Fatty acid composition and characteristics of Pentadesma butyracea fat extracted from ghana seeds

Recent interest in the development of the tallow tree (Pentadesma butyracea S) as an oil-tree crop has stimulated agronomic and chemical studies of the tree and the fat obtained from its seeds. Tallow fat extracted from local seeds has been analysed for its chemical and physical constants and fatty acid composition. These characteristics have been compared with those of the better known cocoa butter and shea butter. Dry tallow kernels, shea butter kernels and cocoa beans contained 50, 52.1 and 53.4% fat, respectively. Tallow fat and shea butter are similar in several of their characteristics, particularly slip point, saponification number, solidification point and fatty acid composition; but tallow fat has a much lower unsaponifiable matter content (1.5–1.8%) than shea butter (7.3–9.0%). Both are markedly different from cocoa butter and cocoa butter replacement fats in respect of their melting points and fatty acid composition. Cooling curves of 3:1, 1:1, and 1:3 mixtures of tallow fat and cocoa butter indicate poor compatibility between the two fats.     

Keep the conversations going: engagement-based customer segmentation on online social service platforms

Most businesses and organizations develop online services as a value-added offering, which is a significant revenue stream from their existing user base. Such services may be enhanced with social elements to serve as value-added tools for user attraction and retention. Social elements may allow users to post content, share information and directly interact with each other. Investments in these social features are for naught if they do not encourage users to engage on the platform effectively. However, common ways to segment customers by their engagement is hindered by the statistical nature of behavioral data based on social elements. To address this important concern, this paper presents a methodological framework for engagement-based customer segmentation able to appropriately consider signals from social elements. It argues why the traditional approaches for user segmentation is ill-suited and advocates for the integration of kernel functions with clustering to segment, identify and understand user engagement profiles. The framework is demonstrated with real data from a large, very active OSS.     

Laser dissimilar welding of CoCrFeMnNi-high entropy alloy and duplex stainless steel

High entropy alloys(HEAs)have superior mechanical properties that have enabled them to be used as structural materials in nuclear and aerospace applications.As a dissimilar joint design is required for these applications,we created a dissimilar joint between CoCrFeMnNi-HEA and duplex stainless steel(DSS)through laser beam welding;a technique capable of producing a sound joint between the two materials.Microstructure examination using SEM/EBSD/XRD analysis revealed that the weld metal(WM)exhibits an FCC phase regardless of the postweld heat treatment(PWHT)temperature(800 and 1000℃)without forming detrimental intermetallic compounds or microsegregation.The heat-affected zone of the CoCrFeMnNi-HEA showed CrMn oxide inclusions while that of the DSS showed no inclusions.Moreover,a lower hardness was recorded by the WM compared to the base metal after welding.After PWHT,the hardness of the WM,CoCrFeMnNi-HEA,and DSS decreased with an increase in the PWHT temperature.However,the decrease in the hardness of the HEA was more significant than in the WM and DSS.The cause for this reduction in hardness was attributed to recrystallization and grain growth.In addition,a strength of 584 MPa with low ductility was recorded after welding.The obtained strength was lower than that of the BMs,but comparable to that of the welded CoCrFeMnNi-HEA.The application of PWHT resulted in over a 20％increment in ductility,with only a marginal reduction in strength.The deformation mechanism in the as-weld joint was mainly dominated by dislocation while that for the PWHT joint was twinning.We propose laser beam offset welding as a technique to improve the mechanical properties of the dissimilar joint,which will be the subject of future studies.     

Increase in rice grain arsenic for regions of Bangladesh irrigating paddies with elevated arsenic in groundwaters

Concern has been raised by Bangladeshi and international scientists about elevated levels of arsenic in Bengali food, particularly in rice grain. This is the first inclusive food market-basket survey from Bangladesh, which addresses the speciation and concentration of arsenic in rice, vegetables, pulses, and spices. Three hundred thirty aman and boro rice, 94 vegetables, and 50 pulse and spice samples were analyzed for total arsenic, using inductivity coupled plasma mass spectrometry (ICP-MS). The districts with the highest mean arsenic rice grain levels were all from southwestern Bangladesh: Faridpur (boro) 0.51 > Satkhira (boro) 0.38 > Satkhira (aman) 0.36 > Chuadanga (boro) 0.32 > Meherpur (boro) 0.29 microg As g(-1). The vast majority of food ingested arsenic in Bangladesh diets was found to be inorganic; with the predominant species detected in Bangladesh rice being arsenite (AsIII) or arsenate (AsV) with dimethyl arsinic acid (DMAV) being a minor component. Vegetables, pulses, and spices are less important to total arsenic intake than water and rice. Predicted inorganic arsenic intake from rice is modeled with the equivalent intake from drinking water for a typical Bangladesh diet. Daily consumption of rice with a total arsenic level of 0.08 microg As g(-1) would be equivalent to a drinking water arsenic level of 10 microg L(-1).     

Acidification,proteolysis and flavour potential in fermenting cocoa beans

Cocoa fermentations in Ghana and Trinidad as well as anaerobic fermentation-like incubations of fresh cocoa beans in Germany were carried out under controlled conditions. Samples of beans were taken during the course of these treatments and determinations were made as to acidification (pH, acetic acid content), proteolysis (free α-amino nitrogen, peptide nitrogen and SDS electrophoresis of the protein peptides) and flavour potential (gas chromatography of the highly volatile compounds, in particular isopentanal and organoleptic analysis after thin layer roasting). A positive correlation between acidification, proteolysis and the development of flavour potential during anaerobic fermentation can be demonstrated in principle. However, the flavour potential is increased if the temperature rise is comparatively slow in both normal fermentation and laboratory incubation. Strong acidification and high accumulation of amino acids and peptides were not essential for a good flavour potential. The isopentanal content proved to be a useful indicator of the progress of normal fermentation in the tropics. These findings can be interpreted on the basis of earlier results about germination-like processes in the protein vacuoles, pre- and post-mortem subcellular structures and the special characteristics of acetic acid diffusion. Conclusions which are relevant to the practice of cocoa fermentation are discussed in more detail.