Papers by Keyword: Digestion

Abstract: Riceberry rice has a dark purple color; and a high content of antioxidants, which could affect the digestion behaviors and its application. This study is aimed to analyze the starch digestion rate and predict the bio-accessibility of polyphenols in various modified Riceberry flours during the in vitro digestive process. It also discussed the relationship between the rate of digestion and polyphenol release, which provided basic information about the digestion behavior of Riceberry flour. Seven rice flour samples were used for this study, which included six physically treated flours: annealed flour (AF), heat moisture-treated flour (HMT), pregelatinized flour (Pregel), ultra-sonicated flour (US), wet microwave-treated flour (Wet), dry microwave treated flour (Dry), and untreated (control sample). The obtained results showed that, compared with the control sample, the digestion rate of the Pregel sample was higher, while the others had lower values. However, the Pregel sample showed the second highest rank of bio-accessible polyphenol during digestion after the US sample. While the HMT sample presented the lowest rate of starch digestion and release of bioactive compounds. This investigation also used an artificial neural network (ANN) to forecast the starch digestion and polyphenol bio-accessibility of rice flours. During digestion, the ANN model demonstrated a high capacity to predict the polyphenol bio-accessibility and starch hydrolysis percentage. There was a goodness of fit between the ANN-predicted and the actual values (R² >0.95). The importance of the bioavailability and bio-accessibility analysis indicates the functional potential that flour can have, which could be predicted effectively by applying modern techniques such as the ANN model. Moreover, it was also concluded that the digestive tract readily absorbs released polyphenol compounds in rice flour, which also influences the rate of starch hydrolysis. However, the impact could vary depending on the flour’s starch fraction content and the polyphenol activity, which is a topic for future investigation. The high antioxidant content and low digestion rate of flour could be highly promising functional materials for application in the food industry.

Abstract: As consumer awareness of heavy metal content in textile increased, it is necessary to develop analytical methods that identify and quantify heavy metals. In order to comprehensively investigate the potential risks of antimony (Sb) in recycled polyester fiber to humans health, this study developed acid digestion method, with the condition that the volume ratio of concentrated sulfuric acid to hydrogen peroxide was 1, and digested at 200°Cfor 1.5h, which produced clear and colorless solutions.Currently, microwave and dry ashing are also common methods for digesting polyethylene terephthalate samples. Three pretreatment methods for determining the content of Sb in recycled polyester fibers was evaluated. Results showed that inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis of acid digested recycled polyester samples resulted in Sb content higher than for the microwave and dry ashing digestion methods which incompletely digest recycled polyester. Moreover, compared with microwave digestion and dry ashing, acid digestion had a low detection limit of 0.0116 ug/mL, a high spike recovery of 82% to 106% and the RSD value less than 2%, which indicates that the data was accurate and reproducible. Therefore, in this study, acid digestion - ICP-OES was an effective method for detecting the content of heavy metal Sb in recycled polyester.

Abstract: A novel method for the determination of rhodium in waste thiourea rhodium samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Rh for tested solution was 9 ng mL^-1. The relative standard deviations (RSDs) for Rh was 1.98 % (C_Rh = 1 mg L^-1, n = 7). The linear range of calibration graph for Rh was 0 ~ 150.00 mg L^-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Abstract: A novel method for the determination of platinum in waste platinum-loaded carbon catalyst samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Pt for tested solution was 15 ng mL^-1. The relative standard deviations (RSDs) for Pt was 2.35 % (C_Pt = 5 mg L^-1, n = 7). The linear range of calibration graph for Pt was 0 ~ 150.00 mg L^-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Abstract: A novel method for the determination of rhodium in rhodium octanoate organic waste liquid samples was established by inductively coupled plasma atomic emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the linear range of calibration graph for Rh was 0 ~ 150.00 mg L^-1, and the recovery was 96.20% ~ 102.36%. The relative standard deviation (RSDs) for Rh was 1.75 %. The proposed method was applied to determine the same samples with atomic absorption spectrometry with the results consistently, which is suitable for the determination of rhodium in rhodium octanoate organic waste liquid samples.

Abstract: A novel method for the determination of ruthenium in waste ruthenium-loaded carbon catalyst samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Ru for tested solution was 9 ng mL^-1. The relative standard deviations (RSDs) for Ru was 2.12 % (C_Ru = 1 mg L^-1, n = 7). The linear range of calibration graph for Ru and Zn was 0 ~ 100.00 mg L^-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Abstract: A novel method for the determination of rhodium in waste rhodium-loaded carbon catalyst samples was established by inductively coupled plasma atomic emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. The results indicated that the digestion effect was optimum with samples digested 8 hour at 180 ^°C. Al, Fe, Mg, Ca and Si in samples had no effect on the determination of rhodium. Experiment indicated rhodium concentration within the range of 0 ~ 150 mg L^-1 had a linear relation with emission intensity. The recovery was 99.20% ~ 100.73 %, and the relative standard deviation was 1.8 %. A satisfactory result was obtained when applying the proposed method in the practical sample.

Abstract: This paper reviews all possible traditional methods to digest natural polysaccharides, which have been widely used as depressants or flocculants in flotation. Its characteristics of environmental friendly, highly selectivity and availability helps a lot in its application either in food or mining industries. The common digestion methods in flotation of polysaccharides, such as starch or dextrin, include thermal treatment at different temperatures or alkali-digestion at different concentrations.

Abstract: This research aims to give an overview on how to improve the biogas yeild in Balinese digester plants using various co-substrates which are available in Bali. A series testing on the digestibility of substrates were set up either in the field or in the biogas laboratory. In-field analyses like testing the CO₂-content and taking samples from digested manure were undertaken. Analyses such as dry matter (DM) and organic dry matter (oDM) determination, pH measurement and FOS/TAC were handled in the biogas laboratory. The huge number of different fruits in Bali gives a good opportunity to use their wastes like Durian hulls and Banana peelings, which can not be used anymore, as co-substrates in biogas plants. The results of these investigations allow to estimate the additional biogas yield, when adding co-substrates to a cow manure biogas plant.

Abstract: Total phosphorus is an much important key water quality parameter . In view of the technical defects of existing detection methods and instruments for in situ monitoring total phosphorus, a new detection method based on ultrasonic assisted sample digestion and spectrum analysis was put forward in this paper, and the automatic monitoring system prototype based on such detection method had been developed. Aiming at wastewater treatment, the spot experiment had been carried out to contrast prototype with Chinas national standard analysis method for on line measuring total phosphorus in the water, and the results of the comparative experiment showed that the automatic monitoring instrument prototypes had good repeatability (10%) and high accuracy (±10%), which met the technical qualifications of Chinas environmental protection industry standards.