Molecular Hydrogen Maintains the Storage Quality of Chinese Chive through Improving Antioxidant Capacity

Abstract

Chinese chive usually becomes decayed after a short storage time, which was closely observed with the redox imbalance. To cope with this practical problem, in this report, molecular hydrogen (H2) was used to evaluate its influence in maintaining storage quality of Chinese chive, and the changes in antioxidant capacity were also analyzed. Chives were treated with 1%, 2%, or 3% H2, and with air as the control, and then were stored at 4 ± 1 °C. We observed that, compared with other treatment groups, the application of 3% H2 could significantly prolong the shelf life of Chinese chive, which was also confirmed by the obvious mitigation of decreased decay index, the loss ratio of weight, and the reduction in soluble protein content. Meanwhile, the decreasing tendency in total phenolic, flavonoid, and vitamin C contents was obviously impaired or slowed down by H2. Results of antioxidant capacity revealed that the accumulation of reactive oxygen species (ROS) and hydrogen peroxide (H2O2) was differentially alleviated, which positively matched with 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and the improved activities of antioxidant enzymes, including superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Above results clearly suggest that postharvest molecular hydrogen application might be a potential useful approach to improve the storage quality of Chinese chive, which is partially achieved through the alleviation of oxidative damage happening during the storage periods. These findings also provide potential theoretical and practical significance for transportation and consumption of perishable vegetables.

Molecular Hydrogen Increases Quantitative and Qualitative Traits of Rice Grain in Field Trials

“…For above cases, H 2 might be integrated with other downstream gasotransmitters, including nitric oxide and hydrogen sulfide, as well as regulating some phytohormones [11,16]. In terms of postharvest storage period, previous results also revealed that H 2 could prolong the shelf life of some vegetables, fruits, and flowers, including kiwifruit [17] and daylily bud [18], as well as lisianthus [19], carnation [20], and Chinese chive [21] when hydrogen-rich water, H 2 fumigation, or magnesium hydride (a H 2 -releasing material) were separately applied. Since there were numerous functions of H 2 observed in the vegetative growth stage and postharvest period, it is reasonable to deduce that molecular hydrogen might have significant influence in reproductive growth and seed developmental stages, both of which are very important for crop production, especially for rice.…”

The Applications of Molecular Hydrogen in Horticulture

“…Recent studies have been observed that H 2 -modified atmosphere can also prolong the shelf life of vegetables and fruits. For example, a ~1.2 × 10 3 µM H 2 fumigation can maintain the postharvest quality of Chinese chive at 4 • C [21]. In kiwifruit, the positive effect of ~0.2 µM H 2 gas on prolonging shelf life was similar with that of 1-MCP (0.04 µM) [22].…”

“…Pretreatment with HRW by soaking fruits (such as kiwifruit [17], tomato [47], and lychee [18] as well as fresh-cut kiwifruit [48]) for less than 30 min can significantly maintain storage quality and prolong shelf life. H 2 fumigation for pretreatment or throughout storage period can achieve similar effects in kiwifruit [22] (Figure 1) and Chinese chive [21].…”

“…Although H 2 applied in gas form is not practical in the field, it is possible to use it under controlled airtight conditions. Previous studies observed that a 3 vol% or lower concentration of H 2 was below the lower flammability limit of H 2 (4 vol%), but the modified atmosphere can prolong the shelf life of Chinese chive (Allium tuberosum) [21] or kiwifruit [22] stored at 4 • C or room temperature. Surprisingly, under pure H 2 atmosphere, grapes did not show obvious signs of decay during 90 days of storage [23].…”

“…), disturbing the delicate redox homeostasis and causing cellular damage inside the plant cells. In postharvest fruits, vegetables, and cut flowers, ROS overproduction accelerated senescence process [16][17][18]21,52]. Additionally, ROS and RNS are vital signaling transducers in plant signaling networks for stress and development [72].…”