Cocktail enzyme-assisted alkaline extraction and identification of jujube peel pigments

2021 ◽  
pp. 129747
Author(s):  
Dongbei Shen ◽  
Xiaohong Kou ◽  
Caie Wu ◽  
Gongjian Fan ◽  
Tingting Li ◽  
...  
Keyword(s):  
Alkaline Extraction

Elemental chlorine-free bleaching of North American hardwood kraft pulps: Evaluation of oxidant-reinforced extraction variables on overall bleaching optimization

TAPPI Journal ◽  
2013 ◽  
Vol 12 (10) ◽  
pp. 33-41 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Response Surface ◽  
Chlorine Dioxide ◽  
North American ◽  
Yield Loss ◽  
Alkaline Extraction ◽  
Kraft Pulps ◽  
Pulp Bleaching ◽  
Response Surface Models ◽  
Elemental Chlorine ◽  
Surface Models

This investigation evaluates how higher reaction temperatures or oxidant reinforcement of caustic extraction affects chlorine dioxide consumption during elemental chlorine-free bleaching of North American hardwood pulps. Bleaching data from the published literature were used to develop statistical response surface models for chlorine dioxide delignification and brightening sequences for a variety of hardwood pulps. The effects of higher (EO) temperature and of peroxide reinforcement were estimated from observations reported in the literature. The addition of peroxide to an (EO) stage roughly displaces 0.6 to 1.2 kg chlorine dioxide per kilogram peroxide used in elemental chlorine-free (ECF) bleach sequences. Increasing the (EO) temperature by Δ20°C (e.g., 70°C to 90°C) lowers the overall chlorine dioxide demand by 0.4 to 1.5 kg. Unlike what is observed for ECF softwood bleaching, the presented findings suggest that hot oxidant-reinforced extraction stages result in somewhat higher bleaching costs when compared to milder alkaline extraction stages for hardwoods. The substitution of an (EOP) in place of (EO) resulted in small changes to the overall bleaching cost. The models employed in this study did not take into account pulp bleaching shrinkage (yield loss), to simplify the calculations.

Optimization of elemental chlorine-free bleaching for a softwood kraft pulp • part 2: economic analysis of chemical and steam consumption

TAPPI Journal ◽  
2010 ◽  
Vol 9 (9) ◽  
pp. 47-53 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Chlorine Dioxide ◽  
Previous Investigation ◽  
Kraft Pulp ◽  
Energy Costs ◽  
Alkaline Extraction ◽  
Stage Versus ◽  
Kraft Pulps ◽  
Steam Consumption ◽  
Elemental Chlorine ◽  
Softwood Kraft Pulp

Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping Conference) to demonstrate how oxidative alkaline extraction can be augmented and how these changes affect chlorine dioxide consumption with elemental chlorine-free (ECF) sequences. The current study manipulates extraction delignification variables to curtail bleaching costs with a conventional U.S. Southern softwood kraft pulp. The economic advantages of ~0.35% to 0.65% H2O2 peroxide reinforcement in a 70°C (EOP)-stage versus 90°C (EO)-stage are predisposed to the brightness targets, to short or long bleach sequences, and to mill energy costs. Minimized bleaching costs are generally realized when a 90°C (EO) is employed in D0(EO)D1 bleaching, whereas a 70°C (EOP) is economically advantageous for D0(EOP)D1E2D2 bleaching. The findings we disclose here help to clarify previous ECF optimization studies of conventional softwood kraft pulps.

Alkaline extraction of xylan from wood using microwave and conventional heating

2014 ◽  
Vol 132 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Suhara Panthapulakkal ◽  
Donald Kirk ◽  
Mohini Sain
Keyword(s):  
Conventional Heating ◽  
Alkaline Extraction

scholarly journals Preliminary Investigation on Sodium Alginate Extracted from Sargassum Subrepandum of Red Sea of Eritrea as Tablet Binder

2011 ◽  
Vol 3 (3) ◽  
pp. 609-618 ◽  
Author(s):  
N. S. Basha ◽  
R. Rekha ◽  
A. Letensie ◽  
S. Mensura
Keyword(s):  
High Temperature ◽  
Sodium Alginate ◽  
Room Temperature ◽  
Preliminary Investigation ◽  
Hydroxypropyl Methylcellulose ◽  
Extraction Methods ◽  
Binding Property ◽  
Alkaline Extraction ◽  
Suitable Alternative ◽  
Binding Strength

Natural polysaccharides hold advantages over synthetic polymers for conventional and novel dosage forms, because these are non-toxic, less expensive, and biodegradable. These can also be modified to tailor-made materials and thus can compete with the available synthetic excipients. Therefore, the aim of present work is to extract sodium alginate from the seaweed S. subrepandum to assess its binding property using propranolol as model drug. Sodium alginate was extracted by room-temperature alkaline extraction and high-temperature (80°C) alkaline extraction methods. Binding strength was evaluated by using two different formulations i.e., formulation 1 with sodium alginate as a binder and formulation 2 with hydroxypropylmethylcellulose (HPMC) as reference standard. The two tablet formulations were evaluated and compared for parameters such as friability, hardness and disintegration. The percentage yield was found to be 17.5% w/w by room-temperature alkaline extraction and 21%w/w by high-temperature extraction method. The results obtained for all tested parameters for tablets with sodium alginate were found within acceptable range of USP standards. It was also founded that both sodium alginate and HPMC have similar binding strength at similar concentration. So, it can be concluded that sodium alginate of S. subrepandum can be used as suitable alternative binder in tablet formulations.Keywords: Sargassum subrepandum; Sodium alginate; Hydroxypropyl methylcellulose; Friability; Hardness; Disintegration.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i3.6770                     J. Sci. Res. 3 (3), 619-628 (2011)

Optimization of steam pretreatment conditions for enzymatic hydrolysis of poplar wood

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Fokko Schütt ◽  
Jürgen Puls ◽  
Bodo Saake
Keyword(s):  
Enzymatic Hydrolysis ◽  
Raw Material ◽  
Steam Pretreatment ◽  
Alkaline Extraction ◽  
Poplar Wood ◽  
Steam Refining ◽  
Severity Factor ◽  
Short Rotation ◽  
Pretreatment Conditions ◽  
Hydrolysis Of

Abstract Steam refining was investigated as a pretreatment for enzymatic hydrolysis of poplar wood from a short rotation plantation. The experiments were carried out without debarking to use an economically realistic raw material. Steam refining conditions were varied in the range of 3–30 min and 170–220°C, according to a factorial design created with the software JMP from SAS Institute Inc., Cary, NC, USA. Predicted steaming conditions for highest glucose and xylose yields after enzymatic hydrolysis were at 210°C and 15 min. Control tests under the optimized conditions verified the predicted results. Further pretreatments without bark showed that the enzymes were not significantly inhibited by the bark. The yield of glucose and xylose was 61.9% of theoretical for the experiments with the whole raw material, whereas the yield for the experiments without bark was 63.6%. Alkaline extraction of lignin from the fibers before enzymatic hydrolysis resulted in an increase of glucose yields from mild pretreated fibers and a decrease for severe pretreated fibers. The extracted lignin had a high content of xylose of up to 14% after very mild pretreatments. On the other hand, molecular weights of the extracted lignin increased substantially after pretreatments with a severity factor above 4. Hence, alkaline extraction of the lignin seems only attractive in a narrow range of steaming conditions.

scholarly journals FRACTIONATION OF HEMICELLULOSE FROM RICE STRAW BY ALKALINE EXTRACTION AND ETHANOL PRECIPITATION

2016 ◽  
Vol 20 (2) ◽  
pp. 329-334 ◽  
Author(s):  
Nur Hazlilla Zulyadi ◽  
Sabiha Hanim Saleh ◽  
Siti Halimah Sarijo
Keyword(s):  
Rice Straw ◽  
Alkaline Extraction ◽  
Ethanol Precipitation

scholarly journals Enhancement of UV Light Sensitivity of a Vibrio parahaemolyticus O3:K6 Pandemic Strain Due to Natural Lysogenization by a Telomeric Phage

2009 ◽  
Vol 75 (6) ◽  
pp. 1697-1702 ◽  
Author(s):  
Beatriz Zabala ◽  
Katherine García ◽  
Romilio T. Espejo
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Uv Light ◽  
Bacterial Pathogen ◽  
Light Sensitivity ◽  
Alkaline Extraction ◽  
Clonal Population ◽  
Pandemic Strain ◽  
Clonal Strain ◽  
Similar Restriction

ABSTRACT The Vibrio parahaemolyticus O3:K6 pandemic clonal strain was first observed in southern Chile in 2004 and has since caused approximately 8,000 seafood-related diarrhea cases in this region. The massive proliferation of the original clonal population offers a unique opportunity to study the evolution of a bacterial pathogen in its natural environment by detection and characterization of emerging bacterial variants. Here, we describe a group of pandemic variants characterized by the presence of a 42-kb extrachromosomal DNA that can be recovered by alkaline extraction. Upon treatment with mitomycin C, these variants lyse with production of a myovirus containing DNA of equal size to the plasmid but which cannot be recovered by alkaline extraction. Plasmid and phage DNAs show similar restriction patterns corresponding to enzyme sites in a circular permutation. Sequenced regions showed 81 to 99% nucleotide similarity to bacteriophage VHML of Vibrio harveyi. Altogether these observations indicate that the 42-kb plasmid corresponds to a prophage, consisting of a linear DNA with terminal hairpins of a telomeric temperate phage with a linear genome. Bacteria containing the prophage were 7 to 15 times more sensitive to UV radiation, likely due to phage induction by UV irradiation as plasmid curing restored the original sensitivity. The enhanced UV sensitivity could have a significant role in reducing the survival and propagation capability of the V. parahaemolyticus pandemic strain in the ocean.

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