Grape pomace represents a widely available agro-industrial by-product in Chile with considerable potential for valorization within circular economy frameworks; however, its functionality as a cosmetic ingredient depends on both grape cultivar and processing strategy. In this study, the direct incorporation of solid grape pomace residues into cream formulations was first evaluated, revealing limitations related to color control, homogeneity, and sensory performance. Subsequently, the influence of varietal origin (Malbec, Merlot, Syrah, and Grenache) on the extraction, stability, color behavior, and functional performance of anthocyanin-rich extracts was investigated for cosmetic applications. pH-standardized color analysis revealed statistically significant (p < 0.05) varietal differences, with Malbec extracts showing superior chromatic stability under acidic and near-neutral conditions, exhibiting lower reduction in a* values across the pH range compared to other varieties. In contrast, Syrah, Grenache, and Merlot showed a more pronounced decrease in red chromaticity, indicating higher sensitivity to pH-induced structural transformations. Although Merlot and Syrah exhibited higher ABTS antioxidant activity, Malbec presented the highest total phenolic content and the most balanced functional profile when considering both stability and color retention. Incorporation of anthocyanin-rich extracts into cosmetic cream formulations demonstrated that a 4.5% (m/v) loading ensured a skin-compatible pH (4.5–5.5), with Malbec-based creams exhibiting superior color stability and formulation performance over time. These findings demonstrate that grape pomace valorization requires variety-specific evaluation and identify extraction as a key enabling step for the development of sustainable, bio-based color-functional cosmetic ingredients.

Microbial inoculants are increasingly proposed within ecological-intensification strategies, yet their performance under heterogeneous commercial conditions remains uncertain. We evaluated a tripartite consortium of Funneliformis mosseae, Naganishia albida, and Bacillus tequilensis across six tomato production sites in central Chile using a 2 × 2 factorial randomized complete block design (irrigation × microbial management; three blocks per site; 72 plots). Normal irrigation was compared with reduced irrigation designed to receive 38% of the nominal irrigation depth. The same plots were followed across two growing seasons differing in fertilization and crop-management practices. Soil properties, arbuscular mycorrhizal (AM) colonization, enzyme activities, substrate-induced responses, plant physiology, biomass, and yield were assessed. Site and growing-season context strongly structured responses. Consortium application increased total AM colonization from 46.18% to 52.47% (p < 0.001; partial η² = 0.176) and altered substrate-use composition (p = 0.009). The simple-sugars-to-other-substrates ILR balance increased under consortium application (Holm-adjusted p = 0.005), while the glucose-to-fructose balance decreased (Holm-adjusted p = 0.004), without increasing overall respiratory activity. Total and commercial yield showed no significant consortium response, and reduced irrigation did not enhance agronomic responses. Field evaluation of microbial inoculants should therefore prioritize agronomic outcomes across production contexts rather than colonization alone.