Periodic Reporting for period 1 - ACOFOOD (Acorns revaluation for human consumption: genomic selection and development of new functional foods)
Período documentado: 2022-11-01 hasta 2025-06-30
Facing the global challenge of eradicating hunger and malnutrition, there is a growing need to redefine agricultural systems towards nutritious, safe, and environmentally and socio-culturally sustainable food sources, such as acorns (Quercus). Although acorn is a nut with a healthy nutritional profile (rich in fiber and carbohydrates, and with a healthy lipid profile) and strong antioxidant activity due to its high concentration of phenolic compounds, its global production has been relegated almost exclusively to livestock feed. This underutilization is mainly due to the astringency and potential cytotoxicity of tannins (a type of phenolic compound), which affect its palatability and digestibility for human consumption, making its use only occasional and without significant commercialization.
Scientifically, the variability and limited information on hydrolyzable tannins hinder systematic research. However, significant advances have been made in the genetic and metabolomic knowledge of Quercus ilex subsp. ballota, opening the door to genetic improvement or post-harvest strategies to obtain sweeter and tastier acorns. This will allow for the extension of its cultivation areas and the design of attractive and easy-to-consume products that permanently integrate this nutritious fruit into the human diet, thus contributing to food security.
Thus, the overall objective of the project is to contribute to the integration of acorns into the human diet as a healthy and sustainable food, offering scientific bases and practical solutions for their valorization. To this end, this project proposes:
• Identify key acorn compounds: Especially those related to astringency and its nutritional value.
• Unravel genetic and molecular mechanisms: Investigate the processes of acorn ripening and the factors influencing its astringency.
• Analyze the impact of acorn consumption on gut health: Including its effect on the microbiota.
• Develop healthy and innovative acorn-based food products: With good consumer acceptability.
Scientifically, the variability and limited information on hydrolyzable tannins hinder systematic research. However, significant advances have been made in the genetic and metabolomic knowledge of Quercus ilex subsp. ballota, opening the door to genetic improvement or post-harvest strategies to obtain sweeter and tastier acorns. This will allow for the extension of its cultivation areas and the design of attractive and easy-to-consume products that permanently integrate this nutritious fruit into the human diet, thus contributing to food security.
Thus, the overall objective of the project is to contribute to the integration of acorns into the human diet as a healthy and sustainable food, offering scientific bases and practical solutions for their valorization. To this end, this project proposes:
• Identify key acorn compounds: Especially those related to astringency and its nutritional value.
• Unravel genetic and molecular mechanisms: Investigate the processes of acorn ripening and the factors influencing its astringency.
• Analyze the impact of acorn consumption on gut health: Including its effect on the microbiota.
• Develop healthy and innovative acorn-based food products: With good consumer acceptability.
This project adopted an interdisciplinary approach to enhance the value of Quercus acorns, a traditional and sustainable resource, through advanced scientific research and the development of innovative food products. The work combined molecular biology, food technology, and sensory evaluation techniques to understand their characteristics and potential for human consumption.
A significant line of work involved an exhaustive transcriptomic analysis of Quercus ilex subsp. ballota acorns, characterizing the genes involved in ripening and gene expression at different developmental stages and with different organoleptic profiles (sweet and astringent). This study generated a valuable genomic resource for understanding acorn development.
In parallel, molecular markers for astringency in Quercus ilex acorns were investigated using advanced genomic and genetic tools, including the generation and application of the Quercus ilex genome sequence. These efforts provided fundamental insights into the genetic factors of astringency and established crucial genomic resources.
A metabolomic analysis of acorns at different ripening stages was carried out, which allowed for the identification of metabolites related to astringency and confirmed the fruit's healthy nutritional profile. This information is vital for future post-harvest strategies to improve palatability.
Additionally, the gastrointestinal effects of acorn consumption were explored, investigating the metabolite profile during digestion and observing a positive impact on the intestinal microbiota.
Finally, a key achievement was the design and consumer acceptance evaluation of healthy acorn-based snacks. New products such as energy bars, fresh spaghetti, and gnocchi were developed. Sensory evaluation confirmed the viability of these products and the importance of their natural and healthy properties, demonstrating the significant potential of acorn as an innovative ingredient for snacks.
A significant line of work involved an exhaustive transcriptomic analysis of Quercus ilex subsp. ballota acorns, characterizing the genes involved in ripening and gene expression at different developmental stages and with different organoleptic profiles (sweet and astringent). This study generated a valuable genomic resource for understanding acorn development.
In parallel, molecular markers for astringency in Quercus ilex acorns were investigated using advanced genomic and genetic tools, including the generation and application of the Quercus ilex genome sequence. These efforts provided fundamental insights into the genetic factors of astringency and established crucial genomic resources.
A metabolomic analysis of acorns at different ripening stages was carried out, which allowed for the identification of metabolites related to astringency and confirmed the fruit's healthy nutritional profile. This information is vital for future post-harvest strategies to improve palatability.
Additionally, the gastrointestinal effects of acorn consumption were explored, investigating the metabolite profile during digestion and observing a positive impact on the intestinal microbiota.
Finally, a key achievement was the design and consumer acceptance evaluation of healthy acorn-based snacks. New products such as energy bars, fresh spaghetti, and gnocchi were developed. Sensory evaluation confirmed the viability of these products and the importance of their natural and healthy properties, demonstrating the significant potential of acorn as an innovative ingredient for snacks.
This project has significantly advanced the understanding and utilization of Quercus ilex acorns, moving beyond existing knowledge by integrating fundamental genomic and metabolomic research with practical food product development. The integration of scientific insights into product development demonstrates a value chain for the valorization of underutilized natural resources.
The key results that push the state of the art include:
• Understanding of Acorn Ripening at Transcriptomic Level: By identifying genes induced and repressed by ripening and characterizing their associated biological functions in early and late stages, this research offers a fundamental genomic framework for future breeding efforts aimed at optimizing desirable traits or developing new varieties. The detailed temporal analysis of transcriptome remodeling provides a more granular understanding than previously available studies.
• Novel Insights into Astringency Mechanisms: While a definitive molecular marker for astringency was not achieved, the project significantly advanced the genetic understanding of this complex trait. The generation and utilization of the Quercus ilex genome sequence is a major step forward, offering a high-resolution tool for future genetic research. The identification of candidate genomic regions and genes related to tannin biosynthesis and their differential regulation between astringent and non-astringent samples provides critical leads for future targeted breeding and biotechnological interventions to reduce undesirable astringency.
• Identification of Astringency-Related Metabolites: Through advanced metabolomic profiling, the project identified specific metabolites correlated with astringency in Quercus ilex acorns at different developmental stages. This goes beyond general compositional analysis by pinpointing specific compounds whose fluctuations during ripening could be targeted for post-harvest treatments to improve palatability. This offers a new avenue for practical application in acorn processing.
• Demonstrated Beneficial Gastrointestinal Effects of Acorn: The research revealed specific positive impacts of acorn digestion on gut microbiota, particularly the increase in beneficial Bifidobacteria, even surpassing fructooligosaccharide-supplemented controls. This concrete evidence of acorn's prebiotic potential is a significant finding that elevates its status from a mere traditional ingredient to a functional food component with quantifiable health benefits.
• Successful Development of Highly Acceptable Acorn-Based Food Products: The project successfully designed and tested novel food prototypes, particularly fresh spaghetti and an optimized energy bar, integrating acorn derivatives. The high consumer acceptability demonstrates that acorns can be successfully incorporated into everyday human foodstuffs beyond traditional uses. This directly addresses the challenge of diversifying healthy, sustainable food sources and offers tangible, market-ready concepts, expanding the limits of acorn utilization in the human diet.
These results, collectively, provide a comprehensive scientific basis for the valorization of acorns, moving beyond traditional animal feed uses and laying the groundwork for a new generation of healthy, sustainable, and consumer-accepted food products derived from this underutilized resource. Future research will build on these findings to overcome remaining challenges for full market integration.
The key results that push the state of the art include:
• Understanding of Acorn Ripening at Transcriptomic Level: By identifying genes induced and repressed by ripening and characterizing their associated biological functions in early and late stages, this research offers a fundamental genomic framework for future breeding efforts aimed at optimizing desirable traits or developing new varieties. The detailed temporal analysis of transcriptome remodeling provides a more granular understanding than previously available studies.
• Novel Insights into Astringency Mechanisms: While a definitive molecular marker for astringency was not achieved, the project significantly advanced the genetic understanding of this complex trait. The generation and utilization of the Quercus ilex genome sequence is a major step forward, offering a high-resolution tool for future genetic research. The identification of candidate genomic regions and genes related to tannin biosynthesis and their differential regulation between astringent and non-astringent samples provides critical leads for future targeted breeding and biotechnological interventions to reduce undesirable astringency.
• Identification of Astringency-Related Metabolites: Through advanced metabolomic profiling, the project identified specific metabolites correlated with astringency in Quercus ilex acorns at different developmental stages. This goes beyond general compositional analysis by pinpointing specific compounds whose fluctuations during ripening could be targeted for post-harvest treatments to improve palatability. This offers a new avenue for practical application in acorn processing.
• Demonstrated Beneficial Gastrointestinal Effects of Acorn: The research revealed specific positive impacts of acorn digestion on gut microbiota, particularly the increase in beneficial Bifidobacteria, even surpassing fructooligosaccharide-supplemented controls. This concrete evidence of acorn's prebiotic potential is a significant finding that elevates its status from a mere traditional ingredient to a functional food component with quantifiable health benefits.
• Successful Development of Highly Acceptable Acorn-Based Food Products: The project successfully designed and tested novel food prototypes, particularly fresh spaghetti and an optimized energy bar, integrating acorn derivatives. The high consumer acceptability demonstrates that acorns can be successfully incorporated into everyday human foodstuffs beyond traditional uses. This directly addresses the challenge of diversifying healthy, sustainable food sources and offers tangible, market-ready concepts, expanding the limits of acorn utilization in the human diet.
These results, collectively, provide a comprehensive scientific basis for the valorization of acorns, moving beyond traditional animal feed uses and laying the groundwork for a new generation of healthy, sustainable, and consumer-accepted food products derived from this underutilized resource. Future research will build on these findings to overcome remaining challenges for full market integration.