Effects of irradiation on decolourisation and biological activity in Schizandra chinensis extracts

Effects of Gamma Irradiation on Changes in Chemical Composition and Antioxidant Activity of Euphorbia maculata Callus

In this study, we investigated the effects of gamma irradiation on the antioxidant activity and metabolite profiles of Euphorbia maculata calli (PC3012). Gamma irradiation at various doses (0, 0.05, 0.5, and 10 kGy) significantly enhanced the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS+) radical scavenging activities of the callus extracts of PC3012 in a dose-dependent manner. High-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) analyses revealed that irradiation increased the lysophospholipid content, although no new antioxidant compounds were formed. Furthermore, a PLS-DA analysis revealed evident metabolic differences between non-irradiated and irradiated samples, which were further verified by statistical validation. These findings suggest that gamma irradiation induces specific biochemical modifications that enhance the bioactive properties of PC3012 calli. This technology exhibits potential for utilization in the natural product and food sectors, particularly in the development of functional foods and nutraceuticals with improved health benefits.

Effect of ajwain (Trachyspermum ammi) extract and gamma irradiation on the shelf-life extension of rohu (Labeo rohita) and seer (Scomberomorus guttatus) fish steaks during chilled storage

Fishes are highly perishable, mainly stored and transported under frozen condition; however, they are mainly preferred as fresh or in chilled form for consumption because frozen storage compromises the texture quality and other sensory attributes. Shelf-life enhancement of rohu and seer fish steaks was studied using combination of ajwain extract (various concentrations) and γ-irradiation (various doses) under chilled storage (4 °C). These were analyzed periodically by microbiological, sensory, color and biochemical analyses during storage. Gas chromatography - mass spectrometry (GC-MS) analysis showed thymol as major component. High performance liquid chromatography (HPLC) analysis showed the presence of nine phenolic compounds including thymol in ajwain extract. The best result was achieved when samples were dipped in 10 % ajwain extract with 2 kGy gamma irradiation dose. An extended shelf-life of 5 and 10 days in case of rohu and seer fish steaks were attained respectively using this combination. These results were confirmed by microbial, biochemical and sensory analyses. The present study thus promises potential application of the above protocol in fishery industry for good quality of fish and commercial benefits.

Radiolytic Cyclization Products of Phloridzin as Potent Anti-Glycation Agents

The current research examined for radiolytic structure modification and improved bioefficacy of phloridzin by γ-ray, subsequent to a 50 kGy irradiation dose. Structures of the unusual degraded products phlorocyclin, isophlorocyclin, and radiophlorisin were determined spectroscopically, by detailed nuclear magnetic resonance (NMR) and mass spectrometry (MS). Additionally, absolute configuration of the novel cyclized phlorocyclin and isophlorocyclin were proposed by circular dichroism (CD) spectrum analysis. Among the compounds tested, phlorocyclin and isophlorocyclin exhibit potent antidiabetic complication capacities toward advanced glycation end products (AGEs) formation inhibition assay, with IC₅₀ values of 9.1±0.5 and 13.8±0.7 μM, respectively. Furthermore, the predominantly formed products phlorocyclin and isophlorocyclin exerted significantly enhanced DPPH radical scavenging activity compared to the parent phloridzin. These results indicate that γ-ray mediated cyclization of phloridzin exerts a positive influence on the bioactivity.

Effects of a rotational UV-C irradiation system and packaging on the shelf life of fresh pistachio

BACKGROUND

In this study, fresh pistachio was exposed to UV-C irradiation (2.1 and 4.5 kJ m^-2 ) in a rotating cylindrical system with seven germicidal UV-C lamps and immediately packed in perforated and non-perforated polyethylene terephthalate (PET). The fruit were evaluated for weight loss, total phenolic content, enzyme activities, color indices (L*, a*, b* and browning index), and microbial counts during 35 days of storage at 4 °C.

RESULTS

UV-C treatment caused a significant decrease (P < 0.05) in the weight loss of fresh pistachios compared to the control. The activity of catalase and peroxidase enzymes was significantly higher (P < 0.05) in irradiated samples packed in non-perforated PET in comparison to those of untreated samples. Irradiation did not inhibit the activity of polyphenol oxidase in treated samples, although a slight decrease in polyphenol oxidase activity was observed in irradiated samples compared to control. The fruit treated with 2.1 kJ m^-2 of UV-C and the control packed in non-perforated PET were lighter (L*), redder (a*), and less yellow (b*) compared to 4.5 kJ m^-2 treated samples. Furthermore, a dose of 4.5 kJ m^-2 UV-C significantly decreased sensory attributes of fresh pistachios compared to the other irradiation level and control.

CONCLUSION

UV-C irradiation at a dose of 2.1 kJ m^-2 and packing in non-perforated PET are recommended for fresh pistachio preservation based on the physicochemical, microbial, and sensory parameters. © 2019 Society of Chemical Industry.

Effect of atmospheric pressure dielectric barrier discharge plasma on the biological activity of naringin

The biological activity of naringin treated with atmospheric pressure plasma was evaluated to investigate whether exposure to plasma can be used as a method to improve the biological activity of natural materials. Naringin was dissolved in methanol (at 500 ppm) and transferred to a container. A dielectric barrier discharge (DBD) (250 W, 15 kHz, ambient air) was then generated. Treatment with the plasma for 20 min increased the radical-scavenging activity, FRAP value, and the total phenolic compound content of naringin from 1.45% to 38.20%, from 27.78 to 207.78 μM/g, and from 172.50 to 225.83 ppm, respectively. Moreover, the tyrosinase-inhibition effect of naringin increased from 6.12% to 83.30% upon plasma treatment. Naringin treated with plasma exhibited antimicrobial activity against foodborne pathogens, especially Salmonella Typhimurium; an activity that was absent before plasma treatment. Structural modifications induced in the naringin molecule by plasma might be responsible for improving the biological activity of naringin.

Degradation of cyanidin-3-rutinoside and formation of protocatechuic acid methyl ester in methanol solution by gamma irradiation

Anthocyanins are naturally occurring phenolic compounds having broad biological activities including anti-mutagenesis and anti-carcinogenesis. We studied the effects and the degradation mechanisms of the most common type of anthocyanins, cyanidin-3-rutinoside (cya-3-rut), by using gamma ray. Cya-3-rut in methanol (1mg/ml) was exposed to gamma-rays from 1 to 10kGy. We found that the reddish colour of cya-3-rut in methanol disappeared gradually in a dose-dependent manner and effectively disappeared (>97%) at 10kGy of gamma ray. Concomitantly, a new phenolic compound was generated and identified as a protocatechuic acid methyl ester by liquid chromatography, (1)H, and (13)C NMR. The formation of protocatechuic acid methyl ester increased with increasing irradiation and the amount of protocatechuic acid methyl ester formed by decomposition of cya-3-rut (20μg) at 10kGy of gamma ray was 1.95μg. In addition, the radical-scavenging activities were not affected by gamma irradiation.

Sauchinone, a lignan from Saururus chinensis, protects human skin keratinocytes against ultraviolet B-induced photoaging by regulating the oxidative defense system

Ultraviolet (UV) radiation from sunlight induces matrix metalloproteinase (MMP) expression, which are responsible for collagenous extracellular matrix proteins breakdown in skin, causing photoaging. Sauchinone is reported to have various bioactivity such as antioxidative, hepatoprotective, and anti-inflammatory effects. In the present study, we investigated the protective effect of sauchinone against UVB (50 mJ/cm(2))-induced photoaging in HaCaT human epidermal keratinocytes. Sauchinone, at 5-40 µM, significantly protected keratinocytes against UVB-induced damage as assessed by cell viability and toxicity assay. Additionally, sauchinone, at 20-40 µM, prevented the upregulation of MMP-1 proteins and reduction of type 1 collagen induced by UVB. Other assays revealed that, in keratinocytes, sauchinone decreased reactive oxygen species (ROS) production and increased glutathione levels and heme oxygenase-1. Sauchinone also inhibited UVB-induced phosphorylation of mitogen-activated protein kinase (MAPK) signaling pathways. These results demonstrated that sauchinone protects skin keratinocytes through inhibition of extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 MAPK signaling via upregulation of oxidative defense enzymes.

Content and color stability of anthocyanins isolated from Schisandra chinensis fruit

In this work, a multivariate study based on Box-Behnken Design was used to evaluate the influence of three major variables affecting the performance of the extraction process of Schisandra chinensis anthocyanins. The optimum parameters were 5.5 h extraction time; 1:19 solid-liquid ratio and 260 r/min stirring rate, respectively. The extraction yield of anthocyanins was 29.06 mg/g under the optimum conditions. Moreover, many factors on the impact of heating, ultrasound, microwave treatment and ultraviolet irradiation on content and color stability of anthocyanins from Schisandra chinensis fruit were investigated. The results show that thermal degradation reaction of anthocyanins complies with the first order reaction kinetics, and the correlation coefficient is greater than 0.9950 at 40-80°C. Ultrasound and microwave treatment has little effect on the stability of anthocyanins, and the extraction time of ultrasound and microwave should be no more than 60 min and 5 min, respectively. The anthocyanins degradation effect of UVC ultraviolet radiation is greater than UVA and UVB; after 9 h ultraviolet radiation, the anthocyanins content degradation of UVC is 23.9 ± 0.7%, and the ∆E* was changed from 62.81 to 76.52 ± 2.3. Through LC-MS analysis, the major composition of Schisandra chinensis anthocyanins was cyanidin-3-O-xylosylrutinoside.

Chemical composition and antioxidant properties of γ-irradiated Iranian Zataria multiflora extracts

CONTEXT

Irradiation is the process of exposing food such as herbal plant to ionizing radiation to destroy microorganisms. Zataria multiflora Boiss (Lamiaceae), known as Avishan-e-Shirazi in Persian, is a thyme-like plant that grows naturally in central and southern parts of Iran and is used in traditional folk medicine.

OBJECTIVE

In this study, the effects of γ-radiation on chemical composition and antioxidant properties of Z. multiflora were investigated.

MATERIALS AND METHODS

The plants were first irradiated with Co60 source (0, 10, and 25 kGy) and then subjected to Clevenger extraction to obtain essential oils. The composition of the oil was analyzed by a gas chromatography and compared with samples pretreated under different conditions. In parallel, the hydroalcoholic extract was prepared and used for measuring flavonoid content. Thereafter, the free-radical scavenging and antioxidant properties of essential oils and hydroalcoholic extract were examined.

RESULTS

Despite the minor change in the individual oil constituents, the total percentage of the main components remained unaffected before and after irradiation (~95%). In addition, the total flavonoid content of hydroalcoholic extract was also unchanged due to irradiation (~32 mg QE/g extract). The high radical scavenging activity of the oil (~67%) and hydroalcoholic extract (~71%), in addition, the antioxidant properties of the oil (~91%) and hydroalcoholic extract (~95%), were unaffected after irradiation.

DISCUSSION AND CONCLUSIONS

These findings may suggest the sustainability of Z. multiflora extract properties pretreated with γ-radiation. With a view to its antioxidant applications, resistance of Z. multiflora and its properties against radiation effects are promising findings.