Sorption Mechanism of Lead Ions From Aqueous Solution By Imperata Cylindrica Dried Leaf Particle: Effect of Temperatures

This study was conducted to investigate the sorption mechanism of Pb2+ ions from aqueous solution onto Imperata cylindrica (IC) dried leaf particles. The effect of temperatures (30, 35 and 40oC) was scrutinised from a batch adsorption system using a synthetic liquid waste containing Pb2+ ions. Adsorption of lead ions mechanism was investigated by intraparticle diffusion model. The results showed that higher adsorption rate occurred at higher temperature, and obeyed the pseudo second order adsorption model. The overall rate of lead uptake was found to be controlled by external mass transfer at the beginning of adsorption, then gradually changes to intraparticle diffusion controlled at a later stage. The intraparticle diffusion constant increased with increasing temperature. The values of effective diffusion coefficient (Di) increased at higher temperatures, which were 5.5466 × 10−9, 6.8215 × 10−9, and 7.3726 × 10−9 m2/s at 30, 35, and 40 ◦C, respectivel

Dissolution Rates of Mangosteen (Garcinia mangostana L.) Pericarps Extract Granules in Synthetic Human Gastrointestinal Fluid

Mangosteen (Garcinia mangostana L.) pericarps contain prenylated xanthone derivates, which exhibit some pharmacological activities, such as antiinflammatory, antihistamine, antibacterial, antivirus, antifungal, antioxidant, and antiulcerogenic. The purpose of this research was to study the dissolution rates of mangosteen pericarp extract granules in synthetic human gastrointestinal fluid at various pH and temperatures, which include experimental and modeling works. The granules were prepared by wet granulation of methanol extracts of mangosteen pericarps with addition of 25% w/v Arabic gum and 5% w/v maltodextrin. Dissolution rate study was performed by dissolving 0.5 g granules in 500 mL of 0.02M phosphate buffer solution with constant agitation at various pH (5.5, 6, 6.5, 7 and 7.5) and temperatures (30, 37 and 40oC) for two hours. Every 20 minutes, a liquid sample was withdrawn from the system for xanthone analysis. The results showed that mangosteen pericarps granules dissolution rates increased with pH under acidic condition. At pH 7.5 (basic condition), the dissolution rate was faster than that at pH 7. As expected, the dissolution rates were higher at higher temperatures. The semi empirical Korsmeyer-Peppas model showed its superiority over other models to predict the mangosteen pericarps granules dissolution rates. However, the mass transfer model proposed in this work also agreed well with the experimental data with error percentages closely similar to that of Korsmeyer-Peppas model

Removal of Cyanides from Gadung (Dioscorea hispida Dennst.) Tuber Chips using Leaching and Steaming Techniques

Gadung (Dioscorea hispida Dennst.) has been considered as one of staple foods in Indonesia. However, its high cyanides content has limited its utilisation for commercial food production. This work is aimed to investigate the removal of cyanides content from gadung tuber chips through two consecutive treatments, i.e. leaching and steaming and to propose mathematics model for the leaching process. The results showed that processing water flow rate and leaching time affected the efficiency of cyanides removal in the leaching process. The proposed mathematical model was able to represent the removal of cyanides through leaching process very well. The cyanides content removal was also found to be affected by steaming time. Best processing condition was at leaching using 5.00 10-5 m3.s-1 for 3,600 s, followed by steaming for 3,600 s to obtain cyanides content of 29.9 mgkg-1. While the yielded gadung tuber chips are considered as safe for consumption, further research on physicochemical characteristic of the gadung tuber flour is necessary for its utilisation consideration

Preparation, Proximate Composition and Culinary Properties of Yellow Alkaline Noodles from Wheat and Raw/Pregelatinized Gadung (Dioscorea Hispida Dennst) Composite Flours

The steady increase of wheat flour price and noodle consumptions has driven researchers to find substitutes for wheat flour in the noodle making process. In this work, yellow alkaline noodles were prepared from composite flours comprising wheat and raw/pregelatinized gadung (Dioscorea hispida Dennst) flours. The purpose of this work was to investigate the effect of composite flour compositions on the cooking properties (cooking yield, cooking loss and swelling index) of yellow alkaline noodle. In addition, the sensory test and nutrition content of the yellow alkaline noodle were also evaluated for further recommendation. The experimental results showed that a good quality yellow alkaline noodle can be prepared from composite flour containing 20% w/w raw gadung flour. The cooking yield, cooking loss and swelling index of this noodle were 10.32 g, 1.20 and 2.30, respectively. Another good quality yellow alkaline noodle can be made from composite flour containing 40% w/w pregelatinized gadung flour. This noodle had cooking yield 8.93 g, cooking loss 1.20, and swelling index of 1.88. The sensory evaluation suggested that although the color, aroma and firmness of the noodles were significantly different (p ≤ 0.05) from wheat flour noodle, but their flavor remained closely similar. The nutrition content of the noodles also satisfied the Indonesian National Standard for noodle. Therefore, it can be concluded that wheat and raw/pregelatinized gadung composite flours can be used to manufacture yellow alkaline noodle with good quality and suitable for functional food

Cisadane River Water Pollution

Sungai Cisadane berfungsi sebagai sumber air baku untuk sistem penyediaan air bersih wilayah Serpong dan Tangerang, Kabupaten Tangerang. Meskipun demikian, sungai Cisadane berfungsi pula sebagai tempat pembuangan limbah bagi rumah tangga dan industri yang berlokasi di sepanjang sungai tersebut. Untuk memperoleh gambaran mengenai tingkat pencemaran airnya, pada bulan September 1992 telah dilakukan pengambilan sampel air sungai Cisadane. Sampel air diambil di sebelah hulu intake instalasi pengolahan air di Cikokol (Tangerang) dan Serpong, masing-masing sebanyak lima dan tiga lokasi. Sebanyak 21 parameter dianalisis, kemudian dihitung Individual Index (II) dan Pollution Index (PI) - nya. Hasil yang diperoleh, yang menggambarkan kualitas pencemaran air sungai Cisadane pada saat itu, adalah sebagai berikut : Tangerang PI=1891. Pencemar utama adalah fenol, dengan II- 110 dan lemak & minyak, dengan II = 2670.Serpong, PI=574. Pencemar utama adalah fenol, dengan 11 = 810 Parameter lain yang mempunyai II > 1 adalah oksigen terlarut, fosfat, zat besi, fecal coli, nitrat, COD dan zat padat tersuspensi. Hasil tersebut menggambarkan Baliwa sungai Cisadane telah tercemar oleh limbah industri dan rumah tangga, serta mungkin pula telah tercemar oleh limbah pertanian, peternakan dan perbengkelan

Penurunan Sianida dalam Umbi Gadung dengan Proses Leaching yang Bekerja Batch

Yam is a tuber plant usually grown in tropical area. The starch contained is potential to be developed as food material like flour as a substitute for wheat in bread making. Although yam tubers were found to have high amount protein and amino acid, they also contained some antinutritional components like cyanogen substances, which can be toxic for human. Cyanogens substances were reduced by batch leaching process which used water as a leaching agent. Yam tuber was sliced into small chips and placed inside the leaching column. Later, 3 L per minute water was flown to the heap of yam chips. The changes of cyanogens content in the tuber chips were analyzed and, presented as HCN equivalent in mg per kg fresh sample every 0.5 hour. After the process, the cyanide content in the yam tuber decreased to an average of 24 ppm at solvent-to-solid ratio from 15 to 40 l/kg and leaching time 2.5 hours