大蒜精油对食用油脂的抗氧化特性

以过氧化值（POV）为指标研究了大蒜精油对花生油的抗氧化性能。结果表明：大蒜精油对花生油具有较强的抗氧化作用，且具有剂量效应关系；添加了大蒜精油的花生油应尽量贮存于低温条件下；VC、柠檬酸、酒石酸对大蒜精油的抗氧化作用均有协同增效作用；大蒜精油与合成抗氧化剂混合使用时，其抗氧化能力均好于只添加单一抗氧化剂的效果；使用0．2％大蒜精油和0．04％大蒜精油＋0．005％PG为花生油的抗氧化剂时，可使花生油在20℃下的贷架寿命由4．2个月延长至24．3个月和14．1个月。     

大蒜精油和姜精油对大豆油的抗氧化活性研究

为了进一步证明大蒜精油和姜油的抗氧化活性,力求为两种精油作为天然多功能食品添加的应用提供一定的理论基础。因此,以用超临界CO2萃取的大蒜油和姜油为主要研究对象,并以精炼大豆油为底物,采用史卡尔(Schaal)法,研究了不同剂量的大蒜精油和姜精油的抗氧化活性,同时将其与用量均为0.02%的TBHQ和维生素E抗氧化能力进行了比较。结果表明,大蒜精油和姜精油对大豆油具有明显的抗氧化效果,并有一定的剂量效应关系,大蒜精油对大豆油的抗氧化能力整体上要明显强于姜精油,并且0.02%大蒜精油的抗氧化性能明显优于0.02%TBHQ和0.02%维生素E,然而实验中姜精油的抗氧化性能均不及0.02%TBHQ和0.02%维生素E。此外,实验研究还发现两种精油添加于油脂中,都会对油脂的颜色和气味产生不同程度的影响。     

葡萄柚精油对食用油脂的抗氧化研究

以葵花籽油为介质,以过氧化值为指标研究了葡萄柚精油的抗氧化性能。结果表明:葡萄柚精油对葵花籽油有较强的抗氧化作用,且抗氧化效果与添加量有关;当精油添加量达到0.1%时抗氧化效果就已高于0.02%BHT;添加了葡萄柚精油的葵花籽油应在低温避光条件下保存;α-生育酚对葡萄柚精油的抗氧化作用起到增效作用。     

柑橘类精油对食用油脂的抗氧化研究

以过氧化值为指标,以橄榄油和猪油为介质,分析了柠檬精油、葡萄柚精油及甜橙精油的抗氧化性能及增效剂的影响作用.结果表明:葡萄柚精油的抗氧化效果最好,0.2%的葡萄柚精油在橄榄油中无需增效剂,0.02%的Vc在橄榄油中对柠檬精油和甜橙精油有增效作用,在猪油中0.02%柠檬酸的增效作用最好.     

大蒜及大蒜精油的化学成分

本文综述了大蒜及大蒜精油的化学成分,着重讨论了大蒜的特征风味成分和重要的生理活性物质-大蒜素等含硫化合物,对其在产后加工中的生成机制作了简要的阐述。     

分子蒸馏法分离提取大蒜精油

采用分子蒸馏技术,依据Box-Behnken 设计原理和响应面分析法,探讨分子蒸馏不同因素对分离、提取大蒜中大蒜精油的影响,选择最佳提取条件。结果表明：当控制系统的压力105Pa、进料速度1.2g/min、进料温度40～55℃范围内,蒸馏温度45.1℃时具有最好的二次分子蒸馏效果,大蒜精油的外观质量明显提高,平均总提取率可达0.476%,大蒜精油中水分为0.15%,纯度达99.85%。     

植物油萃提大蒜精油工艺研究

将大蒜破碎后加入精炼植物油直接常温浸提大蒜精油,通过研究大蒜切碎度、搅拌时间、大蒜与植物油质量比、搅拌速度等因素对成品大蒜油中蒜素含量的影响,得出最佳的工艺条件为:切碎度为细颗粒、搅拌时间为24h、大蒜与植物油质量比为1.0、搅拌速度为低速(168r/min).     

提高大蒜精油提取得率的酶调控技术

报道了通过调控蒜氨酸酶活性提高大蒜精油提取得率的方法,并初步确定了提取大蒜精油的最适工艺条件。实验结果表明其提取得率较常规方法提高2倍。     

大蒜精油的功效和用法

1944年意大利化学家Gavallito首先发现大蒜中有药用价值的是大蒜挥发油,它只占大蒜千分之二的含量。     

The production of pork with garlic flavour notes using garlic essential oil

Garlic essential oil (GEO) added directly to pork mince or to the diet of pigs was evaluated for its effectiveness in masking undesirable mutton flavour. Pork was from 31 female pigs (Duroc × (Large White × Landrace)) grown on diets containing either animal-plus-plant products (AP diet) or plant products only (P diet) with four levels of GEO: 0, 0.55, 1.44 and 1.84 g/kg feed and 0, 0.55, 1.44 and 2.15 g/kg feed in the AP and P diet, respectively. Garlic flavour increased and mutton flavour decreased in pork from pigs that consumed more than about 150 g and 220 g of GEO in P and AP diets, respectively over the 57-day feeding period. The garlic flavour was stronger and the mutton flavour less intense for pork from pigs on the P diet. When GEO was added to pork mince at 125 ppm, it significantly reduced mutton flavour.     

爬山虎叶片提取物对食用油脂抗氧化效应的研究

采用Schall烘箱法,以过氧化值(POV)和酸价(AV)为指标,研究了爬山虎叶片不同溶剂提取物对猪油和菜籽油的抗氧化效应,并与化学抗氧化剂V C和TBHQ进行了比较。结果表明:爬山虎叶片几种溶剂的粗提物均能有效的抑制这两种油脂的氧化,在相同条件下不同溶剂粗提物的抗氧化能力为乙酸乙酯>75%乙醇>蒸馏水。除水提取物外,其他两种溶剂提取物对猪油和菜籽油的抗氧化作用均弱于TBHQ但强于V C;对POV的抑制率高于AV;对菜籽油的抗氧化效应强于猪油。      

Application of edible coating with essential oil in food preservation

Abstract

Compared with other types of packaging, edible coatings are becoming more and more popular because of their more environmentally friendly properties and active ingredients carrying ability.

The edible coating can reduce the influence of essential oils (EOs) on the flavor of the product and also can prolong the action time of EOs through the slow-release effect, which effectively promote the application of EOs in food. Understanding the different combinations of edible coatings and EOs as well as their antimicrobial effects on different microorganisms will be more powerful and targeted to promote the application of EOs in real food systems.

The review focus on the contribution of the combination of EOs and edible coatings (EO-edible coatings) to prolong the shelf life of food products, (1) specifically addressing the main materials used in the preparation of EO-edible coatings and the application of EO-edible coatings in the product, (2) systematically summarizing the main production method of EO-edible coatings, (3) discussing the antiseptic activity of EO-edible coatings on different microorganisms in food.     

Investigation of the volatile aroma components of garlic leaves essential oil. Possibility of utilization to enrich garlic bulb oil

The volatile aroma components of Egyptian green garlic leaves essential oil was investigated for the first time. After the utilization of garlic bulbs to prepare garlic oil or after drying the bulbs to produce garlic powder, garlic leaves are considered to be waste material, which is disposed of without any benefit. In this investigation, green garlic leaves were distilled and the essential oil was subjected to GC and GC-MS identification. The yield of the oil was 0.06% (based on wet weight of the leaves). The most prominent compounds of the essential oil were diallyl trisulfide (32.32%), followed by diallyl disulfide (31.35%) and methyl allyl trisulfide (11.40%); these compounds are the same as those found in garlic bulb oil. This means that garlic leaf oil is a rich, renewable and priceless source of garlic aroma compounds which could be utilized in fortification and enriching of garlic bulb essential oil to increase its quantity without changing the quality. Utilization of green garlic leaves for production of essential oil will also save, to some extent, the costs of disposing of large amounts of leaves in garlic possessing factories, transforming them into profits.     

Physical and antibacte rial properties of alginate-based edible film incorporated with garlic oil

Antibacterial alginate-based edible film has been studied by incorporation of garlic oil as a natural antibacterial agent. Initially, 0.1% v/v garlic oil was tested in in vitro experiments against some food pathogenic bacteria. The presence of 0.1% v/v garlic oil in the nutrient broth decreased viable cell counts for Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Bacillus cereus by 2.28, 1.24, 4.31 and 5.61 log cycles, respectively after 24 h incubation. Meanwhile, an increased cell population occurred on all accompanying controls. Antimicrobial alginate films were prepared by incorporating garlic oil up to 0.4% v/v. They were characterized for antibacterial activity, mechanical and physical properties. The edible film exhibited antibacterial activity against Staphylococcus aureus and B. cereus among bacteria tested by using agar diffusion assay. Tensile strength and elongation at break were significantly (p < 0.05) changed by incorporation of garlic oil at 0.3% and 0.4% v/v, respectively. Water vapor permeability decreased significantly (p < 0.05) with 0.4% v/v garlic oil incorporation, whereas total color difference remained same until 0.4% v/v. These results revealed that garlic oil has a good potential to be incorporated into alginate to make antimicrobial edible film or coating for various food applications.     

自组装多肽水凝胶包埋大蒜精油的控释研究

研究Fmoc–F自组装多肽水凝胶对大蒜精油的包埋作用、控释特性和稳定作用。结果表明:该水凝胶对大蒜精油的包埋率可达到97.07%;当p H≥6.5时,包埋大蒜精油后的水凝胶结构分解率不高于12.17%,可提高大蒜精油的稳定性;当5p H6.5时,凝胶结构部分分解;当p H≤5.0时,凝胶结构迅速分解,快速释放大蒜精油抑制大肠杆菌的生长;感官评价表明Fmoc–F水凝胶可显著掩盖大蒜精油的不良气味。     

天然调味香料芹菜籽精油的研究进展

天然调味香料芹菜籽精油具有抗氧化、抗肿瘤及抑菌杀虫等生物活性,在调味品、医药、化妆品等领域有着很大的应用前景,近年来激起了食品、化学、医药和生物学家的研究热情.文章从芹菜籽精油的提取方法、化学成份、生物活性及应用前景出发,对已有的研究成果进行了综述.     

Stability enhancement of garlic essential oil using new opopanax gum/gelatin nanofibres

Opopanax gum/gelatin nanofibre was produced by the electrospinning method, and the efficiency of this new technique for encapsulation of garlic essential oil was investigated. Fourier-transform infrared spectroscopy results showed the physical and weak interactions between opopanax gum and gelatin, as well as the improvement of their thermal stability in the nanofibres structure. Incorporating 10% garlic essential oil based on biopolymer weight in nanofibres was considered the best percentage. The results confirmed the presence of garlic essential oil in the nanofibres and the improvement of its thermal stability by entrapment to the nanofibre structure. The data of analysis of the stability of garlic essential oil in the forms of free and encapsulated conditions showed that its stability increased at 25 °C from 20 days to more than 60 days. It indicated the efficiency of opopanax gum/gelatin nanofibres as an applicable coating material for stability enhancement of essential oils.     

Characterization of edible films based on hydroxypropylmethylcellulose and tea tree essential oil

Edible films based on hydroxypropylmethylcellulose (HPMC) and different concentrations of tea tree essential oil (TTO) were prepared. Film-forming dispersions (FFD) were characterized in terms of rheological properties, particle size distribution and ζ-potential. In order to study the impact of the incorporation of TTO into the HPMC matrix, the water sorption isotherms, water vapour permeability (WVP), mechanical and optical properties of the dry films were evaluated. Results showed that the increase in TTO content promoted significant changes in the size and surface charge of the FFD particles. With regards to the film properties, the higher the TTO content, the lower the WVP and the moisture sorption capacity. In general, the addition of TTO into the HPMC matrix leads to a significant decrease in gloss and transparency and a decrease in the tensile strength and elastic modulus of the composite films. The properties of the films were related with their microstructure, which was observed by SEM.