High‐Pressure Processing and Brine Acidity for Enhanced Quality Attributes of Refrigerated Pickled Cucumbers

To substantiate high-pressure processing (HPP) as a nonthermal alternative for fresh-like acidified vegetables with extended refrigerated shelf life, this study evaluated HPP at 200, 400, and 600 MPa (3 min, 5°C) on pickled cucumbers in 0.30% and 0.95% acetic acid brine (AA), compared to thermal processing (100°C for 25 min and 77°C for 30 min). Texture, color, microbial load, methanol content, and microstructure were evaluated over 6 months. HPP significantly reduced total aerobic plate counts compared to untreated samples, except 200 MPa with 0.95% AA. The average log reduction was 1 (200 MPa), 1.5 (400 MPa), 2.5 (600 MPa), and 1.2 (thermal). Yeasts and molds remained <1.00 log colony-forming unit (CFU)/mL, except for 400 MPa with 0.30% AA at Month 5. Color and texture were better preserved under HPP, resulting from gentler processing and lower pH. Initial greenness was highest for HPP, and 600 MPa-treated pickles remained greener (a* = -2.95 ± 0.59) than thermally treated pickles (a* = -1.00 ± 0.60) at 6 months. Hardness for pickles with 0.95% AA increased significantly from 70.2 ± 3.2 N (untreated) to 90 ± 11 N (400 MPa) and 95.1 ± 6.9 N (600 MPa). Thermal samples were softer (67.5 ± 2.5 N). Methanol content ranged from 225 to 613 mg/kg for 0.95% AA and 59 to 194 mg/kg for 0.30% AA, suggesting pH-dependent pectin demethoxylation drove firmness. 600 MPa provided a useful alternative to processing pickles through better microbial reduction, firmer texture, and color retention, whereas 400 MPa may offer a viable option for acidified products with a shorter shelf life. PRACTICAL APPLICATIONS: This research indicates an opportunity for industrial application of high-pressure processing to acidified whole fruits and vegetables. This will expand the technology's application beyond juiced and pureed products and open opportunities to reduce post-harvest losses, while meeting current consumers' demands for minimally processed, clean-label products.