UV‐C irradiation delays browning of fresh‐cut “Fuji” apples

Abstract

In order to explore the effect and the corresponding physiological mechanisms of UV-C irradiation on browning of fresh-cut apples, both whole and sliced apple were irradiated with UV-C (254 nm) for 5 min before or after processing. The browning index (BI) of slices was immediately measured, while other relevant physiological parameters were evaluated on quick-frozen samples during refrigerated storage. Results indicated that both pre-and post-processing UV-C treatments effectively delayed browning of apple slices; nevertheless, post-processing UV-C treatment was more efficient. BI significantly negatively correlated with non-enzymatic capacities, and activities of catalase, ascorbate peroxidase, and glutathione reductase (GR). BI was positively correlated with the contents of H 2 O 2 and malondialdehyde (MDA). These findings suggested that UV-C treatment delayed browning of apple slices during cold storage by improving the antioxidant system. Post-processing UV-C treatment was more efficient than pre-processing. Practical applicationsUV-C treatment is a technique of preservation for fresh-cut fruits. It is widely applied in food processing and many other fields due to its convenience, safety, low cost, etc.In the present study, both pre-and post-processing UV-C (254 nm) irradiation for 5 min could (1) delay the browning of fresh-cut apple, (2) improve the polyphenol oxidase activity and reduce the phenylalanine ammonia-lyase (PAL) activity and total phenolic content (TPC), and (3) reduce the accumulation of H 2 O 2 and malondialdehyde, and increase the antioxidant activities of fresh-cut apples. Thus, UV-C treatments maintain the fresh-cut quality of fresh-cut apple slices and extend their shelf life.

Effect of UV‐C treatments on quality and browning‐related enzyme activity of fresh‐cut eggplant ( Solanum melongena L.) during cold storage

“…Similar behavior has been also reported in minimally processed yam slices (Li et al, 2016) and fresh‐cut Chinese yams (Luo et al, 2015). On the other hand, Yuan et al (2022) observed an increase in PPO activity and a reduction in browning with the application of UV‐C in fresh‐cut apples, indicating that the factor that limited the color change was the phenol content. Therefore, it could be deduced that the effect of UV‐C on the enzymatic browning prevention mechanism varies depending on the vegetal and the dose used, as indicated by Gutiérrez et al (2018) and Yuan et al (2022).…”

“…On the other hand, Yuan et al (2022) observed an increase in PPO activity and a reduction in browning with the application of UV‐C in fresh‐cut apples, indicating that the factor that limited the color change was the phenol content. Therefore, it could be deduced that the effect of UV‐C on the enzymatic browning prevention mechanism varies depending on the vegetal and the dose used, as indicated by Gutiérrez et al (2018) and Yuan et al (2022). These results indicate that exposure to a dose of 1 kJ/m 2 of UV‐C could modulate a signaling pathway that is beneficial for the vegetable since it involves an attenuated activity of the PPO enzyme and preservation of the levels of phenolic compounds and ascorbic acid content.…”

Short‐term nitric oxide treatment enhances the antioxidant capacity and maintains the preservation quality of Meizao cherries

“…MDA content was measured referred to Yuan et al . (2022). The pulp (1 g) and trichloroacetic (TCA, 100 g L −1 , 5 mL) were homogenised and centrifuged at 10 000 g at 4 °C for 20 min.…”

Enzymatic browning in apple products and its inhibition treatments: A comprehensive review

“…Recently, a study investigated the effect of UV‐C treatment at 254 nm for 5 min on browning inhibition of Fuji fresh‐cut (Yuan et al., 2022). The treatment was conducted before or after processing (cutting, coring, peeling).…”

“…The PPO activity of apple treated either before or after processing was lower than control after 8 days of storage at 4°C, while in contrast, it was higher than control before 8 days of storage. UV‐C treatment reduced H 2 O 2 accumulation and TPC, but the antioxidant activity (2,2′‐Azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) or ABTS) of treated apple was higher than control, especially up to 6 days of storage (Yuan et al., 2022). Another study used the same wavelength of UV‐C treatment, but could not find a significant PPO inhibition in Gala juice, even at 53 kJ/L (Müller et al., 2013).…”