Physical degradation of genomic DNA of soybean flours does not impair relative quantification of its transgenic content

In this paper, four different physical treatments (microwaves, heating by conduction, sonication and pressure autoclaving) were performed to degrade a pure DNA extract, and their influence on GMO quantification was studied. The aim was to check the hypothesis that processing of agrofood products results in a similar degradation rate for both the transgenic target and the specific target. Indeed we could observe that even if the used physical treatments could lead to a significant increase of C _t values for both transgenic and specific targets, the resulting ΔC _t remained stable. So, the main conclusion of the study is that the aforementioned hypothesis seems valid and thus a physical degradation of DNA will not affect the relative quantitation of the GMO content, provided that both the specific and transgenic targets have very similar size. A second important issue of the experiments performed was that DNA is a very robust molecule as it is extremely difficult to reach a mean size below 100 bp. The study also gives evidence of the importance of using small targets.     

Lactic acid bacteria profiles and tyramine and tryptamine contents of Turkish tulum cheeses

Tulum cheese, commonly produced in Turkey, is a traditional Turkish dairy product made from raw milk. In this research, 20 samples of tulum cheese were purchased from different markets in Isparta and Ankara (Turkey) and the populations of lactic acid bacteria (LAB) and contents of biogenic amines of Turkish tulum cheeses were investigated. The mean counts of LAB (as log10 cfu/g) were 7.22±0.67 on MRS agar, 6.93±1.77 on M17 agar, 7.28±0.72 on APT agar and 5.98±2.20 on ADA agar. Isolates of LAB obtained from 20 tulum cheeses were characterised as lactobacilli (48.5%), enterococci (32.7%), lactococci (15.8%) and streptococci (3.0%). Lactobacillus paracasei ssp. paracasei, Lactobacillus bifermentans and Enterococcus faecium predominated among the LAB in the samples of tulum cheeses; these organisms represented 30.2% of the isolates. As amino acids, tyrosine and tryptophan were determined in tulum cheeses. Tyramine and tryptamine, biogenic amines, were found at 0.00–329.00 and 0.32–40.44 mg/kg, respectively.     

Analysis of the volatile profile and identification of odour-active compounds in Bayonne ham

The aim of this work was to reliably identify odour-active compounds in dry-cured ham using powerful analysis methods for the volatile fraction. For this purpose, dynamic headspace gas chromatography combined with eight-way olfactometry using a panel of eight sniffers was used. One- and two-dimensional gas chromatography coupled with mass spectrometry and (or) olfactometry were also used. More than 600 compounds from the volatile fraction of dry-cured ham were identified and their biochemical origins are discussed. They covered a wide diversity of structures and chemical functions. Only 29 of them proved odour-active. Comparison of the results of GC–O analysis with those obtained by orthonasal sniffing of the dry-cured ham helped to gain a better understanding of how these substances contributed to the overall aroma of the product. Thus, “Fruity–Floral”, “Green–Vegetable” or “Plastic–Chemical” odours intensively perceived by GC–O have been poorly perceived by orthonasal sniffing. By contrast, “Animal–Meat products” or “Butter–Lactic–Cheesy” odours have been much better perceived by orthonasal sniffing. These results indicate that to understand the interactions between odour-active compounds, experimental doping with carefully selected odour-active compounds will be necessary.     

Performance of different fermentation methods and the effect of their duration on the quality of raw cocoa beans

This study aims to compare the effect of three cocoa fermentation methods and their duration on raw cocoa quality. Results showed a decrease in percentage of physical quality defects on fermentation method. Cocoa fermented for 4 days presented higher percentage of purple beans reached 45% and about 10% of slaty beans than cocoa fermented for 6 days whatever the process. Fermentation duration did not influence the mouldy beans that were around 1%. Formation of brown beans increased from 16% to 50% depending on the fermentation duration and process. Using wooden boxes allowed higher percentage of 77%–90% brown beans than others materials. Acidity of cocoa decreased on fermentation duration but beans treated in boxes were significantly (P = 0.05) acidic from 1.40 and 3.07 meq of NaOH g^?1. Fungal population did not vary in number depending both on the duration and the fermentation method with rates that ranged from 3.32 × 10⁷ to 8.63 × 10⁷ CFU g^?1.     

Identification and kinetics of oxidized compounds from phosphatidylcholine molecular species

Heat-induced oxidative modifications of two phosphatidylcholine molecular species as potential functional food components were evaluated. 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) and 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine (SLPC) were chosen as models. The optimal temperature for hydroperoxide formation was determined by MS for each standard: 125 °C for SLPC and 150 °C for SOPC. Oxidation was performed at these temperatures and degradation products were identified using LC–ESI-MS combined to an acid treatment. Kinetics of formation of oxidation products from SOPC and SLPC were monitored over 120 min and curves were drawn for each identified structure. Results showed that native phospholipids rapidly decreased with heat and that oxidation products showed functions, such as hydroxyl, oxo or epoxy groups. Kinetics pointed out that some of these quite stable oxidation products are likely to be found in sizable amounts in processed foods containing phospholipids.     

钢丝电镀生产线控制系统的设计

介绍钢丝电镀铜和锌的工艺流程,分析钢丝电镀生产线传统控制系统中存在的问题,根据工艺流程和要求,设计出基于PROFIBUS-DP总线系统的PLC分布式控制系统,并用九点控制器对系统中温度进行控制,避免了原有的分散模拟系统存在的缺点,提高了电镀系统的自动化程度,稳定了产品质量。     

Interactions between fecal bacteria,bile acids and components of tomato pomace

Food Science and Biotechnology - The tomato pomace obtained during processing as a residue of tomato processing from large industry. The interactions between tomato pomace and fecal bacteria, bile...     

Development of a portable spectrofluorimeter for measuring the microbial spoilage of minced beef

The evaluation of meat spoilage is based on sensory and microbiological analyses. The disadvantages of sensory analyses are its reliance on highly trained panelists, a procedure which makes it costly and unattractive for routine analyses. Moreover, the classical microbiological analyses are lengthy, costly and destructive. In this study a portable fluorescence spectrometer was tested to quantify minced beef spoilage. This study was investigated on samples stored aerobically and under vacuum at 5 and 15 °C. Total viable counts (TVC), Pseudomonas, lactic acid bacteria, and yeast/molds counts were investigated with classical culture methods. Fluorescence spectra were recorded on the same samples using different excitation LEDs (280, 320, and 380 nm). PLS-R with leave-one-out cross validation was used to perform calibration and validation models. The PLS-R models presented good R2(CV) (0.50-0.99) and ratio of standard deviation (RPD(CV): 1.40-8.95) values after cross-validation. It could be concluded that portable spectrofluorimeters are promising devices to evaluate spoilage in minced beef.     

Influence of the harvesting year and fertilizer on the fatty acid composition and some physicochemical properties of linseed (Linum usitatissimum L.)

Sar? 85 (Linum usitatissimum L.) linseed variety was used in this study. Linseed was cultivated at 2008 (LS-08) and 2009 (LS-09) without fertilizer. In addition, at 2009 diammonium phosphate [(NH₄)₂HPO₄] and ammonium nitrate (NH₄NO₃) were applied (LSF-09). The linseeds were analyzed for protein, ash and oil contents and fatty acid compositions. There were differences among harvesting years for oil, protein and ash contents of the seeds. The greater oil and protein contents were obtained during LS-08 compared with LS-09. There were no significant difference in protein and ash content between LS-09 and LSF-09 while a significant difference was observed in oil content. Seed protein, oil and ash contents were significantly affected by the harvesting year, but only oil content was affected by the fertilizer treatment. There are significant differences in palmitic, stearic, oleic, ??-linolenic and arachidic acid between LS-08 and LS-09. While palmitic, stearic, oleic acid decreased, ??-linolenic and arachidic acid increased during 2009 harvesting year. LSF-09 has the highest amount of ??-linolenic acid. The fertilizing treatment seems to have an increasing effect on the amount of ??-linolenic acid, while it has a decreasing effect on the oleic acid content.