Enhancing antioxidant activity, microbial and sensory quality of mango (Mangifera indica L.) juice by γ-irradiation and its in vitro radioprotective potential

Abstract

Gamma irradiation is an effective method currently being used for microbial decontamination and insect disinfestations of foods. In the present study, mango (Mangifera indica L.) juice was irradiated at doses of 0, 1.0, 3.0 and 5.0 kGy and microbial load, total polyphenols, flavonoids, ascorbic acid content, antioxidant activities, colour and sensory properties were evaluated immediately after irradiation and also during storage. Microbiological assay of the fresh and stored mango juice showed better quality after γ-irradiation. The total polyphenols and flavonoids were significantly (p<0.05) increased while the ascorbic acid content decreased with the irradiation doses applied. As a result of γ-irradiation, a significant increment in gallic, syringic and chlorogenic acids and a significant reduction in ferulic and synapic acids were noted when analyzed by HPLC. In vitro antioxidant potentials were measured using DPPH, FRAP and NO scavenging assays; the results showed significant enhancement in the activities after irradiation, that correlated well with the increase in phenolic and flavonoid content. γ-irradiation improved the colour of mango juice without any adverse changes in the sensory qualities. Significant in vitro plasmid DNA protection was observed in the presence of mango juice against radiation induced damage, even at the dose of 5 kGy. This study confirmed the potential of γ-irradiation as a method for microbial decontamination and improving the quality of the mango juice without compromising on the sensory attributes.

Comparison between irradiating and autoclaving citrus wastes as substrate for solid‐state fermentation by Aspergillus aculeatus

“…Earlier studies elsewhere show that irradiation from 1 to 10 kGy can be effective to reduce spoilage and pathogenic micro-organisms in food, and the dose above 3 kGy can inactivate mold, yeast and bacteria (Stefanova et al 2010). It is also reported that irradiation at 3 to 5 kGy can completely inactivate mold and bacteria (Naresh et al 2015). Our results agree well with these reported results to inhibit microbial contamination at low irradiation doses.…”

“…Therefore, proper level of flavonoids in the fermentation substrate may favour the production of some enzymes. Compared with autoclaved substrate, irradiated substrate had higher level of flavonoids (Figure 4c) that agrees well with previous studies (Naresh et al 2015). Therefore, fungal fermentation on irradiated substrate produced more enzymes.…”

“…It is also reported that irradiation at 3 to 5 kGy can completely inactivate mold and bacteria (Naresh et al . ). Our results agree well with these reported results to inhibit microbial contamination at low irradiation doses.…”

“…Compared with autoclaved substrate, irradiated substrate had higher level of flavonoids (Figure c) that agrees well with previous studies (Naresh et al . ). Therefore, fungal fermentation on irradiated substrate produced more enzymes.…”

Effect of Gamma irradiation on some biochemical properties, antioxidant and antimicrobial activities of Sakouti and Bondoky dry dates fruits genotypes

“…The contemporary findings have been reported by Harrison & Were (2007), who showed that the rise of date fruits phenolic content should be given to their launch from glycosidic precursors and the degradation of bigger polymeric phenolic compound to lower gadgets through gamma-ray treatments. Furthermore, Naresh, Varakumar, Variyar, Sharma, & Sarathi Reddy (2015) indicated that the degradation of conjugated phenolic compounds should define the higher phenolic content in gamma-irradiated date samples. In the same concern Aly, Maraei, & Ali (2016) found that phenolic and flavonoids were significantly expanded by expanding irradiation dose levels of Egyptian Moringa oleifera seed oils.…”