Physiochemical Responses of the Kernel Quality, Total Phenols and Antioxidant Enzymes of Walnut in Different Forms to the Low-Temperature Storage

Ma, Yanping; Wang, Chaoye; Liu, Chaobin; Tan, Jiawei; Ma, Hui; Wang, Jin

doi:10.3390/foods10092027

Cited by 11 publications

(4 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These findings support and confirm the potent antioxidant activity of Juglans regia kernels reported in several studies [75,[101][102][103][104] .…”

Section: Dpph and Abts Radical Scavenging Activitysupporting

confidence: 91%

Bioactivity of Walnut: Investigating the Triterpenoid Saponin Extracts of Juglans regia Kernels for Antioxidant, Anti-diabetic, and Antimicrobial Properties

Elouafy¹,

Mortada²,

Yadini³

et al. 2023

Prog Micobes Mol Biol

View full text Add to dashboard Cite

The increasing demand for plant-based medicines makes plant research attractive to find natural alternatives that can replace synthetic products or at least reduce their use. Saponins are a group of natural phytochemical compounds in most herbs, vegetables, and legumes. There are two different types of saponin compounds, which can be classified based on the nature of the aglycone bound to the oligosaccharide fragments, whether it is a steroid or triterpenoid. This paper is devoted to saponins with triterpenoid aglycone and aims to study the relationship between their content and several biological activities in different Juglans regia kernel extracts, including antioxidant, antimicrobial and antibacterial activities. Antioxidant activity was assessed against two free radicals: DPPH and ABTS. Oleanolic acid was used as a standard to quantify triterpenoid saponins, measured by the vanillin method, whereas Acarbose and Tetracycline were used as positive controls to evaluate the α-glucosidase inhibitory and antimicrobial activities, respectively, of walnut kernel extracts. Findings show that hydroalcoholic extract (EtOH 70%) has a considerable content of phenolic compounds, with 59.51 ± 0.26 mg GAE/g in total polyphenol contents, while the content of total flavonoids and condensed tannins were 3.14 ± 0.27 mg QE/g and 85.65 ± 0.37 mg CE/g of crude extract, respectively. In terms of antioxidant activity, the butanolic extract proved to be the most effective against DPPH with IC50 = 7.74 ± 1.49 µg/mL, while the precipitated extract showed the highest scavenging activity against the ABTS free radical with IC50 = 33.14 ± 2.96 µg/mL. In addition, butanolic and hydroalcoholic extracts of Juglans regia kernels showed an α-glucosidase inhibitory activity even more efficiently than synthetic drugs such as Acarbose, with IC50 values of 11.66 µg/mL and 16.17 µg/mL, respectively, versus 18.01 µg/mL in Acarbose. The evaluation of the antimicrobial activity against Bacillus subtilis, Escherichia coli and Klebsiella pneumonia strains revealed that some extracts could inhibit these bacteria. This study successfully assessed the bioactivities of the extracts, suggesting that the extracts of medicinal plants can demonstrate stronger bioactivity than pure synthetic compounds.

show abstract

“…These findings support and confirm the potent antioxidant activity of Juglans regia kernels reported in several studies [75,[101][102][103][104] .…”

Section: Dpph and Abts Radical Scavenging Activitysupporting

confidence: 91%

Bioactivity of Walnut: Investigating the Triterpenoid Saponin Extracts of Juglans regia Kernels for Antioxidant, Anti-diabetic, and Antimicrobial Properties

Elouafy¹,

Mortada²,

Yadini³

et al. 2023

Prog Micobes Mol Biol

View full text Add to dashboard Cite

show abstract

“…Some studies indicate a number of factors that could be responsible for the observed differences in the results of the irradiation effect on FRSA for nuts. The genotype, geographical and environmental conditions, cultivation technique that occur during the pre-harvest period, post-harvest storage conditions [ 26 ], extraction solvent and procedure [ 27 ], treatment of the sample (drying, roasting, irradiation) [ 28 ], dose of irradiation, etc., may affect the chemical composition of plant food and play decisive roles in the phenolic content. The irradiation might break the covalent bounds in polyphenols, and they probably become decomposed to compounds without antioxidant abilities.…”

Section: Resultsmentioning

confidence: 99%

Effect of Gamma Irradiation on Fat Content, Fatty Acids, Antioxidants and Oxidative Stability of Almonds, and Electron Paramagnetic Resonance (EPR) Study of Treated Nuts

et al. 2023

View full text Add to dashboard Cite

Gamma irradiation has been applied as an efficient and inexpensive method for the sterilization of nuts for years. However, along with the benefits of such treatment, negative effects are possible because of the formation of reactive oxygen species with a toxic effect on important biologically active substances. Because of the scarce and contradictory information in the literature about gamma-irradiated almonds, the aim of our work was the examination of the lipid changes, antioxidant activity, and oxidative stability of almonds treated by 10 and 25 kGy gamma rays, as well as changes in intensity of the EPR spectra as an indicator for the stability of radiation-induced free radicals. The results revealed no significant differences in the EPR spectra of almonds treated at 10 and 25 kGy doses, neither in their intensity nor in kinetic behaviour. The EPR signals decayed exponentially over 250 days, with a decreasing of central line by 90%, with satellite lines by about 73%. No significant changes in the fat content, fatty acids composition, and acid value of irradiated almonds were observed. However, the amount of (alpha)tocopherols decreased from 292 to 175 mg/kg, whereas the conjugated dienes and trienes increased, K232 from 1.3 to 3 and K268 from 0.04 to 0.15, respectively, with the increasing of irradiation dose. The same was observed for total polyphenols in defatted almonds (1374 to 1520 mg/100 g), where in vitro antioxidant activity determined by ORAC and HORAC methods increased from 100 to 156 µmol TE/g and from 61 to 86 µmol GAE/g, respectively. The oxidative stability of oil decreased from 6 to 4 h at 120 °C and from 24.6 to 18.6 h at 100 °C (measured by Rancimat equipment). The kinetic parameters characterizing the oxidative stability of oil from 10 kGy irradiated almonds were studied before and after addition of different concentrations of ascorbyl palmitate as a synergist of tocopherols. Its effectiveness was concentration-dependent, and 0.75 mM ensured the same induction period as that of non-irradiated nut oil. Further enrichment with alpha-tocopherol in equimolar ratio with palmitate did not improve the oil stability. In conclusion, gamma irradiation is an appropriate method for the treatment of almonds without significant changes in fat content and fatty acids composition. The decreasing of oxidative stability after higher irradiation could be prevented by the addition of ascorbyl palmitate.

show abstract

“…The presence of polyphenols, tocopherols, squalene, unsaturated fatty acids, phytosterols, and bioactive peptides in walnut kernels contributes to their nutritional and medicinal value [ 28 , 29 ]. Polyphenols, which have both antibacterial and antioxidant properties [ 30 , 31 ], are plentiful secondary metabolites in plants.…”

Section: Introductionmentioning

confidence: 99%

The Antioxidant Activities In Vitro and In Vivo and Extraction Conditions Optimization of Defatted Walnut Kernel Extract

Zhou,

Gong,

et al. 2023

Foods

View full text Add to dashboard Cite

The objective of this study was to determine the antioxidant activities of defatted walnut kernel extract (DWE) and whole walnut kernel extract (WE) in vitro and in vivo. Three spectrophotometric methods, DPPH, ABTS, and FRAP, were used in in vitro experiments, and mice were used in in vivo experiments. In addition, response surface methodology (RSM) was used to optimize reflux-assisted ethanol extraction of DWE for maximum antioxidant activity and total phenolic content. The results of in vitro experiments showed that both extracts showed antioxidant activity; however, the antioxidant activity of DWE was higher than that of WE. Both extracts improved the mice’s oxidative damage status in in vivo studies. An ethanol concentration of 58%, an extraction temperature of 48 °C, and an extraction time of 77 min were the ideal parameters for reflux-assisted ethanol extraction of DWE. The results may provide useful information for further applications of defatted walnut kernels and the development of functional foods.

show abstract

Physiochemical Responses of the Kernel Quality, Total Phenols and Antioxidant Enzymes of Walnut in Different Forms to the Low-Temperature Storage

Cited by 11 publications

References 35 publications

Bioactivity of Walnut: Investigating the Triterpenoid Saponin Extracts of Juglans regia Kernels for Antioxidant, Anti-diabetic, and Antimicrobial Properties

Bioactivity of Walnut: Investigating the Triterpenoid Saponin Extracts of Juglans regia Kernels for Antioxidant, Anti-diabetic, and Antimicrobial Properties

Effect of Gamma Irradiation on Fat Content, Fatty Acids, Antioxidants and Oxidative Stability of Almonds, and Electron Paramagnetic Resonance (EPR) Study of Treated Nuts

The Antioxidant Activities In Vitro and In Vivo and Extraction Conditions Optimization of Defatted Walnut Kernel Extract

Contact Info

Product

Resources

About