添加新鲜橄榄叶和复合果胶酶压榨对油橄榄果出油率和初榨橄榄油品质的影响

为提高油橄榄果出油率、改善初榨橄榄油(VOO)品质,以甘肃陇南主栽的成熟度为7的莱星品种油橄榄鲜果为原料,考察压榨过程中新鲜橄榄叶(0、3%、5%)和复合果胶酶(0、0.01%、0.02%)添加量(以油橄榄果质量计)对油橄榄果出油率和VOO色泽、叶绿素含量、基本理化性质、总酚含量、脂肪酸组成及含量的影响。结果表明：添加适量的新鲜橄榄叶可提高出油率及总酚含量,降低酸值,但色泽加深,叶绿素含量和过氧化值升高;添加适量的复合果胶酶在提高出油率的同时,VOO的总酚含量上升,叶绿素含量和过氧化值降低,但酸值升高,色泽加深;压榨过程中添加新鲜橄榄叶和复合果胶酶对VOO脂肪酸组成没有影响,但对油酸、亚油酸、棕榈酸和棕榈烯酸等主要脂肪酸含量有一定影响。在压榨制取VOO时添加适量的新鲜橄榄叶与复合果胶酶可提高出油率,获得富含多酚的VOO。     

3种酵母发酵橄榄酒的发酵规律及香气分析

以橄榄为原料,分别利用三种酵母对橄榄酒进行发酵,研究橄榄酒整个发酵过程中酒精度、还原糖及酸度的变化规律;采取顶空固相微萃取和气相色谱质谱联用法对橄榄酒的香气成分进行分析比较。结果表明:三种酵母发酵过程中橄榄酒酒精度均逐渐上升,还原糖含量逐渐降低,酸度先上升后下降;果酒干酵母发酵周期最短,最终果酒酵母1383所酿橄榄酒酒精度最高,残留还原糖含量最低,酸度最低;同时果酒酵母1383、果酒干酵母和果酒酵母1596发酵的橄榄酒分别检出50、49、52种香气成分,其中相同的有35种,三种酒样的主要香气成分均为异戊醇。初步确定果酒酵母1383酿制的橄榄酒最优。      

Distribution of dimorphic yeast species in commercial extra virgin olive oil

Recent microbiological research has demonstrated the presence of a rich microflora mainly composed of yeasts in the suspended fraction of freshly produced olive oil. Some of the yeasts are considered useful as they improve the organoleptic characteristics of the oil during preservation, whereas others are considered harmful as they can damage the quality of the oil through the hydrolysis of the triglycerides. However, some dimorphic species can also be found among the unwanted yeasts present in the oil, considered to be opportunistic pathogens to man as they have often been isolated from immunocompromised hospital patients. Present research demonstrates the presence of dimorphic yeast forms in 26% of the commercial extra virgin olive oil originating from different geographical areas, where the dimorphic yeasts are represented by 3–99.5% of the total yeasts. The classified isolates belonged to the opportunistic pathogen species Candida parapsilosis and Candida guilliermondii, while among the dimorphic yeasts considered not pathogenic to man, the Candida diddensiae species was highlighted for the first time in olive oil. The majority of the studied yeast strains resulted lipase positive, and can consequently negatively influence the oil quality through the hydrolysis of the triglycerides. Furthermore, all the strains showed a high level of affinity with some organic solvents and a differing production of biofilm in “vitro” corresponded to a greater or lesser hydrophobia of their cells. Laboratory trials indicated that the dimorphic yeasts studied are sensitive towards some components of the oil among which oleic acid, linoleic acid and triolein, whereas a less inhibiting effect was observed with tricaprilin or when the total polyphenols extracted from the oil were used. The observations carried out on a scanning electron microscope (SEM), demonstrated the production of long un-branched pseudohyphae in all the tested dimorphic yeasts when cultivated on nutrient-deficient substrates.     

总迁移量测试橄榄油提取次数的探究

目的 探究试样吸收橄榄油是否完全提取对橄榄油总迁移量测试结果的影响。方法 采用乙醚对迁移试验后的试样提取一次和三次两种不同方法进行总迁移量的测试。结果 乙醚提取一次的橄榄油总迁移量明显低于乙醚提取三次的橄榄油总迁移量。结论 进行橄榄油总迁移量测试时须保证试样吸收橄榄油的完全提取,以获得准确的测试结果。     

不同制油工艺及去除红衣对花生黄曲霉毒素的影响

研究不同制油工艺对花生黄曲霉毒素迁移的影响以及去除红衣对花生黄曲霉毒素削减的影响。结果表明:采用溶剂浸提法制取花生油时,约3%的黄曲霉毒素B1(AFB1)和黄曲霉毒素B2(AFB2)迁移至油中,而剩下的97%迁移至粕中;采用水酶法制取花生油过程中,约10%的AFB1、0. 1%的AFB2迁移至油中,AFB1、AFB2分别有69. 25%、77. 70%迁移至液相中;采用压榨法制取花生油时,AFB1、AFB2有约10%迁移至油中,剩下的约90%迁移至饼中;当花生仁中黄曲霉毒素含量较低时,去除红衣对其削减率影响较大;而当黄曲霉毒素含量较高时,去除红衣对其削减率影响较小。     

发酵刺梨干红酵母菌的鉴定及优良菌株的筛选

对8株法国引进发酵刺梨干红酵母菌进行形态学、生理生化学及分子生物学分类鉴定;并结合刺梨干红生产特点,检测其发酵性能、抗逆性能等。经比较筛选出RC212号葡萄汁酵母(Saccharomyces uvarum)与DV10号汉氏德巴利氏酵母(De-baryomyces hansenii)2菌株。其表现出高发酵能力(残糖量≤1.00g/100mL);高产酒性能(原汁发酵酒度均达4°以上);发酵周期适中,发酵体系中生酸少,单宁含量少,同时还具有耐60%糖浓度、耐10%盐浓度及耐8%醋酸浓度的性能。为“刺梨干红工业化生产技术研究”提供了试验菌株。     

特级初榨橄榄油中酚类化合物不同提取方法对比研究

采用液液萃取法(LLE)、固相萃取法(SPE)和液液微萃取法(LLME)分别对特级初榨橄榄油中酚类成分进行提取,应用超高效液相色谱-高分辨质谱法(UPLC-HRMS)及Folin-Ciocalteus比色法分别进行酚类化合物组成研究和总酚含量测定,比较3种方法的提取效率。结果表明:特级初榨橄榄油中共检测到40种酚类化合物,其中液液萃取样品检出33种,固相萃取样品检出20种,液液微萃取样品检出15种,液液萃取法提取酚类化合物种类显著多于其他两种方法;液液萃取法提取的总酚含量分别为固相萃取法及液液微萃取法的2. 9倍和3. 7倍,液液萃取法对酚类化合物的提取效率明显优于其他两种方法;但从实验过程角度考量,液液微萃取法具有操作简单、省时省力、有机溶剂用量少、对实验人员伤害小、环境污染小等优点,具有进一步优化的潜力。     

LLE-UPLC-FLD法测定橄榄油中羟基酪醇和酪醇的含量

建立了液液萃取-超高效液相色谱串联荧光检测器(LLE-UPLC-FLD)快速分离和测定橄榄油中羟基酪醇和酪醇含量的方法。橄榄油样品经乙醇提取后,以0.2%(v/v)甲酸乙腈溶液和0.2%(v/v)甲酸水为流动相,梯度洗脱,采用BEH(50 mm×1.0 mm,1.7 μm)色谱柱,柱温为35 ℃,流速为0.15 mL/min,进样量为2.0 μL,使用荧光检测器在激发波长为300 nm,发射波长为350 nm下进行检测,整个分析过程仅需10 min。羟基酪醇和酪醇的检出限(S/N=3)及定量限(S/N=10)分别为0.11,0.13和0.31,0.39 μg/g,2种组分按高、中、低3个浓度水平加标回收率均高于89.52%;在最优条件下,对20批不同产地橄榄油中的羟基酪醇和酪醇进行检测,羟基酪醇和酪醇的含量范围分别在1.28~20.34及1.03~21.22 μg/g之间;该法简便快速,重复性良好,结果准确可靠,可用于橄榄油中酪醇和羟基酪醇含量的测定。     

超声波破壁提取葡萄酒酵母泥中多糖的研究

目的 利用超声波法提取葡萄酒酵母泥中多糖。方法 研究了酵母浓度、超声温度、超声时间对葡萄酒酵母泥中多糖得率的影响, 并采用响应面分析法对葡萄酒酵母泥中多糖提取工艺进行优化设计。结果 超声波法提取葡萄酒酵母泥中多糖的最佳条件为: 酵母浓度9.10%, 超声温度为65.42 ℃, 超声时间为132.97 min。最终酵母多糖得率为1.85%, 对最佳工艺条件进行验证, 酵母多糖实际得率为1.86%, 结果重复性较好。结论 超声波辅助提取葡萄酒酵母泥中的多糖, 工艺简便, 多糖得率较高, 具有实际的应用价值。     

Chemical composition of Arbequina virgin olive oil in relation to extraction and storage conditions

The chemical composition of virgin olive oils from Arbequina olives cultivated in Córdoba (Argentina) was studied in relation to the oil extraction system and production year. Significant variations were found between oils obtained by pressure (PEOs) and centrifugation (CEOs) systems. PEOs were characterised by higher values of acidity, pigments and oleic acid, while CEOs showed greater phenol content. Moreover, a significant effect of crop year was observed. Arbequina oils produced in Córdoba contained lower amounts of oleic acid but higher amounts of phenolic compounds than Arbequina oils produced in Spain. A storage stability test was carried out in order to study the combined effects of oil extraction system and storage conditions (packaging material and illumination) on quality indices related to oxidative stability. Multivariate analysis applied to the chemical data emphasised the differences between PEOs and CEOs, indicating that variations due to extraction system were greater than those due to illumination condition and package type. Cluster analysis of oils from each extraction system stressed the influence of illumination condition on the oxidative stability of olive oils, showing increased amounts of secondary oxidation products in oils exposed to light. Glass and tin packages appear to be the most appropriate containers for maintaining the quality of olive oils, but this supposition is strongly dependent on the type of oil (PEO or CEO) and its initial chemical properties. Copyright © 2006 Society of Chemical Industry     

Transfer of phenolic compounds during olive oil extraction in relation to ripening stage of the fruit

The transfer of phenolic compounds of Olea europaea L. cv. Arbequina variety during olive oil extraction in relation to ripening stage was investigated. The parameters of oil extraction by the Abencor system are shown together with mass balances of the products and by products from the olive oil extraction in relation to olive paste. The phenolic compounds in olive paste, pomace, oil and wastewater were identified and measured by HPLC. Throughout the study, the concentrations of simple phenols, secoiridoids and flavonoids were higher in the olive paste and pomace phases than in oil and wastewater phases. High concentrations of 4‐(acetoxyethyl)‐1,2‐dihydroxybenzene (3,4‐DHPEA‐AC) and secoiridoid derivatives such as the dialdehydic form of elenolic acid linked to 3,4‐DHPEA (hydroxytyrosol) or p‐HPEA (tyrosol) (3,4‐DHPEA–EDA, p‐HPEA–EDA, where EDA is elenolic acid dialdehyde) and an isomer of oleuropein aglycone (3,4‐DHPEA–EA, where EA is elenolic acid aldehyde) were found in olive oil, together with lignan compounds. It was observed that 3,4‐DHPEA–EDA was the most abundant polyphenol present in the wastewater phase. This indicates that biotransformation occurred during olive extraction, especially in the crushing and malaxation operations, and reflects the possible chemical changes that lead to the formation of new compounds. Moreover, the distribution of compounds showed their affinities toward different phases. Copyright © 2005 Society of Chemical Industry     

液液萃取-UPLC快速测定初榨橄榄油中叶绿素铜钠的含量

建立了液液萃取-超高效液相色谱（UPLC）快速测定初榨橄榄油中叶绿素铜钠含量的方法。初榨橄榄油样品经80%的乙醇溶液提取后,在UPLC条件为采用SVEA C18色谱柱（50 mm×1.0 mm, 1.7 μm）,柱温30 ℃,乙腈-水（体积比95∶ 5）为流动相,等度洗脱,流速0.3 mL/min,进样量2.0 μL,检测波长405 nm下,可实现初榨橄榄油中叶绿素铜钠的有效分离,整个分析过程仅需6 min。通过方法学考察,该方法的检出限及定量限分别为0.20 mg/L和0.50 mg/L,叶绿素铜钠加标回收率均在84.00%~97.90%之间,方法的重复性、精密度和稳定性较好。所建立的方法可用于初榨橄榄油中叶绿素铜钠含量的快速测定。     

The utilisation solutions of olive mill by-products in the terms of sustainable olive oil production: a review

Despite the high economic and nutritional value as major positive aspects, olive oil production has an unfavourable side, which is the negative environmental impact caused by the generation of significant amounts of liquid and solid wastes. Therefore, the implementation of sustainable technologies to add value to the olive oil production process is a matter of great interest. This study aimed to review novel solutions dealing with the utilisation of olive oil production by-products while taking into account sustainable waste management options. The most promising technologies for the production of high-added value products from olive oil production by-products have been described with a special attention to the sustainable nonthermal technologies for the extraction of bioactive phenolic compounds, and the key findings of such investigations were reviewed. All described technologies are environmentally friendly and show great potential. Nevertheless, further researches are required to optimise and increase their applicability.     

A kinetic study on extraction and transformation phenomena of phenolic compounds during red wine fermentation

The aim of this work was both to model the kinetics of the extraction and transformation of phenolic compounds during fermentation and to propose an index to compare fermentation procedures. Six lots of Sangiovese grapes from five vineyards were used for red wine fermentation tests on lab and industrial scale during 2005 and 2006 vintages. Total phenol index, colour parameters, anthocyanin and pigmented polymer contents were measured during fermentations as variables related to phenolics. Microvinifications performed during vintage 2005 were used to model the evolution of total phenol index at 280 nm, malvidine content, colour parameter a* and pigmented polymer content during fermentation. Vinifications performed during vintage 2006 were used to validate the models. A specific adimensional number, called equivalent index, was set up to specify the operating conditions of red wine fermentation being a function of the extraction and transformation phenomena of phenolic compounds.     

微提取—离子色谱法快速测定干红葡萄酒中亚硫酸盐

目的:结合离子色谱法的优势,对国标方法蒸馏前处理进行改进,建立一种快速测定干红葡萄酒中亚硫酸盐的微提取—离子色谱准确定量的检测方法。方法:样品通过微提取装置释放出二氧化硫,被氢氧化钠溶液吸收生成亚硫酸根,再将其氧化为硫酸根,经0.45μm滤膜过滤除杂后,用离子色谱仪进行测定。结果:亚硫酸根离子质量浓度为1.0～50 mg/L亚硫酸根浓度与其峰面积呈良好的线性关系,相关系数为0.999 9,检出限为0.24 mg/L。添加不同水平硫酸盐加标回收率平均值为95.2%～99.1%,相对标准偏差(RSD)为6.84%～8.65%。结论:该方法的前处理操作简单、快速,杂质干扰明显减少,适合批量样品的检测。     

Carbon footprint as an instrument for enhancing food quality: overview of the wine,olive oil and cereals sectors

The quantification of greenhouse gases (GHG) emissions represents a critical issue for the future development of agro‐food produces. Consumers' behaviour could play an important role in requiring environmental performance as an essential element for food quality. Nowadays, the carbon footprint (CFP) is a tool used worldwide by agro‐food industries to communicate environmental information. This paper aims to investigate the role that CFP could have in consumers' choices in three significant agro‐food sectors in the Mediterranean area: wine, olive oil and cereals. A critical review about the use of CFP was carried out along the supply chain of these three sectors, in order to identify opportunities for enhancing food quality and environmental sustainability and highlighting how environmental information could influence consumers' preferences. The analysis of the state of the art shows a great variability of the results about GHG emissions referred to agricultural and industrial processes. In many cases, the main environmental criticisms are linked to the agricultural phase, but the other phases of the supply chain could also contribute to the increased CFP. However, despite the wide use of CFP by companies as a communication tool to help consumers' choices in agro‐food products, some improvements are needed in order to provide clearer and more understandable information. © 2016 Society of Chemical Industry     

红提葡萄酒发酵酵母菌的分离及耐受性研究

该实验从红提葡萄发酵过程中分离出酵母菌株,并对其耐受性进行研究,旨在提高红提葡萄酒酿造品质。通过培养不同发酵时期菌株,并用肉眼和显微镜分别观察其菌落和细胞形态,再测定其发酵能力、耐糖性、耐酸性、耐酒精度。结果表明,共分离出酵母菌140株,经菌落形状和细胞形态鉴定后,获得典型的三类共6株酵母菌;在发酵过程中,加入分离菌株比自然发酵可多发酵1.6%葡萄糖,多产生0.78% CO2和0.82%vol的酒精,且发酵趋势和安琪酵母、自然发酵过程一致;以安琪酵母为对照,对6株菌进行耐糖性、耐酸性、耐酒精度试验,得出综合耐受性较好的酵母菌株为A3、B7和C1。