Tomato Pomace Research Articles

Small-Sized Tomato Pomace: Source of Bioactive Compounds and Ingredient for Sustainable Production of Functional Bread.

Tomato processing generates a by-product known as tomato pomace (TP), which contains chemically diverse valuable components such as lycopene, phenols, dietary fibre, proteins, and oil. The aim of this study was to characterize bioactive compounds in small-sized tomato pomace from cherry and date tomatoes and to evaluate the effects of the addition of 10 and 20% (w/w) of tomato pomace flour (TPF) to durum wheat dough for bread production. Bread containing different amounts of TPF was characterized by physical, chemical, nutritional, and sensory characteristics. TPF is an important source of dietary fibre with a total content of approximately 52.3%, of which 5.3% is soluble and 47% is insoluble. It is also a potential source of natural antioxidants and contains remarkable residual levels of both total carotenoids and polyphenols. TPF addition reduced water loss during baking and significantly affected colour parameters and acidity; furthermore, both fortified TPF breads could use these nutrition and health claims and label the breads as "High Fibre". The "overall" sensory attribute showed similar values in the control and fortified bread samples, suggesting that the overall quality of the bread remained relatively constant, regardless of the percentage of added TPF.

Biodegradable Polymers: Environmental Sustainability, Challenges, and Considerations

The increasing global production of polymers and plastics has led to the development of a new environmentally friendly material that is degraded in the environment by enzymatic action and/or smaller units are created by the breakdown of microorganisms such as bacteria, fungi, and algae. In the present review, the analysis of biodegradable polymers was presented on the global production of these polymers and industrial and environmental applications. In addition, the work focuses on sustainability in the environment, because the biodegradable polymers have become spread as sustainable alternative options to the non-biodegradable polymers. Additionally, the study provided an explanation of how to produce biodegradable polymers using agricultural waste, including tomato pomace and pineapple peel waste. Generally, the creation and application of biodegradable polymers need to take into account their environmental effect and performance along with aspects like cost, availability, recyclability, and printing methods.

Metagenomic Analysis during Co-Digestion Buffalo Sludge and Tomato Pomace Post Thermal Stress: A Case Study

The tomato industry and buffalo farming generate waste, including sludge (BS) and tomato pomace (TP), which can significantly impact their economic and environmental sustainability. The case study tracked changes in microflora composition after a thermal shock during anaerobic co-digestion. The inoculum-to-substrate ratio was 0.5 based on volatile solid content under mesophilic conditions. An Automatic Methane Potential Test System was used to monitor the process before and after thermal stress (50°C) occurred for three days. Next-generation sequencing analyzed the bacterial and archaeal communities. The pH decreased, and methane production plateaued due to the high volatile solid content (87 g/L). After thermal stress, the pH returned to neutral, and the batch resumed biogas production. The cumulative CH4 production reached 3,115 Nml. The biogas had a maximum methane peak of 78.5% compared to 58.4% in BS. The taxonomic classification showed that Firmicutes (51.7%) and Bacteroidetes (29.9%) represented 81.6% of the total OTUs among the bacteria. Fonticella, the most abundant Clostridiaceae (average 4.3%), was absent in BS and increased (up to 17.1%) in TP during methane production. Methanocorpusculum was the most abundant in the archaeal community. However, Metanosarcina showed a stronger correlation with methane production. Brief thermal stress significantly altered bacterial and archaeal populations and allowed to resume biogas production.

The Use of Pomace as Animal Feed: A Review of Grape and Tomato Pomace

Pomace is generated in large quantities yearly; high water content and bulkiness make it difficult to be easily disposed of thereby contributing to environmental pollution and providing breeding space for flies which can transmit diseases. Incorporating the pomace generated from grape and tomato fruits in animal nutrition will improve sustainable agriculture; the animals will also benefit from the polyphenols in the pomace which can improve their antioxidant status thereby improving animal health and welfare. Pomace consists of unfermentable sugars, tannins, anthocyanins, lycopene, and cellulose which have natural antioxidants, anti-inflammatory and antimicrobial properties. This review focused on the utilization of grape and tomato pomace as feedstuff for animals, the knowledge gap in the use of pomace in animal nutrition was also outlined. Supplementation of pomace generated from grape and tomato was evaluated on animal growth and reproductive performance, health, oxidative stress, animal products and gut health. In conclusion, incorporating agro-industrial byproducts into animal diet can be beneficial to farm animals by improving their health, welfare, performance as well as the environment, thereby leading to a more sustainable agricultural practice.

Valorisation of tomato pomace in anti-pollution and microbiome-balance face cream

Tomato pomace, the main by-product of tomato processing, is also an underestimated source of many active substances. This study aimed to determine the possibility of using oil obtained from tomato pomace in a face cream formulation. The bacterial community structure, face skin biophysical parameters and protection against air pollution were examined after daily application of the cosmetic by volunteers. In the tomato pomace oil, the profile of fatty acids was determined by GC‒MS, and the profile of volatile compounds was determined using the HS-SPME technique. The dominant bioactive component in the oil was linoleic acid (63.6%), and among the volatile compounds, it was carvotanacetone (25.8%). The application of the cream with tomato pomace oil resulted in an increase in the dominant genera Staphylococcus, Anaerococcus and Cutibacterium in the epibiome, particularly beneficial Staphylococcus epidermidis, while limiting the growth of the potentially opportunistic pathogens Kocuria spp., Micrococcus spp., Veillonella spp., and Rothia spp. This study showed the usefulness of tomato pomace oil as a natural ingredient in skin care cosmetics, reducing skin inflammation, sensitivity and melanin level, with potential protective effects against air pollution and microbiome-balance properties. Tomato pomace, which is commonly considered waste after tomato processing, can be used in the development of new cosmetics and may additionally contribute to reducing environmental nuisance.

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.

Valorization of tomato processing by-products: Predictive modeling and optimization for ultrasound-assisted lycopene extraction

Lycopene is a carotenoid highly valuable to the food, pharmaceutical, dye, and cosmetic industries, present in ripe tomatoes and other fruits with a distinctive red color. The main source of lycopene is tomato crops. This bioactive component can be successfully isolated from tomato processing waste, commonly called tomato pomace, mostly made from tomato skins, seeds, and some residual tomato tissue. The main investigative focus in this work was the application of green engineering principles in each stage of the optimized ultrasound-assisted extraction (UAE) of enzymatically treated tomato skins to obtain functional extracts rich in lycopene. The experimental plan was designed to determine the influence of studied operating parameters: enzymatic reaction time (60, 120, and 180 min), extraction time (0, 5, 10, 15, 30, 60, and 120 min), and temperature (25, 35 and 45 ℃) on lycopene yield. Process optimization was performed based on the yield of lycopene [1018, 1067, and 1120 mg/kg] achieved at optimal operating conditions. An artificial neural network (ANN) model was developed and trained for predictive modeling of the closed extraction system, with operating parameters used as input neurons and experimentally obtained values for lycopene content defined as the output neural layer. Applied ANN architecture provided a high correlation of experimental output with ANN-generated data (R=0.99914) with a model deviation error for the entire data set of RMSE=5.3 mg/kg. The k-Nearest Neighbor algorithm was introduced to predict lycopene yield using experimental key features: operating temperature, extraction time, and time of enzymatic treatment, split into training and testing sets with an 85/15 ratio. The model interpretation was conducted through the SHAP (SHapley Additive exPlanations) methodology.

Extraction of Bioactive Compounds from Oxheart Tomato Pomace (Lycopersicon esculentum L.) Using Different Solvents: Characterization of Extracts

The aim of this study was to investigate an ultrasound-assisted method for the extraction of bioactive compounds from tomato pomace. This method was based on a simple ultrasound treatment using different solvents (e.g., acetone, ethanol, ethyl acetate) as extraction media. Three different variables were chosen to determine their influence on extraction efficiency, such as solvent/liquid ratio (0.1:25 g/mL, 0.2:25 g/mL, 0.3:25 g/mL), temperature (30 °C, 40 °C, 50 °C), and time (2 h, 6 h, 10 h); the variables were selected through Box–Behnken design experiments. These parameters were optimized to achieve the highest yield, and the results showed that acetone was the best extraction solvent for lycopene (3.36 mg/100 g), total phenolic content (TPC) (31.15 QUE mg/L), and total flavone content (TFC) (66.80 GAE mg/L), while DPPH activity (82.94%) was the highest when ethanol was used as the solvent. Regarding the solvent/liquid ratio, the best results were obtained at a ratio of 0.1:25. Temperature influenced the extraction, with the best results observed at 50 °C for lycopene, DPPH, and polyphenols, while the flavonoids were better extracted at 30 °C. Time played an important role as well, with the best extractions observed at 10 h. The results indicated that ultrasound-assisted extraction was suitable for extracting bioactive compounds from tomato pomace.

The Effect of Covering Corn Silage with Tomato or Apple Pomace on Fermentation Parameters and Feed Quality

The current study assessed the effects of covering corn silage with tomato or apple pomace on fermentability and feed quality. The in vitro gas production test was performed using graded 100 mL syringes. Incubation times were 3, 6, 12, 24, 48, 72, and 96 h. In vitro gas generation characteristics were significantly altered by TP (tomato pomace) and AP (apple pomace), both alone and in conjunction with PE (polyethylene) films, regardless of their presence. As a result of the effects found on NH3-N concentration, aerobic stability, and yeast activity, TP and AP have the potential to become an eco-friendly alternative to PE films. The gas production from the immediately soluble fraction (a) of corn silage was only affected when the corn silage was covered with a combination of AP and PE compared to the CPE group (p < 0.001). The largest cluster includes correlations of the DOM-TDDM (r = 0.90), DOM-AA (r = 0.88), and Ash-TDDM (r = 0.86) correlations. The most substantial negative correlations were identified between DM-CO2 (r = −82), DM-Yeast (r = −0.79), and CF-DOM (r = −0.79). Nonetheless, the use of pomace as a silage cover presents an inexpensive alternative to plastic films for silage that does not have the environmental problems associated with persistent micro- and nanoplastics.

Agro-industrial by-products as a feeding strategy for producing functional milk

Agro-industrial by-products contain valuable components such as polyphenols that can play a significant role in producing milk with specific properties through rumen fermentation. In Egypt, the buffalo milk chain has a potential market, which is larger than that for cow milk, especially in small villages. Therefore, this study aims to explore different feed ingredients from agro-waste for enhancing the functional properties of raw buffalo milk including polyphenols, flavonoids, vitamins A, C, α-tocopherol, and conjugated linoleic acid (CLA) contents. For this purpose, thirty dairy water buffalo (Bubalus bubalis) with a weight of about 520 kg were randomly divided into five groups of six animals each. The first group was fed a basal diet (silage) without agro-waste, while the other four groups were fed the basal diet after replacing 25% of the diet with different agro-wastes including barley (snack/bakery waste), sweet potato/carrot, biscuit/cake waste and tomato pomace. The feeding experimental period lasted 90 days, then milk samples (n = 150) were collected. Our results show that adding sweet potato/ carrot or tomato pomace to the basal diet enhanced the contents of vitamins A, C, and phenolic compounds reflecting on the enhancement of the antioxidant capacity of raw buffalo milk. Concerning the CLA content, the milk samples collected from buffalo fed the basal diet fortified with tomato pomace and biscuit/cake waste had the highest CLA and α-tocopherol content. Therefore, this study recommends using the tested agro-waste ingredients for producing functional buffalo milk, especially for small-medium milk producers.

EFFECT OF TOMATO POMACE ON SENSORY AND TEXTURAL PROPERTIES OF RAW-COOKED MEAT PRODUCT

In the meat industry, there is a growing interest in the use of innovative processing methods, reformulated products, and the replacement of synthetic ingredients with natural bioactive compounds. Replacing synthetic antioxidants with natural antioxidants is a challenging process, but it can bring positive results. Our current research focuses on sensory and textural properties of raw-cooked meat product (frankfurters), which we observed on the 1st, 7th, 14th and 21st days of storage. We incorporated extract from tomato pomace into frankfurters as natural antioxidants. We used two concentrations of extract (3 mL.kg-1 and 5 mL.kg-1), the control with the addition of ascorbic acid and negative control. Sensory quality of meat product is one of the most important indicators that can influence the consumer. In the taste parameter, the best rated groups were Con-C and TCP-2. Furthermore, the addition of tomato pomace extract does not cause a significant change in the consistency of the meat products. After textural analysis, no statistically significant differences were observed between individual samples in any of the evaluated parameters.

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.

Microencapsulation of tomato oleoresin using tomato waste fibre and its application for orange juice fortification

SummaryFood waste by‐products contain many bioactive compounds, such as proteins, carbohydrates, polyphenols and carotenoids. The purposes of this study was to extract oleoresin from tomato waste, apply tomato pomace powder (TPP) as a new shell material for encapsulation of oleoresin and to fortify orange juice using the developed microcapsules. Microencapsulation was carried out based on different TPP (2% and 3%) and oleoresin (20% and 30%) concentrations by spray drying at two temperatures (130 and 140 °C). Different features of microcapsules such as the encapsulation load, encapsulation efficiency, moisture content, hygroscopicity, bulk and tapped densities and the Hausner ratio were analysed. Based on properties of microcapsules, samples containing 3% TPP and 30% oleoresin dried at 130 °C were selected as the best treatment and their characteristics such as morphology, chemical structure and thermal behaviour were investigated. Scanning electron microscopy indicated that spherical micron‐size particles were formed and their crack‐free fine surface showed their potential for encapsulation of anti‐oxidants to reduce oxygen diffusion. Microencapsulated oleoresin was then added to the orange juice and the samples' pH, acidity, total soluble solids and colour were evaluated and compared with pure orange juice. Free radical scavenging method was used to investigate the anti‐oxidant properties of orange juice during storage. The results indicated that at the end of the 30 days of storage the fortified orange juice had anti‐oxidant activity equal to pure fresh orange juice on day one. Sensory evaluation results showed no significant differences between appearance, colour, thickness and overall acceptance of fresh and the fortified juices (P < 0.05). The results of this study showed the potential application of food and agricultural waste in production of value‐added ingredients to be used as natural additives in food industries.

Comparative Study Effect of Different Urea Fertilizers and Tomato Pomace Composts on the Performance and Quality Traits of Processing Tomato (Lycopersicon esculentum Mill.).

Processing tomato (Lycopersicon esculentum Mill.) is regarded amongst the most dominant horticultural crops globally. Yet, due to its elevated water and fertilization needs, its environmental footprint is significantly high. The recent efforts to reduce the footprint of agriculture have rekindled the search for optimized fertilization regimes in tomato. The aim of the present study was to assess the effect of different urea fertilizers and tomato pomace-based composts on the performance and quality traits of processing tomato. A two-year field experiment was conducted in the Larissa region, Central Greece, during 2018-2019. The experiment was set up in a randomized complete block design (RCBD), with five treatments: control, urea (Urea), urea with nitrification and urease inhibitors (Urea + NI + UI), processing tomato pomace with farmyard manure (TP + FM), and processing tomato pomace with compost from plant residues (TP + CM). Measurements included soil total nitrogen (STN), soil organic matter (SOM), root length density (RLD), arbuscular mycorrhiza fungi (AMF) colonization, dry weight per plant, fruit yield (number per plant, total yield, weight, diameter), fruit firmness, total soluble solids (TSS), titratable acidity (TA), lycopene content and yield, and fruit surface color (L*, a*, b*, CI). Overall, the best results in soil properties and quality traits were reported in the organic fertilization treatments (STN, SOM, AMF, TSS, TA, lycopene content, L*, a*, b*) and the differences among TP + FM and TP + CM were insignificant in their majority. On the contrary, fruit yield and its components were significantly improved in Urea + NI + UI.

Tomato Pomace Powder as a Functional Ingredient in Minced Meat Products—Influence on Technological and Sensory Properties of Traditional Serbian Minced Meat Product Ćevapi

Tomato Pomace Powder as a Functional Ingredient in Minced Meat Products—Influence on Technological and Sensory Properties of Traditional Serbian Minced Meat Product Ćevapi

The addition of Citrus aurantium leaves and tomato pomace in the diet of Awassi ewes and the impact on milk composition and matured cheese

The purpose of this study was to use concentrated feed alternatives with other less expensive feed alternatives in feeding the Awassi ewes and the impact on milk composition and matured cheese. A total of twenty Awassi ewes were used, they were selected in the middle of lactation and divided into two homogeneous groups with weights (47±1.7 kg) and aged 3-4 years, given two different servings of feed (1.5 kg/sheep/day) Milk composition was measured weekly, to make cheese, raw milk control (CON) and Citrus aurantium leaves and tomato pomace (CALTP) is kept separately and chilled. Results indicated that fat and total solid content were high in milk and cheese manufactured in the diet that contained CALTP; the proportion of medium-chain fatty acids (c10-c16) and free fatty acids was lower compared to the diet (CON). While the proportion of unsaturated fatty acids (UFA) in the diet increased CALTP. Therefore, the inclusion of CALTP in the diet is helpful because it has a positive impact on the composition of milk and mature cheese, reduces the cost of the diet and helps recycle byproducts.

Effects of Process Conditions on Drying of Tomato Pomace in a Novel Daylight Simulated Photovoltaic-Assisted Drying System

The tomato pomace (TP), which is a by-product of the production of tomato paste, was dried in a novel custom-designed daylight simulated photovoltaic assisted dryer (DPVD). The different light applications (daylight, UV light, daylight + UV light, and without light), different air velocities (1.5 and 2 m/s), and different heating source modes (hot air and infrared) were applied to dry TP having a moisture content of 80.60 ± 0.73% to the moisture content of 7.66 ± 1.72%. The average water activity values of all dried samples were measured as 0.52 ± 0.08. Analysis was conducted to compare sun drying with the effects of process conditions on the quality (color properties, lycopene, β-carotene, and total mesophilic aerobic bacteria count) and performance (energy efficiency, exergy efficiency, specific moisture evaporation rate, and improvement potential) characteristics of TP. The effects of process conditions for each heating source mode were determined separately, and the improvement of the system performance for each mode was investigated. The effect of the process conditions on total aerobic mesophilic bacteria (TAMB) count was similar in general. In the infrared heating mode, the loss in lycopene and β-carotene contents was 59.55 ± 2.22 and 57.87 ± 2.51 minimum for 1.5 m/s air velocity without light application and for 2 m/s with ultraviolet + daylight application. In general, the performance of the system decreased in case of using ultraviolet light. The retention in the lycopene and β-carotene contents was higher in the infrared mode with light applications compared to hot air mode without light. The optimum drying conditions were air velocity of 2 m/s with “daylight” assistance in the hot air heating mode and with “ultraviolet + daylight” assistance in the infrared heating mode. All the energy and the daylight source used in drying applications were obtained from the sun, a renewable energy source, thanks to the photovoltaic panel and the solar tube units in the novel custom-designed drying system.

Tomato pomace food waste from different variants as a high antioxidant potential resource

Pomaces obtained from three San Marzano tomato genotypes including the wild type (WT), Sun Black (SB), and colorless fruit epidermis (CL) were dried at 50 °C and analyzed for nutritional composition, total polyphenol (TPC), flavonoid (TFC) content, polyphenol qualitative profile, total antioxidant capacity (TAC), and antimicrobial activity. Commercial dried tomato powder (CTRP) was included as a control. No differences were detected nutritionally, in TPC and antimicrobial activity, but significant changes were observed for TFC and TAC, underlying variation in the phenolic profile. SB pomace (SBP) had the highest TFC and TAC. LC-HRMS analysis showed a flavonoid-enriched profile in SBP besides the exclusive presence of anthocyanins, with petanin and negretein as the most abundant. Among flavonoids, quercetin-hexose-deoxyhexose-pentose, naringenin, and rutin were the major. Overall, we showed the potential of dried tomato pomace, especially SBP, as an extremely valuable waste product to be transformed into a functional ingredient, reducing the food industry waste.

Validation of Diets with Tomato Pomace in Complete Cycle Breeding of Tenebrio molitor (L.) (Coleoptera: Tenebrionidae).

By-product-based diets have the potential to improve the environmental and economic sustainability of Tenebrio molitor (Linnaeus, 1758) production. However, evaluations of the efficacy of new diets are generally focused on larval performance, while the effect on adults is poorly understood. This aim of this study was to evaluate diets enriched with tomato pomace over a complete breeding cycle. The results showed that when used as an oviposition substrate, all the tested diets, including tomato pomace (T), outperformed the control bran-yeast diet (WY, 95:5 ratio), possibly due to the presence of cholesterol and linoleic acid. The adults fed with the bran-tomato pomace-brewer's spent grain diet (WTB, 50:27:23 ratio), the bran-tomato pomace-yeast diet (WTY, 50:41:9 ratio), and the bran-tomato pomace diet (WT, 50:50 ratio) produced significantly more larvae than those fed with the WY diet. The WTB diet (despite being yeast-free) performed similarly to the WY control diet during the subsequent larval growth phase, making it suitable for the entire production cycle. In conclusion, the results show that tomato pomace can be used a valid by-product in the formulation of efficient diets for the breeding of T. molitor and also provide an alternative to expensive yeast.

Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste.

The current effort to valorize waste byproducts to increase sustainability and reduce agricultural loss has stimulated interest in potential utilization of waste components as health-promoting supplements. Tomato seeds are often discarded in tomato pomace, a byproduct of tomato processing, yet these seeds are known to contain an array of compounds with biological activity and prebiotic potential. Here, extract from tomato seeds (TSE), acquired from pomace, was evaluated for their ability to effect changes on the gut microbiota using an ex vivo strategy. The results found that TSE significantly increased levels of the beneficial taxa Bifidobacteriaceae in a donor-independent manner, from a range of 18.6-24.0% to 27.0-51.6% relative abundance following treatment, yet the specific strain of Bifidobacteriaceae enhanced was inter-individually variable. These structural changes corresponded with a significant increase in total short-chain fatty acids, specifically acetate and propionate, from an average of 13.3 to 22.8 mmol/L and 4.6 to 7.4 mmol/L, respectively. Together, these results demonstrated that TSE has prebiotic potential by shaping the gut microbiota in a donor-independent manner that may be beneficial to human health. These findings provide a novel application for TSE harvested from tomato pomace and demonstrate the potential to further valorize tomato waste products.