Periodic Reporting for period 1 - BIG (Effect of bioactive compounds from novel tomato on glycaemia - short title (Bioactive compounds Impact on Glycaemia))
Reporting period: 2023-11-01 to 2025-10-31
The project addresses the urgent need for innovative dietary interventions to reduce the incidence of type 2 diabetes (T2D), where projections indicate a 13% rise in cases by 2045 in Europe. This increase is closely linked to high-glycaemic diets, as frequent glucose peaks after a meal can strain the glucose metabolism, often leading to impaired glucose tolerance and increased diabetes risk. Timely dietary and lifestyle interventions have proven effective in delaying or preventing T2D onset. However, there is a need for sustainable, feasible solutions that allow individuals to manage glycaemia without drastic dietary changes.
This project aims to address these gaps by exploring the potential of tomato-derived bioactive compounds, polyphenols and carotenoids, to mitigate the glycaemic impact of high-starch foods commonly consumed in Mediterranean diets, such as bread and pasta.
The project will explore the interactions between bioactive compounds in tomatoes and starch in carbohydrate-based foods. The goal is to determine whether the presence of bioactive compounds can reduce the glycaemic impact of starch-based foods, contributing to better metabolic health outcomes. Tomatoes are rich in polyphenols and carotenoids that may inhibit starch digestibility, offering a promising pathway to moderating blood glucose levels. By using tomato skins as a source for these compounds, the project also presents a sustainable solution, transforming agricultural by-products into valuable dietary supplements and supporting the UN’s sustainable development goals.
The objectives of this study are: 1) To measure digestibility of starch when in combination with different concentrations of polyphenols and carotenoids from tomatoes using an established single-enzyme system that is well-correlated with glycaemic response measured in vivo. 2) To determine the bioaccessibility of starch and bioactive compounds within a food matrix using the INFOGEST static simulated digestion system. 3) To determine the effect of bioactive compounds daily intake from tomato on glycaemia using biological samples from an ongoing dietary intervention study in the Polyphenol Research Group (MITOS).
The project’s research framework spans multiple levels, from generating new data using in vitro digestion models and analytical techniques for compounds identification and quantification to data re-use from human dietary studies. The aim is to examine how bioactive compounds from tomatoes interact with starch in different food matrices. These findings are expected to support the development of glycaemia-moderating functional foods, directly targeting dietary factors in T2D prevention strategies.
Expected impact include:
1. Public Health: Providing evidence-based dietary interventions could improve glycaemic control across Europe, reducing T2D incidence rates.
2. Sustainable Food Production: By valorising tomato by-products, the project encourages waste reduction in agriculture, aligning with circular economy goals.
3. Policy and Industry Relevance: Project findings could shape public health recommendations and inspire the food industry to develop biofortified, low-glycaemic foods.
To promote wider awareness and application, findings will be disseminated through open-access publications, public science events, and targeted engagement with stakeholders, including industry and policymakers. These outreach activities will ensure that the project’s contributions to nutritional science and sustainable food systems reach diverse audiences, setting a foundation for impactful public health interventions and innovations in food production.
This project aims to address these gaps by exploring the potential of tomato-derived bioactive compounds, polyphenols and carotenoids, to mitigate the glycaemic impact of high-starch foods commonly consumed in Mediterranean diets, such as bread and pasta.
The project will explore the interactions between bioactive compounds in tomatoes and starch in carbohydrate-based foods. The goal is to determine whether the presence of bioactive compounds can reduce the glycaemic impact of starch-based foods, contributing to better metabolic health outcomes. Tomatoes are rich in polyphenols and carotenoids that may inhibit starch digestibility, offering a promising pathway to moderating blood glucose levels. By using tomato skins as a source for these compounds, the project also presents a sustainable solution, transforming agricultural by-products into valuable dietary supplements and supporting the UN’s sustainable development goals.
The objectives of this study are: 1) To measure digestibility of starch when in combination with different concentrations of polyphenols and carotenoids from tomatoes using an established single-enzyme system that is well-correlated with glycaemic response measured in vivo. 2) To determine the bioaccessibility of starch and bioactive compounds within a food matrix using the INFOGEST static simulated digestion system. 3) To determine the effect of bioactive compounds daily intake from tomato on glycaemia using biological samples from an ongoing dietary intervention study in the Polyphenol Research Group (MITOS).
The project’s research framework spans multiple levels, from generating new data using in vitro digestion models and analytical techniques for compounds identification and quantification to data re-use from human dietary studies. The aim is to examine how bioactive compounds from tomatoes interact with starch in different food matrices. These findings are expected to support the development of glycaemia-moderating functional foods, directly targeting dietary factors in T2D prevention strategies.
Expected impact include:
1. Public Health: Providing evidence-based dietary interventions could improve glycaemic control across Europe, reducing T2D incidence rates.
2. Sustainable Food Production: By valorising tomato by-products, the project encourages waste reduction in agriculture, aligning with circular economy goals.
3. Policy and Industry Relevance: Project findings could shape public health recommendations and inspire the food industry to develop biofortified, low-glycaemic foods.
To promote wider awareness and application, findings will be disseminated through open-access publications, public science events, and targeted engagement with stakeholders, including industry and policymakers. These outreach activities will ensure that the project’s contributions to nutritional science and sustainable food systems reach diverse audiences, setting a foundation for impactful public health interventions and innovations in food production.
In Phase 1, this research focused on how compounds in tomatoes, specifically polyphenols and carotenoids, interact with starch at a molecular level. The aim was to determine whether these bioactive compounds could reduce the digestibility of starch, potentially mitigating the sharp rise in blood sugar typically experienced after consuming starchy foods. A single-enzyme digestion system, simulating starch breakdown in the human digestive process, was used to explore this interaction and its potential effects on blood sugar responses.
Selection of Tomato Varieties
Three tomato types were selected for their unique bioactive profiles, providing insight into the optimal source of polyphenols and carotenoids:
MITOS Tomato Sauce: Used in the MITOS clinical study examining the effects of long-term tomato intake on metabolic health, this source offered a unique opportunity to align in vitro-based results from this research project with the outcomes from the MITOS ongoing dietary intervention, which samples and data will be used to achieve objective 3 in this project.
Blue Tomatoes (cultivar Mar Azul): Known for their high anthocyanin levels, blue tomatoes offer an ideal source of these bioactive compounds, which are thought to affect starch breakdown by digestive enzymes.
Pebroter Tomatoes (cultivar Corno Andino): Locally grown in Catalonia and harvested in September 2024, these tomatoes are rich in polyphenols. Previous studies have shown that this variety has a consistently high polyphenol content and promising yield characteristics, making it a strong candidate for this research project.
Extraction and Analysis of Bioactive Compounds
To extract polyphenols and carotenoids, a green solvent extraction method using methanol and ethanol was employed. Each tomato source underwent specific preparation to ensure accurate fractionation:
• Blue and Pebroter Tomatoes: These raw tomatoes were washed, manually peeled, and deseeded, allowing for the separation and analysis of bioactive compounds in the peel, seeds, and pulp.
• Tomaro paste: As this sauce was industrially processed, it was not possible to separate fractions; instead, the entire sauce was analysed.
Following extraction, liquid chromatography–mass spectrometry (LC-MS) was used to identify and quantify polyphenols (currently ongoing), while the total polyphenol content was determined using the Folin-Ciocalteu method. Extracts were tested in various concentrations with wheat and rice starch to determine the concentration required for an effect on starch digestibility and whether starch type significantly impacted digestion profiles.
Carotenoids were extracted and will be quantified to be later used for in vitro digestions.
Starch Digestibility Assay and Quantification of Reducing Sugars
The starch digestibility assay applied here was previously validated to correlate well with glycaemic index (GI) values obtained in vivo. Digestibility was measured by assessing the reducing sugars released during starch breakdown, analysed through colorimetric methods based on p-hydroxybenzoic acid hydrazide (PAHBAH) and dinitrosalicylic acid (DNS) assays. Due to potential UV/visible absorbance interference from polyphenols in the extracts, a high-performance liquid chromatography (HPLC) coupled with Refractive Index detector method was also developed to accurately quantify polysaccharides and ensure reliable digestion data.
Phenolic and carotenoids copounds were identified and quantified using LC-MS/MS and UPLC-DAD, respectively.
Selection of Tomato Varieties
Three tomato types were selected for their unique bioactive profiles, providing insight into the optimal source of polyphenols and carotenoids:
MITOS Tomato Sauce: Used in the MITOS clinical study examining the effects of long-term tomato intake on metabolic health, this source offered a unique opportunity to align in vitro-based results from this research project with the outcomes from the MITOS ongoing dietary intervention, which samples and data will be used to achieve objective 3 in this project.
Blue Tomatoes (cultivar Mar Azul): Known for their high anthocyanin levels, blue tomatoes offer an ideal source of these bioactive compounds, which are thought to affect starch breakdown by digestive enzymes.
Pebroter Tomatoes (cultivar Corno Andino): Locally grown in Catalonia and harvested in September 2024, these tomatoes are rich in polyphenols. Previous studies have shown that this variety has a consistently high polyphenol content and promising yield characteristics, making it a strong candidate for this research project.
Extraction and Analysis of Bioactive Compounds
To extract polyphenols and carotenoids, a green solvent extraction method using methanol and ethanol was employed. Each tomato source underwent specific preparation to ensure accurate fractionation:
• Blue and Pebroter Tomatoes: These raw tomatoes were washed, manually peeled, and deseeded, allowing for the separation and analysis of bioactive compounds in the peel, seeds, and pulp.
• Tomaro paste: As this sauce was industrially processed, it was not possible to separate fractions; instead, the entire sauce was analysed.
Following extraction, liquid chromatography–mass spectrometry (LC-MS) was used to identify and quantify polyphenols (currently ongoing), while the total polyphenol content was determined using the Folin-Ciocalteu method. Extracts were tested in various concentrations with wheat and rice starch to determine the concentration required for an effect on starch digestibility and whether starch type significantly impacted digestion profiles.
Carotenoids were extracted and will be quantified to be later used for in vitro digestions.
Starch Digestibility Assay and Quantification of Reducing Sugars
The starch digestibility assay applied here was previously validated to correlate well with glycaemic index (GI) values obtained in vivo. Digestibility was measured by assessing the reducing sugars released during starch breakdown, analysed through colorimetric methods based on p-hydroxybenzoic acid hydrazide (PAHBAH) and dinitrosalicylic acid (DNS) assays. Due to potential UV/visible absorbance interference from polyphenols in the extracts, a high-performance liquid chromatography (HPLC) coupled with Refractive Index detector method was also developed to accurately quantify polysaccharides and ensure reliable digestion data.
Phenolic and carotenoids copounds were identified and quantified using LC-MS/MS and UPLC-DAD, respectively.
Overview of Findings: Preliminary findings have established that a specific concentration of polyphenols, when combined with starch at a balanced ratio, may reduce starch digestibility. This insight highlights the potential for developing functional foods aimed at moderating glycaemic response. Initial testing focused on polyphenol- and anthocyanin-rich extracts from selected tomato varieties to assess their effectiveness and suitability for food applications targeting blood sugar management.
Minimum Effective Concentrations of Key Polyphenols and Carotenoids
Early-stage investigations have identified tomato extracts as a promising source of polyphenols for this application. Future studies will continue to refine the necessary concentrations and explore the impact of phenolic-rich tomato peels on the functional quality of carbohydrate-based foods.
Optimising Bioactive-Rich Tomato Preparations
Hypotheiss generating experiemtns were carried out to enrich carbohydrate foods with bioactive-rich products, such as enriched sauces or fortification with tomato by-products. These preparations aimed to maximise the bioavailability of beneficial compounds while preserving food quality.
The effect of bioactive compounds intake on glycaemic biomarkers was evaluated in a clinical trial involving daily intake of tomato paste.
Potential Impacts and Next Steps: This work holds potential for developing innovative food products with added health benefits, particularly for glycaemic management. To support broader uptake, future needs include additional research and knowledge transfer projects to bridge the gap between the research outcomes and market-ready solutions. Collaboration with industry partners will be key for progressing towards commercialisation and ensuring alignment with EU food safety and health standards.
Minimum Effective Concentrations of Key Polyphenols and Carotenoids
Early-stage investigations have identified tomato extracts as a promising source of polyphenols for this application. Future studies will continue to refine the necessary concentrations and explore the impact of phenolic-rich tomato peels on the functional quality of carbohydrate-based foods.
Optimising Bioactive-Rich Tomato Preparations
Hypotheiss generating experiemtns were carried out to enrich carbohydrate foods with bioactive-rich products, such as enriched sauces or fortification with tomato by-products. These preparations aimed to maximise the bioavailability of beneficial compounds while preserving food quality.
The effect of bioactive compounds intake on glycaemic biomarkers was evaluated in a clinical trial involving daily intake of tomato paste.
Potential Impacts and Next Steps: This work holds potential for developing innovative food products with added health benefits, particularly for glycaemic management. To support broader uptake, future needs include additional research and knowledge transfer projects to bridge the gap between the research outcomes and market-ready solutions. Collaboration with industry partners will be key for progressing towards commercialisation and ensuring alignment with EU food safety and health standards.