Improving the yield of Jatropha curcas's FAME through sol–gel derived meso-porous hydrotalcites

The conversion of fatty acid methyl ester (FAME) from triglycerides using heterogeneous catalysis has gained increasing interest due to the prospect of increased yield at reduced operating costs and reaction conditions. In this paper, meso-porous hydrotalcite was used to catalyze jatropha oil into FAME with relatively higher yield at atmospheric pressure and relatively low reaction temperature. The molar ratio of methanol to oil required was relatively low and the conversion was completed within few hours of reaction time. The reaction was promoted when moderate calcination temperature was applied, the disordered structure of the catalyst was maintained, counterbalance anions was removed, and phase transitions within the oxide lattice was induced. Despite the observed deactivation during successive reaction cycles due to adsorption of residual triglycerides, the catalyst performance was restored effectively by air-re-calcination.     

A critical review of soil moisture measurement

Soil moisture content has paramount importance in dictating engineering, agronomic, geological, ecological, biological and hydrological characteristics of the soil mass. Though earlier researchers have employed various techniques of moisture content determination of soils, both in laboratory and in situ conditions, ascertaining the applicability of these techniques to soils of entirely different characteristics and the ‘types of moisture content’, which they can measure, is still a point of debate. As such, a critical review of all the established and emerging soil moisture measurement techniques with respect to their merits and demerits becomes necessary. With this in view, efforts have been made in this paper to critically evaluate all the soil moisture measurement techniques, limitations associated with them and the influence of various soil-specific parameters (viz., mineralogy, salinity, porosity, ambient temperature, presence of the organic matter and matrix structure of the soil) on the measured soil moisture content. This paper also highlights the importance of various innovations based on Micro Electro Mechanical Systems (MEMS) and nano-sensors that are emerging in this context.     

Diversity of Bacillus cereus strains in extended shelf life

Characterisation of 49 Bacillus cereus strains obtained from extended shelf life (ESL) milk and filler nozzles was done using (GTG)₅ rep PCR fingerprinting, determining the presence of the virulence genes cytK, nheA, cer and hblA, and discrimination of psychrotrophic and mesophilic strains with 16S rDNA. Fourteen isolates were selected for 16S partial sequencing. Fingerprinting and sequencing showed evidence of filler nozzles contaminating ESL milk despite high heterogeneity existing between the isolates. While there is high prevalence of cer, hblA and nheA; cytK was not widely distributed. There was 100% and 8% prevalence of mesophilic and psychrotrophic signatures, respectively. Despite the large diversity of the B. cereus strains in this study, there is evidence that filler nozzles and raw milk are a source of contamination of B. cereus in ESL milk.     

Helicase-dependent amplification is effective in distinguishing Asian ginseng from American ginseng

This study describes for the first time the application of helicase-dependent amplification (HDA) to authenticate botanical species and processed products. Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius) are consumed worldwide as functional food and health remedies. The two herbs share similar morphological appearance but have different pharmacological effects. In this work, a novel isothermal amplification mediated DNA method was applied to authenticate the two ginseng species. Internal control and P. ginseng specific primers were designed based on the ribosomal external transcribed spacer (ETS) region. The amplification results were confirmed by real-time monitoring, gel electrophoresis and DNA sequencing. The screened retail samples included dried ginseng root, ginseng powder, ginseng tea granules as well as a four-herb formulation. Our HDA protocol worked well on both purified DNA and crude water extract. In conclusion, HDA is a highly sensitive and specific approach for differentiating Asian ginseng from American ginseng and it has the potential for on-site authentication of herbal products.     

Development and validation of a scale to capture social desirability in food safety culture

The evaluation of food safety culture in a food company is influenced by human factors such as employees' tendency to respond to social desirability – a reflection of respondents' tendency to answer questions in a manner that will be viewed favorably by others. Building on previous research a self-assessment scale consisting of 18-statements (FSDRS) was developed to capture desirable responding in food safety. Statistical analyses of data collected from 816 North-American food manufacturing professionals revealed that a shortened 14-item version of the FSDRS scale provides a reliable and valid measurement of the extent to which employees deceive themselves. It is concluded that the proposed FSDRS will enrich food safety culture measurement and food safety performance.     

Identification and characterisation of steel corrosion using passive high frequency RFID sensors

High frequency RFID sensors are attractive in diverse applications where sensor performance is required at a low cost and dimension restriction. An approach adapting commercial passive 13.56 MHz RFID tags has been developed for sensing corrosion stage. This investigation includes balance of sensing and positioning of RFID sensors for corrosion detection by analysing real and imaginary parts of the complex impedance. With passive HF RFID sensors, real part and imaginary part of complex impedance have been extracted from the reader coil with VNA (vector network analyser) and delivering a unique capability for corrosion sensing with different atmospheric exposure time steel samples (1 month, 6 months, 10 months and 12 months). With different positioning (5–25 mm), features extraction based on the complex impedance with PCA (principal component analysis) has been designed for position-independent corrosion evaluation.     

Energy needs for Morocco 2030, as obtained from GDP-energy and GDP-energy intensity correlations

We present forecasts of the energy consumption of Morocco towards 2030. Two models have been developed and their results compared: one based on the energy intensity (IE) and another one on a link with the country urbanization rate (URB). The IE model allowed to segment energy consumption in four posts while the URB model only in two posts. For the sensitivity analysis to economic growth, three future GDP evolution scenarios are proposed. The retrospective correlations of both models are excellent but their future extrapolations finish in slightly different results. Through their correlation to electricity consumption, peak power forecasts are also presented. A forecast of the country energy intensity is commented. As the average yearly increase of electricity should still be between 4.9% and 7.1% during 2020–2030, the electric equipment program continuation after 2020 must soon be clarified and avoid the former implementation delays. As the white combustibles needs should yearly increase between 6.3% and 7.8% in 2020–2030, electrical equipment programs should also make provisions for the case of deployment of electric cars. Butane subsidies widen the gap with other fuels and must be removed very soon possible to reduce the growth of its consumption and energy intensity.     

Determination of organochlorine pesticides in shrimp by gas chromatography–mass spectrometry using a modified QuEChERS approach

Pacific white shrimp (Litopenaeus vannamei) collected during dry and rainy seasons from three different states in Malaysia were analyzed for nine organochlorine pesticides (OCPs) (α-HCH, β-HCH, γ-HCH, δ-HCH, trans-chlordane, cis-chlordane, p,p′-DDE, p,p′-DDD and p,p′-DDT) using QuEChERS sample preparation method and GC–MS SIM with split/splitless injection mode. The efficiency of combination of primary and secondary amine (PSA) and octadecyl (C18) at 25 mg of PSA and 25 mg of C18 per mL of shrimp extract as the clean-up sorbent to remove matrix interferences was evaluated. By combining PSA and C18, matrix interferences such as gamma-tocopherol and cholesterol were not able to be eliminated. Good separation and high recoveries which ranged from 90 to 105% with associated RSD < 15% were obtained for all OCPs at 3–75 ng/g. No significant difference in recoveries due to seasonal variation for studied OCPs, except for α-HCH, β-HCH, δ-HCH and p,p′-DDT were obtained. The limits of detection and quantification ranged from 0.3 to 4.5 ng/g and 3 to 15 ng/g, respectively. The linearity for matrix matched standard calibrations was >0.99.     

Influence of pre-treatments on yield,chemical composition and antioxidant activity of Satureja montana extracts obtained by supercritical carbon dioxide

Main objective of this work was to investigate the influence of pre-treatments of Satureja montana herbal material on supercritical extraction process, in terms: influence on extraction yield, composition and antioxidant activity of extracts. Four different pretreatments were investigated: water pre-treatment, ethanol pre-treatment, ultrasound and high pressure pre-treatment. Extraction yields were in the range from 1.68 to 2.35 g/100 g. Pre-treatments with water and ethanol increase the yield of extraction for 25% and 17%, respectively. According to GC/MS results the main compound of obtained extracts was carvacrol. Analyses confirmed that carvacrol content in extracts can be significantly increased by application of pre-treatments. Ultrasound pre-treatment and high pressure pre-treatment yielded highest concentration of carvacrol in extracts (around 66%). Using these two pre-treatments of herbal material, concentration of carvacrol, in extracts obtained by supercritical carbon dioxide extraction, could be increased for around 25%. Antioxidant activity of all extract was very high and in the range of well-known antioxidants.