Single-pulse silicic acid immersion for extending the shelf life of lettuce

Fresh produce is nutritious but perishable. This study investigated the efficacy of single-pulse silicic acid immersion for extending shelf life and examined the underlying physiological and microbial mechanisms. A concentration gradient of 0, 1, 5, 10, and 20 mM silicic acid was evaluated, with 10 mM determined as optimal considering both efficacy and cost-effectiveness. Following single-pulse immersion in 10 mM silicic acid for 1 minute, lettuce stored at 25 °C for 5 days exhibited only 5% weight loss, substantially lower than the 16% observed in controls. SEM-EDS analysis confirmed silicon deposition on leaf surfaces. Silicon application increased chlorophyll content by 38% and vitamin C by 13%, while reducing nitrite levels by 91% below safety standards. Antioxidant enzyme activities (SOD, CAT, POD) increased by 74%–383%. Microbial analysis revealed 83% reduction in bacterial load, altered β-diversity, and decreased spoilage-associated microorganisms including Pseudomonas , Stenotrophomonas , and Pantoea . Washing removed 31% of deposited silicon, ensuring consumer safety with silicon intake far below established thresholds. The method demonstrated broad applicability: cherry tomatoes and Kyoho grapes showed negligible decay after 5 days, with hardness increasing by 38% and 30%, respectively. Single-pulse silicic acid immersion provides a non-toxic approach for extending produce shelf life while maintaining nutritional quality. • Single-pulse 10 mM silicic acid immersion reduced lettuce weight loss by 69%. • Silicon application increased antioxidant enzyme activities by 74%–383% and cut nitrite 91%. • Bacterial load on lettuce surfaces decreased by 83% with fewer spoilage microbes. • Silicon formed washable barrier ensuring safety with intake below thresholds. • Method extended shelf life of cherry tomatoes and grapes with enhanced hardness.