Research perspectives and further studies on catalyst effects on the stability of different polyethylenes during multiple extrusion: Inter‐relationship of oxidation chemistry and antioxidant activity

2021 ◽  
Author(s):  
Norman S. Allen ◽  
Christopher M. Liauw ◽  
Michele Edge ◽  
Eric Hoang ◽  
Eusebio Fontan
Keyword(s):  
Antioxidant Activity ◽  
Research Perspectives ◽  
The Stability ◽  
Oxidation Chemistry ◽  
Relationship Of

A FORECAST OF PRODUCTIVE LONGEVITY OF HOLSTEIN COWS BY INDIRECT SIGNS

2020 ◽  
Author(s):  
З.С. САНОВА
Keyword(s):  
Correlation Coefficient ◽  
Aging Process ◽  
Direct Relationship ◽  
Stability Index ◽  
Age At First Calving ◽  
Group I ◽  
Predicted Values ◽  
The Stability ◽  
Relationship Of ◽  
The Relationship

В статье представлены материалы о взаимосвязи продолжительности продуктивного использования коров с характеристикой устойчивости к деградации, с возрастом отела и удоем. В исследованной, разнородной по происхождению, группе животных для прогноза продуктивного периода коров, обусловленного устойчивостью к деградации и возрастом первого отела, пригодно уравнение регрессии, аргументами в котором являются индекс устойчивости, возраст первого отела в первой и второй степенях. Коэффициент корреляции межу предсказанными значениями продуктивного периода и его фактическими величинами в I группе составляет 0,502, во II - 0,604. При этом крайние варианты прогнозируются со статистическими ошибками 5 мес при оценке индекса устойчивости по 2 лактациям и 4,1 мес по 3, а средние варианты, соответственно, 1,6 и 1,51 мес. Индекс устойчивости к процессу старения является важной характеристикой биологических особенностей коров, определяющий их продуктивное долголетие. Его оценка по первым 2 и 3 лактациям имеет прямолинейную связь с продуктивным периодом (r=0,4109 и r=0,5270), соответственно. Зависимость продуктивного периода от возраста первого отела криволинейная — с увеличением возраста первого отела сокращается срок продуктивного использования, при возрасте первого отела более 1400 дней срок продуктивного использования колеблется от 1,33 до 1,41 лактации. Коэффициент корреляции между этими характеристиками коров составляет - 0,2164 в I и - 0,2620 во II группах. The article presents materials about the relationship of the duration of productive use of cows with the characteristic of resistance to degradation, with the age of calving and milk yield. In the studied group of animals, which is heterogeneous in origin, the regression equation is suitable for predicting the productive period of cows due to resistance to degradation and the age of the first calving, the arguments of which are the stability index, the age of the first calving in the first and second degrees. The correlation coefficient between the predicted values of the productive period and its actual values in group I is 0.502, in group II - 0.604. At the same time, the extreme variants are predicted with statistical errors of 5 months when evaluating the stability index for 2 lactations and 4.1 months for 3, and the average variants, respectively, are 1.6 and 1.51 months. The index of resistance to the aging process is an important characteristic of the biological characteristics of cows, which determines their productive longevity. Its estimate for the first 2 and 3 lactations has a direct relationship with the productive period (r=0.4109 and r=0.5270), respectively. The dependence of the productive period age at first calving curvilinear with increasing age at first calving reduces the time to productive use, while age at first calving of more than 1400 days, the period of productive use ranges from 1.33 to 1.41 lactation. The correlation coefficient between these characteristics of cows is-0.2164 in I and-0.2620 in II groups.

Radix Pseudostellariae protein-curcumin nanocomplex: Improvement on the stability, cellular uptake and antioxidant activity of curcumin

2021 ◽  
Vol 151 ◽  
pp. 112110
Author(s):  
Xixi Cai ◽  
Qingxia Weng ◽  
Jiaming Lin ◽  
Guiqing Chen ◽  
Shaoyun Wang
Keyword(s):  
Antioxidant Activity ◽  
Cellular Uptake ◽  
The Stability

scholarly journals Effect of food processing on the antioxidant activity of flavones from Polygonatum odoratum (Mill.) Druce

2021 ◽  
Vol 16 (1) ◽  
pp. 92-101
Author(s):  
Guanghui Xia ◽  
Xinhua Li ◽  
Zhen Zhang ◽  
Yuhang Jiang
Keyword(s):  
Antioxidant Activity ◽  
High Pressure ◽  
Food Processing ◽  
Yeast Fermentation ◽  
Pressure Treatment ◽  
Processing Methods ◽  
High Pressure Treatment ◽  
Effect Of Food ◽  
The Stability

Abstract Polygonatum odoratum (Mill.) Druce (POD) is a natural plant widely used for food and medicine, thanks to its rich content of a strong antioxidant agent called homoisoflavones. However, food processing methods could affect the stability of POD flavones, resulting in changes to their antioxidant activity. This study attempts to evaluate the antioxidant activity of POD flavones subject to different processing methods and determines which method could preserve the antioxidant activity of POD flavones. Therefore, flavones were extracted from POD samples, which had been treated separately with one of the four processing methods: extrusion, baking, high-pressure treatment, and yeast fermentation. After that, the antioxidant activity of the flavones was subject to in vivo tests in zebrafish embryos. The results show that yeast fermentation had the least disruption to the antioxidant activity of POD flavones, making it the most suitable food processing method for POD. By contrast, extrusion and high-pressure treatment both slightly weakened the antioxidant activity of the flavones and should be avoided in food processing. The research results provide a reference for the development and utilization of POD and the protection of its biological activity.

scholarly journals Complexes of Copper and Iron with Pyridoxamine, Ascorbic Acid, and a Model Amadori Compound: Exploring Pyridoxamine’s Secondary Antioxidant Activity

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 208
Author(s):  
Guillermo García-Díez ◽  
Roger Monreal-Corona ◽  
Nelaine Mora-Diez
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Rate Constant ◽  
Stable Complex ◽  
Aqueous Environment ◽  
Oh Radicals ◽  
Bidentate Ligands ◽  
Superoxide Radical Anion ◽  
Amadori Compound ◽  
The Stability

The thermodynamic stability of 11 complexes of Cu(II) and 26 complexes of Fe(III) is studied, comprising the ligands pyridoxamine (PM), ascorbic acid (ASC), and a model Amadori compound (AMD). In addition, the secondary antioxidant activity of PM is analyzed when chelating both Cu(II) and Fe(III), relative to the rate constant of the first step of the Haber-Weiss cycle, in the presence of the superoxide radical anion (O2•−) or ascorbate (ASC−). Calculations are performed at the M05(SMD)/6-311+G(d,p) level of theory. The aqueous environment is modeled by making use of the SMD solvation method in all calculations. This level of theory accurately reproduces the experimental data available. When put in perspective with the stability of various complexes of aminoguanidine (AG) (which we have previously studied), the following stability trends can be found for the Cu(II) and Fe(III) complexes, respectively: ASC < AG < AMD < PM and AG < ASC < AMD < PM. The most stable complex of Cu(II) with PM (with two bidentate ligands) presents a ΔGf0 value of −35.8 kcal/mol, whereas the Fe(III) complex with the highest stability (with three bidentate ligands) possesses a ΔGf0 of −58.9 kcal/mol. These complexes can significantly reduce the rate constant of the first step of the Haber-Weiss cycle with both O2•− and ASC−. In the case of the copper-containing reaction, the rates are reduced up to 9.70 × 103 and 4.09 × 1013 times, respectively. With iron, the rates become 1.78 × 103 and 4.45 × 1015 times smaller, respectively. Thus, PM presents significant secondary antioxidant activity since it is able to inhibit the production of ·OH radicals. This work concludes a series of studies on secondary antioxidant activity and allows potentially new glycation inhibitors to be investigated and compared relative to both PM and AG.

A review of lignin hydrogen peroxide oxidation chemistry with emphasis on aromatic aldehydes and acids

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ajinkya More ◽  
Thomas Elder ◽  
Zhihua Jiang
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Degradation ◽  
Reaction Medium ◽  
Dicarboxylic Acids ◽  
Aromatic Aldehydes ◽  
Product Distribution ◽  
Reaction Conditions ◽  
Alkaline Conditions ◽  
The Stability ◽  
Oxidation Chemistry

Abstract This review discusses the main factors that govern the oxidation processes of lignins into aromatic aldehydes and acids using hydrogen peroxide. Aromatic aldehydes and acids are produced in the oxidative degradation of lignin whereas mono and dicarboxylic acids are the main products. The stability of hydrogen peroxide under the reaction conditions is an important factor that needs to be addressed for selectively improving the yield of aromatic aldehydes. Hydrogen peroxide in the presence of heavy metal ions readily decomposes, leading to minor degradation of lignin. This degradation results in quinones which are highly reactive towards peroxide. Under these reaction conditions, the pH of the reaction medium defines the reaction mechanism and the product distribution. Under acidic conditions, hydrogen peroxide reacts electrophilically with electron rich aromatic and olefinic structures at comparatively higher temperatures. In contrast, under alkaline conditions it reacts nucleophilically with electron deficient carbonyl and conjugated carbonyl structures in lignin. The reaction pattern in the oxidation of lignin usually involves cleavage of the aromatic ring, the aliphatic side chain or other linkages which will be discussed in this review.

scholarly journals Antioxidant Activity and Anti-Nutritional Factors in Acacia Nilotica Gum

2021 ◽  
Vol 11 (6) ◽  
pp. 42-51
Author(s):  
Kazi Layla Khaled ◽  
Rukshana Irani
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Properties ◽  
Nutritional Composition ◽  
Acacia Nilotica ◽  
Nutritional Factors ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging ◽  
Relationship Of ◽  
Gallic Acid Equivalent ◽  
Food Commodity

The rapidly growing civilization and economy need the judicious usage of floral and faunal heritage. Acacia nilotica (Family: Fabaceae) is a beneficial plant species and each part of it exhibits numerous biological and pharmacological effects. The gum exudates of Acacia nilotica trees are underutilized plant products that can be explored for their potential as a therapeutic and curative agent. Its nutritional composition, interaction with anti-nutritional factors and antioxidants can determine its utility as a food. The present investigation was aimed to estimate the anti-nutritional factors and antioxidant activity of Acacia nilotica gum. It also focused on establishing a relationship of the obtained data with the ethnomedicinal and pharmacological properties claimed in the literature. The analysis was carried out using standard methods and protocols involving spectrophotometric and gravimetric principles. The anti-nutritional components like tannin, trypsin inhibitor, phytate, oxalate, total saponin, steroidal saponins, alkaloid content of Acacia nilotica gum was found to be 0.2369±0.0354 g tannic acid equivalent/100 g, 0.0108±0.0037 TIU/mg, 156.3333±9.4516 mg/100 g, 132.5±28.3152mg/100 g, 12.7183±6.7788 mg diosgenin equivalent /g, 0.0705±0.01 mg diosgenin equivalent /g, 0.1333±0.0577 g/100 g respectively. The amounts of total phenols and flavonoids was determined to be 8.0033±2.7211 mg of gallic acid equivalent/g sample, 0.0458±0.0186 mg quercetin equivalent /g sample respectively with a significant DPPH Scavenging activity. The results indicate that the quantity of anti-nutritional factors in gum is within the range of the contents of anti-nutritional factors found in commonly consumed foods. The substantial presence of phenol, flavonoids and DPPH activity in the gum indicates the presence of high antioxidant properties. The presence of anti-nutritional factors and antioxidants in favourable levels can impart diverse physiological responses. The present study concluded that Acacia nilotica gum can be used as a nutritious food commodity with a plethora of recuperative activities.

scholarly journals Antioxidant Activity and Anti-Nutritional Factors in Acacia Nilotica Gum

2021 ◽  
Vol 11 (6) ◽  
pp. 42-51
Author(s):  
Layla Khaled Kazi ◽  
Rukshana Irani
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Properties ◽  
Nutritional Composition ◽  
Acacia Nilotica ◽  
Nutritional Factors ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging ◽  
Relationship Of ◽  
Gallic Acid Equivalent ◽  
Food Commodity

The rapidly growing civilization and economy need the judicious usage of floral and faunal heritage. Acacia nilotica (Family: Fabaceae) is a beneficial plant species and each part of it exhibits numerous biological and pharmacological effects. The gum exudates of Acacia nilotica trees are underutilized plant products that can be explored for their potential as a therapeutic and curative agent. Its nutritional composition, interaction with anti-nutritional factors and antioxidants can determine its utility as a food. The present investigation was aimed to estimate the anti-nutritional factors and antioxidant activity of Acacia nilotica gum. It also focused on establishing a relationship of the obtained data with the ethnomedicinal and pharmacological properties claimed in the literature. The analysis was carried out using standard methods and protocols involving spectrophotometric and gravimetric principles. The anti-nutritional components like tannin, trypsin inhibitor, phytate, oxalate, total saponin, steroidal saponins, alkaloid content of Acacia nilotica gum was found to be 0.2369±0.0354 g tannic acid equivalent/100 g, 0.0108±0.0037 TIU/mg, 156.3333±9.4516 mg/100 g, 132.5±28.3152mg/100 g, 12.7183±6.7788 mg diosgenin equivalent /g, 0.0705±0.01 mg diosgenin equivalent /g, 0.1333±0.0577 g/100 g respectively. The amounts of total phenols and flavonoids was determined to be 8.0033±2.7211 mg of gallic acid equivalent/g sample, 0.0458±0.0186 mg quercetin equivalent /g sample respectively with a significant DPPH Scavenging activity. The results indicate that the quantity of anti-nutritional factors in gum is within the range of the contents of anti-nutritional factors found in commonly consumed foods. The substantial presence of phenol, flavonoids and DPPH activity in the gum indicates the presence of high antioxidant properties. The presence of anti-nutritional factors and antioxidants in favourable levels can impart diverse physiological responses. The present study concluded that Acacia nilotica gum can be used as a nutritious food commodity with a plethora of recuperative activities.

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