Effect of Extraction Solvent on Tannin-Formaldehyde Adhesives for Plywood Production

2018 ◽  
Vol 1 (2) ◽  
pp. 120-126 ◽  
Author(s):  
N.S.A. Derkyi

Pine bark is a good source of natural polyphenolic compounds for wood adhesives. The objective of this study was to obtainthe most suitable solvent for extracting pine tannins in the preparation of tannin-formaldehyde plywood adhesives. Aqueousacetone, aqueous ethanol, aqueous NaOH and water as solvents were used to obtain crude tannins from pine bark. Thetannin content, sugar content and Stiasny number of the extracts were determined. Using the extracts from the solventextractions, synthesis of tannin-formaldehyde resin was carried out. Plywood panels were made using the synthesized resinsand the quality of the resins in plywood application determined. The quality of tannin-formaldehyde resins produced from thetannins were generally in close agreement with the chemical characteristics of the extracts obtained from the various solventextractions. The aqueous NaOH extraction although gave very high tannin yield (16.1%), its associated high sugar content(33.8%) and very low Stiasny number (49) resulted in poor quality resin. Similarly, although aqueous extraction gave a veryhigh Stiasny number (91), its low tannin yield (8.7%) might not be of commercial interest. The extraction process that gave ahigh tannin yield (12.9%) and a very good Stiasny number (81.5) with a corresponding good quality resin (shear strength =1.9 MPa, 22% delamination) was found for 60% aqueous ethanol extraction.

Author(s):  
Nana S. A. Derkyi ◽  
Daniel Sekyere ◽  
Nicholas A. Darkwa ◽  
Nana B. Boakye

The properties of plywood depend on many factors, including the quality of resin applied, and the curing or pressing conditions. The bark extracts of various commercially important trees containing polyphenolics in the form of tannins can be condensed with formaldehyde to produce wood resins. In the present work, aqueous ethanol was used as solvent to extract formaldehyde-condensable polyphenolics from Pinus caribaea Morelet bark. The contents of the co-extracted tannin and sugars were determined as well as the Stiasny number. Applying response surface methodology, a four factor, five level central composite rotatable design (CCRD) was employed to examine the optimum conditions of extraction variables for the pine bark polyphenolics. To study the effect of extraction optimization conditions on the resin quality, resins were processed from tannins extracted at the following response parameters; i) only tannin content was optimized, ii) only sugar content was optimized, iii) only Stiasny number was optimized and iv) tannin content, sugar content and Stiasny number were optimized simultaneously. The resins were characterized by viscosity, pot life and plywood bond strength. Each experiment was done in triplicate. Industrial grade phenol-formaldehyde adhesive was used as the control. The optimization models developed were found to adequately represent the extraction of polyphenolic compounds from P. caribaea bark. The quality of resin prepared from the extracted polyphenolics was found to be dependent on the extraction process parameters employed. The extraction process that gave a high tannin yield (18.85%) with a corresponding good quality resin (shear strength = 2.26 MPa, 11.4% delamination) similar to that of the control (industrial phenol-formaldehyde resin) was found for the optimization model when the objective function was to maximize both the tannin yield and Stiasny number and minimize the sugar content simultaneously. This corresponded to optimum extraction conditions of 52.2°C extraction temperature, 150 min extraction time, 43.6% solvent concentration and 10:1 liquid-solid ratio.


Author(s):  
M.A. Egyan ◽  

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.


2018 ◽  
Vol 3 (4) ◽  
pp. 822-829
Author(s):  
Achmad Dairobbi ◽  
Irfan Irfan ◽  
Ismail Sulaiman

Buah kopi memiliki kandungan gula tinggi yang dapat diproses dengan cara fermentasi alami. Fermentasi kopi arabika bertujuan untuk mengurangi rasa pahit dan meningkatkan citarasa kopi. Senyawa-senyawa kompleks pada kopi fermentasi akan meningkatkan mutu kopi. Penelitian ini menggunakan metode survey purposive sampling, yaitu cara pengambilan sampel berdasarkan pertimbangan tertentu dan disesuaikan dengan ketersediaan produsen wine coffee. kadar air wine coffee rata-rata 9.08% (SNI), kadar abu rata-rata 4.5% (SNI) dan kadar alkohol 0%. Dari 6 sampel wine coffee yang di analisis, total skor terbaik uji deskriptif ditunjukkan pada sampel E yaitu 83,75 dan sampel F yaitu 83,00. Secara keseluruhan, 6 sampel wine coffee di Kabupaten Aceh Tengah terdapat perbedaan pada lamanya waktu fermentasi wine coffee yang dibutuhkan. Hal ini dibuktikan pada sampel E yaitu proses pembuatan wine coffee dilakukan dengan waktu fermentasi 7-10 hari pada suhu secara natural di dalam ruang tertutup. Abstract: Coffee fruit has a high sugar content that can be processed by natural fermentation. Fermented arabica coffee aims to reduce bitterness and improve coffee flavor. The complex compounds in fermented coffee will improve the quality of coffee. This research uses survey purposive sampling method, that is the way of sampling based on certain consideration and adjusted with the availability of wine coffee producer. Water wine coffee average 9.08% (SNI), average ash content of 4.5% (SNI) and alcohol content 0%. From 6 samples of analyzed wine coffee, the best total score of descriptive test is shown on sample E that is 83,75 and sample F is 83,00. Overall, 6 samples of wine coffee in Aceh Tengah District have differences in the duration of fermentation of the required coffee. This is evidenced in the sample E is the process of making wine coffee is done with a fermentation time of 7-10 days at a temperature naturally in a closed space.


2020 ◽  
pp. 28-32
Author(s):  
Л.Н. Тимакова ◽  
В.А. Борисов ◽  
Н.А. Фильрозе ◽  
 О.Н. Успенская ◽  
Л.М. Соколова

Пищевая ценность свеклы столовой определяется высоким содержанием сахаров, своеобразным составом азотистых веществ. Эта культура – источник натурального красителя бетанина, который обладает антиканцерогенным, антибактериальным и противовирусным действием на организм человека. В статье представлены результаты изучения биохимических качеств корнеплодов свеклы столовой. Исследования проводились в период 2014–2019 годов на шести сортах свеклы столовой селекции Агрохолдинга «Поиск». За стандарт взяты широко распространенные образцы отечественной и голландской селекции Бордо 237 (ВНИИССОК) и F1 Пабло (Bejo), районированные во всех регионах РФ. Полевые опыты выполнены по единой методике на базе ВНИИО – филиала ФГБНУ ФНЦО в Раменском районе Московской области. Почва опытного участка относится к типу аллювиальных луговых, среднесуглинистая, насыщенная, влагоемкая. Погодные условия наиболее благоприятно для роста и развития растений свеклы столовой складывались в периоды вегетации 2014–2017 годов. Особенность погодных условий 2018–2019 годов – неравномерное выпадение осадков, что повлияло на время прорастания семян. Дефицит влаги в период вегетации компенсировали поливами методом дождевания, поддерживая НВ на уровне 80–85%. Наибольшее количество сухого вещества накапливает сорт Русская односемянная – 18,4%, что соответствует уровню стандарта Бордо 237. Высокое содержание сахаров свойственно сорту Креолка – 10,7%, и превосходит стандарты на 1,8%. Образцы, восприимчивые к заболеваниям листовой розетки во время вегетации культуры – Эфиопка и F1  Пабло накапливают меньше пигмента бетанина. Биохимические качества корнеплодов сорта Креолка больше сопряжены с его генотипом. Накопление нитратов у образцов крайне подвержено условиям года. Более чем в десять раз изменяется содержание нитратов в зависимости от года у сортов Славянка, Русская односемянная, Креолка и Бордо 237. Выход товарной продукции после шести месяцев хранения по изучаемым образцам колебался от 49,1 до 91,4%. Отличную сохранность на уровне стандартов – свыше 85% показал сорт Русская односемянная. The nutritional value of table beets is determined by a high content of sugars, a peculiar composition of nitrogenous substances. This culture is a source of the natural dye betanin, which has anti-carcinogenic, antibacterial and antiviral effects on the human body. The article presents the results of a study of biochemical qualities of root crops of table beet. Research was conducted in the period 2014–2019 on 6 varieties of beet of table selection of the Poisk Agrо Holding. Widespread samples of domestic and Dutch breeding Bordo 237 (FSCVG) and Pablo F1 (Bejo), zoned in all regions of the Russian Federation, were taken as a standard. Field experiments were performed according to a single methodology on the basis of ARRIVG – branch of FSCVG. The soil of the experimental site belongs to the type of alluvial meadow, medium-loamy, saturated, moisture-intensive. Weather conditions were most favorable for the growth and development of table beet plants during the growing season of 2014–2017. A feature of the weather conditions of 2018-2019 was uneven precipitation, which affected the time of germination of seeds. The lack of moisture during the growing season was compensated by irrigation by sprinkling, maintaining the HB at the level of 80–85%. The largest amount of dry matter accumulates Russian single-seeded variety – 18.4%, which corresponds to the level of the standard Bordeaux 237. High sugar content is characteristic of the Creole variety – 10.7%, and exceeds the standards by 1.8%. Samples that are susceptible to diseases of the leaf rosette during the growing season of the culture-Ethiopian and F1Pablo accumulate less of the pigment betanin. The biochemical qualities of Creole root crops are more associated with its genotype. The accumulation of nitrates in samples is highly susceptible to the conditions of the year. The nitrate content varies more than 10 times depending on the year in the varieties Slavyanka, Russian single-seeded, Creole and Bordo 237. The output of marketable products after 6 months of storage in the studied samples ranged from 49.1 to 91.4%. Excellent preservation at the level of standards – over 85% showed the Russian single-seeded variety.


2011 ◽  
Vol 50-51 ◽  
pp. 363-367
Author(s):  
Bo Liu ◽  
Hai Ning Wang

In order to solve the low automatic degree and poor quality of extract production to traditional Chinese medicine, a new automatic cone-shaped dynamic traditional Chinese medicine extraction equipment is designed. This equipment has innovation research in extraction process, structure design aspects, to achieve high efficiency, saving energy and automatic extraction purpose.


2020 ◽  
Vol 1 (1) ◽  
pp. 29-32
Author(s):  
Witri Ardini ◽  
Siti Nur Aisyah Jauharoh ◽  
Erike A. Suwarsono

Background: Food is an important requi-rement supporting the human activities, including academic activities on campus. The composition and quality of nutrients, both macro, and micronutrients in a diet, plays an important role in ensuring the availability of energy sources for daily activities and long-term health. This study is a preliminary study to evaluate the nutritional value of food provided in the canteen of campus.Method: This research will use a cross-sectional design on food samples sold in the canteen of Syarif Hidayatullah State Islamic University Jakarta. The macronutrient composition analysis was calculated using a list of foodstuffscompositions.Results: Most of the packaged food menu do not meet the macronutrient composition in a manner of balanced nutrition. The dominant side dish is chicken, the fat composition is higher than the recommendation due to fried processing. The portion of rice is not standard on various packages, with an average of 1.6 servings of standard rice. The content of vegetables is minimal. A snack menu is predominantly carbohydrate foods with a moderate to high sugar content, with minimal ber content, and processed by frying.Conclusion: The nutritional quality of the food menu in the canteen has largely not yet fulfilled the recommended macronutrient composition.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1113
Author(s):  
Ivan Lozada Lawag ◽  
Okhee Yoo ◽  
Lee Yong Lim ◽  
Katherine Hammer ◽  
Cornelia Locher

This paper presents the findings of a comprehensive review on common bee pollen processing methods which can impact extraction efficiency and lead to differences in measured total phenolic content (TPC) and radical scavenging activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) data. This hampers the comparative analysis of bee pollen from different floral sources and geographical locations. Based on the review, an in-depth investigation was carried out to identify the most efficient process to maximise the extraction of components for measurement of TPC, DPPH and FRAP antioxidant activity for two bee pollen samples from western Australia (Jarrah and Marri pollen). Optimisation by Design of Experiment with Multilevel Factorial Analysis (Categorical) modelling was performed. The independent variables included pollen pulverisation, the extraction solvent (70% aqueous ethanol, ethanol, methanol and water) and the extraction process (agitation, maceration, reflux and sonication). The data demonstrate that non-pulverised bee pollen extracted with 70% aqueous ethanol using the agitation extraction method constitute the optimal conditions to maximise the extraction of phenolics and antioxidant principles in these bee pollen samples.


Author(s):  
J. C. Tondare ◽  
A. S. Hembade

Amrakhand is a variation of shrikhand where it is mixed with pureed mango popular in western part of southern peninsula of India; consumers in Gujarat prefer its sweet variety while those in Maharashtra prefer the tangy/soury variety. High sugar content in the Amrakhand contributes to the total energy intake; carbohydrate is the most restricted item in the diet of both dietetic and diabetic individuals. Stevia is a natural sweetener with zero calories and its beneficial influence on human health, there is a great possibility of its use in food industry. The main aim of study was to investigate the sensory quality of Amrakhand prepared by using stevia leaf extract powder at different level of concentrations. Six different concentrations of sucrose and stevia used were 30:70(T1), 25:75 (T2), 20:80 (T3), 15:85 (T4), 10:90 (T5) based on quantity of chakka. Control sample (T0) was prepared from 100:0 sucrose and stevia leaf extract powder concentration. Sensory attributes (colour and appearance, flavor, Mouthfeel, Body and texture, taste and overall acceptability) were judged by panel using 9- point hedonic scale the preferred order of samples was as follows : T1>T2>T0>T3>T4>T5. Amrakhand with treatment T1 (30:70) was more acceptable by the panel of judges.


Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 155
Author(s):  
Jean-Roch Mouret ◽  
Evelyne Aguera ◽  
Marc Perez ◽  
Vincent Farines ◽  
Jean-Marie Sablayrolles

Wine fermentation is a specific and complex research subject and its control is essential to ensure full process completion while improving wine quality. It displays several specificities, in particular, (i) musts with a very high sugar content, low pH, and some limiting nutrients, as well as a great variability in must composition according to the year, grape variety, and so on; (ii) atypical fermentation conditions with non-isothermal temperature profiles, a quasi-anaerobiosis and legal constraints with a limited and predefined list of authorized operations. New challenges have emerged, related to the increasing diversity of commercially available yeast strains; the fluctuating composition of musts, particularly owing to climate change; and sustainability, which has become a key issue. This paper synthesizes approaches implemented to address all these issues. It details the example of our laboratory that, for many years, has been developing an integrated approach to study yeast diversity, understand their metabolism, and develop new fermentation control strategies. This approach requires the development of specific fermentation devices to study yeast metabolism in a controlled environment that mimics practical conditions and to develop original fermentation control strategies. All these tools are described here, together with their role in the overall scientific strategy and complementary approaches in the literature.


2020 ◽  
pp. 34-36
Author(s):  
M. A. Pokhaznikova ◽  
E. A. Andreeva ◽  
O. Yu. Kuznetsova

The article discusses the experience of teaching and conducting spirometry of general practitioners as part of the RESPECT study (RESearch on the PrEvalence and the diagnosis of COPD and its Tobacco-related aetiology). A total of 33 trained in spirometry general practitioners performed a study of 3119 patients. Quality criteria met 84.1% of spirometric studies. The analysis of the most common mistakes made by doctors during the forced expiratory maneuver is included. The most frequent errors were expiration exhalation of less than 6s (54%), non-maximal effort throughout the test and lack of reproducibility (11.3%). Independent predictors of poor spirogram quality were male gender, obstruction (FEV1 /FVC<0.7), and the center where the study was performed. The number of good-quality spirograms ranged from 96.1% (95% CI 83.2–110.4) to 59.8% (95% CI 49.6–71.4) depending on the center. Subsequently, an analysis of the reasons behind the poor quality of research in individual centers was conducted and the identified shortcomings were eliminated. The poor quality of the spirograms was associated either with the errors of the doctors who undertook the study or with the technical malfunctions of the spirometer.


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