Flavor production from a non-stick oil by moulds

Natural flavor was accidentally produced from rice cake products in Japan. A non-stick oil had been sprayed on the products during the production process. It was found that a Penicillium corylophilum strain, a contaminant of the oil, produced the flavor from the oil. The ingredients of the flavor were four volatile substances, 2-heptanone, 2-nonanone, 2-heptanol, and 2-nonanol. Challenge tests with the mould strain in a rice cake system were performed under various conditions. The volatile substances were produced in the largest amounts at 25 degrees C, followed by 20 or 30 degrees C then 10 degrees C. 2-Heptanone was produced most remarkably at 25 degrees C, followed by 2-nonanone, 2-heptanol, and 2-nonanol. The growth patterns of the mould were similar between 20-30 degrees C, and the growth at 10 degrees C was delayed. The non-stick oil itself had neither flavor nor volatile substance. The flavor was also produced from coconut oil, which was one of the materials of the non-stick oil. No bacteria or yeasts tested produced any flavor from the non-stick oil, whereas most of the moulds tested produced flavor components.     

FUNCTIONALITY OF PALM OIL IN FOODS

The functional properties of commercial solid fats such as shortening and margarine are closely related to their fatty acid and triacylglycerol compositions. Plastic fats produced from hydrogenated seed oils may suffer from undesirable crystal structure changes during handling and storage. It has been demonstrated that this problem increases with increasing chain length uniformity of the component fatty acids. This is also evidenced by the carbon number composition of the high melting triacylglycerols of the plastic fats. Triacylglycerols with carbon numbers 48 and 54 promote β crystallization, those with carbon numbers 50 and 52 promote β' crystallization. Since palm oil and its products contain high levels of C50 and C52 triacylglycerols they are useful for improving the functional properties of plastic fats.     

3种坚果油的挥发性成分提取及关键风味成分分析

对比了溶剂辅助蒸发萃取(SAFE)和顶空固相微萃取(HS-SPME)对3种坚果油(花生油、核桃油、巴旦木油)挥发性风味成分的提取效果,并通过芳香提取物稀释分析确定关键风味成分。结果表明:采用HS-SPME可以从3种坚果油中分别分离并检出21、26和25种挥发性成分;采用SAFE可以分别分离并检出27、40和40种挥发性成分。根据香气稀释因子,花生油的关键风味成分包括苯甲醛、2-苯乙醛、2-甲基吡嗪、2,5-二甲基吡嗪、2-乙基-5-甲基吡嗪、3-乙基-2,5-二甲基吡嗪、2-乙基吡嗪和2-戊基呋喃,核桃油的关键风味成分包括反,反-2,4-庚二烯醛、苯甲醛、癸酸、辛酸、壬酸、2-乙基-5-甲基吡嗪和2-戊基呋喃,巴旦木油的关键风味成分以壬醛、己酸、辛酸和4-烯丙基苯甲醚为主。     

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.     

不同压榨工艺下花生油风味成分的变化

该研究采用顶空固相微萃取-气相色谱-质谱联用仪（HS-SPME-GC-MS）及电子鼻对不同压榨工艺下花生油挥发性风味成分和脂肪酸组成进行分析。6种不同压榨工艺花生油中共检测到10类38种挥发性成分,其中包含19种风味成分。在热榨花生油中以呋喃类（63.43%~66.68%）、醛类（10.04%~5.47%）、酚类（8.83%~7.18%）为主要的挥发性成分,在冷榨花生油中以酯类（26.43%）、醛类（23.47%）、酸类（22.10%）为主要的挥发性成分。此外,热榨花生油检测出少部分吡嗪、吡啶、酮类关键风味成分,其在冷榨花生油中并没有检出。电子鼻结果基本与GC-MS一致,硫化物、芳香化合物、氮氧化合物和甲基类化合物对花生油整体风味贡献率较大,通过主成分分析和K-mean聚类分析结果显示6种花生油挥发性成分变化差异显著。6种花生油脂肪酸组成都以油酸、亚油酸、棕榈酸为主,含量可达到90%以上。然而通过对比不同温度下花生油脂肪酸组成发现随着压榨温度的升高,不饱和脂肪酸的氧化加速。综上,对比不同压榨工艺下花生油风味和营养成分的变化发现高温条件压榨下花生油的风味成分显著增加,花生油品质略有下降,利用电子鼻可快速区分不同压榨工艺花生油。     

Fatty acids and triacylglycerols in the seed oils of Saudi Arabian date (Phoenix dactylifera L.) palms

Total lipids, fatty acids and triacylglycerols in seeds of the four Saudi Arabian date cultivars ‘Anbra’, ‘Megadwel’, ‘Sacai’ and ‘Sfwai’ were analysed. Total lipid contents ranged between 7.3 and 8.6%. Oleic, lauric and myristic acid represented the most abundant fatty acids in date seed oil. HPLC-DAD-ESI-MSⁿ analysis enabled the identification of 40 triacylglycerols with equivalent carbon number (ECN) 36–54, of which 17 were detected for the first time. Triacylglycerols mainly comprised LaOL, LaLaL, LaML, MML/LaPL and LaOO. ‘Anbra’ oil was characterised by highest proportions of saturated fatty acids and triacylglycerols with ECN 36 and 48–54. Unsaturated fatty acids prevailed in the three remaining varieties. Elevated proportions of triacylglycerols with medium ECNs were found in ‘Megadwel’ and ‘Sfwai’ oils. Aside from highest total lipid contents, ‘Sacai’ seeds predominantly contained triacylglycerols with low ECNs. Multivariate statistical analyses elucidated varietal influences on the fatty acid and triacylglycerol composition of date seed oil.     

Influence of lipid type on gastrointestinal fate of oil-in-water emulsions: In vitro digestion study

The potential gastrointestinal fate of oil-in-water emulsions containing lipid phases from different sources was examined: vegetable oils (corn, olive, sunflower, and canola oil); marine oils (fish and krill oil); flavor oils (orange and lemon oil); and, medium chain triglycerides (MCT). The lowest rates and extents of lipid digestion were observed for emulsified flavor oil, followed by emulsified krill oil. There was no appreciable difference between the final amounts of free fatty acids released for emulsified digestible oils. Differences in the digestibility of emulsions prepared using different oils were attributed to differences in their compositions, e.g., fatty acid chain length and unsaturation. The particle size distribution, particle charge, microstructure, and macroscopic appearance of the emulsions during passage through the simulated GIT depended on oil type. The results of this study may facilitate the design of functional foods that control the digestion and absorption of triglycerides, as well as the bioaccessibility of hydrophobic bioactives.     

豉香型白酒肥肉浸制产脂肪油及脂质氧化研究

以黑米、黑豆、黑木耳为原料,以木糖醇代替蔗糖,将黑米黑豆黑木耳混合液与牛乳共同发酵,研制一种低糖复合发酵乳,并采用单因素及正交试验优化其发酵工艺条件。结果表明,通过高温烘焙香气试验确定黑米、黑豆烘烤条件分别为160 ℃烘烤8 min、180 ℃烘烤10 min。低糖复合发酵乳的最佳工艺条件为黑米∶黑豆∶黑木耳=3∶2∶1（g∶g）,黑米黑豆黑木耳混合液∶牛乳=6∶4（V/V）,混合菌种（保加利亚乳杆菌∶嗜热链球菌=1∶2）接种量4.0%,木糖醇添加量8%。在此优化工艺条件下,低糖复合发酵乳的感官评分为94.2分,脂肪含量为3.6%,蛋白质含量为5.9%,酸度为79 °T,还原糖含量为5.2%,全乳固体为16.1%;乳酸菌数为1.91×106 CFU/g;未检出致病菌,符合相关国家标准。     

Palatase 20,000L催化对黄油脂肪酸和风味特征的影响

研究了脂肪酶Palatase20,000 L催化对黄油脂肪酸和风味物质的影响。采用薄层层析(TLC)和气相色谱(GC)相结合分析黄油及其酶解物的脂肪酸,采用顶空固相微萃取-气相-质谱(SPME-GC-MS)分析风味物质。Palatase 20,000 L脂肪酶催化黄油显著改变了脂肪酸的组成,促进了风味物质(特别是主要风味物质:辛酸和癸酸)的释放(P<0.05)。结果表明,Palatase 20,000 L脂肪酶催化改变了黄油脂肪酸和风味物质的种类和含量。因此,Palatase20,000 L脂肪酶催化能够提高黄油的营养价值和应用领域。     

5 种脱色剂对粗鱼油挥发性风味物质及脂肪酸组成的影响

为探究凹凸棒土、硅藻土、活性炭、沸石及活性白土5?种脱色剂对粗鱼油挥发性风味物质及脂肪酸组成的影响,采用气相色谱仪和顶空固相微萃取-气相色谱-质谱联用仪,对脱色鱼油的挥发性风味物质及脂肪酸的相对含量进行测定分析,并结合感觉阈值确定该鱼油主体风味成分。结果表明,赋予鱼油腥味、脂肪香味、蜡香等主要风味的壬醛、己醛、2-壬酮,其相对含量经脱色后有明显降低,风味改善效果显著。脱色后,鱼油的饱和脂肪酸相对含量呈下降趋势,而不饱和脂肪酸的相对含量则有增加趋势;酸价与过氧化值变化差异较大,而碘值及皂化值则无明显变化。凹凸棒土和活性白土脱色效果最佳,但脱腥效果较硅藻土、活性炭和沸石差。本研究结果对改善鱼油脱色工艺及脱色剂选择和不良风味等方面有一定理论指导意义。     

Milk composition and flavor under different feeding systems: A survey of dairy farms

Understanding the influence of regional dietary factors on the flavors of milk and dairy products will provide consumers with more options and promote the conservation of regional resources and the original terroir. The objective of this study was to evaluate the influence of regional differences in feeding systems on the composition, fatty acid content, and flavor of pasteurized milk at the farm level. Nine dairy farms using grass silage (GS), 6 farms using maize silage (MS), and 4 farms using by-products (BP) as the characteristic feed components were chosen for this survey. Fresh milk was sampled once per month from September 2008 to February 2009 at each dairy farm. The percentages of GS, MS, and BP (soybean curd residue or brewer's grain) in the feed were 32.4, 22.1, and 15.1%, respectively. The milk fat, protein, and lactose contents did not differ among the milks from farms with different feeding systems. Fatty acids with chain lengths of less than C16 and saturated fatty acids were present at higher concentrations in the milks from the GS and MS farms than in the milk from the BP farms; conversely, fatty acids with chain lengths greater than C18 and unsaturated fatty acids (UFA), including mono- (MUFA) and polyunsaturated fatty acids (PUFA), were present at higher concentrations in the milks from the BP farms than in the milks from the GS farms. No significant differences were detected in milk flavor, evaluated as sweetness, body, texture, aftertaste, and palatability, between the milks from the farms with different feeding systems. The proportion of BP in the cow's diet was positively correlated with the concentrations of fatty acids with chain lengths greater than C18 and with UFA, MUFA, and PUFA. In contrast, the proportion of GS in the diet was positively associated with the levels of milk fat, protein, fatty acids with chain lengths less than C16, and SFA. The MUFA, PUFA, UFA, and fatty acids with chain lengths greater than C18 were not associated with any of the milk flavors. These results suggest the regional differences in feeding systems contribute to the differences in the fatty acid compositions of milk at the farm level. However, these differences do not influence the flavor of pasteurized milk. Thus, more specific feed profiles will be required to provide a specific regional flavor to pasteurized milk.     

预处理对低温压榨花生油风味物质的影响

采用顶空固相微萃取(HS-SPME)和气相色谱–质谱联用(GC-MS)技术检测不同预处理低温压榨花生油中挥发性风味物质,探讨不同预处理低温压榨花生油中醛类、酮类、吡嗪类等挥发性风味物质的种类和相对含量。结果表明:被检测的花生油样品中共鉴定出97种挥发性风味物质,不同预处理方式制得的低温压榨花生油其挥发性风味物质差异很大。脉冲电场预处理低温压榨花生油主要呈味物质为3-羟基-2-丁酮;微波预处理低温压榨花生油挥发性风味物质以吡嗪类和吡咯类物质居多;超声波预处理低温压榨花生油挥发性风味物质主要是酸类。预处理方式对低温压榨花生油挥发性风味物质的影响有显著差异,不同预处理方式可以获得不同风味的低温压榨花生油。     

竹柏种仁油脂成分及其抗氧化活性分析

采用5种方法对竹柏种仁油脂进行提取,并通过核磁共振和气相色谱-质谱技术分别对其油脂成分和脂肪酸组成进行分析,同时采用DPPH自由基清除法和羟基自由基清除法对竹柏种仁油脂的抗氧化活性进行研究。结果表明,5种方法对竹柏种仁油脂的提取率存在显著差异(P 0.05),其中Folch法的提取率最高,为53. 81%。竹柏种仁油脂以甘油三酯为主,磷脂、游离脂肪酸和甾醇含量极低。竹柏种仁油脂经2 mol/L KOH-甲醇溶液室温衍生3 min,甲酯转化率即达99. 80%;且其脂肪酸以油酸(18. 65%)、亚油酸(43.49%)和花生烯酸(30.65%)为主,不饱和脂肪酸含量高达90%以上。竹柏种仁油脂对DPPH自由基和羟基自由基的IC_(50)分别为3.36 mg/mL和0. 38 mg/mL,表明竹柏种仁油脂具有较好的抗氧化能力,可作为健康植物油脂进行开发利用,具有良好的开发潜力和应用前景。本研究为竹柏种仁油脂的提取、成分分析和抗氧化活性研究提供了一定的参考。     

不同提取方式下小黄鱼下脚料粗鱼油脂肪酸组成及挥发性风味成分的变化

为提高小黄鱼下脚料的高值化利用，研究以小黄鱼下脚料为试材，将其进行前处理分别制成湿样（Wet Sample，W）和干样（Dry Sample，D），采用索氏提取法（Soxhlet Extractor Method，S）及酶解法[碱性蛋白酶（1）、中性蛋白酶（2）、木瓜蛋白酶（3）]提取粗鱼油，对其理化指标进行评价、并分析其脂肪酸组成及挥发性风味成分。结果表明，7种不同提取方式（DS、D1、D2、D3、W1、W2、W3）制备的粗鱼油其理化指标值均满足水产标准（SC/T 3502-2016）三级的规定。所得粗鱼油中棕榈酸（C16:0）、硬脂酸（C18:0）、棕榈油酸（C16:1）、油酸（C18:1n9）均为主要脂肪酸，其中D1处理组粗鱼油EPA和DHA相对含量最高，为25.59%。不同提取方式所提粗鱼油中共检出99种挥发性风味成分，包括醇类16种、醛类16种、酮类15种、酯类3种、酸类8种、碳氢化合物16种、酰胺类化合物3种、杂环化合物及其他22种，其中DS处理组粗鱼油的风味与酶解法相比较差，表明冷冻干燥前处理在一定程度上改善了粗鱼油的风味。综上，采用冷冻干燥前处理结合酶解法对小黄鱼下脚料进行提取，提取得到的粗鱼油的品质优良，就其脂肪酸组成而言，多不饱和脂肪酸含量较高，因此其营养价值较高，且该处理有效改善了粗鱼油的风味，可为小黄鱼下脚料的高值化利用提供一定的理论依据与参考。     

SPME-GC-MS对不同牛奶香精和稀奶油中的挥发性风味物质比较

利用SPME-GC-MS分析方法,分析比较了稀奶油与不同牛奶香精中挥发性风味组分。稀奶油中共鉴定得到58种挥发性化合物,复配香精A、天然香精B和自制酶解香精C中分别鉴定得到67种、41种和30种挥发性化合物。通过对不同奶油香精与稀奶油风味中挥发性化合物的比较,得到稀奶油中的主要挥发性物质为甲基酮类、醛类化合物,复配香精A中的主要挥发性物质为酯类化合物;天然香精B与自制酶解香精C中的主要挥发性风味组分相似,均为中、短碳链的脂肪酸。     

PaIatase 20，000L催化对黄油脂肪酸和风味特征的影响

研究了脂肪酶Palatase20,000L催化对黄油脂肪酸和风殊物质的影响。采用薄层层析（TLC）和气相色谱（GC）井目结合分析黄油及其酶解物的脂肪酸,采用顶空固相微萃取-气相-质谱（SPME-GC-MS）分析风味物质。Palatase20,000L脂肪酶催化黄油显著改变了脂肪酸的组成,促进了风味物质（特别是主要风味物质：辛酸和癸酸）的释放佃〈0．05）。结果表明,Palatase20,000L脂肪酶催化改变了黄油脂肪酸和风味物质的种类和含量。因此,Palatase20,000L脂肪酶催化能够提高黄油的营养价值和应用领域。     

GC-TOF-MS定性和定量评估5 种木本油料种籽油的脂肪酸

采用气相色谱-飞行时间串联质谱和超临界二氧化碳提取技术,分析评价5 种木本油料种籽油的脂肪酸组成及相对含量。油茶和榛子种籽油中富含油酸,亚油酸是沙棘和文冠果种籽油中的主要脂肪酸,牡丹种籽油中的亚麻酸含量最高。沙棘种籽油的单不饱和脂肪酸与饱和脂肪酸比值为1.57：1,亚油酸与亚麻酸的比值为1.56：1,符合功能性健康食用油的标准;牡丹种籽油是补充人体ω-3脂肪酸的优质食用油;油茶和榛子种籽富含单不饱和脂肪酸,适合食品加工;文冠果种籽油含有3 种长链单不饱和脂肪酸（如神经酸等）。本实验评价了5 种木本油料油脂脂肪酸的组分,对指导企业生产生物活性油和人们的健康消费具有重要意义。     

Using Lipid Profiles for the Characterization of Turkish Monocultivar Olive Oils Produced by Different Systems

The aim of this study was to characterize the biochemical profiles of the virgin olive oils produced in various districts of Aegean and South East Anatolia regions of Turkey over two growing seasons (2001–2002). The olive oils were extracted by classic hydraulic pressing, three phase continuous system, Abencor oil method at laboratory scale, and foot oil process from monocultivar Turkish olives, including Ayvalik, Memecik, Nizip Yaglik, Gemlik, Domat, and Uslu. Total phenolics, ortho-diphenols, oxidative stability, and total chlorophylls of the oils differed by location. The cis-trans fatty acids, triacylglycerols, and the actual versus theoretical equivalent carbon number of 42 (ECN 42) triglycerol content (ΔECN42) were within national and international averages. Oil samples from the three phase continuous system had higher total phenolic contents than those of the hydraulic pressure system. Turkish monocultivar virgin olive oil samples were classified by biochemical profiles using the principal component and hierarchical cluster analyses multivariate statistical methods. Clustering analysis defined groups according to growing location. Triacylglycerols and fatty acid profiles can be used for identification of monocultivar olive oils with regard to authenticity and classification.     

Enhancement of antilisterial activity of essential oil constituents by nisin and diglycerol fatty acid ester

Plant-derived essential oil components in combination with nisin and diglycerol fatty acid esters were investigated for their antibacterial activity against Listeria monocytogenes. Carvacrol and thymol were found to have the strongest antilisterial properties, followed by eugenol, cinnamaldehyde and isoeugenol. The antilisterial activity of the other essential oils (limonene, pinene, ally lisothiocyanate and linalool) was found to be low, even at the highest concentration used (0.1%). Among the diglycerol esters of fatty acids with different carbon chain lengths, diglycerol monolaurate was the most active against L. monocytogenes. A combined antilisterial effect was observed between nisin and the essential oils (carvacrol, thymol and eugenol); moreover, the addition of diglycerol monolaurate as a third preservative factor led to further combined antilisterial activities between the essential oil constituents (carvacrol, thymol and eugenol) and nisin even at lower, sub-lethal concentrations. These results indicate that nisin and diglycerol monolaurate can be used to enhance the antilisterial activity of essential oils, allowing for a reduction in the dosage used in food preservation and thereby resulting in the reduction of undesirable flavors.     

3种淡水鱼内脏粗鱼油品质及挥发性风味成分分析比较

为提高淡水鱼类加工副产物的高值化利用,本文以3种常见的淡水鱼(草鱼、青鱼和鲢鱼)内脏为原料提取粗鱼油,进行理化指标评价、脂肪酸组成及挥发性风味成分分析。结果表明,青鱼油的理化指标最佳,其过氧化值、酸价、水分及挥发物、茴香胺值、不皂化物等较低;鲢鱼油次之,草鱼油最差。青鱼油、鲢鱼油和草鱼油中分别检测出16、22、27种脂肪酸,均以棕榈酸(C_16:0)、油酸(C_18:1n-9c)、亚油酸(C_18:2n-6c)为主,鲢鱼油的相对营养价值最高。3种粗鱼油共检测出66种挥发性物质,包括烃类17种,醇类7种,醛类15种,酮类3种,酯类8种,酸类10种,酚类3种,其他类3种。草鱼油中含量最高的是酚类物质(59.86%);青鱼油中挥发性物质以醇类为主,含量为53.23%;鲢鱼油中含量最高的是酸类物质(27.64%)。3种粗鱼油共得到10种关键风味成分,主要以醛类、醇类和酚类物质为主。反式-2,4-癸二烯醛、壬醛、反式-2,4-庚二烯醛、苯乙醛、1-辛烯-3-醇等是粗鱼油中主要的鱼腥味、油脂味风味物质。