Temporal and Compositional Dynamics of Waste in Tomato Packaging and Its Environmental Footprint: Implications for Agri-Food Sustainability and SDG 12.3

This single-plant, single-cycle study characterizes waste dynamics in export tomato packing and quantifies its embedded environmental footprint, contributing to SDG Target 12.3. In total, 196 daily records from six production plants at one Mexican facility were analyzed over an open-field cycle (March–May 2024). Waste composition was analyzed with compositional (long-ratio) methods, and daily magnitude was modeled with four predictive algorithms. Mean waste was 41.4 ± 6.0%, rising steadily across the cycle (+1.8 percentage points per week; 95% CI [1.59, 2.05], robust to serial correlation; r = 0.75). No overall change in waste composition was detected (p = 0.135), and discoloration showed the only positive trend, with no significance after correcting for multiple comparisons (p = 0.159), while equivalence tests were inconclusive for every category. Differences between fields were confounded with their operating windows and could not be separated. With only pre-sort variables, a parsimonious Gradient Boosting model was used to predict daily waste, with R2 = 0.846, which is close to the value of 0.898 achieved through the incorporation of same-day grading data. Time-blocked validation showed that neither model outperformed the training mean, indicating interpolation rather than forecasting, with cycle day as the dominant predictor (73% relative importance). Monte Carlo propagation gave a footprint averaging 162 t CO2eq (90% CI [50, 310]) and 141 million liters of water (90% CI [81, 209]). For the 1127 t discarded, closing the gap between the early and late phases would avoid roughly 21 t CO2eq and 18 million liters. These findings identify cycle phase as the primary driver of waste and support the use of phase-targeted interventions to reduce both economic loss and environmental impact, contributing to SDGs 2 and 12.