64 research outputs found
The effect of feeding rosemary, oregano, saffron and α-tocopheryl acetate on hen performance and oxidative stability of eggs
In this study the effects of feeding rosemary, oregano, saffron and α-tocopheryl acetate on hen performance and egg quality were investigated. One hundred-twenty Lohmann laying hens, 32 weeks old, were divided into five groups replicated four times with six hens per replicate. One group was given a basal diet and served as control (CON). The experimental diets given to the other four groups were based on the basal diet but contained an additional 200 mg α-tocopheryl acetate/kg (TOC), or rosemary at 5 g/kg diet (ROS), oregano at 5 g/kg diet (ORE) or saffron at 20 mg/kg diet (SAF). At the end of the feeding trial that lasted 56 days, hen performance and some egg quality characteristics were determined, whereas the oxidative stability of the refrigerated stored shell eggs and liquid yolks were also examined. Results showed no significant differences in egg production, feed intake, feed conversion ratio, egg weight and shape, yolk shape, Haugh units and shell thickness among treatments. However, yolk colour was significantly improved in the SAF group compared to all other groups. The extent of lipid oxidation in shell eggs differed among the dietary treatments, but did not change with storage time. In liquid yolk at pH 6.2, lipid oxidation was higher in the CON group compared to all other groups. The ORE group presented lower oxidation rate than the ROS group, but higher than the SAF group, which in turn exhibited higher oxidation rate than the TOC group. When liquid yolk was acidified to pH 4.2, the lipid oxidation profile remained unchanged but the rate was much more intense. Keywords: Rosemary; oregano; saffron; α-tocopherol acetate;egg quality; hen performance; oxidative stability South African Journal of Animal Sciences Vol. 35 (3) 2005: pp.143-15
Marginal discoloration of all-ceramic restorations cemented adhesively versus nonadhesively
BACKGROUND: The authors conducted a systematic review to correlate the clinical incidence of marginal discoloration of all-ceramic restorations with the mode of cementation (adhesive versus nonadhesive). TYPES OF STUDIES REVIEWED: The authors conducted a literature search by using electronic databases, relevant references, database citations and journal hand searches for clinical studies of marginal discoloration of all-ceramic restorations with a mean follow-up time of at least five years. The search period spanned January 1990 through February 2011. The authors reported and compared summary estimates and five-year event rates. RESULTS: The authors selected 16 studies for final analysis from an initial yield of 346 articles. The mean observation time ranged between five and 10 years. The majority of studies used adhesive luting procedures for definitive cementation. In only one study did investigators report regarding the incidence of marginal discoloration of both adhesively and nonadhesively cemented all-ceramic restorations, and the difference between the luting types in terms of discoloration was not statistically significant (P = .5). CLINICAL IMPLICATIONS: The results of this systematic review showed that there is a lack of studies with findings regarding marginal discoloration rates of nonadhesively luted all-ceramic restorations. Unacceptable marginal discoloration rates of adhesively luted all-ceramic prostheses were relatively low even at 10 years of service
Bonding indirect resin composites to metal: Part 1. Comparison of shear bond strengths between different metal-resin bonding systems and a metal-ceramic system
PURPOSE: This laboratory study compared the shear bond strength between three indirect resin composites and a noble alloy using their respective bonding systems. MATERIALS AND METHODS: One hundred twenty disks cast in a medium-gold, high-noble metal-ceramic alloy (V-Deltaloy) were divided equally into four groups and received different treatments for veneering: Conventional feldspathic porcelain (Omega) was applied on one set of specimens to be used as a control, and three indirect resin composites (Artglass, Sculpture, Targis) with their respective bonding systems were used for the other groups. The specimens were tested in a parallel shear test, half of them after 24-hour dry storage at room temperature and the rest after 10-day storage in normal saline solution at 37 degrees C and thermocycling. The fractured specimens were evaluated to determine the nature of the failure. RESULTS: The mean shear bond strength values (in MPa), before and after wet storage and thermocycling, were 30 and 23 for the metal-ceramic group, 29 and 23 for the Artglass group, 20 and 19 for the Sculpture group, and 17 and 14 for the Targis group, respectively. The metal-ceramic and Artglass groups exhibited significantly higher bond strengths than the other two groups. All specimens, with the exception of the Sculpture group, showed a significant decrease in bond strength after wet storage and thermocycling. CONCLUSION: No group exceeded the shear bond strength of the metal-ceramic group, but the Artglass group with its respective metal-resin bonding system exhibited similar bond strengths. The Sculpture group showed a stable bond after water storage and thermocycling
Multianalyte analysis of volatile compounds in virgin olive oils using SPME-GC with FID or MS detection: results of an international interlaboratory validation
The organoleptic assessment (Panel test) is the only procedure within the official methods for determining the quality of virgin olive oils that involves an expert panel. There is an urgent need for analytical methodology that can reliably measure volatile compounds in virgin olive oils that is capable of supporting and anticipating the official Panel test. For this reason, a new method based on solid-phase microextraction–gas chromatography with the choice of two possible detectors (FID or MS) was subjected to a large international interlaboratory validation study. The study involved a two-stage process: first, a pretrial phase in which 7 participants were exposed to the method for the first time to identify any initial problems with the methodology; then, a formal validation stage (trial proper), which involved 20 laboratories from Europe, USA, Japan and China. The performance of the different detectors was investigated. While both methods have advantages, the method using FID provided better results for 11 compounds, in terms of reproducibility, compared to MS. This information will allow to implement the method with accurate information of the method performance depending on the detector used. Practical applications: This study provides information from an interlaboratory validation of a method for measuring volatile compounds in virgin olive oils conducted with laboratories (from industry and academia) working in the olive oil sector. The information on the expected analytical errors in the determination of each volatile compound is necessary to apply this method for supporting the official Panel test (sensory analysis). The SPME-GC-MS/FID methods proposed in this work can be used for the internal quality control of a company/distributor/quality control laboratory and could also be used in cases of difficult/contradictory organoleptic assessment, or to confirm results from sensory panels in cases of disputes/disagreement (Reg. EU 2022/2105)
Evaluation of the effectiveness of ozone as a sanitizer for fish experimentally contaminated with Salmonella sp.
Evaluation of volatile profiles obtained for minimally-processed pineapple fruit samples during storage by headspace-solid phase microextraction gas chromatography-mass spectrometry
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