Improvement of storage quality of ‘Hayward’ kiwifruit by MeJA combined with SA treatment through activation of phenylpropane metabolism

Abstract

Kiwifruit are highly susceptible to pathogenic infestation, which can lead to spoilage during postharvest storage. Therefore, there is an urgent need to develop natural and efficient preservation methods. A compound preservative consisting of 10 μM MeJA (methyl jasmonate) and 1 mM SA (salicylic acid) was used to preserve kiwifruit during storage. Sensory, quality, and phenylpropane metabolism-related indicators were assessed at 20 °C during kiwifruit storage in groups treated with sterile water, MeJA, SA, or a combination of MeJA and SA. The results indicated that the hormone treatment groups exhibited varying degrees of efficacy in suppressing spoilage caused by pathogenic infestation. The combination treatment group demonstrated superior efficacy in comparison to the other treatment groups, as evidenced by its ability to suppress hardness reduction, delay decay rate, and disease index increase, retard soluble solids accumulation, activate enzymes PAL, C4H, and 4CL involved in phenylpropane metabolism and enhance total phenol content. The SA treatment group exhibited the second highest efficacy, whereas the MeJA treatment group demonstrated the lowest efficacy. The results showed that at the end of storage, the PAL activity and total phenolic content of kiwifruit in the combination treatment increased by 52.72%, 39.98%, 17.89%, and 98.19%, 22.47%, 14.93% compared to the control, MeJA and SA treatment alone, respectively. The findings of this study may serve as a theoretical foundation and technical guide for the utilization of MeJA in combination with SA during kiwifruit storage and preservation.