scholarly journals Homogeneous Synthesis of Cationic Chitosan via New Avenue

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1921 ◽  
Author(s):  
Huanlu Song ◽  
Hao Wu ◽  
ShuJing Li ◽  
Huafeng Tian ◽  
YanRu Li ◽  
...  

Using a solvent formed of alkali and urea, chitosan was successfully dissolved in a new solvent via the freezing–thawing process. Subsequently, quaternized chitosan (QC) was synthesized using 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) as the cationic reagent under different incubation times and temperatures in a homogeneous system. QCs cannot be synthesized at temperatures above 60 °C, as gel formation will occur. The structure and properties of the prepared QC were characterized and quaternary groups were comfirmed to be successfully incorporated onto chitosan backbones. The degree of substitution (DS) ranged from 16.5% to 46.8% and the yields ranged from 32.6% to 89.7%, which can be adjusted by changing the molar ratio of the chitosan unit to CHPTAC and the reaction time. QCs inhibits the growth of Alicyclobacillus acidoterrestris effectively. Thus, this work offers a simple and green method of functionalizing chitosan and producing quaternized chitosan with an antibacterial effect for potential applications in the food industry.

2019 ◽  
Author(s):  
javier enriquez ◽  
Ignacio Chi-Duran ◽  
Carolina Manquian ◽  
Felipe Herrera ◽  
Ruben Fritz ◽  
...  

Non-centrosymmetric single-crystal metal-organic frameworks (MOF) are promising candidates for phase-matched nonlinear optical communication, but typical hydrothermal synthesis produces small crystals with relatively low transmittance and poor phase matching. We study the effect of the metal-to-ligand molar ratio and reaction pH on the hydro-thermal synthesis of the non-centrosymmetric Zn(3-ptz)<sub>2</sub> and Zn(OH)(3-ptz) MOFs with <i>in-situ </i>ligand formation. In acidic environments, we find that decreasing the amount of ligand below the stoichiometric molar ratio 1:2 also produces highly transparent single-crystal octahedrons of <b>Zn(3-ptz)<sub>2</sub></b>. In alkaline environments, we obtain long rod-like <b>Zn(OH)(3-ptz) </b>crystals whose length exceeds previous reports by up to four orders of magnitude. Potential applications of these results in the development of MOF-based nonlinear optical devices are discussed.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jerry Fredy Gomez Cahuata ◽  
Yessica Estefany Rosas-Quina ◽  
Erika Pachari Vera

Purpose The purpose of this paper is to divulge the current knowledge about the nutritional and functional characteristics of Cañihua (Chenopodium pallidicaule Aellen), in addition to its potential applications in the food industry since research studies related to it are still limited compared to other cereals of greater diffusion. Design/methodology/approach The scientific information was collected from Web of Science, Scopus and Google Scholar databases, using keywords such as nutrition value of Chenopodium pallidicaule, amaranth and pseudocereals. Consistent information was selected according to its relevance, year of publication and accuracy with the topic. A total of 49 research papers were selected. Findings Cañihua is a grain with high nutritional potential, considered a superfood because it has a high protein quality, a balanced composition of essential amino acids and unsaturated fatty acids, with a high concentration of linoleic and oleic acid. Besides, it has a good level of bioactive compounds with high antioxidant capacity. However, its production and consumption are limited outside its area of origin, although its cultivation is possible under harsh conditions. Originality/value This paper, through a systematic bibliographic review, highlights the potential of cañihua to be considered in the development of food products with high nutritional and functional value. The information compiled will help researchers and professionals become aware of the importance of this grain and join forces in its processing and enhancement of its attributes.


Author(s):  
Vijay A. Juwar ◽  
Ajit P. Rathod

Abstract The present study deals with the treatment of complex waste (WW) treated for removal of chemical oxygen demand (COD) of the food industry by a sono-Fenton process using a batch reactor. The response surface methodology (RSM) was employed to investigate the five independent variables, such as reaction time, the molar ratio of H2O2/Fe2+, volume ratio of H2O2/WW, pH of waste, and ultrasonic density on COD removal. The experimental data was optimized. The optimization yields the conditions: Reaction time of 24 min, HP:Fe molar ratio of 2.8, HP:WW volume ratio of 1.9 ml/L, pH of 3.6 and an ultrasonic density of 1.8 W/L. The predicted value of COD was 91% and the experimental result was 90%. The composite desirability value (D) of the predicted percent of COD removal at the optimized level of variables was close to one (D = 0.991).


Author(s):  
X Sober√≥n ◽  
M D√≠az ◽  
G del R√≠o ◽  
G Saab-Rinc√≥n ◽  
A L√≥pez-Mungu√≠a ◽  
...  

1991 ◽  
Vol 37 (7) ◽  
pp. 1269-1272 ◽  
Author(s):  
H Ihara ◽  
H Nakamura ◽  
Y Aoki ◽  
T Aoki ◽  
M Yoshida

Abstract Bush and Reed reported (Clin Chem 1987;33:821-3) that the reaction of albumin with bromcresol purple but not with bromcresol green underestimated the concentration of albumin in synthetically obtained bilirubin-albumin (Bd) by 29%. Their unproven assumption was that chemically synthesized Bd behaved in a manner indistinguishable from the natural Bd in icteric serum. Here we verify that Bd, whether synthetically obtained or isolated from serum, causes an underestimation of albumin in the bromcresol purple but not in the bromcresol green method. The molar ratio of Bd from either source to underestimated albumin approximates 1.0, suggesting that one molecule of Bd would react equivalently to a molecule of albumin in the bromcresol purple method. This underestimation might falsely suggest hypoalbuminemia in patients with increased serum Bd.


Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2867
Author(s):  
Rui Ferreira ◽  
Sílvia Lourenço ◽  
André Lopes ◽  
Carlos Andrade ◽  
José S. Câmara ◽  
...  

Worldwide, the food industry generates a large number of by-products from a wide variety of sources. These by-products represent an interesting and economical source of added value components with potential functionalities and/or bioactivities, which might be explored for industrial purposes, encouraging and promoting the circular economy concept. In this context, the current work aimed to evaluate the fatty acids (FAs) profile using gas chromatography–flame ionization detector (GC–FID) and Fourier Transform Infrared (FTIR), as well as the determination of related health lipid indices (e.g., atherogenic (AI) and thrombogenic (TI)) as a powerful strategy to investigate the potential applications of different agri-food by-products for human nutrition and animal feeding. This work results showed that polyunsaturated fatty acids (PUFAs) are the predominant group in grape pomace (72.7%), grape bunches (54.3%), and brewer’s spent grain (BSG, 59.0%), whereas carrot peels are dominated by monounsaturated fatty acids (MUFAs, 47.3%), and grape stems (46.2%), lees (from 50.8 to 74.1%), and potato peels (77.2%) by saturated fatty acids (SFAs). These findings represent a scientific basis for exploring the nutritional properties of agri-food by-products. Special attention should be given to grape pomace, grape bunches, and BSG since they have a high content of PUFAs (from 54.3 to 72.7%) and lower AI (from 0.11 to 0.38) and TI (from 0.30 to 0.56) indexes, suggesting their potential to provide a variety of health benefits against cardiovascular diseases including well-established hypotriglyceridemia and anti-inflammatory effects, products to which they are added.


Author(s):  
Afsaneh Salari ◽  
Mohammad Hashemi ◽  
Asma Afshari

: Kefir is produced through the fermentation of milk using kefir grain as a starter culture. Kefir grains include heterogeneous microorganisms embedded in a polysaccharide matrix called kefiran which is considered a biofilm, it also has many uses due to its therapeutic values. Kefiran is a microbial exopolysaccharide (EPS) obtained from the flora (acid- lactic bacteria and yeasts) of kefir grains and glucose units, in almost the same proportion. Kefiran has prebiotic nature agitating the growth of probiotics in the gastrointestinal tract of the human entity. It extends certain therapeutic benefits through balancing the microbiota in the intestine. This review presents the most recent advances regarding kefir and kefiran, their cultural condition, biological activities, and potential applications in the health and food industries.


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