Sustainable valorisation of tomato pomace: A comprehensive review

New Insight into Microbial Exploitation to Produce Bioactive Molecules from Agrifood and By-Products' Fermentation

Consumers are increasingly interested in a healthy lifestyle, and choosing foods and ingredients with proven human health benefits has become a current trend. Recently, scientific evidence has proven that the use of microorganisms in different food matrices appears to play a key role in the production of bioactive molecules with biological effects on human health. In particular, selected microorganisms with specific traits can be exploited for the production of specific molecules with high nutraceutical value that can be used in the food industry. This review aims to explore the most recent studies that correlate the use of microorganisms to produce high-value molecules through fermentation and synthetic biology, confirming their strategic role in obtaining nutraceuticals for human consumption with health-promoting effects.

A Revisit of Plant Food Waste Along Food Supply Chains: Impacts and Perspectives

More than one billion tons of the food produced in the world ends up being wasted every year, accounting for about one-third of the food produced globally. For this reason, the problem of food waste management has been the focus of the different actors intervening in the food supply chains, who recognize that food waste has not only environmental but also economic and social impacts. This review focuses on foods of plant origin wasted at different stages of their life, namely primary production, transformation/processing, transportation, sales, catering and the domestic level. It addresses the subject from multiple angles, considering the environmental, economic and social perspectives. The review was based on a search carried out within scientific databases, for example, ScienceDirect, Scopus and the Web of Science. The results highlighted that in the generation and management of food waste from plant origin, there is a clear difference between developed and developing countries, with these last showing higher losses in production, principally the transportation and storage of the foods. Contrarily, in developed countries, excess food produced and not consumed is the strongest contributor to food waste. Valorization of agricultural waste and industrial residues for application into animal feed or agricultural fertilizers, or through the recovery of valuable compounds for industrial purposes, are some of the ways to deal with food waste while generating additional economic value and reducing environmental impact. However, there is still a need to modify processes and behaviors to reduce food waste and improve the sustainability of supply chains. Therefore, it is crucial to conduct research to identify and report food waste so that stakeholders can contribute positively to solving this problem.

Tomato yields and quality declines due to elevated soil CO2

The potential risk for CO2 leakage from carbon capture and storage (CCS) systems has raised significant concerns. While numerous studies have explored how crops respond to elevated soil CO2 levels, relatively few have examined the impacts on vegetables. Tomatoes (Solanum lycopersicum) are a key vegetable crop, and this study sought to investigate how CO2 leakage affects their yield and quality. We conducted pot experiments comparing tomatoes grown under control conditions (no added CO2) with those exposed to elevated soil CO2 levels (1500 g m-2d-1). Our findings indicate that under CO2 leakage conditions, the overall biomass of tomato plants, average fruit weight, and fruit size decreased by 47.42%, 47.65%, and 20.2%, respectively. Notably, the titratable acid content in the tomatoes increased by 27.5%, resulting in a sourer taste. The tomato fruit grades and sugar acid ratio declined leading to a seriously commercial value loss of tomatoes in response to elevated soil CO2 levels. This study provides a more quantitative understanding of how vegetables like tomatoes respond to CO2 leakage, which is crucial for CCS decision-makers to comprehend the adverse effects of CO2 leaks on agriculture.

A review of antioxidant strategies to improve reproduction in aging male broiler breeders

As only 10% of the broiler breeder flock is roosters, their fertility is very important. The rooster sperm plasma membrane has high concentrations of polyunsaturated fatty acids that are sensitive to oxidative stress. Lipid peroxidation can change membrane structure, permeability, and fluidity, adversely affecting the acrosome reaction and fertility. Aging roosters have decreases in sexual behavior, serum androgen concentrations, sperm quantity and quality, and fertility. Low fertility in aging roosters is attributed to an imbalanced testicular oxidant-antioxidant system, with increased reactive oxygen species (ROS) damaging spermatogenic epithelium. However, antioxidant components can enhance antioxidant defenses in aging broiler breeder roosters. Protection against oxidative damage, particularly in the testes, improves reproductive hormone concentrations, testicular histology, sperm membrane function, and mitochondrial activity and thereby improves semen volume, sperm concentration, viability, motility, and sperm polyunsaturated fatty acid content, sperm-egg penetration, fertility, and reproductive performance. This review summarizes antioxidants that could improve fertility and reproductive performance and delay or prevent age-related declines in broiler breeder roosters, with benefits for poultry production.

Nutraceutical potential of Mediterranean agri-food waste and wild plants: Green extraction and bioactive characterization

The agricultural waste and wild plants of the Mediterranean region offer significant nutraceutical potential, rich in bioactive compounds such as phenolics, carotenoids, lipids and volatile organic compounds. These compounds exhibit health-promoting properties, including antioxidant, neuroprotective and anti-inflammatory effects. Advanced analytical techniques such as HPLC, GC-MS and NMR are essential for the accurate chemical characterization of these bioactives. Green extraction methods, including ultrasound-assisted, enzyme-assisted and cold plasma-assisted extractions, provide efficient and environmentally friendly alternatives to classical techniques for the isolation of bioactive compounds. The valorization of Mediterranean agricultural by-products, such as olive pomace, grape seeds, and citrus peels, exemplifies sustainable approaches to the utilization of these underutilized resources. This chapter explores the bioactive characterization and green extraction methods that contribute to unlocking the nutraceutical potential of Mediterranean plant waste and wild plants, highlighting their role in the development of functional foods and natural health products.

Valorization of Date By-Products: Enhancement of Antioxidant and Antimicrobial Potentials through Fermentation

The by-products from three varieties of dates-Mozafati, Sayer, and Kabkab-were subjected to solid-state fermentation using Aspergillus niger alone or in co-culture with Lactiplantibacillus plantarum or Limosilactobacillus reuteri to enhance their phenolic and flavonoid content, along with antioxidant and antimicrobial activities. Solid-state fermentation, being environmentally friendly and cost-effective, is particularly suitable for agricultural residues. Significant increases (p < 0.05) in total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant power were observed post-fermentation, especially under co-culture conditions. The highest TPC (12.98 ± 0.29 mg GA/g) and TFC (1.83 ± 0.07 mg QE/g) were recorded in the co-culture fermentation of by-products from the Mozafati and Sayer varieties, respectively. HPLC analysis revealed changes in polyphenol profiles post-fermentation, with reductions in gallic and ferulic acids and increases in caffeic acid, p-coumaric acid, rutin, quercetin, and kaempferol. FT-IR analysis confirmed significant alterations in polyphenolic functional groups. Enhanced antimicrobial activity was also observed, with inhibition zones ranging from 8.26 ± 0.06 mm for Kabkab to 17.73 ± 0.09 mm for Mozafati. These results suggest that co-culture solid-state fermentation is a promising strategy for valorizing date by-products, with potential applications in nutraceuticals and/or pharmaceutical products and as valuable additives in the food industry.

Chemometric study on the effect of cooking on bioactive compounds in tomato pomace enriched sauces

Tomato pomace (TP) is an underutilized source of bioactive compounds with potential application in the food sector. A factorial experiment was designed to compare three culinary techniques, Thermomix®, Roner®, and traditional pan-frying, for the preparation of tomato sauces, enriched or not with TP, applying two temperatures and two cooking times. A multivariate analysis was performed on all the results obtained for the metabolites. The addition of TP significantly increased the content of bioactive compounds, especially phenolic compounds. OPLS-DA models were generated using cooking technique, temperature, and time as discriminant factors. The cooking technique had a greater effect on the phenolic content than cooking temperature or time. Thermomix® released bioactive compounds from the tomato into the sauce to a similar extent as pan-frying. Roner® proved to be effective in preserving the volatile fraction of the sauce. The Thermomix® significantly increased the amount of bioactive compounds, while the Roner® increased the volatile compounds.

Optimization of lactic acid production from apple and tomato pomaces by thermotolerant bacteria

The production of lactic acid (LA) through biomass fermentation represents a promising alternative to the chemical synthesis. The use of agri-food by-products as fermentable carbohydrate sources can improve process sustainability by reducing waste and valorizing residual biomass. This study assessed the use of apple and tomato pomaces for producing LA through fermentation using thermotolerant bacteria under aerobic and non-sterile conditions. Three bacteria were evaluated and Heyndrickxia coagulans DSM 2314 was selected for its ability to produce LA from hydrolyzates of apple pomace (APH) and tomato pomace (TPH). The fermentation conditions were optimized to maximize LA production from APH, TPH and a mixture of both hydrolyzates. Therefore, LA productions ranged from 36.98 ± 0.41 to 40.72 ± 0.43 g/L, with yields from 0.86 ± 0.02 to 1.01 ± 0.01 g/g. Yeast extract was necessary as a nitrogen source for fermenting APH, while TPH and the mixture of both hydrolyzates did not require any supplementation. Other nitrogen sources, such as wine lees, urea and NH3Cl, were tested for fermenting APH. However, mixing this hydrolyzate with TPH proved to be the most viable alternative. This study demonstrates the potential for valorizing apple and tomato pomaces into LA under feasible fermentation conditions.

Tomato pomace-derived nitrated fatty acids: Synthesis and antiplatelet activity

This study investigates the antiplatelet properties of tomato pulp to combat cardiovascular diseases. Notably, it examines the formation of nitrated fatty acids (NO2-FA) in tomato pomace, renowned for its potential antiplatelet effects. Through diverse assays, including tandem mass spectrometry, microplate-based platelet aggregation, and flow cytometry, the research identifies NO2-OA, NO2-LA, and NO2-LnA as pivotal antiplatelet compounds. It demonstrates the concentration-dependent antiplatelet effects of nitrated tomato pomace against thrombin receptor activator peptide 6 (TRAP-6) and collagen-induced platelet activation, alongside the modulation of platelet activation markers. Additionally, synergistic effects were observed with nitrated tomato pomace extracts. The findings suggest therapeutic potential for NO2-FA derived from tomato pomace in preventing blood clot formation, with nitrated extracts exhibiting superior efficacy compared to non-nitrated ones. This research highlights the promising role of natural products, such as tomato pomace, in mitigating cardiovascular risks and proposes novel strategies for population health enhancement and cardiovascular disease management.

From Waste to Consumption: Tomato Peel Flour in Hamburger Patty Production

Tomato is a widely cultivated crop and its processing produces large quantities of wastes, such as pulp, seed, and peel. In recent years, the valorization of these wastes in the production of high-value-added food products has gained popularity in achieving environmental sustainability and zero waste. From this viewpoint, dried tomato peel (DTP-1%, 2%, 3%, 4%) flour was included in hamburger formulations. In patty samples, ash, carbohydrate, and dietary fiber amounts were increased due to the high fiber content of DTP flour, while moisture and fat percentages decreased with increasing amounts of DTP flour (p < 0.05). The inclusion of DTP flour retarded lipid oxidation during cooking (p < 0.05). The significantly highest cooking yield was calculated in samples including 4% DTP flour. In parallel, water-holding capacity, moisture, and fat retention values increased with increasing levels of DTP flour (p < 0.05). The enrichment of patties with DTP flour resulted in hard texture, less gumminess, and a darker, more reddish and yellowish color (p < 0.05). Hamburger samples containing 1% or 2% DTP flour were graded with closer scores in the sensory panel as compared to the control (0% DTP). Overall, our findings demonstrated that DTP flour up to 2% could be used to improve the nutritional and technological properties of patty samples.

Growth performance, plasma metabolites, meat quality, and meat and lipid health indices of New Zealand White rabbits as affected by dietary dried tomato pomace powder supplementation during the summer season

One hundred and twenty New Zealand White rabbits (NZW) (5-week-old; 735.27 ± 27.23 g) were kept in an open-sided house during the summer season. The experiment aims to evaluate the impacts of dried tomato pomace powder (DTPP) supplementation on rabbits' performance, blood metabolites, carcass traits, meat quality, and lipid and health indices of NZW rabbits during 5-13 weeks of age. The four treatments were a standard rabbit feed (control) and the control diet supplemented with 0.5, 1.0, and 1.5% DTPP, respectively. Rabbits fed a diet containing 1.5% DTPP showed the highest growth rate through weeks 9-13 of age despite having the lowest feed intake spanning 5-13 weeks. The best feed conversion ratio (FCR) was recorded in rabbits fed with 1.5% DTPP-supplemented diet for 5-13 weeks. Diets supplemented with 0.5 or 1.0% DTPP enhanced markedly dressing %, total edible flesh, saturated (SFAs), monounsaturated (MUFAs), and polyunsaturated fatty acid (PUFAs) contents, as well as the ∑n - 6/∑n - 3 ratio and the total n - 6 of meat. Dietary supplementation with DTPP decreased kidney, abdominal, and back fat. Diets supplemented with DTTP decreased total cholesterol, triglycerides, and very low-density lipoprotein (vLDL) concentrations. The greatest levels of linoleic acid, arachidonic and water-holding capacity in meat were observed in rabbits fed 1.5% DTPP-supplemented diets. Diets containing 1 and 1.5% DTPP improved meats' atherogenic and thrombogenic indices, meat lipid quality desired fatty acids/undesired fatty acids ratio, and meat health index. Conclusively, DTPP up to 1.5% maintained the growth performance of rabbits, boosted meat quality through increasing vitamin E, reduced fat deposition, modified fatty acid composition, and improved atherogenic, thrombogenic, and hypocholesterolemic indices of rabbit meat.

Potential Use of Tomato Peel, a Rich Source of Lycopene, for Cancer Treatment

Tomatoes are well known for their impressive nutritional value among vegetables. However, the industrial processing of tomatoes generates a significant amount of waste. Specifically, 10% to 18% of the raw materials used in tomato processing become waste. This waste can seriously affect ecosystems, such as freshwater bodies, wetlands, rivers, and other natural environments, if not properly managed. Interestingly, tomato waste, specifically the skin, contains lycopene, a potent antioxidant and antimutagenic that offers a range of health benefits. This makes it a valuable ingredient in industries such as food and cosmetics. In addition, researchers are exploring the potential of lycopene in the treatment of various types of cancer. This systematic review, guided by the PRISMA 2020 methodology, examined studies exploring the possibility of tomato peel as a source of lycopene and carotenoids for cancer treatment. The findings suggest that tomato peel extracts exhibit promising anticancer properties, underscoring the need for further investigation of possible therapeutic applications. The compiled literature reveals significant potential for using tomato peel to create new cancer treatments, which could potentially revolutionize the field of oncology. This underscores the importance of continued research and exploration, emphasizing the urgency and importance of the scientific community's contribution to this promising area of study.

Selected fruit pomaces: Nutritional profile, health benefits, and applications in functional foods and feeds

The utmost objective of every nation is to achieve zero hunger and ensure the health and well-being of its population. However, in impoverished nations, particularly in rural areas, such issues persist on a daily basis. Currently, there is a growing demand for fruit consumption due to their potential health benefits. Surprisingly, their most prevalent by-product is pomace, which is produced in millions of tonnes and is usually discarded as waste after processing or consumption. Even food produced with these kinds of raw resources can contribute to the objective of eradicating world hunger. Owing to these advantages, scientists have begun evaluating the nutritional content of various fruit pomace varieties as well as the chemical composition in different bioactive constituents, which have significant health benefits and can be used to formulate a variety of food products with notable nutraceutical and functional potential. So, the purpose of this review is to understand the existing familiarity of nutritional and phytochemical composition of selected fruit pomaces, those derived from pineapple, orange, grape, apple, and tomato. Furthermore, this article covers pre-clinical and clinical investigations conducted on the selected fruit pomace extracts and/or powder forms and its incorporation into food products and animal feed. Adding fruit pomaces reduces the glycemic index, increases the fibre content and total polyphenolic contents, and reduces the cooking loss, etc. In animal feeds, incorporating fruit pomaces improves the antioxidant enzyme activities, humoral immune system, and growth performance and reduces methane emission.

Tomato Residue Management from a Biorefinery Perspective and towards a Circular Economy

The tomato industry is a relevant socio-economic activity in the European Union, while it generates a large variety of residues. Tomatoes unfit for consumption, tomato peels, seeds, industrial pomace, and plants are examples of residues of this industry. Commonly, some of the residues can be left in the field, composted, used for animal feeding, or valorized through anaerobic digestion. However, more economic value can be attributed to these residues if a biorefinery approach is applied. Indeed, many value-added compounds can be obtained by the integration of different processes while closing the carbon and nutrient loops. The extraction of bioactive compounds followed by anaerobic digestion and composting seems to be a viable proposal for a biorefinery approach. Thus, this study aims to review the biorefinery strategies for valorizing tomato residues, highlighting the main processes proposed. The recovery of lycopene, β-carotene, and phenolic compounds has been widely studied at the lab scale, while energy recovery has already been applied at the industrial scale. Although techno-economic analysis is scarce for tomato residue valorization processes, positive net present values (NPV) and low payback times (PBT) have been reported in the literature. Thus, more work comparing multiple extraction technologies and biorefinery strategies coupled with economic and environmental assessment should be performed to select the most promising management route for tomato residues.

Preparation of tomato peel pomace powder/polylactic acid foams under supercritical CO2 conditions: Improvements in cell structure and foaming behavior

Polylactic acid (PLA) is an eco-friendly material that can help address the problems of petroleum depletion and pollution. Blending renewable biomass materials with PLA to create composite foams with a tunable pore structure, superior performance, and low cost is a green technique for improving the pore structure and mechanical characteristics of single PLA foams. PLA/TP composites were created using melted tomato peel pomace powder (TP), which has a lamellar structure, as a reinforcing agent. Then, the relationship between the vesicle structure, morphology, and properties of the PLA/TP composite foams produced through supercritical CO2 intermittent foaming were investigated. The findings revealed that TP considerably enhanced the rheological characteristics and crystalline behavior of PLA. The PLA/TP composite foam had a better cell structure, compression characteristics, and wettability than pure PLA. The expansion ratio of the PLA/TP composite could reach 18.8, and its thermal conductivity decreased from 174.2 mW/m·K at 100 °C to 57.8 mW/m·K at 120 °C. Furthermore, annealing before foaming decreased the average composite foam blister size from 110.09 to 66.53 μm, and the annealing process also improved compression performance. This study contributes to solving environmental difficulties and creating PLA foams with controlled bubble structures, uniform bubble sizes, and outstanding overall performance.

Effect of Roasting on the Chemical Composition and Oxidative Stability of Tomato (Solanum lycopersicum L.) Seed Oil

In this study, tomato seed (TS) samples were subjected to different roasting conditions (90-170 °C and 10-30 min) to compare their effects on the chemical composition and oxidative stability of tomato seed oil (TSO). Unroasted TS was considered as a control sample. Our results revealed that moderate roasting (130 °C/20 min) can significantly increase the content of linoleic acid (54.01-54.89%), linolenic acid (2.17-2.41%), phytosterols (2789.56-3037.31 mg/kg), squalene (5.06-13.10 mg/kg), total phenols (22.37-22.67 mg GAE/100 g), and other functional components (p < 0.05) in TSO, while the antioxidant activity (via DPPH, ABTS, and FRAP assays) also increased. In addition, the tocopherol content decreased significantly (758.53-729.50 mg/kg). Accelerated oxidation experiments showed that roasting (170 °C/30 min) increased the oxidative stability index (OSI) of TSO from 5.35 to 7.07 h (p < 0.05). Furthermore, roasting gradually increased the content of 5-hydroxymethylfurfural (HMF) (0-1.74 mg/kg), which indicates that the oxidative stability and the degree of the Maillard reaction increased upon roasting. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that moderate roasting (130 °C/20 min) improved the chemical composition, antioxidant activity, and oxidative stability of TSO. Furthermore, this work provides a useful theoretical basis for the processing and wide application of TSO in the pharmaceutical and food industries.

Tomato pomace as a source of valuable functional ingredients for improving physicochemical and sensory properties and extending the shelf life of foods: A review

Due to its nutritional and bioactive content, tomato pomace (TP) remains among the world's richest fruits and vegetables. Tomatoes and TP (generated coproduct) are a very rich source of lycopene and other carotenoid compounds and contain an essential amount of polyphenols, policosanol, phytosterols, organic acids, dietary fibers, minerals, and vitamins. TP is a promising source of significant bioactive compounds with antioxidant and antimicrobial potential. Therefore, their consumption is known to be effective in preventing certain chronic diseases. For example, lycopene prevents prostate cancer and acts as a hepatoprotector and genoprotector against mycotoxins, pesticide residues, and heavy metals. Thus, the valorization of TP as a food ingredient can be of great health, economic and environmental interest and contribute to improving nutrition and food security. During the last decades, considerable efforts have been made to valorize TP as a crucial functional ingredient in improving: (i) the nutritional and functional properties, (ii) sensory characteristics and (iii) the shelf life of many foods. The current review aims to update and summarize the knowledge on the recent food applications of TP, particularly its use as a functional ingredient to improve the functional properties and shelf life of foods.

Optimization of tomato (Solanum lycopersicum L.) juice fermentation process and analysis of its metabolites during fermentation

Tomato (Solanum lycopersicum L.) is a nutritious fruit and vegetable. Fermentation can be used to enhance their nutritional value. In this study, the tomato juice was co-fermented with multistrains, optimized by uniform experimental design and response surface methodology. Superoxide dismutase activity reached 496.67 U/g and lycopene content reached 77.12μg/g when P. pentosaceus (53.79%), L. casei (13.17%), L. plantarum (19.87%), L. fermentum (13.17%). To gain insight into the dynamics of metabolites during the tomato fermentation juice process multivariate statistical analysis was performed using the UHPLC-QE-MS/MS method. The main metabolites are peptides, amino acids carbohydrates, organic acids, and phospholipids. Carbohydrates were fully retained at the end of fermentation.The content of galactitol increased from the initial 5.389 to 6.607 while the content of cytarabine decreased by 29% and uridine by 44%. Meanwhile, phospholipids (PS, PE, PC, PG, PI) were all retained by more than 70%. Terpenoids (16-deacetylgairin, (+)-Royleanone, artemisinin) were increased to varying degrees, which gives them good nutritional value and biological activity. Organic acids (malic and citric) were reduced and lactic acid content was increased, changing its original flavor and making it more palatable to the general population. The research results have demonstrated the benefits of lactic acid bacteria fermentation on tomato juice, providing a theoretical basis and reference for the fermentation metabolism process of tomato juice.

Formulated hydroxy fatty acids from fruit pomaces reduce apple scab development caused by Venturia inaequalis through a dual mode of action

The outermost hydrophobic layer of plants, i.e. the cuticle, is mainly composed of cutin, a polyester of hydroxy fatty acids with reported eliciting and/or antimicrobial activities for some of them. By-products of the fruit processing industry (fruit pomaces), often strongly enriched in cuticular material, are therefore a potential source of bioactive compounds for crop protection against pathogen attack. We investigated the utilization of tomato and apple pomaces in the development of a cutin-based biocontrol solution against apple scab, a major apple disease caused by Venturia inaequalis. Several cutin monomer extracts obtained through different strategies of depolymerization and purification were first compared for their ability to induce a targeted set of defense genes in apple seedlings after foliar application. After a step of formulation, some extracts were chosen for further investigation in planta and in vitro. Our results show that formulated cutin monomers could trigger a significant transcriptome reprogramming in apple plants and exhibit an antifungal effect on V. inaequalis. Cutin monomers-treated apple seedlings were significantly protected against infection by the apple scab agent. Altogether, our findings suggest that water-dispersed cutin monomers extracted from pomaces are potential new bio-based solutions for the control of apple scab.

Stabilization and valorization of tomato byproduct: A case study for the bakery industry

Worldwide, tomato production is estimated at 180 million tons per year, which generates a byproduct with highly variable characteristics and volumes. According to the principles of the circular economy, a semi-industrial method for the integral use of the tomato byproduct as an ingredient in the bakery industry is proposed. Using two different dehydration processes (convection or freeze-drying), a tomato byproduct formed by peels and seeds was stabilized and ground into flours that were used as ingredients in focaccia-type flatbread elaboration through a wheat flour partial substitution trial (from 0% to 20% w/w). Based on the kinetics of convection drying and remaining lycopene content results, conditioning of the byproduct at 60°C was proposed. The higher the percentage of substitution, the greater the firmness of the flatbread. However, the cutting force was maximum with 15% replacement. The flatbreads with 5%-15% replacement were rated positively according to consumer acceptance studies. Substitution of up to 15% tomato byproduct is suggested for the formulation, as the higher the byproduct flour content, the lower the volume, the higher the firmness, and reddish-brown tones. Realistically, for the industrial setting, this processing proposal reached the whole food chain, from field to fork. PRACTICAL APPLICATION: Based on the circular economy and considering the whole food chain, a case study is proposed to prove the usefulness of tomato byproduct flour implementation in bakery with consumers' acceptance. Once the tomato byproduct was dehydrated by convection drying and ground, the flour was used to make focaccia-type flatbread. Up to 15% of tomato byproduct flour addition was accepted by consumers. Considering the tons of tomato byproducts generated worldwide and the overall bakery possibilities, this case shows industrial steps toward sustainable food production practices.

First Optimization of Tomato Pomace in Diets for Tenebrio molitor (L.) (Coleoptera: Tenebrionidae)

Tomato pomace (TP), an agricultural industrial waste product from the tomato processing industry, is valorized as a rearing substrate for Tenebrio molitor (L.). This study evaluated bran-based diets with increasing tomato pomace (0%, 27%, 41%, and 100%). Protein sources, such as brewer's spent grain and yeast, were used in TP27 and TP41 diets to ensure equal protein contents to the control diet. Results showed no different for larval and pupal weights between diets; however, the time of development significantly increases in TP100 compared to all diets. The feed conversion rate progressively increases from 2.7 to 4.3, respectively, from the control to the TP100 diet. Conversely, lycopene and β-carotene increase in the larvae. The fatty acid composition improves by increasing polyunsaturated fatty acids (mainly α-linoleic acid). Although the best nutritional quality was obtained in T100, the TP41 is the optimal diet for balance between larval performance and qualitative improvement of larvae. Therefore, tomato pomace is suitable for the formulation of mealworm diets, even in high dosages, when supplemented with sustainable protein and carbohydrate sources.

Food waste biorefinery towards circular economy in Australia

Staggering amounts of food waste are produced in Australia, and this review provides food waste based biorefinery opportunities in moving towards a circular economy in Australia. The current food waste scenario in Australia including an overview of primary food waste sources, government regulation, and current management practices is presented. The major food waste streams include fruit and vegetable (waste from wine grapes, citrus, apple, potato, and tomato), nuts (almond processing waste), seafood (Fish waste), dairy whey, sugarcane bagasse, and household and businesses. The composition of these waste streams indicated their potential for use in biorefineries to produce value-added products via various pathways combining direct extraction and biological and thermochemical conversion. Finally, the efforts made in Australia to utilize food waste as a resource, as well as the challenges and future directions to promote the development of concrete and commercially viable technologies for food waste biorefinery, are described.

High-Pressure Homogenization for Enhanced Bioactive Recovery from Tomato Processing By-Products and Improved Lycopene Bioaccessibility during In Vitro Digestion

The principles of industrial ecology have emerged as pivotal drivers of eco-innovation, aiming to realize a "zero-waste" society where waste materials are repurposed as valuable resources. In this context, High-Pressure Homogenization (HPH) presents a promising, easily scalable micronization technology, capable of enhancing the extractability and bioaccessibility of bioactive compounds found in tomato processing by-products, which are notably abundant waste streams in the Mediterranean region. This study focuses on optimizing HPH treatment parameters to intensify the recovery of bioactive compounds from tomato pomace. Additionally, it investigates the multifaceted impacts of HPH on various aspects, including color, particle size distribution, microscopic characteristics, surface properties, bioactivity, and lycopene bioaccessibility through in vitro digestion simulations. The results demonstrate that the application of HPH under optimized conditions (80 MPa, 25 °C, 10 passes) induces a remarkable 8-fold reduction in mean particle size, reduced surface tension, improved physical stability, uniform color, increased total phenolic content (+31%), antioxidant activity (+30%), dietary fiber content (+9%), and lycopene bioaccessibility during the intestinal digestion phase compared to untreated samples. These encouraging outcomes support the proposition of integrating HPH technology into an environmentally friendly industrial process for the full valorization of tomato processing residues. By utilizing water as the sole solvent, this approach aims to yield a functional ingredient characterized by greater nutritional and health-promoting values.

Cellulose Isolation from Tomato Pomace: Part II-Integrating High-Pressure Homogenization in a Cascade Hydrolysis Process for the Recovery of Nanostructured Cellulose and Bioactive Molecules

This work proposes a biorefinery approach for utilizing tomato pomace (TP) through a top-down deconstructing strategy, combining mild chemical hydrolysis with high-pressure homogenization (HPH). The objective of the study is to isolate cellulose pulp using different combinations of chemical and physical processes: (i) direct HPH treatment of the raw material, (ii) HPH treatment following acid hydrolysis, and (iii) HPH treatment following alkaline hydrolysis. The results demonstrate that these isolation routes enable the production of cellulose with tailored morphological properties from TP with higher yields (up to +21% when HPH was applied before hydrolysis and approximately +6% when applied after acid or after alkaline hydrolysis). Additionally, the side streams generated by this cascade process show a four-fold increase in phenolic compounds when HPH is integrated after acid hydrolysis compared to untreated sample, and they also contain nanoparticles composed of hemicellulose and lignin, as shown by FT-IR and SEM. Notably, the further application of HPH treatment enables the production of nanostructured cellulose from cellulose pulp derived from TP, offering tunable properties. This approach presents a sustainable pathway for the extraction of cellulose and nanocellulose, as well as the valorization of value-added compounds found in residual biomass in the form of side streams.

Waste and by-products as sources of lycopene, phytoene, and phytofluene - Integrative review with bibliometric analysis

Food loss and waste are severe social, economic, and environmental issues. An example is the incorrect handling of waste or by-products used to obtain bioactive compounds, such as carotenoids. This review aimed to present a comprehensive overview of research on lycopene, phytoene, and phytofluene obtained from waste and by-products. In this study, an integrative literature approach was coupled with bibliometric analysis to provide a broad perspective of the topic. PRISMA guidelines were used to search studies in the Web of Science database systematically. Articles were included if (1) employed waste or by-products to obtain lycopene, phytoene, and phytofluene or (2) performed applications of the carotenoids previously extracted from waste sources. Two hundred and four articles were included in the study, and the prevalent theme was research on the recovery of lycopene from tomato processing. However, the scarcity of studies on colorless carotenoids (phytoene and phytofluene) was evidenced, although these are generally associated with lycopene. Different technologies were used to extract lycopene from plant matrices, with a clear current trend toward choosing environmentally friendly alternatives. Microbial production of carotenoids from various wastes is a highly competitive alternative to conventional processes. The results described here can guide future forays into the subject, especially regarding research on phytoene and phytofluene, potential and untapped sources of carotenoids from waste and by-products, and in choosing more efficient, safe, and environmentally sustainable extraction protocols.

Tomato wastes and by-products: upcoming sources of polyphenols and carotenoids for food, nutraceutical, and pharma applications

Tomato pomace, a waste product consisting of peels, seeds, rich on fibrous matter, represents an underutilized source of bioactive compounds, such as polyphenols and carotenoids. Here we present a three-pronged review of the circular utilization of tomato waste in line with the United Nations Sustainable Development Goals. First, we explain why tomato waste is important, highlighting the processing techniques that generate it. The bioactive compounds in these by-products are then comprehensively reviewed, focusing especially on phenolic compounds and carotenoids and the methods used for their extraction. Finally, we examine the potential of these bioactive ingredients for application in food systems and pharmaceutical products.

Integral valorisation of tomato by-products towards bioactive compounds recovery: Human health benefits

The tomato processing industry is one of the world's most important markets. This industry aims to optimise production, minimise energy costs and waste streams while ensuring high-quality products. This sector produces substantial amounts of by-products frequently disposed of as waste rather than reintroducing them with a new intent into the supply chain. However, these by-products are rich in bioactive compounds (BC), including carotenoids, fibre, which exhibit antioxidant, anti-inflammatory and chemopreventive properties, and cardiovascular protection. Reusing these compounds is favourable to reducing the environmental impact and enables the development of added-value products with various possible uses such as food and feed additives, nutraceuticals, cosmeceuticals, etc. This review summarises relevant issues towards the recovery and valorisation of BC from industrial tomato by-products within a circular economy context.

Valorisation of Wasted Immature Tomato to Innovative Fermented Functional Foods

In this study, the lactic fermentation of immature tomatoes as a tool for food ingredient production was evaluated as a circular economy-oriented alternative for valorising industrial tomatoes that are unsuitable for processing and which have wasted away in large quantities in the field. Two lactic acid bacteria (LAB) were assessed as starter cultures in an immature tomato pulp fermentation to produce functional food ingredients with probiotic potential. The first trial evaluated the probiotic character of Lactiplantibacillus plantarum (LAB97, isolated from immature tomato microbiota) and Weissella paramesenteroides (C1090, from the INIAV collection) through in vitro gastrointestinal digestion simulation. The results showed that LAB97 and C1090 met the probiotic potential viability criterion by maintaining 6 log10 CFU/mL counts after in vitro simulation. The second trial assessed the LAB starters’ fermentative ability. Partially decontaminated (110 °C/2 min) immature tomato pulp was used to prepare the individually inoculated samples (Id: LAB97 and C1090). Non-inoculated samples, both with and without thermal treatment (Id: CTR-TT and CTR-NTT, respectively), were prepared as the controls. Fermentation was undertaken (25 °C, 100 rpm) for 14 days. Throughout storage (0, 24, 48, 72 h, 7, and 14 days), all the samples were tested for LAB and Y&M counts, titratable acidity (TA), solid soluble content (SSC), total phenolic content (TPC), antioxidant capacity (AOx), as well as for organic acids and phenolic profiles, and CIELab colour and sensory evaluation (14th day). The LAB growth reached ca. 9 log10 CFU/mL for all samples after 72 h. The LAB97 samples had an earlier and higher acidification rate than the remaining ones, and they were highly correlated to lactic acid increments. The inoculated samples showed a faster and higher decrease rate in their SSC levels when compared to the controls. A nearly two-fold increase (p < 0.05) during the fermentation, over time, was observed in all samples’ AOx and TPC (p < 0.05, r = 0.93; similar pattern). The LAB97 samples obtained the best sensory acceptance for flavour and overall appreciation scores when compared to the others. In conclusion, the L. plantarum LAB97 starter culture was selected as a novel probiotic candidate to obtain a potential probiotic ingredient from immature tomato fruits.

Effects of Extraction Methods on Phenolic Content, Antioxidant and Antiplatelet Activities of Tomato Pomace Extracts

Aqueous and ethanolic extracts of tomato pomace were examined with the aim of optimizing the extraction process of compounds with cardioprotective activity. Once the results of the ORAC response variables, total polyphenols, °Brix, and antiplatelet activity of the extracts were obtained, a multivariate statistical analysis was performed using the Statgraphics Centurion XIX software. This analysis showed that the most relevant positive effects in the inhibition of platelet aggregation were 83 ± 2% when using the agonist TRAP-6, when the working conditions were the type of tomato pomace conditioning (drum-drying process at 115 °C), phase ratio (1/8), type of solvent (ethanol 20%), and type of extraction (ultrasound-assisted solid-liquid extraction). The extracts with the best results were microencapsulated and characterized by HPLC. The presence of chlorogenic acid (0.729 mg/mg of dry sample) was found, a compound that has a potential cardioprotective effect documented in various studies, in addition to rutin (2.747 mg/mg of dry sample) and quercetin (0.255 mg/mg of dry sample). These results show that the extraction efficiency of compounds with cardioprotective activity depends largely on the polarity of the solvent, thus playing an important role in the antioxidant capacity of the extracts of tomato pomace.

Microencapsulation of tomato seed oil using phlorotannins-adducted pea protein isolate-chitosan and pea protein isolate-chitosan complex coacervates

Pea protein isolates (PPI)/phlorotannins (PT)/chitosan (CS) ternary complex and PPI/CS binary complex were synthesized to prepare tomato seed oil (TSO) microcapsules. The concentration of PT was determined to be 0.025% (w/w) based on the solubility, emulsification, and UV-visible spectrum of PPI-PT complex. Subsequently, the optimal pHs associated with the formation of PPI/CS and PPI-PT/CS complex coacervates were determined to be pH 6.6 and 6.1, while the optimal ratios were 9:1 and 6:1, respectively. The coacervate microcapsules were successfully produced by freeze-dried method and those formulated with PPI-PT/CS displayed significantly lower surface oil content (14.57 ± 0.22%), higher encapsulation efficiency (70.54 ± 0.13%), lower particle size (5.97 ± 0.16 μm), and PDI (0.25 ± 0.02) than PPI/CS. The microcapsules were characterized by scanning electron microscopy and Fourier Transform infrared spectroscopy. Furthermore, the encapsulated TSO exhibited enhanced thermal and oxidative stability than that of free oil, along with microcapsules fabricated with PPI-PT/CS ternary complex showed better protection than that of free PT. Overall, PPI-PT/CS complex as an effective wall material in delivery system presented great potential.

Effects of dietary supplementation of tomato pomace (Solanum lycopersicum L.) and L-Arg on reproductive performance of aged male broiler breeders

This study aimed to investigate the effects of different dietary supplementation of tomato pomace (TP) and L-arginine (L-Arg) supplementation on sperm characteristics, reproductive performance, and semen biochemical components of aged commercial male broiler breeders. Thirty Ross 308 male broiler breeders (58 wk old) were provided and assigned to 5 dietary treatment groups, including control (CON), 5% TP (TPS-5), 10% TP (TPS-10), 15% TP (TPS-15), and L-Arg supplemented (10% above the recommendation, LAS-10). The results indicated that the semen volume increased in the TPS-15 group compared to that of the LAS-10 (and CON on wk 9) throughout the study (P < 0.05). The sperm concentration significantly increased in TPS-10 and TPS-15 groups in comparison to the other experimental groups. On wk 5 and 7, the sperm viability increased in all TPS groups compared to the CON and LAS-10, while on wk 9, it only increased in the TPS-10 group in comparison to the LAS-10 group (P < 0.05). The hypo-osmotic swelling test decreased in the LAS-10 group compared to the other experimental groups on wk 5 and all TPS groups on wk 7 and 9 (P < 0.05). The sperm total motility and forward progressive motility decreased in the LAS-10 group compared to the other experimental groups (P < 0.05). In contrast, unprogressive motility and immotile sperms were increased in the LAS-10 group compared to the other experimental groups (P < 0.05). In addition, the sperm penetration and fertility rate increased in TPS-10 and TPS-15 groups in comparison to CON and LAS-10 groups (P < 0.05). However, hatchability was reduced in the LAS-10 group (P < 0.05). The semen adenosine triphosphate increased in TPS-10, TPS-15, and LAS-10 groups compared to the CON (P < 0.05). Finally, the semen TAC and superoxidase dismutase decreased in the LAS-10 group (P < 0.05), while the glutathione peroxidase increased in the TPS-15 group (P < 0.05). In conclusion, 15% dietary TPS is recommended to improve the reproductive performance of aged commercial male broiler breeders.

Recovery and Purification of Cutin from Tomato By-Products for Application in Hydrophobic Films

Tomato pomace is a low-cost, renewable resource that has been studied for the extraction of the biopolyester cutin, which is mainly composed of long-chain hydroxy fatty acids. These are excellent building blocks to produce new hydrophobic biopolymers. In this work, the monomers of cutin were extracted and isolated from tomato pomace and utilized to produce cutin-based films. Several strategies for the depolymerization and isolation of monomeric cutin were explored. Strategies differed in the state of the raw material at the beginning of the extraction process, the existence of a tomato peel dewaxing step, the type of solvent used, the type of alkaline hydrolysis, and the isolation method of cutin monomers. These strategies enabled the production of extracts enriched in fatty acids (16-hydroxyhexadecanoic, hexadecanedioic, stearic, and linoleic, among others). Cutin and chitosan-based films were successfully cast from cutin extracts and commercial chitosan. Films were characterized regarding their thickness (0.103 ± 0.004 mm and 0.106 ± 0.005 mm), color, surface morphology, water contact angle (93.37 ± 0.31° and 95.15 ± 0.53°), and water vapor permeability ((3.84 ± 0.39) × 10^-11 mol·m/m²·s·Pa and (4.91 ± 1.33) × 10^-11 mol·m/m²·s·Pa). Cutin and chitosan-based films showed great potential to be used in food packaging and provide an application for tomato processing waste.

Mechanisms Underlying Neurodegenerative Disorders and Potential Neuroprotective Activity of Agrifood By-Products

Neurodegenerative diseases, characterized by progressive loss in selected areas of the nervous system, are becoming increasingly prevalent worldwide due to an aging population. Despite their diverse clinical manifestations, neurodegenerative diseases are multifactorial disorders with standard features and mechanisms such as abnormal protein aggregation, mitochondrial dysfunction, oxidative stress and inflammation. As there are no effective treatments to counteract neurodegenerative diseases, increasing interest has been directed to the potential neuroprotective activities of plant-derived compounds found abundantly in food and in agrifood by-products. Food waste has an extremely negative impact on the environment, and recycling is needed to promote their disposal and overcome this problem. Many studies have been carried out to develop green and effective strategies to extract bioactive compounds from food by-products, such as peel, leaves, seeds, bran, kernel, pomace, and oil cake, and to investigate their biological activity. In this review, we focused on the potential neuroprotective activity of agrifood wastes obtained by common products widely produced and consumed in Italy, such as grapes, coffee, tomatoes, olives, chestnuts, onions, apples, and pomegranates.

Ecodesigned Formulations with Tomato Pomace Extracts

Tomato pomace (TP) has previously been identified as a coproduct that is rich in bioactive molecules, with potential beneficial effects for health. For tomato pomace that is composed of the skin, seeds and fibers, the challenge is to recover the molecules of interest trapped in the biopolymers. The use of deep eutectic solvents to extract metabolites from vegetable materials could present some advantages. Four natural deep eutectic solvents (NaDESs) were synthesized and characterized by infrared spectroscopy, thermogravimetry (TG) and differential scanning calorimetry (DSC). The TP was treated by maceration at moderate temperatures with the NaDESs. We identified 39 extracted molecules by HPLC–DAD, which revealed an abundance of hydroxy/methoxy flavones, flavanols, flavonols, phenolic acids, carotenoids and tannins, as well as a certain selectivity in the extracted molecules. Four cosmetic formulations that included the NaDESs were prepared. The NaDESs showed film-forming properties, which were harnessed for the final formulations, thanks to their biocompatibilities. Finally, the coupling of the extraction and formulation is a way to preserve the quality of the extracts and prepare ecodesigned formulations.

A Comprehensive Overview of Tomato Processing By-Product Valorization by Conventional Methods versus Emerging Technologies

The tomato processing industry can be considered one of the most widespread food manufacturing industries all over the world, annually generating considerable quantities of residue and determining disposal issues associated not only with the wasting of invaluable resources but also with the rise of significant environmental burdens. In this regard, previous studies have widely ascertained that tomato by-products are still rich in valuable compounds, which, once recovered, could be utilized in different industrial sectors. Currently, conventional solvent extraction is the most widely used method for the recovery of these compounds from tomato pomace. Nevertheless, several well-known drawbacks derive from this process, including the use of large quantities of solvents and the difficulties of utilizing the residual biomass. To overcome these limitations, the recent advances in extraction techniques, including the modification of the process configuration and the use of complementary novel methods to modify or destroy vegetable cells, have greatly and effectively influenced the recovery of different compounds from plant matrices. This review contributes a comprehensive overview on the valorization of tomato processing by-products with a specific focus on the use of "green technologies", including high-pressure homogenization (HPH), pulsed electric fields (PEF), supercritical fluid (SFE-CO₂), ultrasounds (UAE), and microwaves (MAE), suitable to enhancing the extractability of target compounds while reducing the solvent requirement and shortening the extraction time. The effects of conventional processes and the application of green technologies are critically analyzed, and their effectiveness on the recovery of lycopene, polyphenols, cutin, pectin, oil, and proteins from tomato residues is discussed, focusing on their strengths, drawbacks, and critical factors that contribute to maximizing the extraction yields of the target compounds. Moreover, to follow the "near zero discharge concept", the utilization of a cascade approach to recover different valuable compounds and the exploitation of the residual biomass for biogas generation are also pointed out.

Sustainable Valorization of Tomato Pomace (Lycopersicon esculentum) in Animal Nutrition: A Review

Under the background of the current shortage of feed resources, especially the shortage of protein feed, attempts to develop and utilize new feed resources are constantly being made. If the tomato pomace (TP) produced by industrial processing is used improperly, it will not only pollute the environment, but also cause feed resources to be wasted. This review summarizes the nutritional content of TP and its use and impact in animals as an animal feed supplement. Tomato pomace is a by-product of tomato processing, divided into peel, pulp, and tomato seeds, which are rich in proteins, fats, minerals, fatty acids, and amino acids, as well as antioxidant bioactive compounds, such as lycopene, beta-carotenoids, tocopherols, polyphenols, and terpenes. There are mainly two forms of feed: drying and silage. Tomato pomace can improve animal feed intake and growth performance, increase polyunsaturated fatty acids (PUFA) and PUFA n-3 content in meat, improve meat color, nutritional value, and juiciness, enhance immunity and antioxidant capacity of animals, and improve sperm quality. Lowering the rumen pH and reducing CH4 production in ruminants promotes the fermentation of rumen microorganisms and improves economic efficiency. Using tomato pomace instead of soybean meal as a protein supplement is a research hotspot in the animal husbandry industry, and further research should focus on the processing technology of TP and its large-scale application in feed.

Fatty Acids Profile and Antioxidant Properties of Raw Fermented Sausages with the Addition of Tomato Pomace

The aim of the study was to evaluate the effect of tomato pomace (TP) on physicochemical parameters and fatty acid profile as well as antioxidant properties of dry fermented sausages with a reduced content of nitrites. Four different sausage formulations were prepared: control sample, and samples with 0.5%, 1% and 1.5% addition of freeze-dried TP. The sausages were analyzed for: chemical composition, pH and water activity, fatty acid profile, color parameters, biogenic content, and number of lactic acid bacteria and Enterobacteriacea. The antioxidant properties were also assessed depending on the amount of TP used. The products were characterized by similar water activity and pH in the range of 0.877-0.895 and 4.55-4.81, respectively. The effect of the addition of freeze-dried TP on an increase in antioxidant activity along with an increase in the concentration of the additive was observed. This phenomenon was most likely due to the strong antioxidant properties of tomato as well as the high content of lycopene. The antimicrobial properties of TP in raw fermented sausages were also noted as the product with the highest concentration of pomace had the lowest number of Enterobacteriaceae. In addition, sausages with reduced levels of nitrites to which TP was added were characterized by a higher redness, which will probably have a positive impact on the assessment consumers make of them. The most promising results were obtained for the dry fermented sausage with 1.5% addition of TP.

Novel zero waste tactics for commercial vegetables – recent advances

Commercial vegetables include tomatoes, potatoes, onions, and eggplant due to their surplus production, availability, and affordability. The valorisation of the massive wastage of commercial vegetables and providing a long-term solution has been challenging. The review addresses the implications of biowastes on the environment and fosters the recent investigations into valorising commercial vegetable waste to develop multiple value-added products. It discussed the outcomes of the multiple technologies, majorly on green chemistry extraction, while outlining other methods such as fermentation, enzymatic treatments, 3D printing foods, high-pressure homogenisation, microencapsulation, bio-absorption method, and pyrolysis for their respective vegetable wastes. Agri-residues can be a valuable source for formulating functional ingredients, natural additives, biodiesel, dyes, and animal feed. This comprehensive review proposes a strategy to upcycle low-cost biowaste to boost the economic and ecological benefits. The current review captures the interests and great collaborations between researchers, industrialists, policymakers, waste management bodies, and eco-activists.

The recovery from agro-industrial wastes provides different profiles of anti-inflammatory polyphenols for tailored applications

Food and agro-industrial processing produce a great amount of side-stream and waste materials that are excellent sources of functional bioactive molecules such as phenolic compounds that recover them can be beneficial not only for food sustainability but also to human for many industrial applications such as flavor compounds and therapeutic applications such as antimicrobial and anti-inflammatory. The treatments and extraction techniques have major effects on the recovery of bioactive compounds. Along with the conventional extraction methods, numerous innovative techniques have been evolved and have been optimized to facilitate bioactive extraction more efficiently and sustainably. In this work, we have summarized the state-of-the-art technological approaches concerning novel extraction methods applied for five most produced crops in Italy; Grape Pomace (GP), Tomato Pomace (TP), Olive Pomace (OP), Citrus Pomace (CP), and Spent Coffee Grounds (SCG), presenting the extraction yield and the main class of phenolic classes, with the focus on their biological activity as an anti-inflammatory in vitro and in vivo studies via describing their molecular mechanism of action.

Effect of Tomato Pomace Addition on Chemical, Technological, Nutritional, and Sensorial Properties of Cream Crackers

The aim of this research was to determine the influence of tomato pomace (TP) addition on the chemical, nutritional, and technological characteristics of cream crackers made from wheat flour and 4%, 6%, 8%, and 10% TP. The TP-enriched cream crackers showed progressively increasing ash (from 0.69 of the control to 1.22 g/100 g dry matter of the 10% TP sample), fat (from 11.39 to 13.04 g/100 g), protein (from 13.53 to 15.60 g/100 g), total dietary fibre (from 4.08 to 7.80), carotenoids (from 0.55 to 8.56 mg/kg), tocols (from 57.59 to 71.63 mg/kg), free phenolic acids (from 100.08 to 277.37 mg/kg), free flavonoids (from 0.0 to 45.28 mg/kg), bound flavonoids (from 0.0 to 27.71 mg/kg), and fatty acids contents, antioxidant activity and dough viscosity. The colour coordinates increased via augmenting the amounts of TP. Thickness, volume, and specific volume decreased gradually with increasing TP; the enrichment reduced cracker hardness from 65.42 N (control) to 26.28 N (crackers with 10% TP), while the snapping force rose. Cream crackers with 8% TP showed the best sensory quality. Tomato pomace addition improves the nutritional quality of foods; furthermore, its recycling will help to solve the problems linked to the disposal of this industry waste.

Recovery of Antioxidants from Tomato Seed Industrial Wastes by Microwave-Assisted and Ultrasound-Assisted Extraction

Tomato seed (TS) wastes are obtained in large amounts from the tomato processing industry. In this work, microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) of antioxidant compounds from TS were optimized by using response surface methodology. The effect of MAE and UAE main extraction parameters was studied on total phenolic content (TPC) and antioxidant activity (DPPH) responses. Antioxidant, structural, morphological, and thermal properties of MAE and UAE extracts were evaluated. A great influence of ethanol concentration was observed in both extraction methods. Optimal MAE conditions were determined as 15 min, 80 °C, 63% ethanol and 80 mL, with a desirability value of 0.914, whereas 15 min, 61% ethanol and 85% amplitude (desirability = 0.952) were found as optimal conditions for UAE. MAE extracts exhibited higher TPC and antioxidant activity values compared to UAE (1.72 ± 0.04 and 1.61 ± 0.03 mg GAE g TS⁻¹ for MAE and UAE, respectively). Thermogravimetric analysis (TGA) results suggested the presence of some high molecular weight compounds in UAE extracts. Chlorogenic acid, rutin and naringenin were identified and quantified by HPLC-DAD-MS as the main polyphenols found by MAE and UAE, showing MAE extracts higher individual phenolics content (1.11–2.99 mg 100 g TS⁻¹). MAE and UAE have shown as effective green techniques for extracting bioactive molecules with high antioxidant activity from TS with high potential to be scaled-up for valorizing of TS industrial wastes.

Modelling and Optimization of the Processing of a Healthy Snack Bar Made of Grape and Tomato Pomaces

A snack made of 36% by byproducts of grape and tomato pomaces was developed, also including other ingredients, such as oats, chia, quinoa, honey and peanut butter. The recipe was defined as tasty and healthy by a focus group. The snack was produced by using forced air at three different drying temperatures (50 °C, 60 °C and 70 °C). The Newton, Page, Henderson and Pabis, and Midilli-Kucuk models fit the drying curves well. The average values for the Newton's model drying constants were k50 = 2.71 × 10-1 ± 3 × 10-3 min-1, k60 = 2.76 10-1 ± 4 × 10-3 min-1 and k70 = 3.91 × 10-1 ± 8 × 10-3 min-1 at 50 °C, 60 °C and 70 °C, respectively. The product's quality was assessed in terms of storage with respect to water activity and texture (hardness, springiness, cohesiveness, chewiness and resilience). There were no differences among the three tested processing temperatures in terms of their influence the final product's quality. As there were no significant differences between initial and final water activity and texture attributes at any temperature and they were mainly unaltered during storage, the snack bar was considered stable during this period. This new snack, which includes byproducts from the food industry, reduces food waste and contributes to a circular economic model, simultaneously presenting environmental and economic advantages.

Valorization of Agro-Industrial Wastes by Ultrasound-Assisted Extraction as a Source of Proteins, Antioxidants and Cutin: A Cascade Approach

The use of agro-industrial wastes to obtain compounds with a high added-value is increasing in the last few years in accordance with the circular economy concept. In this work, a cascade extraction approach was developed based on ultrasound-assisted extraction (UAE) for tomato, watermelon, and apple peel wastes. The protein and antioxidant compounds were obtained during the first extraction step (NaOH 3 wt.%, 98.6 W, 100% amplitude, 6.48 W/cm², 6 min). The watermelon peels (WP) showed higher proteins and total phenolic contents (857 ± 1 mg BSA/g extract and 107.2 ± 0.2 mg GAE/100 g dm, respectively), whereas the highest antioxidant activity was obtained for apple peels (1559 ± 20 µmol TE/100 g dm, 1767 ± 5 µmol TE/100 g dm, and 902 ± 16 µmol TE/100 g dm for ABTS, FRAP and DPPH assays, respectively). The remaining residue obtained from the first extraction was subsequently extracted to obtain cutin (ethanol 40 wt.%, 58 W, 100% amplitude, 2 W/cm², 17 min, 1/80 g/mL, pH 2.5). The morphological studies confirmed the great efficiency of UAE in damaging the vegetal cell walls. WP showed a higher non-hydrolysable cutin content (55 wt.% of the initial cutin). A different monomers’ profile was obtained for the cutin composition by GC-MS, with the cutin from tomato and apple peels being rich in polyhydroxy fatty acids whereas the cutin extracted from WP was mainly based on unsaturated fatty acids. All of the cutin samples showed an initial degradation temperature higher than 200 °C, presenting an excellent thermal stability. The strategy followed in this work has proved to be an effective valorization methodology with a high scaling-up potential for applications in the food, pharmaceutical, nutraceutical, cosmetics and biopolymer sectors.

Valorization of Tomato Seed By-Products as a Source of Fatty Acids and Bioactive Compounds by Using Advanced Extraction Techniques

In this work, lipids and bioactive compounds from tomato seed by-products were extracted and compared by using advanced extraction techniques, such as microwave-assisted extraction (MAE) and supercritical fluid extraction (SFE). The influence of different extraction parameters, including extraction temperature (T), time (t) and solvent volume (V) for MAE as well as extraction temperature (T), pressure (P) and flow rate (F) for SFE-CO₂, was evaluated on tomato seed oil (TSO) yield and fatty acids composition using response surface methodology (RSM). Optimum extraction conditions for MAE were 56.2 °C, 29.0 min, and 67.6 mL, whereas conditions of 60.2 °C, 400.0 bar, and 64.6 g min⁻¹ were found for SFE-CO₂. Under these conditions, higher TSO extraction yields were obtained by MAE compared to SFE-CO₂ (25.3 wt% and 16.9 wt%, respectively), while similar fatty acids profiles were found by GC in terms of FAMEs composition: methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate, accounting for around 80 wt% of unsaturated fatty acids. TSO MAE extracts showed high DPPH• radical scavenging activity which was related to the presence of tocopherols; in particular γ-tocopherol, which was found as the dominant homologue (260.3 ± 0.6 mg kg_TS⁻¹) followed by a lower amount of α-tocopherol (6.53 ± 0.12 mg kg_TS⁻¹) by HPLC-DAD. The obtained results suggested that tomato seeds are an interesting source of bioactive compounds with potential use in a wide range of nutritional and food applications, increasing the added value of this by-product, which is currently underexploited.