Andri Cahyo Kumoro

Supercritical Carbon Dioxide Extraction of Andrographolide from Andrographis paniculata: Effect of the Solvent Flow Rate, Pressure, and Temperature*

Abstract Andrographis paniculata Nees has been extensively used for traditional medicine and help against fever, dysentery, diarrhoea, inflammation, and sore throat. In this study, andrographolide, the main component of this plant was extracted from the leaves of A. paniculata using supercritical carbon dioxide. The operating pressures were varied from 7.50 to 20MPa, the temperatures were varied from 30°C to 60°C, and the flow rates were varied from 0.5 to 4ml·min-1. The best extraction condition occurred at 10MPa, 40°C, and a flow rate of 2ml·min-1 for a 3g sample of A. paniculata ground-dried leaves. The measured extraction rate was found to be about 0.0174g of andrographolide per gram of andrographolide present in the leaves per hour of operation. The future studies must focus on the interaction between the various operating parameters such as temperature, pressure, and flow rate of supercritical carbon dioxide.

Solubility of Piperine in Supercritical and Near Critical Carbon Dioxide

Abstract Piperine is a member of the lipids family commonly found in peppercorn, ginger and other natural sources and is grouped as an alkaloid. The solubility of piperine has been determined in carbon dioxide at near critical and supercritical conditions in a dynamic extraction apparatus. The conditions studied were at pressures ranging from 10 to 20 MPa and temperatures at 293, 300, 313, 323 and 333 K. The results showed that piperine solubility increased with increasing pressure at all temperatures studied. The solubility of piperine in near critical conditions was slightly higher than that at supercritical conditions only at the low-pressure range. Two semi-empirical density dependent correlations, namely the Chrastil model and the Dilute Solution model, were also used to estimate the solubility data. Although both models showed good correlation with the solubility data, the Dilute Solution model performed better prediction than the Chrastil model.

Experimental study on drying kinetic of cassava starch in a pneumatic drying system

The aims of this study are to present the experimental research on the drying of cassava starch in a pneumatic dryer, to describe its drying curves, as well as to calculate its thermal efficiency. The effects of operating conditions, namely the inlet air temperature (60-100 °C) and solid-gas flow rate ratio (Ms/Mg 0.1-0.3) were studied. Heat transfer is accomplished through convection mechanism in a drying chamber based on the principle of direct contact between the heated air and the moist material. During the drying process, intensive heat and mass transfer between the drying air and the cassava starch take place. In order to meet the SNI standards on solid water content, the drying process was done in two cycles. The higher the temperature of the drying air, the lower the water content of the solids exiting the dryer. Thermal efficiency of the 2nd cycle was found to be lower than the 1st cycle.

Physical, thermal and functional properties of flour derived from Ubi Gembili (Dioscorea esculenta L.) tubers grown in Indonesia

Gembili ( Dioscorea esculenta L.) tuber is one of the important food sources in term of cultural, nutritional and economic perspectives for the people in the Africa, Caribbean islands, Asia, and Oceania regions. The tubers can be eaten after being boiled, roasted, fried or cooked. However, there is lack of information on the advanced utilizations of the tubers as raw material in the manufacture of modern foods. This study aims to characterize the physical, functional and thermal properties of Gembili flour, so that this information can be used as the basis in the development of novel foods. The microstructure, crystallinity, gelatinization temperature, swelling power and solubility of the flour were determined. The electron microscope observation revealed that Gembili flour consisted of smooth surface oval granules, which were light brown in color and having 23 µm average diameter. They are comprised of polygonals or some clusters of irregular fragments. Similar to most of tuber flours, Gembili flour also exhibited B-type crystallinity with approximately 31 ±3.7% crystallinity. The gelatinization temperature of Gembili flour was high and being comparable to that of cereal flour. The enthalpy of gelatinization of Gembili flour (9.52 ±0.80 J.g -1 ) was comparable to that of Dioscorea alata . Unfortunately, Gembili flour exhibited low swelling power (3.90 ±0.01 g.g -1 ). The Gembili flour granules were highly soluble in water (11.07 ±0.05%). Based on those reported properties, Gembili flour can be a suitable raw material for the manufacture of bakery, cookies, noodle and infant foods.

Functional and thermal properties of flour obtained from submerged fermentation of durian (Durio zibethinus Murr.) Seed chips using Lactobacillus plantarum

Durian (Durio zibethinus Murr.) is one of the most popular seasonal fruits in South East Asia, mainly Thailand, Indonesia, Malaysia and the Philippines. After consuming of the fruit pulp, the abundant durian seeds are usually disposed. However, they can be eaten after being boiled, roasted, baked, fried or cooked. Unfortunately, there is no sufficient information on the innovative utilizations of the durian seeds as raw materials in the preparation of modern foods. This study aims to characterize the functional and thermal properties of native and fermented durian seed flour obtained from submerged fermentation of durian seed chips using Lactobacillus plantarum, so that this information can be used as the basis in the development of functional foods. The effect of solid consistency (5 – 25% w/v), inoculum size (2.5 – 15% w/v) and time (0 – 40 h) on the swelling power, water solubility, water absorption capacity, oil absorption capacity, carbonyl and carboxyl content, degree of substitution and gelatinization temperature of the flour were investigated. Fermentation was found to alter all of the functional and thermal properties of durian seed flour. Although fermentation increased the gelatinization temperature and oil absorption capacity of durian seed flour, their value were still lower than that of wheat flour. Based on the carboxyl group content and degree of substitution, the fermented durian seed flour obtained from fermentation of durian seed chips at 15% w/v solid consistency and 5% v/v inoculums size for 24 h is safe for consumption. Fermented durian seed flour exhibits similar functional properties to that of wheat flour and offers its superiority and high potential applications in the food industry over wheat flour due to its high fiber content (8.50 ±0.26%), but low fat content (0.63 ±0.03%). However, rigorous research should be conducted to ensure the acceptability and practical implementation of fermented durian seed flour as raw material for the manufacture of bread, cookies, cake and noodle.

Inhibitory Effects of Cyanide on the Activity of Granular Starch Hydrolyzing Enzyme (GSHE) during Hydrolysis of Cassava (Manihot Esculenta Crantz) Starch

The kinetics and inhibitory effects of cyanide on the granular starch hydrolyzing enzyme (GSHE) activity during hydrolysis of cassava (Manihot esculenta Crantz) starch at low temperature were studied. The substrates included native cassava starch at various concentrations (100-400 g/L) and native cassava starches with added cyanide at various concentrations (50-150 mg/kg), while the concentration of enzyme was 1.5% (w/w). A decrease in reducing sugar concentration during hydrolysis of cassava starch indicated that the cyanide reduced the enzyme activity. Lineweaver-Burk plot of Michaelis-Menten equation was used to study the inhibition kinetics. The maximum velocity (Vmax) value was higher for native cassava starch than that of native cassava starch with added cyanides. The presence of cyanide was found to reduce the Vmax values. No significant different of the saturation constant (Km) value between native cassava starch and native cassava starch with added cyanides was observed. Based on the inhibition type analysis, the effect of cyanide in the cassava starch can be classified as a noncompetitive inhibition, with the Ki value of 0.33 mg/L.

Drying Rate and Product Quality Evaluation of Roselle (Hibiscus sabdariffa L.) Calyces Extract Dried with Foaming Agent under Different Temperatures

The utilisation of roselle (Hibiscus sabdariffa L.) calyx as a source of anthocyanins has been explored through intensive investigations. Due to its perishable property, the transformation of roselle calyces into dried extract without reducing their quality is highly challenging. The aim of this work was to study the effect of air temperatures and relative humidity on the kinetics and product quality during drying of roselle extract foamed with ovalbumin and glycerol monostearate (GMS). The results showed that foam mat drying increased the drying rate significantly and retained the antioxidant activity and colour of roselle calyces extract. Shorter drying time was achieved when higher air temperature and/or lower relative humidity was used. Foam mat drying produced dried brilliant red roselle calyces extract with better antioxidant activity and colour qualities when compared with nonfoam mat drying. The results showed the potential for retaining the roselle calyces extract quality under suggested drying conditions.

H2O2/UV Photo-Oxidation of Gadung (Dioscorea Hispida Dennst.) Starch and its Product Physicochemical Characterization

This work aimed to study the preparation and physicochemical properties characterization of oxidized gadung starch obtained from oxidation process implementing combined H 2 O 2 -UV irradiation. The photo-oxidation process was carried out in a well-mixed slurry reaction system at ambient temperature. The extent of oxidation was determined based on the carboxyl and the carbonyl contents of the oxidized gadung starch. The results show that oxidation process altered the carbonyl and carboxyl contents of the starch. Except the morphology of the starch, the swelling power, solubility and gelatinization temperature of the starch were severely affected by H 2 O 2 /UV oxidation process.

Effect of catalyst concentration and reaction time on the extraction of glucomannan from porang (Amorphophallus oncophyllus) flour via acid hydrolysis

High demand of glucomannan for various applications has attracted the attention of researchers to look for efficient extraction method from its botanical sources. The aim of this study is to investigate the effect of catalyst concentration and reaction time on the yield and purity of glucomannan, and profile of reducing sugar during glucomannan extraction from crude porang flour via acid hydrolysis. The effect of catalyst concentration was found to be more pronounced over the effect of reaction time. When catalyst concentration was varied from 0.03125 to 1 M, extraction of glucomannan from porang flour for 1 hour at 60°C yielded 40.5 to 70% glucomannan with purity of 47.35 to 90.18% (w/w). The yield and purity of glucomannan obtained from extraction using catalyst concentration of 1 M for 0.25 to 3 hour ranged between 49 to 66.67% and 58.32 to 90.18% (w/w), respectively. Reduction in glucomannan yield and purity observed at high catalyst concentration and prolong reaction time was likely to be due to over-decomposition. Glucomannan with highest purity (90.18% w/w) was obtained at 66.67% yield from acid hydrolysis of porang flour using 0.5 M hydrochloric acid solution with flour:water ratio of 1:50 at 60°C for 1 hour.

Implementation of steady state approximation for modelling of reaction kinetic of UV catalysed hydrogen peroxide oxidation of starch

With regard to its low viscosity, high stability, clarity, film forming and binding properties, oxidised starch has been widely used in various applications specifically in the food, paper, textile, laundry finishing and binding materials industries. A number of methods have been used to produce oxidised starch through reactions with various oxidizing agents, such as hydrogen peroxide, air oxygen, ozone, bromine, chromic acid, permanganate, nitrogen dioxide and hypochlorite. Unfortunately, most of previous works reported in the literatures were focused on the study of reaction mechanism and physicochemical properties characterization of the oxidised starches produced without investigation of the reaction kinetics of the oxidation process. This work aimed to develop a simple kinetic model for UV catalysed hydrogen peroxide oxidation of starch through implementation of steady state approximation for the radical reaction rates. The model was then verified using experimental data available in the literature. The model verification revealed that the proposed model shows its good agreement with the experimental data as indicated by an average absolute relative error of only 2.45%. The model also confirmed that carboxyl groups are oxidised further by hydroxyl radical. The carbonyl production rate was found to follow first order reaction with respect to carbonyl concentration. Similarly, carboxyl production rate also followed first order reaction with respect to carbonyl concentration. The apparent reaction rate constant for carbonyl formation and oxidation were 6.24 × 104 s−1 and 1.01 × 104 M−1.s−1, respectively. While apparent reaction rate constant for carboxyl oxidation was 4.86 × 104 M−1.s−1.