SO₂ pulse treatment improves thin-skinned grape storage

Better preservation with lower SO₂ residues

Sulfur dioxide (SO₂) is commonly used to control fungal decay in table grapes after harvest. However, reducing residues while understanding its effects on the grape microbiome remains a challenge.

In this study, researchers compared slow-release SO₂ pads (SR) with intermittent high SO₂ pulses (IHP) in Daqing grapes stored under low-temperature conditions.

The IHP treatment provided the best visual quality and preserved grape skin integrity while reducing SO₂ residues by 49.9% compared to the SR system.

Grapes treated with IHP also showed lower decay rates, reduced browning and weight loss, and maintained higher firmness during storage.

Microbial balance and natural resistance

The IHP treatment increased the activity of enzymes linked to the fruit’s natural defense system, including SOD, POD, PAL and PPO.

Fungal community analysis using ITS sequencing revealed that IHP preserved fungal diversity while effectively reducing pathogens such as Botrytis cinerea, Cladosporium chasmanthicola and Alternaria alternata.

Researchers concluded that grape surface microbiota and immune resistance interact together to regulate postharvest quality.

According to the study, intermittent SO₂ pulses may enhance grape resistance, suppress pathogens and improve the storage quality of thin-skinned grapes.

Source

Kou, R., Zheng, J., Hou, S., Qiao, L., & Liu, X. (2026). The effect of SO2 pulse on synergistic interaction of postharvest quality and fungal community during thin-skinned grape storage. Journal of Food Science. Wiley.

https://ift.onlinelibrary.wiley.com/doi/abs/10.1111/1750-3841.71021