scholarly journals Optimal Design Approach Applied to Headspace GC for the Monitoring of Diacetyl Concentration, Spectrophotometric Assessment of Phenolic Compounds and Antioxidant Potential in Different Fermentation Processes of Barley

2021 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
Fouad El Mansouri ◽  
Hammadi El Farissi ◽  
Francesco Cacciola ◽  
Badr Bouhcain ◽  
Joaquim C. G. Esteves da Silva ◽  
...  

The present study aimed to validate a control method on the gas chromatography system (GC) based on the experimental design strategy, to examine the changes and correlation between the fermentation process and the quality of alcoholic and non-alcoholic beer product, especially the formation of diacetyl. On the other hand, spectrophotometric methods were applied to the determination of polyphenols content and the potential antioxidant activity of beer during different fermentation processes. with this aim, three modes of barley fermentation were used, specifically classical fermentation, stopped fermentation and thermal process. The results showed that the different fermentation modes had a major impact on diacetyl production. The highest concentration was obtained using stopped fermentation 0.36 mg/L, the lowest concentration value 0.07 mg/L was detected using the thermal process. Monitoring the increase of oxygen concentration between fermentation, filtration, and filling of the final product (32, 107, 130 ppm, respectively) has a significant impact on the concentration of diacetyl. The obtained results of spectrophotometric analysis showed that the total antioxidant activity changed during beer fermentation process and demonstrate that the extend of the antioxidant activity was very much dependent on the total polyphenolic content with a higher value in Hopped wort (13.41%, 65 mg GAE 100 mL−1, 28 mg CE 100 mL−1) for antioxidant potential, total phenolic content, and total flavonoids content, respectively, whereas the lowest values was detected in Non-alcoholic beer using thermal process (7.24%, 35 mg GAE 100 mL−1, 10 mg CE 100 mL−1) for antioxidant potential, total phenolic contents, and total flavonoids contents, respectively. Based on the results achieved, we reveal the impact of the fermentation process on the nutritional value of the final product.

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7616
Author(s):  
Justyna Antoniewicz ◽  
Joanna Kochman ◽  
Karolina Jakubczyk ◽  
Katarzyna Janda-Milczarek

Fermented foods have been an integral part of the cuisines of almost all cultures in the world. In recent years, they have gained ground again, mainly due to their potential health benefits. One such product is grape vinegar, which apart from characteristic taste, is also a source of compounds with antioxidant activity. The aim of the study was to determine the changes in the antioxidant potential and the content of polyphenols that occur during the storage of grape vinegar obtained by spontaneous fermentation. The research material consisted of vinegar made from different white grape varieties grown in Poland. For each variety, two variants were prepared: with and without the addition of sugar in the fermentation process. The antioxidant potential, polyphenol content, soluble solids content and pH were monitored both during the two-month fermentation process and the subsequent 6-months storage under various conditions. Storage conditions and time of the storage affected the antioxidant activity and polyphenol content. The content of these compounds was also influenced by the variety of grapes used as well as the method of vinegar preparation.


Foods ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 70
Author(s):  
Sneh Punia ◽  
Kawaljit Singh Sandhu ◽  
Simona Grasso ◽  
Sukhvinder Singh Purewal ◽  
Maninder Kaur ◽  
...  

Rice bran (RB) is a byproduct of the rice industry (milling). For the fermentation process and to add value to it, RB was sprayed with fungal spores (Aspergillus oryzae MTCC 3107). The impact of fermentation duration on antioxidant properties was studied. Total phenolic content (TPC) determined using the Folin–Ciocalteu method, increased during fermentation until the 4th day. The antioxidant activity analyzed using the 2,2 Diphenyl–1′ picrylhydrazyl (DPPH) assay, total antioxidant activity (TAC), 2,2′-azinobis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) assay, reducing power assay (RPA) and hydroxyl free radical scavenging activity (HFRSA) for fermented rice bran (FRB) were determined and compared to unfermented rice bran (URB). TAC, DPPH, ABTS+ and RPA of FRB increased till 4th day of fermentation, and then decreased. The specific bioactive constituents in extracts (Ethanol 50%) from FRB and URB were identified using high performance liquid chromatography (HPLC). HPLC confirmed a significant (p < 0.05) increase in gallic acid and ascorbic acid. On the 4th day of fermentation, the concentrations of gallic acid and ascorbic acid were 23.3 and 12.7 µg/g, respectively. The outcome of present investigation confirms that antioxidant potential and TPC of rice bran may be augmented using SSF.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1262
Author(s):  
Shonisani Eugenia Ramashia ◽  
Felicia Matshepho Mamadisa ◽  
Mpho Edward Mashau

This study investigated the impact of Parinari curatellifolia peel flour on the nutritional, physical and antioxidant properties of formulated biscuits. Biscuits enriched with 5%, 10%, 15% and 20% of Parinari (P). curatellifolia peel flour were formulated and characterised. Thermal, physicochemical, polyphenolic compounds and antioxidant properties of flour and biscuits were determined. The incorporation of P. curatellifolia peel flour significantly increased (p < 0.05) thermal properties (onset, peak and conclusion temperatures) of flour. However, enthalpy of gelatinisation, viscosity and pH of flour samples decreased. Nutritional analysis revealed an increase in ash (0.74% to 2.23%) and crude fibre contents (0.39% to 2.95%) along with an increase of P. curatellifolia peel flour levels. Protein content and carbohydrates decreased while moisture content was insignificantly affected by the addition of P. curatellifolia peel flour. The L*, b* values and whiteness index of formulated biscuits decreased while parameter a* value (10.76 to 21.89) and yellowness index (69.84 to 102.71) decreased. Physical properties such as diameter (3.57 mm to 3.97 mm), spread ratio (2.67 to 3.45) and hardness (1188.13 g to 2432.60 g) increased with the inclusion levels of peel flour while weight and thickness decreased. The inclusion of P. curatellifolia improved the polyphenolic compounds and antioxidant activity of biscuits with values of total flavonoids content ranging from 0.028 to 0.104 mg CE/g, total phenolic content increasing from 20.01 mg to 48.51 mg GAE/g, ferric reducing antioxidant power (FRAP) increasing from 108.33 mg to 162.67 mg GAE/g and DPPH (2,2-diphenyl-1-picrylhydrazyl) from 48.70% to 94.72%. These results lead to the recommendation of the utilisation of P. curatellifolia peel flour to enhance the nutritional value, polyphenolic compounds and antioxidant activity of bakery products such as biscuits.


2021 ◽  
Vol 45 ◽  
Author(s):  
Andréa Michel Sobottka ◽  
Elisandra Tessaro ◽  
Suelen Maier da Silva ◽  
Marina Pedron ◽  
Lara Tortini Seffrin

ABSTRACT Allophylus edulis and Cupania vernalis (Sapindaceae) are Brazilian native trees used as medicinal plants for the treatment of respiratory, digestive, circulatory, and skin diseases. Ubiquitously distributed in the Brazilian territory, these species are indicated for mixed plantations aimed at the recovery of degraded ecosystems. In this study, the total phenolic content (TPC) and total flavonoid content (TFC), and the antioxidant activity of extracts and fractions obtained from A. edulis and C. vernalis leaves were assessed. The TPC and TFC was determined spectrophotometrically. Antioxidant activity was evaluated through radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The extracts were obtained by two methods: maceration (method 1) and Soxhlet (method 2). Solvents of increasing polarity (hexane, dichloromethane, ethyl acetate, and n-butanol) were used to obtained the fractions. The results showed that the ethyl acetate fraction from A. edulis, obtained from the maceration method, had the highest TPC (442.0 ± 18.2 mg GAE g-1) and TFC (58.1 ± 0.4 mg RUE g-1), and antioxidant activity (EC50 = 43.6 ± 2.6 µg mL-1). By C. vernalis, superior results were obtained with the n-butanol fraction (TPC = 126.1 ± 5.8 mg GAE g-1, TFC = 37.7 ± 0.6 mg RUE g-1). The highest antioxidant potential was found in the crude hydroalcoholic extract (EC50 = 816.1 ± 50.9 µg mL-1) and butanol fraction (1,156.4 ± 3.8 µg mL-1). The results of this study show that the fractions obtained by maceration and liquid-liquid partition with more polar solvents (ethyl acetate and n-butanol) are the richest in TPC and TFC, and presented the greater antioxidant activity. Comparing the two plants, A. edulis showed the best results, with a high content of TPC, TFC, and antioxidant potential, and therefore may be used to treat diseases related to oxidative stress.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Muhammad Asam Raza ◽  
Rukhsana Kausar ◽  
Faraz Ali Rana ◽  
Muhammad Danish ◽  
Durre Shahwar ◽  
...  

This study was designed to evaluate the antioxidant potential ofLoranthus pulverulentus. Stem bark, leaves, and seeds ofLoranthus pulverulentuswere extracted in methanol:water (90 : 10) and partitioned with n-hexane, chloroform, ethyl acetate, and n-butanol successively using partition chromatography. Total phenolic contents and antioxidant potential were checked using standard protocols. Total phenolic contents of all extracts were determined, using Folin–Ciocalteu reagent, and ranged between 151 ± 2.1 and 396 ± 1.6 for stem bark, 137 ± 0.9 and 430 ± 2.2 for, and 39 ± 0.6 and 231 ± 1.7 for seeds. The antioxidant potential of extracts was evaluated; namely, DPPH, FRAP, and total antioxidant models. The ethyl acetate extract of stem-bark, leaves, and seeds showed the highest activity in DPPH (94.5 ± 2.1%, 96.30 ± 0.9%, and 92.30 ± 1.1%, IC5015.9 ± 0.5 μg, 14.5 ± 0.8, and 102.7 ± 1.3, resp.), FRAP (7.7 ± 0.6, 7.5 ± 0.7 and 6.6 ± 0.7, resp.), and total antioxidant (0.95 ± 0.09, 1.19 ± 0.09, and 0.686 ± 0.08, resp.). Strong correlations were observed between total phenols versus total antioxidant activity, DPPH, and FRAP withR2values ranging from 0.8185 to 0.9951 (stem-bark), 0.6728 to 0.8648 (leaves), and 0.8658 to 0.9910 (seed) which indicated that phenolic contents are the major constituents responsible for antioxidant activity.


2017 ◽  
Vol 12 (2) ◽  
pp. 1934578X1701200
Author(s):  
Michał Adam Janiak ◽  
Adriana Slavova-Kazakova ◽  
Magdalena Karamać ◽  
Vessela Kancheva ◽  
Anastasiya Terzieva ◽  
...  

Food irradiation technologies are used to reduce the risk of food borne diseases by eliminating pathogenic microorganisms, prolonging shelf life and reducing storage losses by delaying ripening, germination or sprouting. However, application of irradiation in food technology can negatively influence the biologically active compounds in foods. In this research, the effect of gamma-irradiation on the antioxidant activity of Bulgarian teas was investigated. The aim of the study was to evaluate the total phenolic and tannin content and antioxidant activity of ethanolic extracts of Bulgarian herbal teas before and after gamma-irradiation. Mursalski tea ( Sideritis scardica), Mashterka tea ( Thymus serpyllum), Good Night tea (tea mix), Staroplaninski tea (Balkan tea mix), Trakia tea (tea mix), and Mountain tea (Planinski tea mix) were selected for this study. Gamma-irradiation was applied at the absorbed dose of 5 kGy. Antioxidant activity of non-irradiated and irradiated teas was determined by measuring antiradical activity against DPPH• and ABTS•+ and the ability to reduce ferrous ions. The highest total phenolic content was found in Mursalski tea (268 mg/g), and the highest tannin content in Good Night tea (168 mg/g). FRAP, TEAC and DPPH assays revealed that the most active samples were Staroplaninski (2.78 mmol Fe (II)/g), Planinski (0.87 mmol Trolox/g) and Planinski (0.032 mg/mL), respectively. The radical scavenging activity of irradiated tea samples was maintained after gamma-irradiation. The most interesting extract from irradiated tea studied was Staroplaninski, which demonstrated a higher antioxidant potential in the irradiated sample compared with the non-irradiated sample.


2018 ◽  
Vol 46 (1) ◽  
pp. 134-137 ◽  
Author(s):  
Sina COSMULESCU ◽  
Ion TRANDAFIR ◽  
Violeta NOUR ◽  
Gheorghe ACHIM ◽  
Mihai BOTU ◽  
...  

Fruits of two jujube (Ziziphus jujuba Mill.) cultivars were collected at four stages of ripening and analyzed in terms of chemical compounds. The cultivars were grown under the climatic conditions of the Sub-Carpathian area Ramnicu-Valcea in Romania (45°6′17″N, 24°22′32″E). Total phenols content, total flavonoids content, organic acids from jujube fruits and related antioxidant activities were investigated during the ripening stages. The antioxidant activity of alcoholic extracts was investigated by the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. Total phenolic content was determined by using the Folin-Ciocalteu assay, while determination of flavonoids was done by aluminium nitrate colorimetric method, and organic acids were separated by reversed phase chromatography. The results obtained have indicated significant differences (p < 0.05) found in bioactive compounds and antioxidant activity, depending on cultivars and ripening stage. Total phenolic content ranged from 1634.44 to 472.38 mg GAE/100 g in methanolic extracts of the two varieties studied, while total flavonoids content ranged from 19.9 to 48.5 mg QE/100 g. As regards the influence of ripening stage, the results show that the highest antioxidant activity was recorded in the stage of white maturity. The impact of maturity stage was significant on organic acid distribution of jujube extracts, and ascorbic acid is the major organic acid found in jujube fruits, followed by malic acid and lactic acid. Jujube fruits are rich in bioactive compounds and can be a complement in human’s healthy eating.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shweta Goyal ◽  
Geeta Tewari ◽  
H. K Pandey ◽  
Anjali Kumari

Origanum vulgare L., the most complex and variable species of the genus Origanum, is used to cure various diseases in the traditional medicinal system. In the current investigation, O. vulgare was collected from its natural origin and further multiplied for two years at the experimental farm of DIBER field station, Auli, and afterwards, it was grown at three different altitudes, i.e., DIBER field station of Auli (2744 m), Pithoragarh (1524 m), and Haldwani (412 m), under natural field conditions. The essential oil was extracted using the Clevenger apparatus and analyzed by GC/MS and GC/FID. The total phenolic, flavonoid, and tannin content in the methanolic extracts of all the cultivations were estimated by using Folin–Ciocalteu reagent, aluminium chloride reagent, and Folin–Denis methods, respectively. The antioxidant activity of the essential oils and extracts of all the cultivations was also estimated by DPPH, ABTS, and reducing power methods. The highest amount of phenolics, flavonoids, and tannins was obtained in the Pithoragarh cultivation. Thymol was the major component in all the essential oils contributing 38.81% (Auli), 52.83% (Pithoragarh), and 31.86% (Haldwani) of the total oil. The highest antioxidant activity was exhibited by oregano oil of Pithoragarh cultivation, followed by Auli and Haldwani, respectively. The alcoholic extract of Pithoragarh cultivation had the highest antioxidant activity. The study infers that the plant demonstrated good results in terms of fresh weight, oil yield, antioxidant potential, and EO composition when grown at higher altitudes.


2018 ◽  
Vol 6 (2) ◽  
pp. 318-328 ◽  
Author(s):  
Maria Giannakourou ◽  
Irini F. Stratati ◽  
Efthimia Maria Manika ◽  
Victoria Resiti ◽  
Panagiotis Tataridis ◽  
...  

This study aimed at investigating the benefits of immersing oak sticks in the Greek pomace brandy named tsipouro, regarding its total phenolic content, antiradical-antioxidant activity, colour parameters and sensory profile. In order to induce rapid aging of tsipouro, alternative experimental conditions were applied. Results revealed that the phenolic migration from the wood to the tsipouro significantly increased both with temperature increase during aging as well as with the oak sticks /tsipouro ratio (w/v). The impact of oak wood diversity was also tested, by selecting different types of French oak (Quercus robur) and French and American oak mix (Quercus robur- Quercus alba) sticks. Results exhibited a significant effect of wood stick type on total phenolic content, antioxidant and antiradical activity, colour values and sensory attributes, especially on overall acceptance. High positive correlation among total phenolic content, antiradical and antioxidant activity and overall acceptance was found for all the extracts studied. Wood aging promoted the migration of phenolic compounds from the wood into the tsipouro, which, apart from the organoleptic characteristics, could possess health beneficial effects.


2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Hamadia Khurshid ◽  
Syed Mubashar Sabir ◽  
Shahid Iqbal Awan ◽  
Syed Rizwan Abbas ◽  
Muhammad Irshad

Rose petals have been applied as food additives in teas, cakes and flavor extracts. The aim of this research study was to explore and reveal the antioxidant potential of aqueous extracts of rose petals belonging to nine genotypes of rose (wild as well as hybrid). The in vitro antioxidant activities of roses were studied by lipid peroxidation assay, DPPH radical scavenging assay, iron chelation assay, phosphomolybdenum reduction assay and total phenolic and flavonoid contents. The aqueous extract showed inhibition against lipid peroxidation (TBARS), induced by prooxidants (10 µM FeSO4) in mice liver homogenate. The free radical scavenging activities of the extracts were determined by scavenging of the DPPH radical. Extracts also showed metal chelating activities and high antioxidant activity in the phosphomolybdenum assay. The high content of phenolics and flavonoids detected in aqueous extracts may be responsible for the antioxidant activity. Amongst the different rose genotypes, screened, Rosa moschata (musk rose) was found to carry slightly higher antioxidant potential, owing to its higher phytochemical content.


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