scholarly journals Kinetics of Phenolic Compounds Modification during Maize Flour Fermentation

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6702
Author(s):  
Oluwafemi Ayodeji Adebo ◽  
Ajibola Bamikole Oyedeji ◽  
Janet Adeyinka Adebiyi ◽  
Chiemela Enyinnaya Chinma ◽  
Samson Adeoye Oyeyinka ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Phenolic Acids ◽  
Kinetic Models ◽  
Titratable Acidity ◽  
Second Order ◽  
Soluble Solids ◽  
Maize Flour ◽  
First Order ◽  
Compound Modification ◽  
Kinetics Of

This study aimed to investigate the kinetics of phenolic compound modification during the fermentation of maize flour at different times. Maize was spontaneously fermented into sourdough at varying times (24, 48, 72, 96, and 120 h) and, at each point, the pH, titratable acidity (TTA), total soluble solids (TSS), phenolic compounds (flavonoids such as apigenin, kaempferol, luteolin, quercetin, and taxifolin) and phenolic acids (caffeic, gallic, ferulic, p-coumaric, sinapic, and vanillic acids) were investigated. Three kinetic models (zero-, first-, and second-order equations) were used to determine the kinetics of phenolic modification during the fermentation. Results obtained showed that fermentation significantly reduced pH, with a corresponding increase in TTA and TSS. All the investigated flavonoids were significantly reduced after fermentation, while phenolic acids gradually increased during fermentation. Among the kinetic models adopted, first-order (R2 = 0.45–0.96) and zero-order (R2 = 0.20–0.82) equations best described the time-dependent modifications of free and bound flavonoids, respectively. On the other hand, first-order (R2 = 0.46–0.69) and second-order (R2 = 0.005–0.28) equations were best suited to explain the degradation of bound and free phenolic acids, respectively. This study shows that the modification of phenolic compounds during fermentation is compound-specific and that their rates of change may be largely dependent on their forms of existence in the fermented products.

Evidence for general base catalysis by protic solvents in a kinetic study of alcoholyses and hydrolyses of 1-(phenoxycarbonyl)pyridinium ions under both solvolytic and non-solvolytic conditions

2009 ◽  
Vol 74 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Dennis N. Kevill ◽  
Byoung-Chun Park ◽  
Jin Burm Kyong
Keyword(s):  
Second Order ◽  
Base Catalysis ◽  
Substitution Reactions ◽  
Third Order ◽  
Methoxy Derivative ◽  
First Order ◽  
General Base ◽  
Protic Solvents ◽  
Kinetics Of ◽  
Pyridinium Ions

The kinetics of nucleophilic substitution reactions of 1-(phenoxycarbonyl)pyridinium ions, prepared with the essentially non-nucleophilic/non-basic fluoroborate as the counterion, have been studied using up to 1.60 M methanol in acetonitrile as solvent and under solvolytic conditions in 2,2,2-trifluoroethan-1-ol (TFE) and its mixtures with water. Under the non- solvolytic conditions, the parent and three pyridine-ring-substituted derivatives were studied. Both second-order (first-order in methanol) and third-order (second-order in methanol) kinetic contributions were observed. In the solvolysis studies, since solvent ionizing power values were almost constant over the range of aqueous TFE studied, a Grunwald–Winstein equation treatment of the specific rates of solvolysis for the parent and the 4-methoxy derivative could be carried out in terms of variations in solvent nucleophilicity, and an appreciable sensitivity to changes in solvent nucleophilicity was found.

scholarly journals PHYSICOCHEMICAL CHARACTERISTICS, ANTIOXIDANT CAPACITY AND PHENOLIC COMPOUNDS OF TOMATOES FERTIGATED WITH DIFFERENT NITROGEN RATES

2017 ◽  
Vol 30 (1) ◽  
pp. 237-243 ◽  
Author(s):  
MARCOS FILGUEIRAS JORGE ◽  
◽  
KAMILA DE OLIVEIRA DO NASCIMENTO ◽  
JOSÉ LUCENA BARBOSA JUNIOR ◽  
LEONARDO DUARTE BATISTA DA SILVA ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Antioxidant Capacity ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Fecal Coliforms ◽  
Total Phenolic ◽  
Frap Assay ◽  
Antioxidant Capacities ◽  
Microbiological Characteristics ◽  
Nitrogen Rates

ABSTRACT The objective of this work was to evaluate the physicochemical and microbiological characteristics, antioxidant capacity and phenolic compounds of organic cherry tomatoes grown under fertigation with organic dairy cattle wastewater (DCW) with different nitrogen rates. Tomato plants, grown in an agroecological farm in Seropédica, State of Rio de Janeiro, Brazil, were subjected to four different nitrogen rates (T1=0, T2=50, T3=100 and T4=150% of N). The moisture, lipids, ashes, protein and total fiber contents, soluble solids (ºBrix), reducing and total sugars (%), pH and total titratable acidity (mg NaOH per 100 g) were evaluated. The total phenolic content (TPC) and the antioxidant capacity was determined by the DPPH and FRAP methods. The different nitrogen rates (%N) affected the pH, protein and soluble solids contents. The increase in %N increased the antioxidant capacities, according to the DPPH assay, and TPC. On the other hand, the tomatoes under fertigation with the highest %N presented lower antioxidant capacities according to the FRAP assay. The fertigation did not affect the microbiological characteristics of the tomatoes, which presented fecal coliforms count <3 NMP g-1 and absence of Salmonella in 25 g.

scholarly journals Conservation of Sweet Grape tomatoes using albumin coatings containing phenolic compounds of Spirulina sp. LEB-18.

2017 ◽  
Vol 8 (4) ◽  
pp. 128
Author(s):  
Anelise Christ Ribeiro ◽  
Rui Carlos Zambiazi ◽  
Leonor Almeida de Souza Soares
Keyword(s):  
Phenolic Compounds ◽  
Mass Loss ◽  
Shelf Life ◽  
Visual Analysis ◽  
Water Immersion ◽  
Control Sample ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Edible Coatings ◽  
Phenolic Extracts

The objective of this study was to evaluate the influence of protein globulin-based films and with addition of phenolic compounds extracted from Spirulina sp. LEB-18 in the conservation of tomatoes "Sweet Grape". For this, the tomatoes were immersed for one min in edible coatings, the first based on phenolic extracts derived from Spirulina sp. LEB-18 and ovalbumin (extracted from eggwhite), and the second based just on ovalbumin, beyond the control sample with only water immersion. Tests of pH, of titratable acidity, of color, of soluble solids, of mass loss and visual analysis were taken every 96 h during the 20 day period. The results show that the coating made with phenolic compounds increased the shelf life of tomatoes type "sweet grape".

scholarly journals Evaluation of different methodologies for the determination of phenolic compounds in tropical fruits

2020 ◽  
Vol 23 ◽  
Author(s):  
Karina Carvalho Guimarães ◽  
Derlyene Lucas Salgado ◽  
Elisângela Elena Nunes Carvalho
Keyword(s):  
Phenolic Compounds ◽  
Vitamin C ◽  
Fruits And Vegetables ◽  
Titratable Acidity ◽  
Natural Antioxidants ◽  
Soluble Solids ◽  
Total Phenolic ◽  
Fast Blue ◽  
Recent Method

Abstract Phenolic compounds are natural antioxidants and can be found with abundance in fruits and vegetables. One of the first methods created for analyzing phenolic compounds was the Folin-Denis method; and hereafter, the Folin Ciocalteu method was developed and recently, one of the most recent method is the Fast Blue. Due to the importance of these compounds in food, this work aimed to determine the total phenolic compounds in three fruits, such as: Passion Fruit, “Palmer” mango and “Pera” orange. In addition, these fruits were analyzed through three different determination methods. Furthermore, the content of vitamin C, soluble solids, titratable acidity and pH of these fruits were evaluated. Based on the results, it was verified that there was no difference among the values of vitamin C, soluble solids and TA in relation to those found in the literature. When comparing the three methods (Fast Blue BB, Folin-Ciocalteu Reagent and Folin-Denis Reagent), the results showed a difference in the phenolic compounds that may be related to the distinct reagents used in each method and its different action.

scholarly journals Stability of cupuaçu (Theobroma grandiflorum) nectar during storage

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Margarida Cortez Vieira ◽  
Cristina L.M. Silva
Keyword(s):  
Storage Period ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Plate Count ◽  
Life Study ◽  
Conversion Model ◽  
Theobroma Grandiflorum ◽  
First Order ◽  
Microbial Stability ◽  
Environmental Temperatures

A shelf-life study on cupuaçu nectar (Theobroma grandiflorum) was carried out in two parts. Part I studied the microbial stability of the regular nectar (batch R) and the same nectar fortified with synthetic ascorbic acid (AA) (batch F), pasteurized at 90 °C for 3 min and hot filled in glass bottles. Total Plate Count (TPC), yeast and molds as well as pH, total soluble solids (TTS), titratable acidity and hidroxymethylfurfural (HMF) were followed along 43 storage days at 4, 25 and 35 °C. At the end of the storage period neither TPC nor molds or yeast had recovered the initial loads observed before pasteurization, for both R and F batches. Right after pasteurization, acidity increased slightly, pH decreased from 3.52 to 3.3, and TSS increased from 18.7 to 19.0 °Brix, with all stabilizing afterwards.Part II evaluated ascorbic (AA) and dehydroascorbic (DHAA) acids’ stabilization in the two batches, R and F, and dissolved oxygen (DO) was monitored. Both batches were stored at the same temperatures as in Part I for two months. For batch R, the AA degradation results followed a reversible first order reaction (EaAA(R)=-34±6 kJ/mol, kAA(R)25°C=0.006±0.003 days-1, C0AA(R)=0.92±0.01 and C∞AA(R)= 0.43±0.19). For the (F) nectar, the experimental data fitted a first order model well (EaAA(F)=30±17 kJ/mol, kAA(F)25°C =0.0016±0.0004 days-1). DO was modeled as a fractional conversion model (EaDO= 67±17 kJ/mol, kDO25°C= 1.94±0.94 days-1, C0DO=0.97±0.03 and C∞DO= 0.55±0.01). For both nectars, storage at environmental temperatures was preferred (AA retention above 80%) to refrigeration, due to the slower rate of diffusion of DO at lower temperatures.

scholarly journals Adsorption purification of waste water from chromium by ferrite manganese

2020 ◽  
Vol 168 ◽  
pp. 00026
Author(s):  
Liliia Frolova ◽  
Mykola Kharytonov ◽  
Iryna Klimkina ◽  
Oleksandr Kovrov ◽  
Andrii Koveria
Keyword(s):  
Adsorption Process ◽  
Uv Spectroscopy ◽  
Second Order ◽  
Waste Waters ◽  
Equilibrium Isotherms ◽  
X Ray ◽  
First Order ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Kinetics Of

Plasma method is used to synthesize manganese ferrite. The basic properties of ferrite are determined by IR spectroscopy, UV spectroscopy, X-ray phase analysis, vibration magnetometry. The paper shows that the use of magnetically controlled sorbent allows to purify waste waters from chromium (III). The process of adsorption of chromium cations (III) is investigated. The kinetics of the process is studied. To describe the equilibrium isotherms, the experimental data are analysed by the models of Langmuir, Freundlich isotherms. Pseudo-first order, pseudo-second-order, and Weber-Morris are used to elucidate the kinetic parameters and mechanism of the adsorption process. It has been established that the removal of Cr (III) cations is described by the pseudo-second order of the Langmuir reaction and mechanism.

scholarly journals Ripe Ora-pro-nobis (Pereskia aculeata miller) fruits express high contents of bioactive compounds and antioxidant capacity

2018 ◽  
Vol 40 (3) ◽  
Author(s):  
Aline Priscilla Gomes da Silva ◽  
Poliana Cristina Spricigo ◽  
Thais Pádua de Freitas ◽  
Thiago Machado da Silva Acioly ◽  
Severino Matias de Alencar ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Antioxidant Capacity ◽  
Bioactive Compounds ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Total Phenolic ◽  
Maturity Stage ◽  
Total Phenolic Compounds ◽  
Total Carotenoids ◽  
Significant Difference

Abstract Pereskia aculeata Miller is a native cactaceae found from the Northeast to the South of Brazil. This plant is recognized by the high nutritional value of their leaves, which are the most used in cooking and folk medicine. However, studies on the chemical characteristics and antioxidant capacity of the ora-pro-nobis fruits are scarce. Therefore, the aim of this study was to determine the best harvest point of the ora-pro-nobis fruits to optimize the content of bioactive compounds and their antioxidant capacity. The fruits were manually harvested, defined by their peel colors in three maturity stages: unripe (green), intermediate (yellowish green), and ripe (yellow) stages. The following attributes were evaluated: soluble solids (SS), titratable acidity (TA), SS/TA ratio, pH, and content of bioactive compounds, such as total chlorophylls, carotenoids, yellow flavonoids, total phenolic compounds, and antioxidant capacity. There was a decrease in the content of chlorophyll followed by an increase in the of total carotenoids and yellow flavonoids, due to the maturity stage. For the total phenolic compounds, it was not observed significant difference between the stages. The antioxidant capacity was quantified by the ORAC method in lyophilized pulp in the unripe (1.95 mmol 100 g-1 trolox) and ripe (3.85 mmol 100 g-1 trolox) stages. The lowest contents were observed in the intermediate (0.80 mmol 100 g-1 trolox in lyophilized pulp) stage. The maturity stage significantly influenced the bioactive compounds of ora-pro-nobis, which presented higher values of total carotenoids, yellow flavonoids, and antioxidant capacity in ripe fruits.

scholarly journals Physical-chemical properties of exotic and native Brazilian fruits

2019 ◽  
Vol 68 (3) ◽  
pp. 175-181 ◽  
Author(s):  
Veridiana Zocoler de Mendonça ◽  
Rogério Lopes Vieites
Keyword(s):  
Phenolic Compounds ◽  
Antioxidant Capacity ◽  
Chemical Properties ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
High Concentration ◽  
Bioactive Substances ◽  
Fruit Species ◽  
Physical Chemical ◽  
Spondias Purpurea

Many fruit species are still not well-studied, despite being rich in bioactive substances that have functional properties. The objective of this article was to evaluate the antioxidant potential and characterize the physical-chemical characteristics of unconventional brazilian fruits (cabeludinha - Myrciaria glazioviana, sapoti - Manilkara zapota, pitomba - Talisia esculenta, yellow gumixama - Eugenia brasiliensis var. Leucocarpus and seriguela - Spondias purpurea). Total soluble solids, pH, titratable acidity, sugars, pigments, phenolic compounds and antioxidant capacity were measured. Mature fruits were used in the analyses. Pitomba had high levels of soluble solids, 24.6 °Brix, while sapoti had 0.05 g malic acid 100 g-1 pulp. Yellow grumixama and seriguela had the highest concentrations of anthocyanins and carotenoids. Cabeludinha had a high concentration of phenolic compounds, 451.60 mg gallic acid 100 g-1 pulp. With the exception of sapoti, all fruits had a high antioxidant capacity (> 95%).

Kinetics of Glyphosate Adsorption on Composite Resin from Aqueous Solution

2013 ◽  
Vol 803 ◽  
pp. 157-160
Author(s):  
Zhen Zhen Kong ◽  
Dong Mei Jia ◽  
Su Wen Cui
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Composite Resin ◽  
Order Equation ◽  
Second Order ◽  
First Order ◽  
Basic Resin ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Best Fit

The composite weakly basic resin (D301Fe) was prepared and examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption kinetics of glyphosate from aqueous solution onto composite weakly basic resin (D301Fe) were investigated under different conditions. The experimental data was analyzed using various adsorption kinetic models like pseudo-first order, the pseudo-second order, the Elovich and the parabolic diffusion models to determine the best-fit equation for the adsorption of glyphosate onto D301Fe. The results show that the pseudo-second order equation fitted the experimental data well and its adsorption was chemisorption-controlled.

Sign in / Sign up

Export Citation Format

Share Document