Saccharide and fructooligosaccharide accumulation across leaf-bases during growth and bulb development of onion ( Allium cepa L.)

2008 ◽  
Vol 56 (1) ◽  
pp. 21-31 ◽  
Author(s):  
N. Shiomi ◽  
N. Benkeblia ◽  
S. Onodera ◽  
N. Takahashi ◽  
M. Fujishima ◽  
...  
Keyword(s):  
Allium Cepa ◽  
High Performance ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
Degree Of Polymerization ◽  
Exchange Chromatography ◽  
Glucose Content ◽  
Bulb Formation ◽  
Total Carbohydrates ◽  
June July

The accumulation of saccharides and fructooligosaccharides (FOS) in the individual leaf-bases of onion ( Allium cepa L.) was investigated during growth and bulb development. Saccharides and FOS were analysed by means of high performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD). The glucose content was the highest, while the content of saccharides (glucose, fructose and sucrose) increased during June, July and August and decreased slightly during September. The trisaccharides all accumulated to a similar extent, although the neokestose [ 3b , 6 G - β -D fructofuranosylsucrose] content was higher than that of 1-kestose [ 3a , 1 F - β -D-fructofuranosylsucrose]. Tetra-, penta- and high-DP (degree of polymerization) FOS also showed a similar pattern, though the contents of 4b [6 G (1- β -D-fructofuranosyl) 2 sucrose] and 5b [6 G (1- β -D-fructofuranosyl) 3 sucrose] were higher compared with that of other tetra-[ 4a , 1 F (1- β -D-fructofuranosyl) 2 sucrose and 4c , 1 F , 6 G -di- β -D-fructofuranosyl sucrose] and penta-saccharides [ 5a , 1 F (1- β -D-fructofuranosyl) 3 sucrose]. Total FOS accumulated to a greater extent in the inner (youngest) leaf-bases than in the outer (oldest) leaf-bases, and their content was high during August. The total carbohydrates content was 6.71, 7.25, 8.10 and 6.30 g 100 g −1 FW during June, July, August and September, respectively. During bulb formation, a balance was observed between the glucose, fructose, sucrose and FOS contents, with an average ratio of 20:10:10:60 of total carbohydrates, respectively.

scholarly journals Enzymatic Synthesis and Characterization of Different Families of Chitooligosaccharides and Their Bioactive Properties

2021 ◽  
Vol 11 (7) ◽  
pp. 3212
Author(s):  
Noa Miguez ◽  
Peter Kidibule ◽  
Paloma Santos-Moriano ◽  
Antonio O. Ballesteros ◽  
Maria Fernandez-Lobato ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Characterization ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Enzymatic Production ◽  
Bioactive Properties ◽  
Substrate Properties ◽  
Chitin Hydrolysis

Chitooligosaccharides (COS) are homo- or hetero-oligomers of D-glucosamine (GlcN) and N-acetyl-D-glucosamine (GlcNAc) that can be obtained by chitosan or chitin hydrolysis. Their enzymatic production is preferred over other methodologies (physical, chemical, etc.) due to the mild conditions required, the fewer amounts of waste and its efficiency to control product composition. By properly selecting the enzyme (chitinase, chitosanase or nonspecific enzymes) and the substrate properties (degree of deacetylation, molecular weight, etc.), it is possible to direct the synthesis towards any of the three COS types: fully acetylated (faCOS), partially acetylated (paCOS) and fully deacetylated (fdCOS). In this article, we review the main strategies to steer the COS production towards a specific group. The chemical characterization of COS by advanced techniques, e.g., high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and MALDI-TOF mass spectrometry, is critical for structure–function studies. The scaling of processes to synthesize specific COS mixtures is difficult due to the low solubility of chitin/chitosan, the heterogeneity of the reaction mixtures, and high amounts of salts. Enzyme immobilization can help to minimize such hurdles. The main bioactive properties of COS are herein reviewed. Finally, the anti-inflammatory activity of three COS mixtures was assayed in murine macrophages after stimulation with lipopolysaccharides.

scholarly journals Technological and methodological aspects of the production of low- and lactose-free dairy products

Food systems ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 144-153
Author(s):  
Ju. V. Nikitina ◽  
E. V. Topnikova ◽  
O. V. Lepilkina ◽  
O. G. Kashnikova
Keyword(s):  
Dairy Products ◽  
High Performance ◽  
Amperometric Detection ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Special Operations ◽  
Performance Requirements ◽  
Aoac Method ◽  
Methodological Aspects

The features of technologies for low- and lactose-free dairy products, which provide for special operations to hydrolyze lactose or remove it using ultra- or nanofiltration followed by hydrolysis of the residual amount, are considered. Dairy products manufactured using these technologies in different countries as well as enterprises leading in this field of production are presented. The analysis of the methods used to determine the quantitative content of residual lactose in low- and lactose-free dairy products is carried out: enzymatic, HPLC, HPAEC-PAD, amperometric biosensors, Raman spectroscopy. Due to the dairy industry’s need for analytical methods for the determination of lactose in milk and dairy products with low- or lactose-free content, the AOAC Stakeholder Group on Strategic Food Analysis Methods approved Standard Performance Requirements for Biosensor Methods (SMPR®) 2018.009. These requirements were introduced for the quantitative determination of lactose in milk as well as in dairy and milk-containing products with a low or no lactose content. The biosensor method is recommended for use as the official first step of AOAC method. Additionally, it is advisable to use high performance liquid chromatography (HPLC) with mass spectrometric detection, as well as high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) as an international standard method of analysis for the determination of lactose in milk with low- or lactose-free content.

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