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91.
《Food Control》2015
Risk assessments of the fungicides pyraclostrobin, iprodione, tebuconazole and cyprodinil were carried after determining their persistence on strawberries following two applications by spraying in a greenhouse. The Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was used for sample preparation, and high-performance liquid chromatography-tandem mass spectrometry and gas chromatography-tandem mass spectrometry were used for sample analysis. The range for the average recoveries of the four fungicides was 86.2–105.4 %, and the relative standard deviation range was 2.7–6.1 %. The half-lives of pyraclostrobin, iprodione, tebuconazole and cyprodinil after a single application were 3.7, 3.6, 3.3 and 2.8 d, respectively. Compared with a single application, a second application of the fungicides increased the average concentrations of residues left on the strawberries. Risk assessments of the four fungicides were conducted by comparing national estimated daily intakes against acceptable daily intakes under good agricultural practice conditions. With application at the recommended dosage, strawberries sprayed with pyraclostrobin, iprodione and tebuconazole were safe for consumption after two applications. By contrast, while the first application of cyprodinil was safe, the second presented a high health risk. Even at the recommended dosage (720 a. i. g ha-1), repeat applications of cyprodinil should be banned. 相似文献
92.
《Food Control》2017
Heavy metals can be accumulated by marine organisms thought a variety of pathways, including respiration, adsorption and ingestion. The levels of heavy metals are known to increase drastically in marine environment through mainly anthropogenic activities. Fish are good indicators for the long term monitoring of metal accumulation in the marine environment. The aim of this study was to determine the levels of Cd, As, Hg, Pb, Zn and Cu in edible part and gill of seven most consumed Bulgarian fish species collected from north-east coast of Black Sea. These fish species are sprat (Sprattus sprattus sulinus), Mediterranean horse mackerel (Trachurus mediterraneus ponticus), Black sea gobies (Neogobius melanostromus), shad (Alosa pontica), Atlantic bonito (Sarda sarda), bluefish (Pomatomus saltatrix) and grey mullet (Mugil cephalus). The fish samples were collected during 2010. The analytical determination of As, Cd, Pb, Zn and Cu were performed by using flame and graphite furnace atomic absorption spectrometry after microwave digestion procedure. The total mercury determination was determined using a direct mercury analyzer (DMA-80). The metal concentration of analyzed elements was highest in the gill for all fish species. The maximum metal concentration was measured for Cu (1.40 mg kg−1 w.w), Zn (11 mg kg−1 w.w) and Pb (0.08 mg kg−1 w.w) in muscle tissues of shad and sprat. The edible part of horse mackerel has the maximum value for Hg (0.12 mg kg−1 w.w) while Atlantic bonito predominantly accumulates As (1.10 mg kg−1 w.w). The analytical results obtained from this study were compared within acceptable limits for human consumption set by various health institutions. 相似文献
93.
《Food Control》2017
Tomatoes are important in human nutrition, as they are a source of carotenoids and phenolic compounds. However, transformation processes may alter the nutritional value of foods, decreasing the concentration of health-promoting compounds. This work aimed to explore the effects of industrial transformation on processed tomatoes (crushed pulp, puree and paste), as well as the effect of the different pre-processing technologies, rather than different manufacturing sites, in producing tomato paste. Results demonstrate that phenolics profiling can distinguish between different processed products as well as different paste pre-treatments (namely cold, warm and hot break), even though the latter underwent a final thermal treatment at >100 °C. Analogously, the different processing sites could be discriminated thanks to their characteristic phenolic fingerprint. The greatest differences identified were between conjugated forms of flavonoids, phenylpropanoids and lignans. The latter were the most labile phenolics, followed by flavonoids and then phenylpropanoids. Results provide evidence for the potential of phenolic fingerprint to support traceability of transformation processes and to investigate their effect on the nutritional value of processed tomatoes. 相似文献
94.
《Food Control》2017
Microbial fermentations have long represented a way of natural biopreservation of raw materials, which frequently originated new food products. Among them, traditionally fermented products still manufactured by native populations all around the world are source of lactic acid bacteria (LAB) strains with high biotechnological potential. LAB are food grade microorganisms and therefore a good alternative to chemicals to be applied in food preservation. A total of 130 LAB isolates recovered from “chicha” and “tocosh”, traditional fermented Andean products of vegetal origin, were screened for antimicrobial activities against spoiler fungi Meyerozyma guilliermondii CECT 1021 (synonym Pichia guilliermondii), Penicillium roqueforti CECT 2905NT, Aspergillus oryzae CECT 2094NT and Aspergillus niger CECT 2807 as well as against foodborne pathogens Escherichia coli O157:H7 CECT 5947, Listeria innocua CECT 910T and Salmonella enterica subsp. enterica serovar Typhi CECT 4138. LAB isolates represented nine species and four genera that exhibited a general inhibition of food pathogens and were also active against A. oryzae and M. guilliermondii while a poor inhibition of A. niger and P. roqueforti was produced. Antifungal activity of cell free supernatants (CFS) from seven selected strains grown in MRS was confirmed against toxigenic fungi Aspergillus parasiticus CECT 2681, Penicillium expansum CECT 2278 and Fusarium verticilloides CECT 2987 and also on the three foodborne bacteria included in the study. Phenyllactic and 3,5-Di-O-caffeoylquinic acids were identified as the predominant bioactive compounds in CFS by QuEChERS extraction with LC-MS-LIT detection approach. Four out of seven strains free of antibiotic resistances involving L. plantarum M5MA1 and M9MM1 from chicha and L. fermentum T3M3 and Lc. mesenteroides T1M3 from tocosh showed high potential to be used as biopreservatives in food applications. 相似文献
95.
《Food Control》2017
A novel sea water disinfection process to complement and improve the microbial depuration of clams (Ruditapes philippinarum) was tested by employing a potassium peroxymonosulfate (MPS)-based product. A broad and multidisciplinary approach was used to achieve a quite complete pattern of the potential suitability of this innovative MPS-based disinfectant treatment to improve the microbiological quality of cultured Manila clams. The biocidal activity was evaluated against the Vibrio spp. population naturally associated with sea water and against viral nervous necrosis virus (VNNV), genus Betanodavirus, the most threatening among the viral pathogens of marine finfish.The novel depuration process by sea water potassium MPS-based disinfection set up and tested in the present study (1000 ppm disinfectant for 3 h) greatly reduced the tested bacteria and viruses in the sea water column, being able to counteract the restarting of microorganisms during the depuration process. Furthermore, the microbiological quality of harvested clams with respect to their Vibrio spp. load improved after the 1000 ppm disinfectant 3 h treatment. The potential use of this treatment was strengthened by the absence of effects on clam health and welfare. This issue was assessed by direct observation as indicated by Regulation EC 853/2004, and by the unaltered biochemical parameters, cortisol level and histological pattern. The absence of undesired side-effects and surfactant residues in the edible flesh was also ascertained. The whole of data suggests that the proposed treatment may potentially represent an innovative strategy to face, in a quite easy and feasible way, still unresolved matter of concern in clam commercialization. However, further studies are required to check if the 3 h treatment positive effect on clams is preserved during the subsequent out of water maintenance. 相似文献
96.
97.
《Food Control》2016
The effect of carboxylic acids, composed by both organic and phenolic acids, released in a barley malt substrate fermented by lactic acid bacteria was tested against Fusarium culmorum macroconidia and compared under different fermentation conditions. Phenolic acids released by Lactobacillus plantarum FST1.7 and Lactobacillus brevis R2Δ were quantified using a QuEChERS method coupled with a HPLC-UV/PDA system. Their concentration improved with increasing extract content of the barley malt-based substrate and reached maximal concentrations after 48 h of fermentation performed at optimum growth temperature. Generally, phenolic acids were produced at levels far below their minimal inhibitory concentration (MIC), and limited synergistic effects were observed when mixed with organic acids. The fungal growth suppression by the wort fermented by Lb. brevis R2Δ (95 ± 9 h total inhibition) could be fully explained by the presence of antifungal carboxylic acids, whereas only partially accounted for Lb. plantarum FST1.7 (198 ± 19 h). Organic acids were mainly responsible for the ability of LAB fermented wort to cause fungal inhibition, whereas phenolic acids took only a secondary role at the low concentrations released. Longer fermentation times favoured primarily organic acid release, whereas fermentation of higher malt extract substrates encouraged both organic and phenolic acids production. The understanding on how synergy works between antifungal compounds could help to identify strategies to further increase their concentration in wort, with potential to replace synthetic broths and for direct application in food application. 相似文献
98.
99.
本文介绍了非本征硅红外探测器工作机理,叙述了4×4面阵探测器的设计和研制中的要点,给出了4×4掺铟硅CID阵列的部分性能参数。在79K温度下,探测元的D值为(1～4)×108cm~(1/2)W~(-1)。 相似文献
100.
Anna Russo Serafina Caputo Manuela Pantusa Enzo Perri Giovanni Sindona Luigi Sportelli 《Food chemistry》2010
Antioxidant activity is displayed by amino acids, such as tryptophan (Trp), tyrosine (Tyr) and histidine (His) in the spontaneous oxidation of linoleic acid (LA). In addition, when Trp was incubated with soybean lipoxygenase (LOX 1) and LA, a modulating effect was observed. The elucidation of the reaction pathways was achieved through the identification, by electron spin resonance (ESR) spectroscopy, of α-[4-pyridyl 1-oxide]-N-t-butyl nitrone (POBN) adducts with the selected amino acids. The latter, when electrosprayed (ESI) were detected in the gas-phase as radical cations. They were structurally characterized by tandem mass spectrometry (MS/MS) through collision-induced dissociation (CID) of the adducts. The kinetic data obtained from selected model systems suggested a reversible radical scavenging activity of tryptophan on the intermediate dienyl radical formed in the lipids lipoxygenase cascade. 相似文献