Ascorbic acid treatment inhibits wound healing of fresh-cut potato strips by controlling phenylpropanoid metabolism

https://doi.org/10.1016/j.postharvbio.2021.111644Get rights and content

Highlights

  • AA decreased SPP accumulation and wound-healing efficiency of potato strips.

  • AA inhibited the activity of enzymes in the phenylpropanoid pathway.

  • AA treated samples exhibited lower levels of monomeric phenolic acids and lignin.

Abstract

In this study, we investigated the ability of ascorbic acid (AA) to regulate the wound-healing response in fresh-cut potato strips during storage. The results demonstrated that treatments of AA could delay browning, decrease hardening, improve taste, as well as reduce weight loss and respiration rate. Furthermore, AA treatment inhibited wound healing by modulating the activity of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), chalcone synthase (CHS) and coumarate-3-hydroxylase (C3H), increasing total phenolics and flavonoid content, and decreasing monomeric phenolic acid content, including caffeic acid, p-coumaric acid, and ferulic acid. The accumulation of lignin and the polyphenolic component of suberin was also reduced. Overall, our results provided information on wound healing and revealed the potential benefits of AA in regulating the process of suberization in potato strips.

Introduction

With the rapid improvement in people's living standard, needs for convenience foods are on the rise. Fresh-cut products are well-liked by consumers due to their high freshness, convenience and safety (Artés et al., 2009). Fresh-cut potatoes are one of the convenience foods that are with higher requests (Shen et al., 2020). However, the integrity of the potato tuber is destroyed due to mechanical processing, resulting in accelerating series of permanent physiological and biochemical reactions (Xiao et al., 2020). These cause some damages to fresh-cut potatoes, including dehydration, browning, softening or hardening, unpleasant aroma and taste deterioration (Gong et al., 2019). Besides, damages to potato tuber tissues also result in certain complex reactions especially wound healing. Wound healing is the process responsible for the repair of injured tissues, which in fresh-cut potatoes, induces them to rapidly form a compact, superficial surface layer to avoid water loss and infection (Lulai, 2007). The wound healing process involves the formation of a suberized closing layer and wound periderm (Dastmalchi et al., 2014). Fresh-cut potatoes accumulate a variety of antioxidant compounds in the wound healing process, such as phenolics and flavonoids (Huang et al., 2017). Thus, a cultivar with good wound healing ability is considered to be an excellent cultivar because of its storability. While, this process may accelerate surface browning and hardening of fresh-cut potatoes during storage, which leads to significant quality loss (Mondy and Leja, 1986; Zhou et al., 2019). Thus, it is urgent to research proper techniques to control wound healing for a longer shelf-life of fresh-cut potatoes. In recent decades, various strategies have been explored to regulate wound healing (Bajji et al., 2007; Woolfson et al., 2018; Jiang et al., 2019; Zhou et al., 2019), however, studies on ascorbic acid in wound healing of potatoes are still very limited.

Ascorbic acid (AA; vitamin C) is only mildly electronegative, thus can donate electrons to a wide range of substrates (Franceschi and Tarlyn, 2002). Following mechanical wounds in potatoes, reactive oxygen species (ROS) are overproduction, which contributes to the process of lignification (Orozco-Cardenas and Ryan, 1999). AA as a free radical scavenger interacting enzymatically and non-enzymatically with ROS, thus, protecting plants from oxidative stress. The interaction between AA and ROS is indicative of the role of AA in the modulation of the wound healing process (Davey et al., 2000). AA has been reported to increase in response to the wounding of plant tissues (Mondy and Leja, 1986; Tudela et al., 2002b). How AA regulates wound healing, however, is not completely understood. Exogenous ascorbic acid is widely used for anti-browning due to its powerful trait in reducing (Gao et al., 2017; Sikora and Swieca, 2018; Lo’ay and EL-Khateeb, 2018). In Chinese standard GB-2760 (Hygienic Standards for Food Additives in Use), AA is permitted to use in fresh-cut fruit and vegetables with the maximum dosage of 5 g kg−1 of fresh-cut products. In the present study, the effect of AA on the wound healing process of potato strips was analyzed by measuring the changes in the browning index, firmness, weight loss, respiration rate and taste. In addition, observations of microstructure, combined with an assessment of the activity of key enzymes and the level of metabolites related to suberization and lignification were conducted.

Section snippets

Sample preparation and AA treatment

Potatoes (Solanum tuberosum L. cv. Youjin ‘885′) grown in 2020 were harvested in Suihua Farm (Heilongjiang province, China). Dormant potatoes, being healthy in similar sizes were washed with clean water, then sanitized in chlorinated water (1 %). Potatoes, with a sharp knife, were peeled and cut in 7 × 1 × 1 cm strips. Potato strips, being washed in distilled water, were divided randomly into three groups afterwards. The three groups of potato strips were respectively immersed in deionized

Browning index, firmness, weight loss and respiration rate

The browning occurring in 5 g L−1 AA-treated samples was inhibited during the whole storage, however, that in 10 g L−1 AA-treated samples was induced after 2 d of storage, compared with the control samples (Fig. 1A). 10 g L−1 AA-treated samples had the lowest browning index at 1 d of storage (p > 0.05) and had the highest browning index at 2, 3, 4 d of storage (p < 0.05), respectively. The browning index was lower in 5 g L−1 AA-treated samples (226) than that in control samples (231) at 2 d of

Discussion

Mechanical injury induces a variety of physiological responses and renders fresh-cut potatoes susceptible to desiccation and becoming flaccid. Potatoes have the ability, however, to form a periderm on the wounded surface of the potato tuber (Garcia and Barrett, 2002). Ascorbic acid (AA) inhibits the browning of fresh-cut potatoes, however, its impact on the process of wound-induced suberization has not been elucidated. In this study, we observed that AA treatment (5 g L−1) reduced physiological

Conclusion

This research showed the application of ascorbic acid (5 g L−1) contributed to reducing physiological changes and suppressing wound healing of fresh-cut potato strips. Results indicated that treatment of potato strips with AA could inhibit browning and hardening, maintain taste, as well as delay the increases in weight loss and the rate of respiration. Furthermore, lower wound healing capacity in AA-treated samples was achieved thanks to lower enzyme activity (PAL, C4H, 4CL, CHS and C3H) and

Author statement

Chen Chen, Mixia Tiana and Aili Jiang designed the experimental trials. Fuhui Zhou and Dongying Xu performed the experiments, collected the samples. Chenghui Liu and Fuhui Zhou wrote the article. All authors read and approved the final manuscript.

Declaration of Competing Interest

We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (31872908), the National Key R & D Program of China (No. 2016YFD0400903).

References (45)

  • V. Rizzo et al.

    The effect of sous vide packaging with rosemary essential oil on storage quality of fresh-cut potato

    LWT- Food Science and Technology

    (2018)
  • P. Rocculi et al.

    Effects of the application of anti-browning substances on the metabolic activity and sugar composition of fresh-cut potatoes

    Postharvest Biol. Technol.

    (2007)
  • M. Sikora et al.

    Effect of ascorbic acid postharvest treatment on enzymatic browning, phenolics and antioxidant capacity of stored mung bean sprouts

    Food Chem.

    (2018)
  • J.A. Tudela et al.

    Vitamin C retention in fresh-cut potatoes

    Postharvest Biol. Technol.

    (2002)
  • Q.G. Wang et al.

    Effects of postharvest curing treatment on flesh colour and phenolic metabolism in fresh-cut potato products

    Food Chem.

    (2015)
  • S.Y. Zhang et al.

    Carbon monoxide enhances the resistance of jujube fruit against postharvest Alternaria rot

    Postharvest Biol. Technol.

    (2020)
  • X.Y. Zheng et al.

    Comparison of wound healing abilities of four major cultivars of potato tubers in China

    Postharvest Biol. Technol.

    (2020)
  • F.H. Zhou et al.

    Effect of methyl jasmonate on wound healing and resistance in fresh-cut potato cubes

    Postharvest Biol. Technol.

    (2019)
  • G. Ali et al.

    Involvement of salicylic acid on antioxidant and anticancer properties, anthocyanin production and chalcone synthase activity in ginger (Zingiber officinale Roscoe) varieties

    Int. J. Mol. Sci.

    (2012)
  • H.M. Ali et al.

    Browning inhibition mechanisms by cysteine, ascorbic acid and citric acid, and identifying PPO-catechol-cysteine reaction products

    J. Food Sci. Technol.

    (2015)
  • M. Bajji et al.

    Catalase inhibition alters suberization and wound healing in potato (Solanum tuberosum) tubers

    Plant Physiol.

    (2007)
  • K. Dastmalchi et al.

    Solving the jigsaw puzzle of wound-healing potato cultivars: metabolite profiling and antioxidant activity of polar extracts

    J. Agric. Food Chem.

    (2014)
  • Cited by (34)

    View all citing articles on Scopus
    1

    These authors contributed equally to this work.

    View full text