scholarly journals Pretreatment Techniques and Green Extraction Technologies for Agar from Gracilaria lemaneiformis

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 617
Author(s):  
Qiong Xiao ◽  
Xinyi Wang ◽  
Jiabin Zhang ◽  
Yonghui Zhang ◽  
Jun Chen ◽  
...  

Optimizing the alkali treatment process alone without tracking the changes of algae and agar quality with each pretreatment process will not achieve the optimal agar yield and final quality. In this study, we monitored the changes of the morphology and weight of algae with each treatment process, and comprehensively analyzed the effects of each pretreatment process on the quality of agar by combining the changes of the physicochemical properties of agar. In conventional alkali-extraction technology, alkali treatment (7%, w/v) alone significantly reduced the weight of algae (52%), but hindered the dissolution of algae, resulting in a lower yield (4%). Acidification could solve the problem of algal hardening after alkali treatment to improve the yield (12%). In enzymatic extraction technology, agar with high purity cannot be obtained by enzyme treatment alone, but low gel strength (405 g/cm2) and high sulfate content (3.4%) can be obtained by subsequent acidification and bleaching. In enzyme-assisted extraction technology, enzyme damage to the surface fiber of algae promoted the penetration of low-concentration alkali (3%, w/v), which ensured a high desulfurization efficiency and a low gel degradation rate, thus improving yield (24.7%) and gel strength (706 g/cm2), which has the potential to replace the traditional alkali-extraction technology.

Author(s):  
Qianqian Di ◽  
Junhong Yang ◽  
Jun Zhao ◽  
Liqiu Wang

The extraction of functional components from natural plant is one of important processing in the development and further practical application of plant product. Microwave assisted extraction (MAE) has been widely used in the extraction of many samples for its unique heating mechanism, short extraction time and high yield of extract. Astragalus slice is a special and typical plant porous media. We describe an approach by scanning electronic microscope (SEM) to characterize the trachea and aperture of Astragalus slices irradiated 20 min by microwave at 600 W and 900 W, with the aim to analyze the effect of the microwave power on the extraction yield by SEM and discuss further the relationship between the microstructure characteristics of sample and mechanism on mass transfer in micro-scale. It is found that extract with the 20 min irradiation of microwave at 600 W is higher than that at 900 W because the apertures on the trachea wall remain open at 600 W, but shrink at 900 W. Moreover, we confirm the important role of the aperture in the extraction of plant materials. Therefore, this study has significant meanings to develop the optimized extraction technology of plant porous media and maintain or improve the quality of extract.


2021 ◽  
pp. 2397-2409
Author(s):  
Dellen Naomi Matulessy ◽  
Yuny Erwanto ◽  
Nurliyani Nurliyani ◽  
Edi Suryanto ◽  
Mohammad Zainal Abidin ◽  
...  

Background and Aim: Gelatin is a dissolved protein that results from partial extraction of collagen, commonly from pig and bovine skin. There was no study on gelatin production from Kacang goat bones through enzymatic extraction. This study aimed to evaluate the chemical, physical, and functional properties of gelatin from bones of Kacang goat using alcalase and neutrase enzymes. Materials and Methods: Male Kacang goat bones aged 6-12 months and two commercial enzymes (alcalase and neutrase) were used for this study. Descriptive analysis and completely randomized design (one-way analysis of variance) were used to analyze the chemical, physical, and functional properties of gelatin. Kacang goat bone was extracted with four concentrations of alcalase and neutrase enzymes, namely, 0 U/g (AG-0 and NG-0), 0.02 U/g (AG-1 and NG-1), 0.04 U/g (AG-2 and NG-2), and 0.06 U/g (AG-3 and NG-3) with five replications. Results: The highest yield of gelatin extraction with alcalase obtained on AG-3 was 9.78%, and that with neutrase on NG-3 was 6.35%. The moisture content of alcalase gelatin was 9.39-9.94%, and that of neutrase gelatin was 9.15-9.24%. The ash and fat content of gelatin with alcalase was lower than that without enzyme treatment with higher protein content. The lowest fat content was noted in AG-1 (0.50%), with protein that was not different for all enzyme concentrations (69.65-70.21%). Gelatin with neutrase had lower ash content than that without neutrase (1.61-1.90%), with the highest protein content in NG-3 (70.89%). The pH of gelatin with alcalase and neutrase was 6.19-6.92 lower than that without enzymes. Melting points, gel strength, and water holding capacity (WHC) of gelatin with the highest alcalase levels on AG-1 and AG-2 ranged from 28.33 to 28.47°C, 67.41 to 68.14 g bloom, and 324.00 to 334.67%, respectively, with viscosity that did not differ, while the highest foam expansion (FE) and foam stability (FS) were noted in AG-1, which were 71.67% and 52.67%, respectively. The highest oil holding capacity (OHC) was found in AG-2 (283%). FS and OHC of gelatins with the highest neutrase levels in NG-2 were 30.00% and 265.33%, respectively, while gel strength, viscosity, FE, and WHC of gelatins with the highest neutrase levels did not differ with those without enzymes at all enzyme concentrations. B chain was degraded in all gelatins, and high-intensity a-chains in gelatin with alcalase and peptide fraction were formed in gelatin with neutrase. Extraction with enzymes showed loss of the triple helix as demonstrated by Fourier transform infrared spectroscopy. Conclusion: Based on the obtained results, the Kacang goat bone was the potential raw source for gelatin production. Enzymatic extraction can increase the quality of gelatin, especially the alcalase (0.02-0.04 U/g bone) method. This can be used to achieve the preferable quality of gelatin with a higher yield.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Meda ◽  
C. Schaum ◽  
M. Wagner ◽  
P. Cornel ◽  
A. Durth

TIn 2004, the German Association for Wastewater, Water and Waste (DWA) carried out a survey about the current status of sewage sludge treatment and disposal in Germany. The study covered about one third of the wastewater treatment plants and about two thirds of the entire treatment capacity (expressed in population equivalents) in Germany. This provides an up-to-date and representative database. The paper presents the most important results regarding sludge treatment, process engineering, current disposal paths and sewage sludge quality.


1995 ◽  
Vol 31 (5-6) ◽  
pp. 85-89 ◽  
Author(s):  
S. J. Turner ◽  
G. D. Lewis

Over a 12 month period F-specific bacteriophages, faecal coliforms and enterococci were compared as microbial indicator organisms for the quality of a wastewater treatment (oxidation pond) system. Results suggest that enterococci may be the most useful indicator for oxidation pond systems.


2020 ◽  
pp. 1-10
Author(s):  
R. Sathish Kumar ◽  
Nivedhitha Muralidharan ◽  
Ravishankar Sathyamurthy

Separations ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 94
Author(s):  
Anahí J. Borrás-Enríquez ◽  
Elizabeth Reyes-Ventura ◽  
Socorro J. Villanueva-Rodríguez ◽  
Lorena Moreno-Vilet

Manililla is a mango variety whose residues contain bioactive compounds such as polyphenols and flavonoids, with high added value. The use of environmentally friendly extraction technology would be of great relevance; hence, this study aimed to evaluate the effect of solvent relation, sonication time and amplitude on the ultrasound-assisted extraction of total polyphenols in Manililla mango residues (peel, endocarp and kernel) and antioxidant activity. An experimental design 23 with a central point was used to evaluate the curvature behavior of the process variables. Conventional maceration was used as a control. The better conditions were obtained at the central point using 50% ethanol in water, 60% amplitude and 20 min of sonication time. We obtained values of up to 1814 mg GAE/100 g, 469 mg GAE/100 g and 672 mg GAE/100 g of total polyphenols and 1228 mg QE/100 g, 653 mg QE/100 g and 880 mg QE/100 g of total flavonoids for peel, endocarp and kernel, respectively. Mangiferin was quantified in ultrasound-assisted extraction at 150 mg/g in peel and 0.025 mg/g in the kernel, but it was not detectable in maceration. An antioxidant capacity of 87%, 14% and 83% inhibition for peel, endocarp and kernel, respectively, were obtained. Peel and kernel were the residues with higher potential as extraction material, while endocarp was not.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ottaviano Allegretti ◽  
Ignazia Cuccui ◽  
Nasko Terziev ◽  
Laerte Sorini

AbstractMass loss (ML) of wood caused by thermal degradation is one of the most important features of the thermal treatments and referred to as an indicator of intensity and quality of the process. The ML is proportional to the quantity of the effective heat power exchanged during the treatment process, represented by the area of the temperature profile versus time during the process. In this paper a model for the ML prediction based on the relative area was discussed. The model proposed an analytical solution to take into account the non-linear trend of ML when plotted versus temperature and time as observed in isothermal experiments. The model was validated comparing calculated and measured final ML of samples treated during thermal modification tests with different temperature profiles. The results showed that the relative area calculated in a transformed time-temperature space improves the correlation with the measured ML.


Author(s):  
O. L. Moskalenko ◽  
O. V. Smirnova ◽  
E. V. Kasparov ◽  
I. E. Kasparova

The article is devoted to the study of the psychological characteristics of the behavior of patients with non-alcoholic fatty liver disease (NAFLD). The manifestations of NAFLD are a powerful frustrating factor for patients, negatively affect the quality of life, hinder psychosocial adaptation and serve as the basis for the formation of chronic stress from the disease, which blocks the actual needs of the individual. Psychological factors are an important component in the clinical assessment of patients in connection with the individualization of the treatment process and secondary psychoprophylaxis, including methods of somato-centered and personality-centered psychotherapy.


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