Comparative Study of Effects of Different Organic Acid Treatments on Preservation Quality of Two Bamboo Shoot Species Using PCA Comprehensive Evaluation and Quality Index Models

Bamboo shoots undergo rapid postharvest quality deterioration. To evaluate the effects of organic acid treatments on the quality preservation of green bamboo (Dendrocalamopsis oldhami) shoots (GBSs) and lei bamboo (Phyllostachys praecox f. preveynalis) shoots (LBSs), shoots were immersed in oxalic acid (2.5, 5, 7.5 mmol·L−1), ascorbic acid (28.4, 56.8, 85.2 mmol·L−1), citric acid (26, 52, 78 mmol·L−1), or salicylic acid (0.5, 1, 1.5 mmol·L−1) for 10 min and then stored at 4 °C for 14 days. Changes in weight loss, soluble protein, soluble sugar, lignin, cellulose, taste attributes (sweetness, bitterness, astringency, umami), phenylalanine ammonia-lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) activities were monitored. Postharvest organic acid treatments effectively preserved the storage quality of both GBSs and LBSs by reducing weight loss; suppressing lignin and cellulose increases; maintaining higher soluble protein, soluble sugar, sweetness, and umami; and inhibiting bitterness, astringency, and PAL/POD/PPO activities. Optimal treatments were variety-specific when evaluated by the principal component analysis (PCA) comprehensive evaluation model: 5 mmol·L−1 oxalic acid (OA2) for GBSs, and 56.8 mmol·L−1 ascorbic acid (AA2) for LBSs. In contrast, 56.8 mmol·L−1 ascorbic acid (AA2) performed best for both GBSs and LBSs when evaluated by the quality index model. Further comparison revealed that the PCA comprehensive evaluation model provided a more accurate and discriminative assessment of preservation efficacy for different organic acids than the quality index model. Moreover, OA2-treated GBSs had a longer shelf life than AA2-treated LBSs. Consequently, by employing the PCA comprehensive evaluation model, this study demonstrated that 5 mmol·L−1 oxalic acid can effectively preserve bamboo shoot quality, and variety-specific organic acid selection is essential for optimal storage.