微波预处理对奇亚籽出油率及油脂品质的影响

采用微波技术对奇亚籽进行预处理后低温压榨制油,测定奇亚籽油理化指标、营养及抗氧化指标,探讨微波预处理条件对奇亚籽出油率以及奇亚籽油品质的影响。结果表明：原料的水分含量、微波时间、微波功率对奇亚籽出油率和奇亚籽油的理化指标、黄酮含量、多酚含量及DPPH·和O-2·清除能力均有一定的影响,对奇亚籽油脂肪酸相对含量影响较小。经单因素实验和正交实验得出：微波预处理奇亚籽的适宜工艺条件为奇亚籽水分含量12%、微波时间3 min、微波功率600 W,在该条件下奇亚籽出油率可达到21.05%,奇亚籽油酸价（KOH）0.52 mg/g、过氧化值0.44 mmol/kg、黄酮含量318.25 mg/kg、多酚含量28.00 mg/kg,DPPH·和O-2·清除率分别为2479%和26.84%。     

奇亚籽油微胶囊储藏稳定性及释放性质研究北大核心CSCD

为探究奇亚籽油微胶囊的储藏稳定性及释放性质,通过监测奇亚籽油微胶囊在4、25、65℃下储藏过程中过氧化值的变化,对其进行氧化动力学研究及货架期预测;测定了不同温度和pH对其芯材释放率的影响,并采用Avrami′s公式分析微胶囊中芯材的释放率,考察微胶囊在储藏期间的释放动力学。结果表明:奇亚籽油经微胶囊化后,过氧化值上升速率降低,符合一级氧化动力学方程;25℃储藏条件下,奇亚籽油的货架期为16 d,而微胶囊的货架期延长至101 d;且微胶囊在65℃储藏6 d后仍能保持较高α-亚麻酸含量(54.64%);高温、强酸、强碱环境会促进微胶囊中奇亚籽油的释放,其释放介于一级释放动力学和二级释放动力学之间。综上,微胶囊化可有效减缓奇亚籽油的氧化,提高奇亚籽油的储藏稳定性,延长货架期。     

奇亚籽油储藏稳定性研究及货架期预测

为研究奇亚籽油储藏稳定性,以液压法制备的奇亚籽油为原料,探讨储藏温度、氧气和光照条件对奇亚籽油过氧化值、酸价、K₂₃₂、K₂₆₈和TBA的影响,并应用一级动力学模型结合Arrhenius方程建立过氧化值、酸价两个氧化指标随储藏温度、储藏时间变化的货架期预测模型,预测奇亚籽油货架期。结果表明：奇亚籽油的氧化稳定性受光照、氧气和温度的影响,在避光、密封、低温的储藏条件下能有效降低过氧化值、酸价等的增长速率,延长储藏时间;通过模型推算得出密封、避光条件下奇亚籽油在25℃条件下的货架期为94 d。     

奇亚籽油的品质特性及提取工艺研究进展

奇亚籽油富含不饱和脂肪酸,其中α-亚麻酸含量达60%以上,是ω-3脂肪酸的天然来源,对预防与饮食相关的慢性疾病具有重要意义。奇亚籽油中的抗氧化活性成分丰富,涵盖生育酚、植物甾醇、角鲨烯及多酚等。综述了近年来国内外有关奇亚籽油的脂肪酸组成、理化性质、提取工艺、氧化稳定性等领域的研究报道,并对奇亚籽油今后研究方向和重点进行了展望。     

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。     

奇亚籽油脂肪酸乙酯的制备工艺研究

以奇亚籽油为原料,采用碱催化法制备奇亚籽油脂肪酸乙酯。对比甲醇钠、乙醇钠和氢氧化钠的催化效果,并通过单因素实验和正交实验优化奇亚籽油脂肪酸乙酯制备的工艺参数。结果表明：采用氢氧化钠为催化剂,乙酯含量和得率均最高;当酯交换温度为80 ℃、酯交换时间为1.5 h、醇油摩尔比为9∶ 1、氢氧化钠用量为油质量的0.6%时,奇亚籽油脂肪酸乙酯含量可达到89.01%。     

响应面优化水酶法提取奇亚籽油工艺

以奇亚籽为原料,采用水酶法提取奇亚籽油。在单因素实验的基础上,采用响应面法对水酶法提取奇亚籽油的工艺条件进行优化。结果表明,水酶法提取奇亚籽油的最佳工艺条件为:碱性蛋白酶作为酶解用酶,酶解温度45℃,液料比8. 47∶1,pH 10,酶添加量5. 17%,酶解时间2. 16 h。在最佳条件下,奇亚籽油提取率为89. 53%。     

How the inclusion of mushroom powder can affect the physicochemical characteristics of pasta

In this study, a partial substitution of durum wheat semolina with three different species of mushrooms (white button, shitake and porcini) was undertaken to increase the nutritional value of the pasta. The cooking properties and textural characteristics of the pasta produced were also determined. The results showed that the addition of mushroom powder increased the cooking loss, as well as firmness and resistance of the uniaxial tension of the pasta. Porcini mushroom incorporation significantly decreased the swelling index, water absorption index and moisture content values of the cooked pasta, while, for the white button and shiitake mushrooms, there was no noticeable effect on either index compared with the control sample (containing exclusively durum wheat semolina). The addition of shiitake mushroom powder resulted in pasta with the highest firmness and tensile strength.     

The impact of the protein network on the pasting and cooking properties of dry pasta products

Durum wheat semolina gluten and starch as well as processing conditions determine pasta cooking quality. This study investigated whether, for good organoleptic properties, a permanent protein network needs to be formed during pasta drying or can still be formed during cooking. The cooking quality of 16 spaghetti samples was related to the levels of sodium dodecyl sulphate extractable protein (SDSEP), starch gelatinisation temperatures as well as to the swelling properties of milled dry spaghettis. SDSEP levels in dry and cooked products varied between 31% and 56%, and 12% to 21% of total protein contents, respectively. The highest quality spaghettis had relatively higher levels of SDSEP in the dry product, low starch gelatinisation temperatures and swelling powers, and rigid particles. The lowest quality spaghettis had lower levels of SDSEP and higher gelatinisation temperatures. This work implies that high pasta quality results from an optimal degree of protein polymerisation during drying and/or the subsequent cooking.     

Variation in oil quality and content of low molecular lipophilic compounds in chia seed oils

This study was conducted to characterize the lipid fraction of 15 chia seed samples originating from five countries (Argentina, Paraguay, Uganda, Bolivia, and Peru). On average, chia seeds contained 34.5 g oil per 100 g dry-solids, in which the average contents of sterols, tocopherols, squalene, carotenoids, and phenolic compounds were 7,061, 600, 17.7, 2.2, and 9.7 mg/kg of oil, respectively. Alpha-linolenic acid share varied from 54.35% to 60.48%, and was accompanied by declining shares of linoleic, palmitic, oleic, and stearic acid, respectively. Principal component analysis showed that chia oil induction time was positively correlated with tocopherols and phenols, while negatively with quality indices and squalene content.     

Incorporation of chia seed flour into gluten-free rice layer cake: Effects on nutritional quality and physicochemical properties

The purpose of this research was to incorporate 0% to 30% chia seed flour into rice flour gluten-free layer cake and evaluate its effect on nutritional qualities and physicochemical properties. The supplement of chia seed flour resulted in higher batter viscosity, hardness of gluten free layer cake, crude protein, fat, ash, α-linolenic acid (increase up to 10.2% of total fatty acid), total phenolics content, and reducing power but the lower crust, crumb white index, cohesiveness, and resilience of gluten-free layer cake was found. Substitution of rice flour with 10% prehydrated chia seed flour can achieve a higher center height and volume index of gluten-free layer cakes. Higher carosine and angiotension I-converting enzyme (ACE) inhibitory activity was observed in the supplement of 10% chia seed flour when compared to a rice flour layer cake. Gluten-free layer cake with 10% prehydrated chia seeds flour had similar overall acceptability, texture, flavor, and odor scores except for lower appearance score to those of gluten-free layer cake made with 100% rice flour and layer cake made with 100% wheat flour. Incorporation of 10% prehydrated chia seed flour results in more desirable volume index of gluten-free layer cake and it is feasible for gluten-free layer cake application. Gluten-free layer cakes with improved quality characteristics and high nutritional value can be manufactured by the incorporation of chia seed flour.     

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。     

Application of vegetable concentrates and powders in coloured pasta production

Vegetable concentrates and powders can be used in the process of pasta production as natural colouring components. The aim of the work was to investigate the effect of the addition of different vegetable components (powders and concentrates) on the colour, chemical composition, cooking and sensory quality of pasta. Tagliatelle was made from durum semolina substituted with 0%, 2%, 4%, 6% and 8% of beet powder (BP), beet concentrate (BC), carrot powder (CP), carrot concentrate (CC) and kale powder (KP). The addition of concentrates caused a greater change in the colour of the pasta (ΔE: 12.45–48.01) than the analogous addition of the powders (ΔE: 6.24–45.31); however, the colour of the products was unstable and less resistant to cooking. The incorporation of the vegetable powders induced a greater increase in the content of ash and total dietary fibre in the pasta than the addition of the concentrates.     

不同压榨温度下奇亚籽油气味组分的电子鼻分析

以奇亚籽为原料,采用压榨法制取奇亚籽油,考察不同的压榨温度（60~120 ℃）对奇亚籽出油率和奇亚籽油酸值的影响,利用电子鼻对奇亚籽油气味组分进行分析。结果表明：高温对奇亚籽出油率和奇亚籽油酸值有一定程度影响;主成分分析表明,第1主成分和第2主成分总体贡献率为99.91%,可以区分60 ℃、70~100 ℃和110~120 ℃下压榨的奇亚籽油;传感器贡献率分析表明,奇亚籽油的气味组分主要有无机硫化物、甲烷等短链烷烃、氮氧化合物、芳香成分、苯类等,70~100 ℃范围内的油样与60 ℃条件下油样对W2S传感器有不同响应,110~120 ℃范围内的油样与 60 ℃ 条件下油样对W2S和W2W传感器有不同响应;线性判别分析结果表明,80 ℃与90 ℃油样、110 ℃与120 ℃油样气味组分具有一定相似性,与其他压榨温度下油样的气味组分差异度较大。利用电子鼻可以将60 ℃与其他压榨温度下的奇亚籽油进行区分。     

微胶囊化对鳡鱼油贮藏性能的影响

通过喷雾干燥的方法制备微胶囊化鳡鱼油,并对其感官品质与贮藏品质进行评价、结构进行表征。结果表明,微胶囊化处理可使鳡鱼油的贮藏时间由32d延长至256d,DHA衰减率由鳡鱼油的80.8%减少至61.2%。扫描电镜可见微胶囊颗粒基本完整、分散性良好,差示扫描量热分析发现微胶囊产品的玻璃化转变温度为59.2℃、热熔解温度大于130℃,傅里叶红外光谱图显示经微胶囊化处理后,样品的特征峰变化不大。      

高温短时烹饪过程中葵花籽油的品质变化

目的考察烹饪过程中葵花籽油的品质变化规律。方法选取非重复性的短时高温烹饪方式,考察器具材质、温度、时间和食品成分对葵花籽油过氧化值、酸值和脂肪酸组成的影响。结果葵花籽油的过氧化值变化受器具材质、烹饪温度和时间的交互影响,在不锈钢锅210℃高温烹饪8 min的条件下,食品成分(水、食盐、蔗糖、大豆分离蛋白)添加对过氧化值无明显影响。烹饪条件及食品成分添加对葵花籽油酸值的影响程度偏弱,但蔗糖添加可致酸值显著增加(P0.05)。葵花籽油主要由亚油酸(61.81%)、油酸(31.64%)、棕榈酸(2.50%)和硬脂酸(1.64%)组成,经不同条件烹饪处理后,其脂肪酸组成比例并未发生显著变化。结论作为食用油的质量评价指标,过氧化值、酸值和脂肪酸组成并不能有效反映其烹饪品质。