The global food system significantly impacts both human health and the environment. Malnutrition and limited access to nutritious food remain critical issues in developing countries, while overconsumption of processed foods contributes to non-communicable diseases in developed nations. Food insecurity affects a substantial portion of the global population. Climate change further exacerbates these challenges by damaging ecosystems. A shift towards healthy and environmentally sustainable diets is crucial. While food fortification and biofortification strategies have shown success, significant micronutrient losses still occur along the food value chain (FVC). This study focuses on the household level, a significant contributor to nutrient loss and environmental damage, using potatoes as a case study to analyze the nutritional and environmental impacts of home storage and processing. The study employs a life cycle assessment (LCA) and TOPSIS decision modeling to identify optimal pathways considering both nutritional retention and environmental sustainability, aligning with Sustainable Development Goals 2 and 12.

Previous research highlights considerable nutrient losses at various stages of the FVC. Kwofie et al. (2019) reported significant mineral content decline in common beans (up to 88%), while Mba (2019) demonstrated polyphenol degradation related to hydration time and temperature during bean processing. Ellis et al. (2020) quantified substantial economic and nutrient losses in the common bean FVC. Studies by Parajuli et al. (2021), Mouron et al. (2016), and Jungbluth et al. (2022) identified household processing and consumption as a major hotspot for environmental impacts. These studies underscore the need to examine household-level food storage and processing for their combined impact on nutrition and environmental sustainability.

This study used a full factorial experimental design to assess the effects of potato storage and processing on nutrient content and environmental impact. Three storage conditions (cupboard, refrigerator, ideal) and two storage times (2 and 5 weeks) were combined with three processing methods (boiling, baking, frying). Temperature and relative humidity were monitored throughout storage. Nutrient profiling (minerals, fat, calories) was performed on samples using established laboratory methods and compared to USDA FoodData Central. Environmental impact was evaluated using a life cycle assessment (LCA) with the ReCiPe 2016 method, modeling the system from retail purchase to consumption. Data from the experiment provided foreground data. Ecoinvent v.3.7.1 database supplied background data. The LCA considered impacts such as freshwater and marine ecotoxicity, global warming potential, and others. The impact was quantified at both midpoint and endpoint levels using ReCiPe 2016 Midpoint (H) and Endpoint (H) methods and World 2010 (H/H) normalization method. Uncertainty analysis using Monte Carlo simulation assessed the reliability of the LCA results. Finally, TOPSIS decision modeling was used to determine the optimal storage and processing pathways based on varying consumer priorities for nutrition and environmental sustainability.

Storing potatoes for 5 weeks resulted in significantly greater nutrient loss (33.5-40.3%) compared to 2 weeks across all processing methods. Processing after 5 weeks led to approximately 2.2 times more damage to human health, ecosystem safety, and resource availability than processing after 2 weeks. The fried-cupboard pathway after 5 weeks had the most significant negative environmental impact. The boiled-unstored pathway exhibited the lowest environmental impact across all scenarios. The LCA revealed that the frying method generally had a higher environmental impact than boiling or baking. The highest environmental impact contribution was associated with the boiled-refrigerator pathway (BL-FG), primarily due to water resource usage and electricity consumption for refrigeration. The highest environmental impact was with fried potatoes stored in the cupboard for 5 weeks, showing approximately 97 times more damage than freshly processed potatoes. Boiling potatoes stored in the refrigerator after 2 weeks showed around 54 times more damage. Nutrient loss was more significant for frying (56-67%) than boiling or baking. TOPSIS analysis, prioritizing environmental sustainability, identified the boiled-cupboard pathway after 2 weeks as optimal. When nutrition was prioritized, the boiled-refrigerator pathway was optimal. Uncertainty analysis showed reasonable certainty in most impact categories (CV <10%).

The study's findings highlight the significant nutritional and environmental trade-offs associated with household potato storage and processing. The results directly address the research question by quantifying these trade-offs and demonstrating the importance of considering both nutritional value and environmental impact in food choices. The significant difference in environmental impacts between short and long-term storage emphasizes the importance of mindful consumption practices. The LCA results, especially the endpoint damage assessment, clearly show the potential for consumer choices to significantly impact human health, ecosystems, and resource availability. The TOPSIS analysis offers a practical tool for guiding consumer decisions, illustrating how the optimal approach varies based on individual preferences regarding nutrition and environmental sustainability. The identified optimal pathways—boiling potatoes stored in cupboards—provides a tangible recommendation for consumers seeking to minimize environmental impact while maintaining adequate nutrition.

This study demonstrates considerable nutrient loss and environmental damage associated with prolonged potato storage and specific processing methods. The boiled-cupboard pathway, particularly with shorter storage times, emerges as an optimal balance of nutritional retention and environmental sustainability. Future research could expand this framework to other staple crops and explore interventions to reduce nutrient losses and environmental impacts throughout the entire FVC. Further investigation into consumer behavior and education strategies could promote sustainable food choices and minimize the environmental footprint of household food preparation.

The study's scope is limited to household storage and processing of Russet potatoes in the US, limiting the generalizability to other potato varieties or geographical regions. The LCA excludes pre-retail stages of the FVC. The sample size, while sufficient for statistical analysis, could be increased for greater certainty. Finally, the consumer survey was preliminary and self-conducted and may not fully capture the diversity of consumer practices.