scholarly journals The effect method of preservation on selected bioactive compounds and antioxidant activity in blackthorn fruits (Prunus spinosa L.)

2018 ◽  
Vol 73 (3) ◽  
pp. 45-54
Author(s):  
KATARZYNA OLESIŃSKA ◽  
KAMIL WILCZYŃSKI ◽  
KLAUDIA KAŁWA

The effect of freezing (M), freeze drying (L) and convection drying (S) of blackthorn fruits on the content of selected bioactive compounds and antioxidant properties compared to the control sample – fresh fruit (PK), was tested. Changes in the content of flavonoids, anthocyanins, pectins, general acidity and the ability to reduce the DPPPH radical, were determined. The obtained results showed that the freeze-dried fruits had the highest content of anthocyanins and flavonoids, respectively 0.07 and 0.17%. Pectin contents in freeze-dried and convectively dried fruits were similar at the level of 1.66 and 1.64% as well as for acidity respectively 0.076 and 0.071 g·100 g–1 infusion. Frozen fruits did not differ significantly compared to the control in terms of the content of anthocyanins, flavonoids, pectin and acidity. The highest scavenging capacity of free radical DPPH was characterized by the infusion obtained from fresh fruits.

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Wanida Pan-utai ◽  
Siriluck Iamtham

Research background. C-phycocyanin (C-PC) as a water-soluble blue pigment was extracted from microalga Arthrospira. C-PC could be a good substitute for synthetic pigments with high antioxidant activity. However, C-PC is unstable due to sensitivity to temperature, light, pH, and oxygen; therefore applications of C-PC in food and other products are limited. Microencapsulation of C-PC using freeze-drying is a solution to this problem and is considered a suitable method for drying heat-sensitive pigment. Experimental approach. C-phycocyanin was extracted from Arthrospira platensis. C-phycocyanin microcapsules were modified by freeze-drying, with different ratios at 0-100 % of maltodextrin (MD) and gum Arabic (GA) used as microencapsulation wall materials. The powders produced were evaluated for physical properties including moisture content and water activity, solubility, hygroscopicity, bulk density, colour appearance, particle morphology and size distribution. Thermal stability and antioxidant activity of freeze-dried C-PC microencapsulated powders were also assessed. Results and conclusions. Freeze-dried C-PC microencapsulated powders with maltodextrin and gum Arabic as wall materials gave high encapsulation efficiency of around 99 %. At higher gum Arabic percentage, moisture content decreased and water activity improved. Maltodextrin gave higher solubility of C-PC powders whereas gum Arabic led to a similar colour of C-PC without microencapsulation. Freeze-dried C-PC microencapsulated powders were composed of different sized microparticles regardless of the combination of wall materials with amorphous glassy shapes. Thermal stability of encapsulated C-PC increased and also showed high antioxidant properties. Novelty and scientific contribution. C-PC microcapsules that maintain colourant stability with high antioxidant levels and resistance to high temperatures can be applied in a wide variety of products and also in the food industry.


2021 ◽  
Vol 5 (12) ◽  
pp. 326
Author(s):  
Fatemeh Golpira ◽  
Neda Maftoonazad ◽  
Hosahalli S. Ramaswamy

Saffron extract was encapsulated into a gelatin matrix by means of electrospinning and freeze drying techniques and the degradation kinetics of bioactive compounds were evaluated during their storage at 4, 24, and 35 °C as compared to non-encapsulated control. The encapsulation efficiency, thermal properties, storage stability, morphology, and diameter distribution of the encapsulated saffron extract were evaluated as output parameters. In general, both encapsulation techniques demonstrated superior retention of bioactive compounds compared to samples without encapsulation during the entire storage period. Electrospinning and freeze drying techniques were able to retain at least 96.2 and 93.7% of crocin, respectively, after 42 days of storage at 35 °C with the 15% saffron extract. The half-life (t1/2) time parameter for the control sample (with 15% saffron extract without encapsulation) was 22 days at 4 °C temperature, while that encapsulated by electrospinning was 138 days and that obtained for freeze drying was 77 days, The half-lives were longer at lower temperatures. The encapsulation efficiency of crocin, picrocrocin, and safranal associated with the electro-spun gelatin fibers were 76.3, 86.0, and 74.2%, respectively, and in comparison, the freeze drying encapsulation efficiencies were relatively lower, at 69.0, 74.7, and 65.8%, respectively. Electro-spun gelatin fibers also had higher melting and denaturation temperatures of 78.3 °C and 108.1 °C, respectively, as compared to 65.4 °C and 93.2 °C, respectively, for freeze-dried samples. Thus, from all respects, it was concluded that electrospinning was a better and more effective technique than freeze drying in terms of preserving saffron bioactive compounds.


2019 ◽  
Vol 16 (4) ◽  
pp. 377-391 ◽  
Author(s):  
B.S. Jayashree ◽  
H. Venkatachalam ◽  
Sanchari Basu Mallik

Flavonoids constitute a large group of polyphenolic compounds that are known to have antioxidant properties, through their free radical scavenging abilities. They possess a chromone (γ- benzopyrone) moiety, responsible for eliciting many pharmacological activities. Even though, natural flavonoids are highly potent, owing to their poor solubility, they are less used. Therefore, attempts have been made to improve their stability, solubility, efficacy and kinetics by introducing various substituents on the flavone ring. For nearly the last two decades, flavones were synthesized in our laboratory by simple, convenient and cost-effective methods, with the knowledge of both synthetic and semi-synthetic chemistry. In this direction, it was considered worthwhile to present an overview on the synthesized flavonoids. This review creates a platform for highlighting various modifications done on the flavone system along with their biological activity.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 839
Author(s):  
Karina Jasińska ◽  
Bartłomiej Zieniuk ◽  
Dorota Nowak ◽  
Agata Fabiszewska

The study aimed to evaluate the impact of selected factors of the freeze-drying process on the hydrolytic and synthetic activity of the extracellular lipases of Y. lipolytica KKP 379 and to attempt the use of the crude enzyme preparation as a biocatalyst in the synthesis of geranyl 4-hydroxyphenylpropanoate. Antioxidant and antibacterial properties of the geranyl ester derivative were also investigated in order to evaluate their usefulness as a novel food additive. The studies confirmed that freeze-drying was an effective method of dehydrating yeast supernatant and allowed for obtaining lyophilizates with low water activity from 0.055 to 0.160. The type and concentration of the additive (2–6% whey protein hydrolyzate, 0.5% and 1% ammonium sulphate) had a significant effect on the hydrolytic activity of enzyme preparations, while the selected variants of drying temperature during the freeze-drying process were not significant (10 °C and 50 °C). Low yield of geranyl 4-hydroxyphenylopropionate was shown when the lyophilized supernatant was used (5.3%), but the yield of ester synthesis increased when the freeze-dried Y. lipolytica yeast biomass was applied (47.9%). The study confirmed the antioxidant properties of the synthesized ester by the DPPH• and CUPRAC methods, as well as higher antibacterial activity against tested bacteria than its precursor with 0.125 mM MIC (minimal inhibitory concentration) against L. monocytogenes.


2019 ◽  
Vol 74 (1) ◽  
pp. 53-62
Author(s):  
KATARZYNA OLESIŃSKA ◽  
DANUTA SUGIER ◽  
ŁUKASZ SĘCZYK

The aim of the study was to determine the influence of selected methods of preservation and storage time on the content of antioxidants in blackthorn fruit (Prunus spinosa L.). Preserved fruits were stored for 13 and 26 weeks without light at room temperature (freeze-dried and convection dried) and at –20°C (frozen samples). It was shown that both the method of preservation and the storage time had significant influence on the content of polyphenols (anthocyanins, flavonoids, total polyphenols) and antioxidant properties (Fe3+ reduction strength) of blackthorn fruit. As the storage time progressed, the anthocyanins content decreased in all preservation variants. In the case of frozen fruit after 26 weeks of storage, the content of flavonoids (by 12.5%), total polyphenols (by 48%) and the ability to reduce the iron ions were increased (by 55%). In turn, in the dried fruits after this period, the anthocyanins content, the polyphenol content and reduction strength were reduced. The highest values of the parameters evaluated after the assumed storage time has been demonstrated in lyophilizates.


2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Jun Yu ◽  
Zijian Shangguan ◽  
Xingju Yang ◽  
Dan Sun ◽  
Baoqing Zhu ◽  
...  

AbstractDifferent drying methods, including hot air drying (HAD), freeze drying (FD), spray drying and vacuum drying (VD), were investigated to determine their influence on the chromatic coordinates, phenolics, anthocyanins and antioxidant activities of dried red raspberry (Rubus lambertianus). Pelargonidin-3-O-glucoside and catechin were found to be the main anthocyanin and non-anthocyanin phenolics, respectively, in fresh red raspberry. The most effective method for controlling browning was FD. The highest protective effects against bioactive compounds were observed in freeze-dried powders, when measuring the total anthocyanins, the scavenging of DPPH (1,1-diphenyl-2-picrylhydrazyl) and hydroxyl radicals and the inhibition effects on lard oxidation. HAD was effective for the preservation of total phenolics, while VD was useful for protecting catechin and procyanidin B1.


Author(s):  
L Azeez

This study examined the influence of microbial contamination on the antioxidant composition and free radical scavenging effects of fresh and decaying spices: Lycopersicon esculentum, Capsicum frutescens S, Capsicum frutescens T and Capsicum annum used by food vendors. Microbial load was enumerated with potato dextrose agar (PDA) using the pour plate technique, phytochemical components were determined using Folio-Ciocalteu, Aluminium chloride, acetone-hexane methods for phenolic, flavonoids and β-carotene & lycopene respectively while free radical scavenging capacity was determined using DPPH method. Decaying L. esculentum had highest microbial population of 7.14 X 105 cfu/g and fresh C. annum had the lowest microbial population of 0.72 X 101cfu/g. Microbial population in decaying spices were generally significantly higher than fresh spices. Aspergillus spp were found in all decaying spices and in fresh C. frutescens T. Microsporum spp were found in all fresh spices except in C. frutescens T and in decaying spices except in C. annum. There were significant decreases (p <0.05) in phenolic, flavonoid, β-carotene and free radical scavenging capacity contents of all decaying spices compared to fresh spices except for phenolic content in C. annum while significant decrease (p < 0.05) in lycopene content was obtained for only decaying L. esculentum compared to fresh one. Reduction in antioxidant activity and phytochemical contents could not be unconnected with the high microbial population in decaying spices because antioxidant activity and phytochemical contents significantly correlate with antibacterial activity. Thus, consumption of decaying spices as shown by our study could pose a serious health challenges due to the presence of high number of microbes detected and loss of healthprotecting ability of the spices. Â


Author(s):  
Chandrasekaran Swaminathan

Objective: The present study was designed to evaluate the phytochemical composition and antibacterial and antioxidant potential of methanolic leaf and root extracts of Indigofera tinctoria L.Methods: Phytochemical analysis was done using standard methods. The methanolic leaf and root extracts of the plant were tested against Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Enterobacter aerogenes, and Salmonella paratyphi B by cup-plate agar diffusion method. The free radical scavenging activities of the methanol extracts of leaves and roots were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.Results: Phytochemical screening revealed the presence of carbohydrates, reducing sugars, alkaloids, saponins, phenolic compounds, and flavonoids in methanolic leaf and root extracts. Methanolic leaf extracts of the plant exhibited antibacterial activity against a wide range of bacteria, but the root extracts failed to inhibit the tested bacterial pathogens. The antioxidant activity determination revealed that at 100 μg/ml, methanolic root extracts had the highest antioxidant activity (89.10%) on DPPH free radicals followed by methanolic leaf extracts (46.74%).Conclusion: The results of the present study conclude that the studied plant possesses broad-spectrum antibacterial and antioxidant properties and may act as a potent antioxidant for biological systems susceptible to free radical-mediated reactions. 


Sign in / Sign up

Export Citation Format

Share Document