Color and thiobarbituric acid values of cooked top sirloin steaks packaged in modified atmospheres of 80% oxygen, or 0.4% carbon monoxide, or vacuum

Case-ready fresh beef is typically packaged in a modified-atmosphere with approximately 80% oxygen and 20% carbon dioxide. Recently, USDA approved distribution of fresh meats in a master bag system using 0.4% carbon monoxide (CO). This study compared effects of packaging system (vacuum, 80% oxygen, 0.4% carbon monoxide), fresh meat storage time (7-21 days) and cooking temperature (49-79 °C) on extent of myoglobin denaturation, color and rancidity in cooked top sirloin steaks. Steaks packaged in 80% oxygen or CO retained desirable red color for 14 and 21 days storage, respectively. Steaks stored in 80% oxygen exhibited the greatest TBA values and myoglobin denaturation at all storage times and cooking temperatures. Steaks stored in high oxygen developed brown interior color at internal temperatures as low as 57 °C, the premature browning effect. Premature browning and rancidity associated with steaks packaged in 80% oxygen was prevented by packaging in 0.4% CO or vacuum.     

Comparison of different extraction methods for the extraction of major bioactive flavonoid compounds from spearmint (Mentha spicata L.) leaves

Different bioactive flavonoid compounds including catechin, epicatechin, rutin, myricetin, luteolin, apigenin and naringenin were obtained from spearmint (Mentha spicata L.) leaves by using conventional soxhlet extraction (CSE) and supercritical carbon dioxide (SC-CO₂) extraction at different extraction schemes and parameters. The effect of different parameters such as temperature (40, 50 and 60 °C), pressure (100, 200 and 300 bar) and dynamic extraction time (30, 60 and 90 min) on the supercritical carbon dioxide (SC-CO₂) extraction of spearmint flavonoids was investigated using full factorial arrangement in a completely randomized design (CRD). The extracts of spearmint leaves obtained by CSE and optimal SC-CO₂ extraction conditions were further analyzed by high performance liquid chromatography (HPLC) to identify and quantify major bioactive flavonoid compounds profile. Comparable results were obtained by optimum SC-CO₂ extraction condition (60 °C, 200 bar, 60 min) and 70% ethanol soxhlet extraction. As revealed by the results, soxhlet extraction had a higher crude extract yield (257.67 mg/g) comparing to the SC-CO₂ extraction (60.57 mg/g). Supercritical carbon dioxide extract (optimum condition) was found to have more main flavonoid compounds (seven bioactive flavonoids) with high concentration comparing to the 70% ethanol soxhlet extraction (five bioactive flavonoids). Therefore, SC-CO₂ extraction is considered as an alternative process compared to the CSE for obtaining the bioactive flavonoid compounds with high concentration from spearmint leaves.     

Leveraging agriculture to improve nutrition in the Philippines

The typical Filipino diet mainly consists of rice, fish and vegetables, with rice being the greatest source of calories. The consumption of a maize, starchy roots and tubers as rice substitutes or supplements, and vegetables and fruits has generally declined, while the consumption of fats, oils and meats has increased. Stunting is the most prevalent form of malnutrition among Filipinos. Vitamin A Deficiency, Iodine Deficiency Disorder, and Iron Deficiency Anemia remain public health problems for children and pregnant and lactating women. The link between nutrition and agriculture in the Philippines has focused on leveraging agriculture to improve nutrition. The programs that had been initiated by the government, NGO/CSO or private sector were conceptualized and implemented before the elements of a nutrition-sensitive agriculture framework were identified. These programs were implemented to address food production and the nutritional needs of individuals, families, and communities only with reference to nutrition security. Many of these programs have been successful as they implemented best practices that could be applied to forge a superior approach that optimizes the agriculture-nutrition nexus. This study identified these best practices or elements of success. The elements that have been noted as reasons for the success of some of these programs are: presence of strong political will and enabling policy environment; forging of new forms of partnerships, strategic collaboration, sound coordination and structures; exploiting the best that science and technology could offer; democratizing community participation; strong capacity building component and access to reliable technical expertise; knowledge and sensitivity to local cultures, beliefs and practices; professionalized promotion and ‘messaging’; use of catchy terms for easy recall; availability of sustainable funding; use of the life cycle approach in nutrition; holistic community nutrition perspective; practice and promotion of biodiversity-based agricultural production system; and control of the means of production.     

Germanium-diffused waveguides in silicon for λ=1.3 μm andλ=1.55 μm with losses below 0.5 dB/cm

The authors present a simple technique for the fabrication of integrated optical channel waveguides that are prepared by indiffusion of an E-beam evaporated amorphous alloy of germanium and silicon into commercially available silicon with low dopant concentration, using only simple technological processes such as standard lithography, PVD, and diffusion. The waveguides are polarization independent and have waveguide losses as low as 0.3 dB/cm at wavelengths of λ=1.3 μm and λ=1.55 μm. The spot sizes are well suited for low-loss single-mode fiber device coupling, being on the order of a few microns in both horizontal and vertical directions     

Patterns of Phytochemical Variation in Mimulus guttatus (Yellow Monkeyflower)

The search for general patterns in the production and allocation of plant defense traits will be facilitated by characterizing multivariate suites of defense, as well as by studying additional plant taxa, particularly those with available genomic resources. Here, we investigated patterns of genetic variation in phytochemical defenses (phenylpropanoid glycosides, PPGs) in Mimulus guttatus (yellow monkeyflower). We grew plants derived from several natural populations, consisting of multiple full-sibling families within each population, in a common greenhouse environment. We found substantial variation in the constitutive multivariate PPG phenotype and in constitutive levels of individual phytochemicals within plants (among leaves of different ages), within populations (among full-sibling families), and among populations. Populations consisting of annual plants generally, but not always, had lower concentrations of phytochemicals than did populations of perennial plants. Populations differed in their plastic response to artificial herbivory, both in the overall multivariate PPG phenotype and in the individual phytochemicals. The relationship between phytochemistry and another defense trait, trichomes, differed among populations. Finally, we demonstrated that one of the PPGs, verbascoside, acts as a feeding stimulant rather than a feeding deterrent for a specialist herbivore of M. guttatus, the buckeye caterpillar (Junonia coenia Nymphalidae). Given its available genetic resources, numerous, easily accessible natural populations, and patterns of genetic variation highlighted in this research, M. guttatus provides an ideal model system in which to test ecological and evolutionary theories of plant-herbivore interactions.     

Meta-analyses of safety data: a comparison of exact versus asymptotic methods

The objectives of this study were to establish and describe a database of Cochrane and non-Cochrane meta-analyses of safety data and to determine under what conditions exact methods differ from asymptotic methods in meta-analyses of safety data. A sample of Cochrane (n = 500) and non-Cochrane (n = 200) systematic reviews was randomly selected and a database of safety meta-analyses established. Point estimates and confidence intervals for each meta-analysis were recalculated using exact methods and compared to the results of asymptotic methods. Cochrane reviews were nearly four times as likely as non-Cochrane reviews to contain meta-analyses of safety data (35% compared to 9%). More than 50% of safety meta-analyses contained an outcome with a rare event rate (<5%) and 30% contained at least one study with no events in one arm of the study. For rare event meta-analyses, exact point estimates differed substantially from asymptotic estimates 46% of the time, compared to 17% for those without rare events. Exact confidence intervals differed substantially from asymptotic ones 67% of the time compared to only 19% for those without rare events. The magnitude of differences was also correlated with the number of studies and the summary statistic used to combine the data. Asymptotic methods will not always be a good approximation for exact methods in safety meta-analyses. Event rates and number of studies should be closely examined when choosing the statistical method for combining rare event data.     

The use of the DR CALUX bioassay and indicator polychlorinated biphenyls for screening of elevated levels of dioxins and dioxin-like polychlorinated biphenyls in eel

The DR CALUX bioassay is a very suitable screening method for dioxins and dioxin-like-PCBs in feed and food. This was, e. g. demonstrated in a survey in the Netherlands to control the dioxin levels in eel. The DR CALUX assay, but also indicator polychlorinated biphenyls (PCB) were evaluated as a screening method. Based on the limit for polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/F) [at that time 8 pg toxic equivalents (TEQ)/g eel], and the relation between PCDD/F and dioxin-like-PCB, a decision limit of 30 pg TEQ/g eel was used for screening of 153 field samples. Suspected samples (21) and part of the higher contaminated negative samples (35) were analyzed by GC/MS for dioxins, non-ortho, mono-ortho and indicator PCB, revealing 13 samples exceeding the action limit of 30 pg TEQ/g eel. Only one sample slightly exceeded the dioxin level of 8 pg TEQ/g eel. The relatively low sensitivity for mono-ortho PCB was overcome by the use of reference samples, as shown by the correlation of 0.93 between GC/MS and CALUX determined total TEQ levels. The present data show that the DR CALUX assay can be used for screening of total TEQ levels in eel. The use for dioxins only requires a safe, and therefore relatively low, decision limit. The indicator PCB also showed a good correlation with total TEQ levels, mainly due to the large contribution of the mono-ortho PCB at higher concentrations. The relation with dioxins was very poor and as such indicator PCB seem less suitable than the DR CALUX assay for screening for dioxins only. The present study clearly shows that part of the wild eel samples contains high total TEQ levels and will exceed the future European Union limit of 12 pg TEQ/g eel for dioxins and dioxin-like PCB. Especially at high TEQ levels, dioxin-like PCB contribute most to the total TEQ. In practice, wild eel presents only a minor part of the eel consumed.     

Comparison of optical waveguide losses in silicon-on-insulator

Waveguide losses in SOI (silicon-on-insulator) material fabricated by different techniques are compared thus enabling one to confirm the theoretical dependence of losses on layer thickness. Single-mode waveguide losses in BE-SOI (bond and etchback-SOI) below 0.5dB/cm are reported for waveguides with cross-sections of several square micrometres.<>