Packaging and storage environment influence post-fermentation quality retention in suansun

Suansun (Chinese fermented sour bamboo shoots) undergoes progressive quality deterioration after fermentation, with browning, texture softening, microbial changes and loss of sensory quality occurring at different rates. This study integrated three sequential component experiments on package systems, storage environment and deterioration kinetics, and then examined selected core conditions in a later 2 × 2 × 2 experiment. The package-system comparison indicated that opaque light-shielding VMPET/PE vacuum packaging retained quality more consistently than transparent PA/PE or non-vacuum alternatives during the 56 d test. A separate pasteurized, vacuum-packaged environmental screen identified 3 °C, dark storage and approximately 80% external relative humidity (RH) as candidate conditions, while the kinetic experiment showed faster browning-related deterioration at 25 °C than at 5 °C. The single-batch 2 × 2 × 2 experiment compared commercial vacuum-bag system type (transparent PA/PE or opaque light-shielding VMPET/PE), storage temperature and external illumination. Among the eight combinations, opaque light-shielding VMPET/PE vacuum packaging at 3 °C in darkness produced the most favorable observed day-56 profile: browning degree 0.24, nitrite 0.18 mg/kg, aerobic plate count 2.88 log CFU/g, L* 46.5, total titratable acidity 1.58 g lactic acid equivalents/kg fresh sample (g LAE/kg), lactic acid bacteria 6.94 log CFU/g, hardness 139.6 N and comparative sensory score 84/100. These findings support candidate conditions for the tested commercial materials and 56 d observation period, without establishing a universal optimum, a validated shelf life or a food-safety claim. The 80% RH result arose from the separate screening experiment and is therefore treated as preliminary.