气湿敏产业化要素分析

以国家“八五”科技攻关“气湿敏传感技术研究开发”课题实施为例，论述气湿敏传感器产业现状和气湿敏传感器技术研究开发课题的攻关目的，分析了气湿敏传感器产业化要素，产业化的关键是管理、技术、经济三要素的协调。只有以气湿敏传感器产业为支撑，才能发展气湿敏传感器技术，形成资金、技术、产品和需求的良性循环．     

胡柚精油纳米乳的制备及品质评价

研制了胡柚精油纳米乳并对其进行了品质评价。利用伪三元相图法优选配方,直接以胡柚精油为油相,从Span系列和Tween系列中筛选出Span-80与Tween-80作为混合表面活性剂,选用丙三醇为助表面活性剂,加入蒸馏水制备胡柚精油纳米乳。通过染色法鉴定染色法该乳液属于O/W型,清澈透明有明显的丁达尔现象,经激光粒度仪测得分散相平均粒径为21 nm,且粒径大小集中,影响因素实验表明该胡柚精油纳米乳有良好的稳定性。     

Detection of low‐quality extra virgin olive oils by fatty acid alkyl esters evaluation: a preliminary and fast mid‐infrared spectroscopy discrimination by a chemometric approach

A set of eighty‐one extra virgin olive oils (EVOOs) was analysed according to the new quality parameters relative to the total amount of methyl and ethyl esters of fatty acids [Σ (FAMEs + FAEEs)] and the ratio between ethyl and methyl esters [ratio of FAEEs/FAMEs (RFF)]. Acquisition of the mid‐infrared spectra was also performed by Fourier Transform Infrared Spectroscopy (FT‐IR). Chemical and spectroscopy data were chemometrically elaborated, and FT‐IR coupled by Partial Least Square (PLS) methodology was developed. Results were statistically similar to official procedure in terms of analytical performance for Σ (FAMEs + FAEEs) and RFF in EVOOs: a good agreement between predicted and actual values on calibration data sets was found (0.98 and 0.83, respectively) and the limit of quantification was low enough (29.3 mg kg^?1) considering the actual limits for Σ (FAMEs+ FAEEs). This new approach, time‐saving and environmentally friendly, can be considered as a useful tool for screening procedures.     

砂糖橘精油化学组成及对指状青霉的抑菌活

采用水蒸气蒸馏法提取砂糖橘(Citrus reticulate Blanco)果皮精油,并用GC-MS对其成分进行分析,共鉴定出17种成分,主要包括柠檬烯(77.99%)、β-月桂烯(3.74%)、β-水芹烯(2.78%)、罗勒烯(2.64%)、β-芳樟醇(2.35%)、α-蒎烯(1.60%)、正辛醇(1.54%)、癸醛(1.24%)、4-松油醇(1.10%)和4-十一烯(1.04%)等。测定不同添加量(0.16、0.31、0.63、1.25、2.50、5.00、10.00μL/mL)砂糖橘精油对指状青霉孢子萌发和菌丝体生长的作用。结果表明：低添加量(＜2.5μL/mL)砂糖橘精油对指状青霉孢子萌发无影响甚至有促进作用,对指状青霉菌丝体生长有轻微的抑制;而高添加量(10μL/mL)则显著抑制孢子萌发和菌丝体生长(P＜0.05)。本实验表明砂糖橘精油在防治指状青霉具有一定作用。     

顶空气相色谱质谱联用法分析芝麻油的挥发性气味成分

应用顶空气相色谱质谱法分析了芝麻油的挥发性气味成分,讨论了顶空和气相色谱质谱联用仪的操作参数.经质谱数据检索可知,芝麻油的挥发性气味成分主要分为含氧、含氮和含硫3类化合物.     

三种柚子精油的香味特征及挥发性成分

为阐明我国主要柚类水果精油的品质特征,运用感官评价和气质联用(GC-MS)研究琯溪蜜柚、沙田柚和梁平柚果皮精油的香味特征和挥发性成分。感官评价结果显示,三种柚子精油香型相似,其中琯溪蜜柚精油风味浓郁且伴有强烈的花香味,沙田柚精油有一定的薄荷味,梁平柚精油则有强烈柚香味和甜味。GC-MS结果显示,虽然三种柚子精油的主要成分均为d-柠檬烯(476,150-741,595μg/mL)、β-月桂烯(13,859-207,255μg/mL),但琯溪蜜柚精油含有更高浓度的β-月桂烯,沉香醇以及醛类成分。香气值(OAVs)分析表明琯溪蜜柚精油(5,015,965)远高于沙田柚香气值(1,307,088)和梁平柚精油香气值(1,159,532),同时琯溪蜜柚精油中强烈的花香味主要来源于β-月桂烯(2,093,489)和沉香醇(387,578)。研究结果说明三种柚子精油主要香气轮廓及成分相似,但不同种类精油间存在特征性差异。该研究结果为我国柚子精油的综合开发利用提供参考。     

豆天蛾氨基酸及脂肪酸分析与评价

对豆天蛾幼虫氨基酸及脂肪酸组成进行了分析测定,结果表明:豆天蛾幼虫含有18种AA和8种EAA,EAA/TAA为53.34%,属于优质完全蛋白质昆虫。豆天蛾幼虫不饱和脂肪酸含量61.74%,其中亚麻酸和油酸的含量较高,亚麻酸含量高达34.11%;饱和脂肪酸含量36.43%,其中棕榈酸的含量较高。     

Physico-chemical properties,morphology and antioxidant activity of film from fish skin gelatin incorporated with root essential oils

The influences of three root essential oils (ginger, turmeric and plai) at different levels (25%, 50% and 100%, based on protein content) on properties and antioxidative activity of fish skin gelatin-based film were investigated. Films incorporated with all essential oils showed the lower tensile strength (TS) but higher elongation at break (EAB) with increasing amount of essential oils, compared with the control film (without oil incorporated), regardless of types of essential oil (p < 0.05). Water vapor permeability (WVP) of films containing essential oils decreased as the amount of essential oils increased (p < 0.05). Decreases in L^*-value and increases in b^*-, ΔE^*- and transparency value were observed with increasing amount of essential oils incorporated (p < 0.05). FTIR spectra indicated that films added with essential oils, especially from plai root, exhibited higher hydrophobicity than the control film, as evidenced by higher amplitude at wavenunber of 2877–2922 cm⁻¹ and 1732 cm⁻¹. Lower degradation temperature was obtained in films containing essential oils. Microstructural study revealed that bilayer films could be formed when essential oils at level above 50% were incorporated. Film incorporated with plai and turmeric essential oils showed the higher DPPH and ABTS radical scavenging activity, respectively, (p < 0.05), compared with the control film and ginger essential oil added film. Thus, the incorporation of root essential oils directly affected properties of fish skin gelatin-based film, depending on types and levels incorporated.     

Antibacterial activity of different essential oils obtained from spices widely used in Mediterranean diet

Raw and processed foods are open to contamination during their production, sale and distribution. At present, therefore, a wide variety of chemical preservatives are used throughout the food industry to prevent the growth of food spoiling bacteria. However health and economic considerations have led to a search for alternatives, such as essentials oils that can safely be used as substitutes for fungicides and bactericides to partially or completely inhibit the growth of fungi and bacteria. The aim of this work was to determine the effectiveness of the essentials oils from oregano (Origanum vulgare), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), cumin (Cuminum cyminum) and clove (Syzygium aromaticum) on the growth of some bacteria commonly used in the food industry, Lactobacillus curvatus, Lactobacillus sakei, Staphylococcus carnosus and Staphylococcus xylosus or related to food spoilage Enterobacter gergoviae, Enterobacter amnigenus. The agar disc diffusion method was used to determine the antibacterial activities of the oils. All six essential oils analysed had an inhibitory effect on the six tested bacteria. Oregano essential oil showed the highest inhibition effect followed by cumin and clove.     

Orange Essential Oils Antimicrobial Activities against Salmonella spp.

ABSTRACT:  Seven citrus essential oils (EOs) were screened by disc diffusion assay for their antibacterial activity against 11 serotypes/strains of Salmonella . The 3 most active oils were selected to determine the minimal inhibitory concentration (MIC) against the same Salmonella . Orange terpenes, single-folded d-limonene, and orange essence terpenes all exhibited inhibitory activity against the Salmonella spp. on the disc diffusion assay. EOs were stabilized in broth by the addition of 0.15% (w/v) agar for performance of the MIC tests. Orange terpenes and d-limonene both had MICs of 1%. The most active compound, terpenes from orange essence, produced an MIC that ranged from 0.125% to 0.5% against the 11 Salmonella tested. Gas chromatography-mass spectrometry (GC/MS) analysis revealed that this orange essence oil was composed principally of d-limonene, 94%, and myrcene at about 3%. EOs from citrus offer the potential for all natural antimicrobials for use in improving the safety of organic or all natural foods.