دانلود رایگان ترجمه مقاله خواص دی الکتریک روغن های خوراکی و اسیدهای چرب – الزویر 2008
دانلود رایگان مقاله انگلیسی + خرید ترجمه فارسی | |
عنوان فارسی مقاله: |
خواص دی الکتریک روغن های خوراکی و اسید های چرب به صورت تابعی از فرکانس، دما، رطوبت و ترکیب |
عنوان انگلیسی مقاله: |
Dielectric properties of edible oils and fatty acids as a function of frequency, temperature, moisture and composition |
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مشخصات مقاله انگلیسی (PDF) | |
سال انتشار | 2008 |
تعداد صفحات مقاله انگلیسی | 8 صفحه با فرمت pdf |
رشته های مرتبط با این مقاله | صنایع غذایی |
گرایش های مرتبط با این مقاله | علوم مواد غذایی و فناوری مواد غذایی |
چاپ شده در مجله (ژورنال) | مجله مهندسی مواد غذایی – Journal of Food Engineering |
کلمات کلیدی | روغن خوراکی، طیف های دی الکتریک، ثابت دی الکتریک، دما، رطوبت |
ارائه شده از دانشگاه | دانشکده علوم و فناوری، دانشگاه کوبه، ژاپن |
رفرنس | دارد ✓ |
کد محصول | F944 |
نشریه | الزویر – Elsevier |
مشخصات و وضعیت ترجمه فارسی این مقاله (Word) | |
وضعیت ترجمه | انجام شده و آماده دانلود |
تعداد صفحات ترجمه تایپ شده با فرمت ورد با قابلیت ویرایش | 16 صفحه با فونت 14 B Nazanin |
ترجمه عناوین تصاویر و جداول | ترجمه شده است ✓ |
ترجمه متون داخل تصاویر | ترجمه نشده است ☓ |
ترجمه متون داخل جداول | ترجمه نشده است ☓ |
درج تصاویر در فایل ترجمه | درج شده است ✓ |
درج جداول در فایل ترجمه | درج شده است ✓ |
درج فرمولها و محاسبات در فایل ترجمه | به صورت عکس درج شده است ✓ |
منابع داخل متن | به صورت فارسی درج شده است ✓ |
کیفیت ترجمه | کیفیت ترجمه این مقاله متوسط میباشد |
فهرست مطالب |
1-مقدمه
2.مواد و روش ها
2.1 نمونه ها
2.2 اندازه گیری خواص دی الکتریک
2.3 تحلیل اماری
3. نتایج و بحث
3.1 اثر فرکانس بر روی خواص دی الکتریک
3.2 اثر ترکیب روغن بر روی خواص دی الکتریک
3.3اثر دما بر خواص دی الکتریک
3.4اثر مقدار روغن بر روی خواص دی الکتریک
4.نتیجه گیری
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بخشی از ترجمه |
مقدمه |
بخشی از مقاله انگلیسی |
1. Introduction As a simple, rapid and non-destructive measuring technique, dielectric spectroscopy provides information about the dielectric response of materials to electromagnetic fields. It is a convenient method for evaluating food quality, especially for detecting moisture content in foods (Toyoda, 2003). This technology has been studied and used extensively in analysis and monitoring quality of various agricultural products and food materials (Nelson, 1991, 2005). The dielectric properties of most materials depend on the frequency of the applied alternating electric field, the temperature, moisture content, density, composition, and structure of the material (Venkatesh and Raghavan, 2004). The studies and applications of these properties were performed in eggs, grains, seeds, fruits, vegetables, juice and wine, baked foods and flours, dairy products, fish, meat products, etc. Much data and information on the dielectric properties of various foods have become available (Christopher, 1997). There have been several attempts to develop relationships between the dielectric properties and composition, based on averages of the dielectric properties of individual components (Sun et al., 1995; Ryyna¨- nen, 1995; Kudra et al., 1992). Bengtsson and Risman (1971) reported that both the dielectric constant and loss factor of various foods increased with increasing moisture content. The representative dielectric properties of milk and its constituents at 2.45 GHz were given by Kudra et al. (1992). The equations predicting dielectric properties of fruits and vegetables as a function of moisture and temperature were developed (Calay et al., 1995). Microwave permittivities of bread dough were measured by Zuercher et al. (1990) as a function of water-flour composition, proofing time, and baking time. Nunes et al. (2006) studied the complex permittivity of milk at room temperature (17– 20 C) over the frequency range of 1–20 GHz, they found that the variations of dielectric parameters with fat content and dilution suggested that they may be useful to roughly determine the milk’s content in terms of ionic compounds, fats, and carbohydrates and proteins. As a low cost condition-monitoring sensor, the dielectric constant has also been used for monitoring lubricating oil quality on-site, the sensor was designed as a direct measurement of the overall quality of the used oil (contaminants and oxidation) as compare to that of the un-used oil (Carey and Hayzen, 2007).1 To guarantee an effective quality control for frying oils and fats, simple and rapid methods for the detection of thermal abuse are needed. Therefore, dielectric method has been studied and applied to determine frying oil deterioration. A patented instrument called Food Oil Sensor (FOS) was developed to measure a change in the e0 of deep-frying oils, the measured value was defined as the FOS readings (Hein et al., 1998). It was reported to be a useful tool in determining heat abuse for frying fats and oils in comparison with conventional analytical techniques (Fritsch et al., 1979). Since the technique was patented in the USA and Germany, the details of the data and information are difficult to access in reported literature. Other similar dielectric measurement instruments have been also developed for evaluating the quality of deep-frying fats and oils (Stier, 2004). Many research works were carried out in dielectric properties of frying fats and oils (EIShaml et al., 1992; Paul and Mittal, 1996; Inoue et al., 2002). They reported that the dielectric constant is the most significant indicator for quality control in commercial deep fat frying operations, it was concluded that polymer content and changes of dielectric constant are useful for monitoring frying oil quality. Venkatesh and Raghavan (2000) reported the summaries of various recent studies related to heated edible oils and their characteristics in an effort to establish comparative standards used in deep frying operations in routine food services and processing scenarios. Pace et al. (1968) conducted the dielectric property measurement of commercial cooking oils at microwave frequencies (100, 300, and 1000 MHz) and at varying frying temperatures. It was reported that the differences in dielectric properties among tested fats and oils appear to be attributable to the phase of the material and generally correspond to the degree of unsaturation as evidenced by iodine values. Rudan-Tasicˇ and Klofutar (1999) investigated the dielectric properties and physical and chemical constants of 11 edible oils. They reported that the values of e0 lie in the range of about 3.0–3.2 (at 298.15 K) for the most oils, the e0 of oils increased somewhat with increasing in the unsaturation (IV) of the oil and decreased with increasing temperature. On-line monitoring of moisture and salt contents of butter was researched over the MW frequency range. It was found that the moisture and salt contents could be independently predicted by measuring the two microwave propagation properties of phase shift and attenuation. It is useful for monitoring the moisture and salt contents of salted butter in its manufacturing process (Shiinoki et al., 1998). Recently, Ahmed et al. (2007) studied dielectric properties of butter with and without salt over the MW frequency range covering 500–3000 MHz. They found that dielectric spectra of unsalted butter differed significantly from the salted one as a function of temperature and moisture content. In past researches on dielectric properties of edible oils, deterioration evaluation of frying oil has been focused chiefly; the study and application of dielectric properties to oil processing, storage, and food making were limited. Therefore, the fundamentals of dielectric properties relevant to the quality of edible oils, the interaction mechanisms of oil/fat molecules subjected to MW radiation at a broad range of approved frequencies and temperature ranges, and dielectric measurement and its simplicity in analysis needs more research (Venkatesh and Raghavan, 2004). The objectives of this study were to investigate the effects of frequency, temperature, moisture content, and fatty acid composition on the dielectric properties of oils and fatty acids, and discuss the relationship between dielectric properties and fatty acid composition of the oils. |