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Determination of optimum condition of leucine content in beef protein hydrolysate using response surface methodology
No full textProducing Defatted Hybrid Catfish with High Protease Activity Via Optimization of Sc-CO2 Extraction Process
Get PDFFish viscera is a great source for recovering polyunsaturated fatty acids (PUFAs), proteins and digestive enzymes. However, the presence of lipids in fish viscera reduces the efficiency of extracting, isolating and purifying the enzymes. Supercritical carbon dioxide (Sc-CO2), a green solvent, is useful in substituting organic solvent defatting process. Sc-CO2 helps to remove the lipid in the viscera with minimal denaturing of the proteins and enzymes found in the defatted sample. The viscera of hybrid catfish (C. gariepinus × C. macrocephalus) in this study were defatted by the Sc-CO2 extraction process. The protease was then, extracted from the defatted viscera. This study aimed to optimize the pressure and temperature of Sc-CO2 in the defatted viscera. The optimization of Sc-CO2 parameters was based on the Central Composite Design (CCD) of Response Surface Methodology (RSM). Optimum points were observed within the variables of pressure (P): 17-25 MPa and temperature (T): 39-43 °C with constant CO2 flow rate (F) and extraction time (text) at 25 g/min and 30 min, respectively. The response variables were executed on the amount of fat residue and protease specific activity in the defatted viscera. The optimum Sc-CO2 parameters were found to be at P: 18.17 MPa and T: 41.33 °C with the highest protease activity of 77.51 U/mg and fat residue of 71.17 %. The coefficient of determination (R2) for protease specific activity and fat residue was 90.27% and 93.03%, respectively. The differences between the verification and predicted values for both responses were less than 5%. Hence, the feasible optimum condition to produce a defatted sample with high specific activity at relatively low fat residue as predicted by the RSM in MINITAB statistical software version 16 was acceptable. Nevertheless, the ability of Sc-CO2 to defat the sample with minimal denaturing proteins and enzymes highlights the usefulness of this technology in substituting other organic solvents for the defatting process
Physico-chemical properties of pineapple peel extract and its application to isolate leucine from beef / Siti Roha Ab. Mutalib
Get PDFDuring canning and juice processing of pineapple, pineapple peel usually discharged. Discharged of pineapple peel during these productions will produce waste and lead to serious environmental pollution. In industrial practices, pineapple waste is either used as animal feed or disposed to the soil as waste. Pineapple peel contain valuable natural enzyme which is bromelain. Bromelain is enzyme which believed to have many benefits and very promising to the development of food and pharmaceutical industries. The purpose of this study is to isolate leucine from beef by using purified bromelain from pineapple peel extract. Purified bromelain powder from pineapple peel was produced through purification process. These include extraction from pineapple peel using purified water as a medium extraction, purification by cation exchange chromatography, desalting using continuous diafiltrator and followed by freeze drying. Each step was found to produce different effect on bromelain activity, protein content, specific enzyme activity and purification level. It was found that bromelain extracted from 100g of pineapple peel could yield 1.0g of bromelain powder. The amino acid composition in 14 beef cuts was also determined in this study. The flank cut was found to contain significantly higher amount of leucine amongst the beef cuts. The enzymatic hydrolysis was done with bromelain enzyme as a substrate to produce beef protein hydrolysate with higher content of leucine. The optimisation condition for the isolation of leucine was found with bromelain concentration of 1.380/0, hydrolysis temperature of 42.5°C and hydrolysis time of 31.59 hours. The isolation of leucine was done by cation exchange chromatography and followed by freeze drying to obtain leucine powder. The leucine produce are as crystalline solid form, clean and white deposit. This leucine powder was used to determine the secretion of insulin in plasma of male Sprague-Dawley rats. It was found that the mean plasma insulin concentration value was achieved maximum at 90 minutes and 180 minutes for intramuscular injection and oral, respectively after leucine administered. The percentage of insulin increment for both intramuscular injection and oral administration of leucine are 80.40% and 79.02%, respectively
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Ultrasound-Assisted Extraction Increases Pectin Yield From Watermelon (Citrullus Lanatus) Rind
No full textDispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Optimisation of Anthocyanin Co-pigmentation from Butterfly Pea (Clitoria ternatea) Flower and its Application in Gummy
Get PDFIn contrast to natural food colours, food manufacturers have increasingly used synthetic food colours to achieve attributes such as low cost, excellent appearance, high colour intensity, increased colour stability, and consistency. Furthermore, natural colourants such as anthocyanins have been linked to potential health advantages such as dietary antioxidants. Pea Flower (Clitoria ternatea) was utilized in this research because the high quantity of polyacylated anthocyanins known as ternatins in blue pea flowers which is a distinctive property of anthocyanins found in blue pea flowers. The purpose of this research is to improve anthocyanin thermal stability via co-pigmentation process from Butterfly Pea flower and to analyse the physicochemical features of gummy. The potential of Response Surface Methodology (RSM) for optimising anthocyanin co-pigmentation from Butterfly Pea (Clitoria ternatea) flower was investigated in this study. The effect of two test variables on the half-life of anthocyanin was studied in a specific range of pH 3-6 and anthocyanin to metal ratio (1:1 to 1:100). The data from the experiment were analysed using the RSM of MINITAB Software (Version 19), and the optimum half-life of anthocyanin of 191 minutes was established and verified. The optimal conditions were stated to be pH 3.75 and an anthocyanin:metal ratio of 1:75. A significant regression equation or model with a correlation value of 95.38% was also achieved at the 5% level. For the application of gummy, three types of gummies (synthetic blue incorporated gummy (F1), anthocyanin incorporated gummy (F2) and co-pigmented anthocyanin incorporated gummy (F3)) were produced to analyse its physicochemical qualities. The physicochemical qualities of F3 gummy were reported to retain the physicochemical since the pH values, water activity, moisture content, and textural properties were not significantly different (p>0.05). However, due to the % difference in polymeric colour present, the colour in terms of hue angle was noted to have a significant difference between F1, F2, and F3
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