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981.
The purpose of this study was to evaluate the use of Lactobacillus plantarum, isolated from table olives "Bella di Cerignola," a traditional variety of Apulian region (Southern Italy), as a starter for this kind of food. We focused on the interaction of the starter with the natural occurring microflora, the quantitative/qualitative composition of yeast population, the decrease of pH, and the content of organic acids. After a preliminary characterization, 3 strains of Lb. plantarum, selected for their probiotic and technological performances, were used as a multiple-strain starter and inoculated (approximately 2%) in olives, processed according to Spanish style, brined at 8% and 10% of NaCl and added with 0.5% of glucose. The combination of the starter and glucose assured a correct fermentation course, decreasing the pH up to a safe value (4.3 to 4.5) and controlled the growth of yeasts. The concentrations of both L- and D-lactic acids increased throughout the fermentation, while citric and malic acids (both the isomers D and L) remained at low levels (0.2 to 0.4 g/L). Concerning yeast species, Candida guilliermondii was mainly isolated at the beginning (7 to 14 d), while C. famata prevailed at the end of fermentation. PRACTICAL APPLICATIONS: To the question "How to standardize and maintain quality of "Bella di Cerignola" olives (Southern Italy)" we can suggest the following answer: use Lb. plantarum and a low amount of glucose (0.5%). The result is a decrease of the pH below the safety break point. 相似文献
982.
Antonio Bevilacqua Marianna Cannarsi Mariangela Gallo Milena Sinigaglia Maria Rosaria Corbo 《Journal of food science》2010,75(1):M53-M60
ABSTRACT: Enterobacter cloacae can be recovered in the spontaneous fermentations of Italian table olives. In this study, the effects of salt (20 to 100 g/L), temperature (10 to 37 °C), pH (4 to 5 and 8 to 10), p -coumaric and vanillic acids (0.5 to 2 g/L), and the acidification of the medium through lactic, citric, and ascorbic acids were investigated on 15 strains of E. cloacae , isolated from Italian table olives "Bella di Cerignola." Finally, a confirmatory experiment in synthetic brine was run. The strains were inhibited only by an NaCl amount of 70 to 80 g/L and by p -coumaric acid; on the other hand, they showed the ability to grow also at low temperatures (10 to 15 °C). The confirmatory experiment highlighted their ability to survive both at 15 °C and at pH 5. Enterobacter cloacae could be a real problem for the fermentation of table olives in southern Italy; some hurdles could be used (salt or brine acidification), but some environmental conditions (for example, the temperature) should be controlled carefully to maintain olive safety at acceptable levels. 相似文献
983.
Nutrition facts and functional potential of quinoa (Chenopodium quinoa willd.), an ancient Andean grain: a review 总被引:3,自引:0,他引:3
Antonio Vega‐Gálvez Margarita Miranda Judith Vergara Elsa Uribe Luis Puente Enrique A Martínez 《Journal of the science of food and agriculture》2010,90(15):2541-2547
Quinoa, Chenopodium quinoa Willd., is an Amaranthacean, stress‐tolerant plant cultivated along the Andes for the last 7000 years, challenging highly different environmental conditions ranging from Bolivia, up to 4.500 m of altitude, to sea level, in Chile. Its grains have higher nutritive value than traditional cereals and it is a promising worldwide cultivar for human consumption and nutrition. The quinoa has been called a pseudo‐cereal for botanical reasons but also because of its unusual composition and exceptional balance between oil, protein and fat. The quinoa is an excellent example of ‘functional food’ that aims at lowering the risk of various diseases. Functional properties are given also by minerals, vitamins, fatty acids and antioxidants that can make a strong contribution to human nutrition, particularly to protect cell membranes, with proven good results in brain neuronal functions. Its minerals work as cofactors in antioxidant enzymes, adding higher value to its rich proteins. Quinoa also contains phytohormones, which offer an advantage over other plant foods for human nutrition. Copyright © 2010 Society of Chemical Industry 相似文献
984.
Grace F. Ghesti Julio L. de Macedo Valdeilson S. Braga Antonio T. C. P. de Souza Vicente C. I. Parente Esdras S. Figuerêdo Inês S. Resck José A. Dias Sílvia C. L. Dias 《Journal of the American Oil Chemists' Society》2006,83(7):597-601
Biodiesel (FA esters) has become very attractive as an alternative diesel fuel owing to its environmental benefits. Transesterification
is the most usual and important method to make biodiesel from vegetable oils. This article investigates the potential for
using Raman spectroscopy to monitor and quantify the transesterification of soybean oil to yield ethyl esters. The differences
observed in the Raman spectra of soybean oil after transesterification were a peak at 2932 cm−1 (
), the displacement of the v
C=O band from 1748 to 1739 cm−1, and the bands at 861 (v
R-C=O and v
C-C) and 372 cm−1 (δ
CO-O-C). Uni- and multivariate analysis methods were used to build several analytical curves and then applied in known samples,
treated as unknowns, to test their ability to predict concentrations. The best results were achieved by Raman/PLS calibration
models (where PLS=partial least squares regression) using an internal normalization standard (v
=C-H band). The correlation coefficient (R
2) values so obtained were 0.9985 for calibration and 0.9977 for validation. Univariate regression analysis between biodiesel
concentration and the increasing intensity of
band or v
C=O displacement showed R
2 values of 0.9983 and 0.9742, respectively. Although spectroscopic methods are less sensitive than chromatographic ones, the
data obtained by spectroscopy can be correlated with other techniques, allowing biodiesel yield and quality to be quickly
assessed. 相似文献
985.
Jos E. Bez ngel Marcos-Fernndez Rosa Lebrn-Aguilar Antonio Martínez-Richa 《Polymer》2006,47(26):8420-8429
A new convenient route for the synthesis of poly(-caprolactone) (PCL) with α,ω-telechelic diols' end-groups is presented. Synthesis of α,ω-telechelic PCL diols (HOPCLOH) was achieved by ring-opening polymerization (ROP) of -caprolactone (CL) catalyzed with ammonium decamolybdate (NH4)8[Mo10O34] and using diethylene glycol (DEG) as initiator. Obtained HOPCLOH was characterized by 1H and 13C NMR, FT-IR, GPC and MALDI-TOF. Comparative studies demonstrate that ammonium decamolybdate (NH4)8[Mo10O34] is better catalyst than Sn-octanoate (SnOct2) toward CL polymerization in presence of DEG, under the conditions tested. A biodegradable poly(ester-urethane-urea) derivative was efficiently prepared from synthesized HOPCLOH. Obtained polymer shows minor differences with respect to the properties recorded for a poly(ester-urethane-urea) obtained from commercial HOPCLOH. 相似文献
986.
An evolutionary procedure based on cultural algorithms for the optimal design of adaptive wavelet filters based on lifting scheme is proposed. Numerical results of characterization, based on statistical experiment design, as well as validation, based on the comparison with a genetic optimization algorithm, are presented. Experimental results of the validation on two case studies for reducing uncertainty arising from noise in on-field corrosion rate measurements are highlighted. 相似文献
987.
Martinez-Lorenzo Jose A. Pino Antonio G. Gutierrez Javier Valdes Borja G. Acuna Marcos A. Rubinos Oscar Las-Heras Fernando 《Antennas and Propagation Magazine, IEEE》2009,51(4):88-96
This work presents a procedure for analyzing multiply fed reflector antennas in both transmission and reception modes, by using the Reflector Antenna Complex Equivalent Length (RA-CEL) concept. The RA-CEL is derived by combining the Feed Element Complex Equivalent Length (FE-CEL) Method with an Equivalent Current (EC) model on the reflector surface. This formulation, in terms of both electric and magnetic equivalent currents, is consistent with the reciprocity theorem. Its application to reflector antenna far-field pattern analysis, in both the transmission and reception modes, is presented. The proposed method accurately considers the mutual coupling among feeding array elements through the reflector surface, and its computational cost is substantially lower than required by a full-wave analysis. Some applications investigating the mutual coupling among feeding elements of reflector antennas are presented, and are compared with a reference solution given by the Method of Moments - Physical Optics hybrid method, and a numerical evaluation of the integral equation. 相似文献
988.
Behavioural models for distributed Fractal components 总被引:2,自引:0,他引:2
Tomás Barros Rabéa Ameur-Boulifa Antonio Cansado Ludovic Henrio Eric Madelaine 《电信纪事》2009,64(1-2):25-43
This paper presents a formal behavioural specification framework for specifying and verifying the correct behaviour of distributed Fractal components. The first contribution is a parameterised and hierarchical behavioural model called pNets that serves as a low-level semantic framework for expressing the behaviour of various classes of distributed languages and as a common internal format for our tools. Then, we use this model to define the generation of behavioural models for applications ranging from sequential Fractal components, to distributed objects, and finally to distributed components. Our models are able to characterise both functional and non-functional behaviours and the interaction between the two concerns. Finally, this work has resulted in the development of tools allowing the non-expert programmer to specify the behaviour of his components and (semi)automatically verify properties of his application. 相似文献
989.
Luisa Torsi Francesco Marinelli M. Daniela Angione Antonio Dell’Aquila Nicola Cioffi Elvira De Giglio Luigia Sabbatini 《Organic Electronics》2009,10(2):233-239
Contact effects in organic thin-film transistors (OTFTs) sensors are here investigated specifically respect to the gate field-induced sensitivity enhancement of more than three orders of magnitude seen in a DHα6T OTFT sensor exposed to 1-butanol vapors. This study shows that such a sensitivity enhancement effect is largely ascribable to changes occurring to the transistor channel resistance. Effects, such as the changes in contact resistance, are seen to influence the low gate voltage regime where the sensitivity is much lower. 相似文献
990.
Massimo F. Bertino Bernd Smarsly Antonio Stocco Arne Stark 《Advanced functional materials》2009,19(8):1235-1240
A technique is presented that allows for altering of the physical characteristics of films of TiO2 nanoparticles by exposure to visible light. In this technique, dye‐sensitized oxide nanoparticles are deposited on a substrate by dip‐coating. Photodissociation of the organic ligand layer leads to cross‐linking of the nanoparticles. Consequently, irradiated films have a decreased porosity, an increased index of refraction and an increased hydrophobicity. Films irradiated with green light are compared to films irradiated with UV light. Within experimental error, visible‐ and UV‐illumination induces the same changes in the films. The mechanism of surfactant elimination in dye‐sensitized oxide particles is discussed, patterning is demonstrated, and prospective applications of the technique are considered. 相似文献