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71.
Fruit juices are generally concentrated in order to improve the stability during storage and to reduce handling, packaging, and transportation costs. Thermal evaporation is the most widely used technique in industrial fruit juice concentrate production. In addition to high energy consumption, a large part of the characteristics determining the quality of the fresh juice including aroma, color, vitamins, and antioxidants undergoes remarkable alterations through the use of high operation temperatures. Increasing consumer demand for minimally or naturally processed stable products able to retain as much possible the uniqueness of the fresh fruit has engendered a growing interest for development of nonthermal approaches for fruit juice concentration. Among them, membrane distillation (MD) and its variants have attracted much attention for allowing very high concentrations to be reached under atmospheric pressure and temperatures near ambient temperature. This review will provide an overview of the current status and recent developments in the use of MD for concentration of fruit juices. In addition to the most basic concepts of MD variants, crucial suggestions for membrane selection and operating parameters will be presented. Challenges and future trends for industrial adaptation taking into account the possibility of integrating MD with other existing processes will be discussed.  相似文献   
72.
There is a group of animal fibers known as “luxury fibers.” These are mohair, cashmere, camel hair, lama, alpaca, vicuna, guanaco, angora, yak, and quivit. In this study, the effects of demographical variables such as gender, education, age, sector, and income on the recognition and usage of luxury fibers in Thrace Region of Turkey were investigated. In order to analyze the obtained data, crosstabulation and chi-square statistical methods are used. According to the experimental results it can be said that the most commonly known and used luxury fibers are cashmere, mohair, and angora. The most important (37.6%) reason for participants to use luxury fibers is their warm feeling. On the other hand the most important (approx. 30%) reason for participants not to use them is that they do not have sufficient information about these fibers. It was determined that the most commonly (37.8%) used textile product made of luxury fibers is outerwear. Furthermore, it was found out that approximately 75% of participants accept paying more for garment containing luxury fibers because of their high quality.  相似文献   
73.
74.
In this study, optimum process parameters for supercritical carbon dioxide (CO2) (SC-CO2) extraction of roasted pistachio (Pistacia vera L.) were investigated by depending on amount of the characteristic flavouring components (α-pinene, limonene-D, α-terpinolene and β-myrcene). The extracts were analysed by DHA/GC-MS for determination of the volatile compounds and the optimum process parameters were decided as 200 g, 350 Bar, 70°C, 75 g CO2/min and 60 min. In the pistachio extracts obtained having the optimum process parameters, α-pinene, β-myrcene, limonene-D and α-terpinolene were detected as 24.47 g/100 g, 0.52 g/100 g, 2.25 g/100 g and 5.70 g/100 g among 31 volatile compounds in total, respectively. The fatty acid composition of the extract, which had the most desirable taste and flavour, was detected by gas chromatography using fatty acid methyl esters (FAME) preparation. The fatty acid composition analysis showed that the pistachio extract had included mostly oleic acid (67.51%, w/w) and linoleic acid (17.85%, w/w).  相似文献   
75.
Rhodobacter capsulatus is purple non-sulfur (PNS) bacterium which can produce hydrogen and CO2 by utilizing volatile organic acids in presence of light under anaerobic conditions. Photofermentation by PNS bacteria is strongly affected by temperature and light intensity. In the present study we present the kinetic analysis of growth, hydrogen production, and dual consumption of acetic acid and lactic acid at different temperatures (20, 30 and 38 °C) and light intensities (1500, 2000, 3000, 4000 and 5000 lux). The cell growth data fitted well to the logistic model and the cumulative hydrogen production data fitted well to the Modified Gompertz Model. The model parameters were affected by temperature and light intensity. Lactic acid was found to be consumed by first order kinetics. Rate of consumption of acetic acid was zero order until most of the lactic acid was consumed, and then it shifted to first order. The results revealed that the optimum light intensities for maximum hydrogen production were 5000 lux for 20 °C and 3000 lux for 30 °C and 38 °C.  相似文献   
76.
The objective of the present study was to obtain data about cooking time and temperature of kiymali pide in the restaurants and to investigate thermal inactivation of E. coli O157:H7 during experimental kiymali pide making. A field study was conducted in randomly selected 23 of 87 pide restaurants. Processing parameters including oven temperature, cooking period and post-cooking temperature were determined. Kiymali pide samples were prepared using ground beef filling experimentally inoculated with E. coli O157:H7 (7.6 log10 CFU/g). Pide samples were cooked at a conventional oven at 180 °C for 180, 240, 270, 300 and 330 s. Results of the current study suggest that cooking kiymali pide at 180 °C for at least 330 s (5.5 min) may provide sufficient food safety assurance (≥ 6 log10 CFU/g) for E. coli O157:H7.  相似文献   
77.
Eight different commercial enzyme‐modified cheeses (EMCs) were analysed, and the distinctive/common features of the products and production methods were investigated. Results showed that the total free fatty acid contents of EMC samples were 10 to 100 times higher than the values reported for the related cheese varieties. A total of 37 volatile compounds were identified, and acids were found as the most dominant group in all EMC samples. While furan compounds and 2‐acetylpyrrole were most intensively detected in the goat cheese EMC, methyl ketones were found in the highest amounts in Blue cheese EMC.  相似文献   
78.
The paper presents an improved sol–gel technique for the preparation of hydroxyapatite–atelocollagen composites suitable as precursor for osseous regeneration. This technique includes a premineralization step of atelocollagen providing a suspension of microfibrils in which the synthesis of the inorganic component was conducted at low temperature. The characterization of the composite was performed by FTIR spectroscopy, X-ray diffraction and scanning electron microscopy. The particle size distribution and the zeta potential were determined by Zetasizer measurements. The time stability of the composite was evaluated by turbidimetric measurements and macroscopic observation. The composites can be stored for a long time in sterile liquid media without a major risk of aggregation or sedimentation. From the final composite a slurry was obtained by sedimentation in centrifugal field and oscillatory rheological experiments were made to get information about its flow behavior. The slurry could be used as an injectable osteoconductive component, able to act as stock form in orthopaedic kits.  相似文献   
79.
The paper contributes to an emerging literature that critically questions the degree to which R&D, at the centre of national and transnational innovation policies, results in firm growth. The differences in how innovation affects firm growth is explored for small and large publicly quoted US pharmaceutical firms between 1950 and 2008. We observe that the positive impact of R&D on firm growth is highly conditional upon a combination of firm-specific characteristics such as firm size, patenting and persistence in patenting. For small firms, R&D boosts growth for only a subset of firms: namely, those that patent persistently for a minimum of five years. For large pharmaceutical firms, on the other hand, R&D may have a negative impact on growth; potentially resulting from the low R&D productivity these firms have suffered from since the mid-1990s. These results raise important issues around the R&D and firm growth relationship for small and large firms as well the role of persistence in innovation for boosting firm performance.  相似文献   
80.
This study assesses the level of background radiation for Kayseri province of Turkey. Natural radionuclide activity concentrations in soil samples were determined using high-resolution gamma spectroscopy. Outdoor gamma dose measurements in air at 1 m above ground level were determined using a portable gamma scintillation detector. The obtained results of uranium and thorium series as well as potassium ((40)K) are discussed. The present data were compared with the data obtained from different areas in Turkey. From the measured gamma-ray spectra, the average activity concentrations were determined for (238)U (range from 3.91 to 794.25 Bq kg(-1)), (232)Th (range from 0.68 to 245.55 Bq kg(-1)) and (40)K (range from 23.68 to 2718.71 Bq kg(-1)). The average activity concentrations of (238)U, (232)Th and (40)K were found to be 35.51, 37.27 and 429.66 Bq kg(-1), respectively, and 11.53 Bq kg(-1) for the fission product (137)Cs. The highest values of (238)U, (232)Th and (40)K concentrations (794.25 Bq kg(-1), 245.55 Bq kg(-1), 2718.71 Bq kg(-1), respectively) were observed in abnormal samples at Hayriye village. The average outdoor gamma dose rate in air at 1 m above the ground was determined as 114.43 nGy h(-1). Using the data obtained in this study, the average annual effective dose for a person living in Kayseri was found to be about 140.34 μSv.  相似文献   
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