。结果表明:脱皮芝麻香油与带皮芝麻香油相比,氧化稳定性较差,而粗蛋白等其他指标品质较好;脱皮芝麻蛋白比带皮芝麻蛋白的蛋白提取率高约4℃,吸油性高约0.5g/g;酶法脱皮芝麻蛋白与碱法脱皮芝麻蛋白相比,除乳化稳定性低一点外整体品质基本相同。综合分析,脱皮对芝麻香油的品质有明显改善,对芝麻蛋白的品质有少量改善,碱法脱皮芝麻香油和芝麻蛋白品质最好。     

加工工艺对芝麻香油中木脂素含量的影响

以白芝麻为原料,研究电热转筒焙炒炉焙炒对压榨法芝麻香油和水代法芝麻香油木脂素含量的影响,并对氧化稳定性进行测定。结果表明:焙炒程度和制油工艺对芝麻素含量的影响不显著(P0.05);水代法芝麻香油中芝麻林素和芝麻酚的含量变化显著高于相应的压榨法芝麻香油(P0.05);随着焙炒程度的增加,芝麻林素发生分解其含量急剧下降,而芝麻酚含量增加;当焙炒温度大于200℃或者焙炒时间大于30min,芝麻酚可能因发生聚合而含量降低。随烘焙程度的增加芝麻香油的氧化稳定性呈增加趋势,主要归因于芝麻酚含量的增加以及美拉德反应产物的生成等多种抗氧化成分协同作用的结果。     

焙炒条件对芝麻油品质的影响

本文以白芝麻为原料,研究了焙炒温度和焙炒时间对芝麻油品质的影响。结果表明：随焙炒温度提高和焙炒时间延长,芝麻油色泽加深、过氧化值升高,而酸值有所降低;芝麻油中生育酚和芝麻素含量降低,芝麻酚含量略有增高,芝麻油的氧化稳定性提高;芝麻油香味增强。可见芝麻香油生产过程中的高温焙炒对芝麻油香味和氧化稳定性有非常重要的作用。但为了减轻芝麻香油的色泽和过氧化值,最好控制其焙炒条件不超过150℃和20～30min。即使要生产香味更浓的芝麻油,其焙炒条件也不要超过200℃和30min。     

油茶籽油中苯并[a]芘溯源及其控制技术研究

为了探明油茶籽油中苯并[a]芘的来源,研究了原料来源、干燥方式、烘烤温度与时间、制油方式等因素对油茶籽油中苯并[a]芘含量的影响,考察了油茶籽油在精炼过程从脱胶、脱酸、脱色至脱臭过程中苯并[a]芘含量的变化。结果表明,制油方式、烘烤工艺与油脂精炼是油茶籽油中苯并[a]芘含量的主要影响因素。与压榨法相比,浸提法制得的油茶籽油中苯并[a]芘的含量无显著差异(P0.05)。当温度在90~150℃、时间为0.5~3 h时,随着烘烤温度升高与时间延长,油茶籽油中苯并[a]芘含量持续增加,因此,在保证油茶籽油品质与生产工艺要求的前提下,应尽量缩短烘烤时间并降低烘烤温度。油茶籽油精炼中的脱色能有效脱除油茶籽油中的苯并[a]芘,温度为120℃,用6%的白土脱色20 min,油茶籽油中的苯并[a]芘从脱色前的3.757 0μg/kg降至0.265 4μg/kg,脱除率达到93.08%。     

红外烘烤对魔芋葡甘露聚糖表观黏度以及微观结构的影响

加热处理能降低魔芋葡甘露聚糖（konjac glucomannan,KGM）的黏度,并显著影响其理化性质。本实验以纯化魔芋微粉为原料,通过KGM水溶胶黏度、流变性质测定和KGM分子质量测定,KGM紫外吸收光谱、傅里叶变换红外光谱分析,以及KGM扫描电子显微镜观察,研究红外烘烤温度、时间对KGM表观黏度以及微观结构的影响。结果表明,随着烘烤温度升高和时间延长,KGM水溶胶的表观黏度均表现出典型的剪切稀化现象,储能模量（G’）和损耗模量（G”）明显下降;在剪切速率为10 s－1时,与未烘烤KGM水溶胶相比,150 ℃烘烤30 min的KGM水溶胶黏度下降了97.18%,180 ℃烘烤10 min的KGM水溶胶黏度下降了99.51%。扫描电子显微镜分析结果显示,烘烤热处理温度和时间均对KGM的微观结构造成了一定程度的破坏,但傅里叶变换红外光谱分析结果表明烘烤热处理对KGM分子重复单元结构与特征功能基团并未造成破坏,其特征基团结构得以保留,仅部分糖苷键及氢键断裂;分子质量测定结果表明,150 ℃烘烤30 min与180 ℃烘烤10 min均会明显降低KGM的分子质量。综上,红外烘烤热处理可作为热降解KGM的有效手段,其理化性质的改变可扩展其在食品、医药等领域的应用。     

亚麻籽烘烤预处理对亚麻籽油得率 及贮藏稳定性的影响

以亚麻籽油得率为指标,对烘烤预处理亚麻籽工艺进行优化,并研究烘烤预处理对亚麻籽油贮藏稳定性及多酚含量的影响。结果表明：亚麻籽烘烤预处理最佳工艺条件为烘烤时间40 min、烘烤温度100?℃、粉碎粒度0.250 mm（60目）,以此条件下的亚麻籽为原料提取油脂,亚麻籽油得率为44.46%,比未预处理提取的亚麻籽油得率高7.91个百分点,多酚含量高12.61个百分点;贮藏8 d,烘烤预处理提取的亚麻籽油过氧化值、K232、K270的增幅均小于未预处理提取的亚麻籽油。研究表明烘烤预处理不仅能提高亚麻籽油得率,同时可延缓亚麻籽油氧化,进而提高亚麻籽油的贮藏稳定性。     

Influence of seed roasting process on the changes in composition and quality of sesame (Sesame indicum) oil

The composition and quality changes of sesame oils prepared at different roasting temperatures (180–260°C) from sesame seed were evaluated and compared with an unroasted oil sample. There were no apparent differences in characteristics, such as acid value, iodine value, saponification value and refractive index, of sesame oils prepared at a roasting temperature between 180 and 220°C. The colour units and total polar content of oils increased in relation to an increase in roasting temperature. The phospholipid content was reduced from 690 mg kg^?1 in unroasted oil to 0 mg kg^?1 in the oil prepared using a 260°C roasting temperature. The fatty acid content of the oil was reduced markedly, especially in oleic and linoleic acids, when the roasting temperature was over 220°C. The amounts of chlorophyll and sesamolin decreased with increasing roasting temperature. However, the highest level of sesamol and γ-tocopherol was found in oils prepared with a 200–220°C roasting temperature. The sesame oil prepared at a 200°C roasting temperature had the best flavour score when compared with the other samples.     

Effect of Infrared Heating on the Formation of Sesamol and Quality of Defatted Flours from Sesamum indicum L.

ABSTRACT:  Infrared (IR) heating offers several advantages over conventional heating in terms of heat transfer efficiency, compactness of equipment, and quality of the products. Roasting of sesame seeds degrades the lignan sesamolin to sesamol, which increases the oxidative stability of sesame oil synergistically with tocopherols. IR (near infrared, 1.1 to 1.3 μm, 6 kW power) roasting conditions were optimized for the conversion of sesamolin to sesamol. The resultant oil was evaluated for sesamol and tocopherol content as well as oxidative stability. The defatted flours were evaluated for their nutritional content and functionality. IR roasting of sesame seeds at 200 °C for 30 min increased the efficiency of conversion of sesamolin to sesamol (51% to 82%) compared to conventional heating. The γ-tocopherol content decreased by 17% and 25% in oils treated at 200 and 220 °C for 30 min, respectively. There were no significant differences in the tocopherol content and oxidative stability of the oil. Methionine and cysteine content of the flours remained unchanged due to roasting. The functional properties of defatted flours obtained from either IR roasted or conventionally roasted sesame seeds remained the same.
Practical Applications: Sesame oil is stable to oxidation compared to other vegetable oils. This stability can be attributed to the presence of tocopherols and the formation of sesamol, the thermal degradation product of sesamolin—a lignan present in sesame. Roasting of sesame seeds before oil extraction increases sesamol content which is a more potent antioxidant than the parent molecule. The conversion efficiency of sesamolin to sesamol is increased by 31% by infrared roasting of seeds compared to electric drum roasting. This can be used industrially to obtain roasted oil with greater oxidative stability.     

焙炒时间对芝麻油风味及芝麻氨基酸含量的影响

本文主要研究焙炒时间对芝麻油挥发性风味成分及芝麻中氨基酸含量(以芝麻脱脂粕中氨基酸含量为依据)的影响。经过不同时间焙炒的芝麻,用水代法提油,然后采用顶空固相微萃取(HS-SPME)结合GC/MS技术,检测芝麻油中的挥发性风味成分。随着焙炒时间的延长,吡嗪类、吡咯类、吡啶和嘧啶类、含硫类、呋喃类、酚类物质的相对含量逐渐增多,醛类、醇类、烃类和环氧烃类等物质的含量逐渐减少。对芝麻脱脂粕中18种氨基酸含量的检测数据显示,随着焙炒程度加深,氨基酸含量呈总体下降趋势,其中精氨酸、丝氨酸、赖氨酸和胱氨酸的含量减少明显,这4种氨基酸对芝麻油香味的形成可能起到了重要的作用。     

Effects of seed roasting temperature and time on the quality characteristics of sesame (Sesamum indicum) oil

The quality characteristics and composition of sesame oils prepared at different roasting temperatures (160–250°C) from sesame seeds using a domestic electric oven were evaluated as compared to an unroasted oil sample: only minor increases (P<0·05) in characteristics, such as peroxide value, carbonyl value, anisidine value and thiobarbituric acid reactive substances, of sesame oils occurred in relation to increasing roasting temperature and time between 160 and 200°C, but colour units of oils increased markedly over a 220°C roasting temperature. Significant decreases (P<0·05) were observed in the amounts of triacylglycerols and phospholipids in the oils prepared using a 250°C roasting temperature. The amounts of γ-tocopherol and sesamin still remained over 80 and 90%, respectively, of the original levels after roasting at 250°C. In the oil prepared using a 250°C roasting temperature, sesamol was detected at 3370 mg per kg oil, but sesamolin was almost depleted after 25 min of roasting. Burning and bitter tastes were found in the oils prepared at roasting temperatures over 220°C. The results suggested that a high-quality product would be obtained by roasting for 25 min at 160 or 180°C, 15 min at 200°C and 5 min at 220°C when compared with the other samples. © 1997 SCI.     

Improvement of the yield and flavour quality of sesame oil from aqueous extraction process by moisture conditioning before roasting

This study was to investigate the effect of conditioning and heat-treatments on the yield and quality of sesame oil. Confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM) were used to explore the microstructure of sesame cotyledon cells. It was found that cell microstructure and oil body membrane of sesame seeds underwent high-pressure steaming pretreatment (HPS), roasting pretreatment (RP), moisture-conditioning plus roasting pretreatment (MRP) was all damaged. All these thermal treatments, especially MRP, contributing to increased oil yield from 45.85 (untreated) to 91.69%. Furthermore, RP or MRP yielded a higher content of sesamol than untreated sesame, whereas sesamin and seasamolin content, fatty acid composition, acid value and peroxide value showed no significant changes (P > 0.05) between heat-treatments. MRP increased the type and content of volatile compounds, which was beneficial to the strong nut-like aroma. Additionally, MRP had a positive effect on oxidative oil stability (induction time of 10.80 h) with respect to untreated oil (7.82 h).     

加工工艺对芝麻酱稳定性的影响

为探明影响芝麻酱贮藏稳定性的关键工艺和核心指标,比较了炒制工艺（焙炒温度、时间）、不同原料处理方式（脱皮与未脱皮）、磨酱次数等关键工艺条件,测定其离心析油率、沉降析油率等贮藏稳定性指标以及粒径、比表面积等物化特性,通对不同工艺条件下各指标的变化进行分析归纳以及相关性分析,阐明加工工艺与贮藏稳定性之间的相关性。结果表明:芝麻的焙炒时间对酱体沉降析油率影响显著,焙炒时间延长析油率呈现先下降趋势,后趋于平稳,焙炒温度对芝麻酱沉降析油率影响不显著,但是温度不宜超过230 ℃,否则产品有焦糊味,研究发现芝麻酱离心析油率与30、60、90 d的沉降析油率的相关系数分别为0.966、0.955、0.967,呈现极显著正相关,离心析油率与芝麻酱的中位径D50、平均粒径Dav值也为显著正相关,相关系数为0.952和0.913,但是与比表面积S/V呈现负相关,相关系数为?0.930。另外,对比了脱皮芝麻和未脱皮芝麻加工成芝麻酱的离心析油率和黏度,发现芝麻皮的存在可以提高酱体黏度而有利于稳定贮藏,降低离心析油率,综合来看,在焙炒温度220 ℃,焙炒时间20 min,磨酱次数3次,离心析油率为3.34%,该条件下加工的芝麻酱的离心析油率最低,稳定性最佳。     

焙炒处理对不同植物油品质特性的影响北大核心CSCD

为了研究焙炒对植物油品质的影响,以油菜籽、亚麻籽、花生、葵花籽和芝麻为原料,经焙炒处理后采用液压压榨法制油(热榨油),分析植物油的理化指标(酸值、过氧化值、水分及挥发物、色泽)、主体组分(脂肪酸组成及含量、甘三酯组成及含量、挥发性组分)和总酚含量,并与未焙炒处理直接压榨制取的油(冷榨油)作对比。结果表明:热榨油酸值和过氧化值显著高于冷榨油(p<0.05),其中,热榨亚麻籽油酸值(KOH)最高(0.96 mg/g),热榨菜籽油过氧化值最高(1.02 mmol/kg);冷榨油水分及挥发物含量显著高于热榨油(p<0.05),其中冷榨花生油水分及挥发物含量最高(0.16%);热榨油的色泽较冷榨油深,其中热榨菜籽油的色泽最深(R1.1,Y31);焙炒对植物油脂肪酸和甘三酯组成及含量无显著影响(p>0.05);热榨油中醇类、醛类和酸类等挥发性组分较少,但杂环类物质较多;热榨菜籽油、亚麻籽油、花生油、葵花籽油和芝麻油总酚含量分别是其冷榨油的1.38、1.57、1.51、1.80倍和1.27倍。因此,焙炒对植物油品质影响较大,应根据生产需要选择合适的预处理方式。     

Application of solid phase-microextraction (SPME) and electronic nose techniques to differentiate volatiles of sesame oils prepared with diverse roasting conditions

Headspace volatiles of sesame oil (SO) from sesame seeds roasted at 9 different conditions were analyzed by a combination of solid phase microextraction (SPME)-gas chromatography/mass spectrometry (GC/MS), electronic nose/metal oxide sensors (MOS), and electronic nose/MS. As roasting temperature increased from 213 to 247 °C, total headspace volatiles and pyrazines increased significantly (P < 0.05). Pyrazines were major volatiles in SO and furans, thiazoles, aldehydes, and alcohols were also detected. Roasting temperature was more discrimination factor than roasting time for the volatiles in SO through the principal component analysis (PCA) of SPME-GC/MS, electronic nose/MOS, and electronic nose/MS. Electronic nose/MS showed that ion fragment 52, 76, 53, and 51 amu played important roles in discriminating volatiles in SO from roasted sesame seeds, which are the major ion fragments from pyrazines, furans, and furfurals. SO roasted at 213, 230, and 247 °C were clearly differentiated from each other on the base of volatile distribution by SPME-GC/MS, electronic nose/MOS, and electronic nose/MS analyses. Practical Application: The results of this study are ready to apply for the discriminating samples using a combinational analysis of volatiles. Not only vegetable oils prepared from roasting process but also any food sample possessing volatiles could be targets for the SPME-GC/MS and electronic nose assays. Contents and types of pyrazines in sesame seed oil could be used as markers to track down the degree of roasting and oxidation during oil preparation.     

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%。     

Effects of Roasting Conditions on the Changes of Stable Carbon Isotope Ratios (δ13C) in Sesame Oil and Usefulness of δ13C to Differentiate Blended Sesame Oil from Corn Oil

Abstract: Differentiating blended sesame oils from authentic sesame oil (SO) is a critical step in protecting consumer rights. Stable carbon isotope ratios (δ¹³C), color, fluorescence intensity, and fatty acid profiles were analyzed in SO prepared from sesame seeds with different roasting conditions and in corn oil blended with SO. Sesame seeds were roasted at 175, 200, 225, or 250 °C for 15 or 30 min at each temperature. SO was mixed with corn oil at varying ratios. Roasting conditions ranging from175 to 250 °C at the 30 min time point did not result in significant changes in δ¹³C (P > 0.05). Values of δ¹³C in corn oil and SO from sesame seeds roasted at 250 °C for 15 min were −17.55 and −32.13 ‰, respectively. Fatty acid ratios, including (O + L)/(P × Ln) and (L × L)/O, where O, L, P, and Ln were oleic, linoleic, palmitic, and linolenic acids, respectively, showed good discriminating abilities among the SO blended with corn oil. Therefore, using different combinations of stable carbon isotope ratios and some fatty acid ratios can allow successful differentiation of authentic SO from SO blended with corn oil. Practical Application: Adulteration of sesame oil with less expensive oils such as corn oil or soybean oil to reduce cost is a common unethical practice in Korea. Due to the unique and strong flavor of sesame oils that may mask other weaker flavors, however, differentiating authentic sesame oils from blended oils is difficult. This study showed that the roasting process did not significantly affect the ratios of the stable carbon isotope (δ¹³C) in sesame oils. δ¹³C was confirmed to be a reliable parameter. Moreover, some fatty acid ratios were designed to discriminate between blended sesame oil with corn oil and authentic sesame oil.