Physicochemical Characteristics and Gelling Properties of Arabinoxylans Recovered from Maize Wastewater: Effect of Lime Soaking Time During Nixtamalization

2020 ◽  
pp. 379-388
Author(s):  
Guillermo Niño-Medina ◽  
Elizabeth Carvajal-Millan ◽  
Benjamín Ramírez-Wong ◽  
Jorge Márquez-Escalante ◽  
Agustin Rascón-Chu
Keyword(s):  
Physicochemical Characteristics ◽  
Soaking Time ◽  
Gelling Properties

scholarly journals Mango (Mangifera indica) and ambarella (Spondias cytherea) peel extracted pectins improve viscoelastic properties of derived jams

2012 ◽  
Vol 12 (51) ◽  
pp. 6200-6212
Author(s):  
BB Koubala ◽  
◽  
G Kansci ◽  
C Garnier ◽  
MC Ralet ◽  
...  
Keyword(s):  
Phase Diagrams ◽  
Sucrose Concentration ◽  
Mangifera Indica ◽  
Sol Gel ◽  
Ammonium Oxalate ◽  
Physicochemical Characteristics ◽  
Gelling Properties ◽  
Sol Gel Transition ◽  
Mechanical Spectra ◽  
Mango Pulp

Food industries in developing countries are faced with the problem of inadequate supply of additives which can be met by proper utilization of local pectin sources. Mango ( Mangifera indica ) and ambarella ( Spondias cytherea ) peels are most of the time thrown into nature or used for animal feeding . The y have been reported to be a potential source of pectins which could be used to process the fruits into various products. In order to assess their feasibility to be used in jam processing, ambarella and mango ( Mango variety) peel pectins were extracted using three different extraction conditions: HCl at 85 °C/1h, water at 70 °C/1h and oxalic acid/ammonium oxalate (OAAO) at 85 °C/1h. Compare to commercial lime pectin with degree of methoxylation (DM) 70%, phase diagrams presenting sol -gel transition of purified pectins established as sucrose concentration (40 -75 %, weight/weight) versus reduced pectin concentration (0.1 -1.8 %, weight/weight) were studied at pH 3. Mango and ambarella jams were prepared with and without highly methoxylated peels pectins (0.4 %; DM 60 -75% ) and the effect of pectins on jam firmness was studied. Prepared hot jams, with 64 % of dry matter, 60 % of sucrose and/or 0.4 % of pectin, were characterized for their gelation kinetics and mechanical spectra at 20 °C . Phase diagrams showed that at pH 3, the minimal sucrose concentration used to obtain the gel is 40 % for OAAO mango pectin, 45 % for HCl mango and OAAO ambarella pectin, and 50 % for HCl ambarella and commercial pectin . Only gelation of OAAO extracted pectins was possible at low polymer (0.2 %) and standard sucrose (60 %) concentrations. Jams prepared without pectins exhibited a week gel behaviour (G’ = 500- 1000 Pa at 10 Hz) with those of ambarella being stronger than those of mango. Because of its good physicochemical characteristics, ambarella pulp was more suitable than mango pulp for jam processing. Mango and ambarella jams exhibited very strong gels (G’= 2000- 5000 Pa at 10 Hz ) behaviour while using OAAO extracted pectins ; the viscoelastic strength of the processing fruits increases 3 -6 folds . Accordingly, OAAO extracted mango and ambarella peel pectins allow to obtain jams with excellent gelling properties

scholarly journals Effects of Three Types of Polymeric Proanthocyanidins on Physicochemical and In Vitro Digestive Properties of Potato Starch

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1394
Author(s):  
Jiahui Xu ◽  
Taotao Dai ◽  
Jun Chen ◽  
Xuemei He ◽  
Xixiang Shuai ◽  
...  
Keyword(s):  
Food Processing ◽  
Potato Starch ◽  
Physicochemical Characteristics ◽  
Inhibitory Effects ◽  
Short Term ◽  
Gelling Properties ◽  
Improved Stability ◽  
Starch Paste

The effects of three types of polymeric proanthocyanidins (PPC) with different degrees of polymerization (DP), namely PPC1 (DP = 6.39 ± 0.13), PPC2 (DP = 8.21 ± 0.76), and PPC3 (DP = 9.92 ± 0.21), on the physicochemical characteristics and in vitro starch digestibility of potato starch were studied. PPC addition (5%, w/w) increased the gelatinization temperature and decreased some viscosity indices of potato starch, including the peak, trough, breakdown, and setback viscosities. Starch-PPC pastes showed reduced thixotropy and improved stability and gelling properties compared to starch paste. The three types of proanthocyanidins all showed evident inhibitory effects on the digestion and retrogradation of potato starch, including short-term and long-term retrogradation. Among the three, PPC with a lower DP had stronger effects on the starch short-term retrogradation and gelling performance, whereas larger PPC molecules exhibited a greater impact on starch recrystallization and digestive characteristics. The research consequences were conducive to explore the application of functional PPC in starch-based food processing.

Applications of SEM/EDXA in cement clinker investigation

1990 ◽  
Vol 48 (4) ◽  
pp. 870-871
Author(s):  
Arezki Tagnit-Hamou ◽  
Shondeep L. Sarkar
Keyword(s):  
Mineralogical Composition ◽  
Physicochemical Characteristics ◽  
Cement Clinker ◽  
Accurate Information ◽  
Phase Identification ◽  
History Of ◽  
Bulk Chemical ◽  
Resolution Imaging ◽  
Proven Method ◽  
Instantaneous Chemical

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.

Common modifications of selenocysteine in selenoproteins

2019 ◽  
Vol 64 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elias S.J. Arnér
Keyword(s):  
Amino Acids ◽  
Covalent Binding ◽  
Physicochemical Characteristics ◽  
Redox Active

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.

Study of the quality and antioxidant properties of tomatoes (Solanum lycopersicum L.) under different postharvest and dehydration conditions

2020 ◽  
Vol 13 (9) ◽  
Author(s):  
María Lorena Luna-Guevara ◽  
Teresita González-Sánchez ◽  
Adriana Delgado-Alvarado ◽  
María Elena Ramos-Cassellis ◽  
José Guillermo Pérez-Luna ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Rural Communities ◽  
Antioxidant Properties ◽  
Titratable Acidity ◽  
Physicochemical Characteristics ◽  
Soluble Solids ◽  
Convective Drying ◽  
Tomato Fruits ◽  
Solanum Lycopersicum L ◽  
Storage Temperatures

Objective: To study the effect of storage temperatures and dehydration conditions (solar and convective drying; SD, CD), on the quality, physicochemical parameters and antioxidant properties of tomato fruits. Methodology: The physicochemical characteristics pH, titratable acidity, soluble solids (°Bx) and color parameters (L*, a* and b*), were evaluated. The lycopene, carotenoids and antioxidant activity percentages retention of tomatoes fruits stored at 7 and 22 ° C for 5 days and subjected to SD (Temperature (T) of 67 °C and luminescence of 685 lum/sqf) and CD (T 70 °C, flow rates 0.5, 1.0 and 1.5 m/s), were analyzed. Results: The fruits reached humidities of 17 and 15% for SD and CD. The parameters pH, °Bx, L*, a*, b* were highest with 22°C and CD (1.5 m/s). The value of the carotenoids was higher in fruits stored at 7 ° C and subjected to CD (1.0 and 1.5 m/s) and SD with values of 83.85, 85.98 and 99.43%, respectively. The CD (0.5 m/s) and SD improved lycopene (94.37 and 95.14%) and the antioxidant activity with values of 73.06 and 97.21%. Implications: The application of solar dehydration depends on luminescence condition; however, it is inexpensive and environmentally friendly alternative. Conclusions: The results derived in a viable alternative for the conservation and commercialization of tomato fruits in rural communities

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