Tomato Pomace Research Articles

Development of a tomato pomace biorefinery based on a CO2-supercritical extraction process for the production of a high value lycopene product, bioenergy and digestate

Abstract Tomato peels and seeds (TP) are the most abundant canning industry waste actually used to produce biogas. TP is rich in lycopene (lyc) and represent a more sustainable feedstock than tomato fruits actually employed. It was therefore chosen as feedstock together with supercritical CO2 extraction (SFE-CO2) technology to develop a TP-SFE-CO2 biorefinery, topic scarcely investigated. Two TP were tested and although TP-SFE-CO2 parameters were the same, lyc recoveries depended by peel structure changes occurred during pre -SFE-CO2 drying step. Higher moisture (102.7 g kg−1 wet weight) permitted 97% lyc recovery and gave a water-in-oil emulsion as extract. Mass balance confirmed that lyc isomerisation did not cause lyc losses. After a significant oil extraction, exhaust TP showed a biodegradability 64% higher than the raw one, attributable to fibre structure disruption. The biorefinery proposed (SFE_CO2+anaerobic digestion) determined positive economic revenue (+787.9 € t−1 TP) on the contrary of the actual TP management.

Meat quality from pigs fed tomato processing waste

Sixteen Nero Siciliano pigs were used to investigate the effect of dietary tomato processing waste on meat quality. During 86 days one group (CON, n = 8) received a pelleted conventional diet, while another group (TOM, n = 8) received the same diet in which tomato waste replaced 15% of corn. The dietary treatment did not affect growth performances. The TOM diet reduced intramuscular fat, SFA and MUFA content, while increasing the n-6:n-3 ratio in meat (P < .05). The TOM diet increased the concentration of PUFA, PUFA n-3, PUFA n-6 and the n-6:n-3 ratio (P < .01). The instrumental colour descriptors of backfat were unaffected by diet. The TOM diet increased deposition of retinol in meat (P < .001) but did not affect oxidative stability parameters measured in fresh meat and meat homogenates with pro-oxidant catalysts. Concluding, tomato pomace fed to pigs at higher levels compared to previous reports had no adverse effects on the investigated meat quality traits.

Development and characterization of novel composite glycerol-plasticized films based on sodium caseinate and lipid fraction of tomato pomace by-product

Tomato processing industries generate many byproducts that are mainly unexploited or underutilized. In order to convert tomato byproducts into added-value products, composite films made of sodium caseinate (NaCas), glycerol (25 wt%), and lipidic fraction of tomato pomace (LFTP) at different contents (0–40 wt%) were produced and characterized in terms of thermal stability, antioxidant activities, mechanical, hydrodynamic and optical properties. Our results showed that increasing LFTP concentration beyond 20 wt% increased the flexibility of NaCas films within the range of 17–25%. Moreover, LFTP incorporation at the highest content improved thermal stability of NaCas films and reduced their water absorption by >72%. Furthermore, increasing LFTP content led to a significant decrease in the light transmission of NaCas/LFTP composite films. Such improvement in functional and physical properties can be attributed not only to the establishment of specific interactions between NaCas and LFTP but also to their good miscibility in the blend along with the homogeneous dispersion of the incorporated LFTP in the polymeric matrix, as confirmed by FTIR and SEM analysis. On the other hand, the antioxidant capacity of NaCas/LFTP composite films was enhanced by increasing LFTP content most likely due to LFTP's high total phenolics content.

Tomato Waste from Processing Industries as a Feedstock for Biofuel Production

Tomato pomace, a solid by-product of tomato processing industries, was assessed for the first time as a feedstock for acetone-butanol-ethanol-isopropanol (ABEI) fermentation. After the pretreatment with hydrothermal process and enzymatic hydrolysis of tomato pomace with a 20% solid-to-solvent ratio, a broth containing 44.1 g/L total sugars was obtained (61.0% saccharification yield). Twelve Clostridium strains were compared to find an appropriate microorganism for the transformation of tomato pomace hydrolysate. Four of these strains produced 0.22–5.95 g/L acetone, 5.82–7.00 g/L butanol, 0.17–0.39 g/L ethanol, 0.05–8.28 g/L isopropanol and 11.03–15.07 g/L ABEI. The strain C. beijerinckii DSM 6423 obtained 2.67 g butanol, 2.99 g isopropanol and 5.92 g ABEI from 100 g dry tomato pomace (containing 30.6 g carbohydrates). In addition, another pretreatment was performed with a 30% solid-to-solvent ratio in order to obtain higher sugar concentrations, obtaining a hydrolysate with 85.1 g/L total sugars (66.8% saccharification efficiency), which was employed for bioethanol production by comparing twelve different yeast and bacterial strains. Kluyveromyces marxianus DSM 5422, Saccharomyces cerevisiae Ethanol Red®, S. cerevisiae Hercules and Lachancea thermotolerans DSM 3434 produced 20.1–21.7 g/L ethanol (about 5.21 g ethanol per 100 g dry tomato pomace). According to these results, tomato pomace could be an interesting feedstock for ABEI biorefineries.

Nutritive Value of Tomato Pomace for Ruminants and Its Influence on In Vitro Methane Production.

Simple SummaryReutilization of agroindustrial by-products in animal feeding could contribute to the reduction of environmental problems associated with their accumulation, but it is necessary to assess their nutritive value. Tomato pomace (TP) is a by-product of the tomato industry that could be used in ruminant feeding, but data on its nutritive value are limited. The aim of this work was to analyze the chemical composition, in vitro rumen fermentation, and intestinal digestibility of 12 TP samples obtained from two processing plants at different times during the tomato campaign and to assess the in vitro fermentation of diets including increased TP amounts. The chemical composition of TP showed little variability. Samples of TP had high fiber, protein, and fat content and were rapidly fermented in the rumen, but the in vitro intestinal digestibility of the protein was low. The in vitro results provide useful information for including TP in ruminant diets, indicating that amounts of TP up to 180 g/kg could be included in a diet for fattening ruminants without negatively affecting rumen fermentation, but these results should be confirmed in vivo.The objective of this study was to determine the variability in nutritive value for ruminants of tomato pomace (TP) samples and analyze its effect on in vitro fermentation when it was included in a high-concentrate diet. Twelve TP samples were obtained from two processing plants at weekly intervals and analyzed for chemical composition, in vitro rumen fermentation, and intestinal digestibility. The chemical composition of TP did not differ between processing plants and only slight variations were observed among sampling times. Tomato pomace had a low dry matter content (<300 g/kg), a high content of neutral detergent fiber, crude protein, and ether extract (572, 160, and 82.7 g/kg dry matter on average, respectively), and was rapidly fermented in the rumen. Protein degradability at 16 h in situ incubation was 510 g/kg and in vitro intestinal digestibility of protein was low (430–475 g/kg). Replacing soybean meal and barley straw by dried TP increased the in vitro fermentation rate and the production of volatile fatty acids and reduced NH3-N concentrations without affecting CH4. In summary, TP samples showed little variability in nutritive value over sampling time and TP of up to 180 g/kg could be included in high-concentrate diets without negatively affecting rumen fermentation.

Tomato Waste as a Source of Biologically Active Compounds

Large amounts of wastes are generated annually by the vegetable processing industry, their efficient management and valorization representing a priority research area. Recent research suggested the possibility of reusing tomato pomace as a cheap source of many bioactive compounds, such as antioxidants, soluble dietary fibers and vitamins. The high initial moisture of fresh tomato pomace and the presence of considerable levels of nutrients make this waste susceptible to microbial degradation. Therefore, the fresh pomace of three tomato varieties were preserved by two different methods and then analyzed regarding the total phenolics content, flavonoids, lycopene and antioxidant activity. The results showed that all samples contained considerable amounts of phenolic compounds and exhibit good antioxidant properties. A higher lycopene content was obtained for dehydrated samples, other similar studies explaining that heat processing can breakdown the cellular walls and the chromoplast membranes, leading to a better release. The obtained results highlight the potential of reusing tomato processing waste as source of bioactive compounds and encourages the implementation of a sustainable valorization plan.

OPTIMISATION OF ORGANIC SOLVENT EXTRACTION OF TOTAL CAROTENOIDS FROM BULGARIAN TOMATO PROCESSING WASTE

The quantity of tomato wastes combined with beneficial characteristics of components of the wastes justifies the great interest of researchers and manufacturers in extracting of carotenoids from this low cost material. In this study the response surface (RSM) approach and Box-Behnken design (BBD) were used to explore the possibility of modelling and optimisation the organic solvent extraction of total carotenoids from Bulgarian tomato processing waste (TPW). Bulgarian TPW consists of tomato pomace was used in this study. Dried and ground TPW was plased in the extraction flask and stirred with acetone at various extraction conditions. The extract obtained was vacuum filtered through filter paper and was subjected to spectrophotometrically total carotenoids content determination. A three-variable, three-level BBD of RSM was employed in optimisation the extraction conditions for the highest recovery of total carotenoids from Bulgarian TPW. A response surface quadratic model was developed and statistical analysis was carried out. Data concerning model adequacy tests indicated that the values of R2 and Radj2 for quadratic model were the higest in comparison to the other models. The obtained F-value of 38.65 implies the model was significant (p &lt; 0.05) and could be used for optimisation. The effects of extraction temperature, solvent to solid ratio and extraction time were significant in total carotenoids yield. Total carotenoids content ranged from 9.78 to 25.28 mg/100 g dried TPW. The predicted values of total carotenoids content were closed to the experimental observed values. By use of RSM the optimal extraction conditions were determined as follow: extraction time of 90 min, solvent to solid ratio of 60 mL/g and extraction temperature of 50ºC. The results obtained showed that predicted (28.40 mg/100 g dried TPW) and experimental (28.86±0.92 mg/100 g dried TPW) values of total carotenoids content were not significant different (p &gt; 0.05).

GROWTH AND ECONOMIC PERFORMANCE OF USING DRIED TOMATO POMACE FOR MALLARD DUCKS

This study was aimed to economic evaluate the effect of Dried Tomato Pomace (DTP) on growth performance, biochemical profiles and economic efficiency of Mallard Ducks from 1 days old until 72 days (age of marketing). A total of 240 unsexed one – day old, Mallard ducklings were used in this study and were randomly and independently allocated to the four dietary treatments, each containing 60 ducks and divided in to four groups, T1 (control ), T2 ( 10 % DTP), T3 (15% DTP) and T4 (20% DTP) . The diets were formulated in mash form fortified with vitamin and mineral premix and chemical analysis were applied for starter and finisher rations. Moreover, feed and water were provided for ad-libitumconsumption. The results showed that, ducks fed 20 % DTP had higher live body weight with a coincident significant increase of the feed intake (P &lt;0.05). In addition, total cholesterol, Triglycerides, high density lipoprotein (HDL) are decreased significantly (P &lt;0.05) meanwhile low density lipoprotein (LDL), total protein profiles non-significant (P &gt; 0.05). In terms of economic analysis, T4 ( 20% DTP) diet revealed the lowest cost per Kg live weight of ducks 77.57 L.E / duck, along with the highest economic return 91.38 L.E per duck and net profit 13.81 L.E per duck. In conclusion, Mallard duck can efficiently utilize diet containing high DTP (20%) diets, consequently, it can be used to optimize their growth performance and maintain the maximum economic return.Key words: Mallard duck; dried tomato pomace; growth performance; economics

Small amounts of agro-industrial byproducts in dairy ewes diets affects milk production traits and hematological parameters

The aim of this study was to evaluate the effect of diets containing different dried byproducts on milk yield and composition, and blood hematological parameters of lactating ewes. Thirty-six Sarda dairy sheep at about 120 ± 10 days in milk and with an average pre-trial milk yield of 1720 ± 430 g/day were assigned to 4 experimental groups and fed four different diets: no byproduct (CON), dry tomato pomace (TP), dry grape marc (GM), and exhausted myrtle berries (EMB) supplementation. Feed intake, milk yield, milk composition and hematological parameters were affected by byproduct supplementation of the diet. In particular, ewes fed byproducts combined diets consumed less dry matter compared with the CON (1.88 vs. 1.79 in GM and 1.71 kg in EMB and TP groups) diet daily. The GM group exhibited a larger milk production (+200 g/day), as well as protein (+8.4 g/day) and fat (+5.5 g/day) milk contents compared to the CON group. The EMB group produced less milk compared to CON group (1050 vs. 1220 g/day). The addition of TP did not affect production performance in comparison to CON group. Any significant interaction among dietary treatment and sampling time was observed on daily feed intake, animal performances and milk coagulation properties. The analysis of the hematological profile showed values within the physiological range of the species for all groups, and were used to assess apparent good health conditions of ewes throughout the experiment. In conclusion, 100 g/day of GM in addition to the basal sheep diet allowed to improve milk yield and to maintain the health status of lactating animals.

Chemical Characterization and Antiplatelet Potential of Bioactive Extract from Tomato Pomace (Byproduct of Tomato Paste).

We examined the ability of tomato pomace extract (by-product) to affect platelet aggregation in healthy humans (clinical pilot study). In phase 1 the tolerance of participants (n = 15; 5 per dose level) ingesting tomato pomace extract across three dose levels (1, 2.5, and 10 g) was evaluated. Phase 2 was a single-blind, placebo-controlled, parallel design human (male, n = 99; 33 per group) pilot intervention trial investigating the acute and repeated dose effects (5 days) of different doses of tomato pomace extract (1 g, 2.5 g or placebo) on platelet aggregation ex vivo. Various flavonoids (coumaric acid, floridzin, floretin, procyanidin B2, luteolin-7-O-glucoside, kaempferol, and quercitin) and nucleosides (adenosine, inosine, and guanosine) were identified in the tomato pomace extract. The clinical study showed that the daily consumption of 1 g of aqueous extract of tomato pomace for 5 days exerted an inhibitory activity on platelet aggregation.

Sustainable approach for lycopene extraction from tomato processing by-product using hydrophobic eutectic solvents.

Lycopene, a non-polar antioxidant compound with important effects on human health and wide commercial applications, was extracted from tomato processing wastes using innovative hydrophobic eutectic mixtures (HEMs) replacing traditional organic solvents. HEMs were prepared using DL-menthol as hydrogen-bond acceptor (HBA) and lactic acid as hydrogen-bond donor (HBD), and the ultrasound-assisted extraction (UAE) was optimized using a Box-Behnken design to evaluate extraction conditions: extraction temperature (°C), molar ratio of eutectic mixture (moles HBA: mol HBD), solvent to sample ratio (volume to mass, mL/g), and extraction time (min), with lycopene extraction yield (µg/g d.w.) as the response variable. Optimization of parameters was performed using response surface methodology, and the optimized extraction conditions were determined to be 70°C, 8:1mol HBA/mol HBD, 120mL/g solvent: sample, and 10min. The experimental optimal yield was 1446.6µg/g, in agreement with the predicted optimal yield, indicating the validity of the model. This new technique for lycopene extraction, using a HEM as extraction solvent in replacement of hazardous organic solvents, and tomato pomace as source material, represents a viable and more sustainable approach for obtaining a high value-added bioactive compound, and can contribute towards the development of greener extraction processes.

Microencapsulation of Tomato (Solanum lycopersicum L.) Pomace Ethanolic Extract by Spray Drying: Optimization of Process Conditions

Microencapsulation by spray-drying is a process used in the stabilization of active compounds from various natural sources, such as tomato by-products, with the purpose to be used as additives in the food industry. The aim of this work was to study the effects of wall material and spray drying conditions on physicochemical properties of microcapsules loaded with lycopene rich extract from tomato pomace. The assays were carried out with ethanolic tomato pomace extract as core material and arabic gum or inulin as wall materials. A central composite rotatable design was used to evaluate the effect of drying air inlet temperature (110–200 °C) and concentration of arabic gum (5–35 wt %) or inulin (5–25 wt %) on the antioxidant activity, encapsulation efficiency, loading capacity, and drying yield. SEM images showed that the produced particles were in the category of skin-forming structures. The most suitable conditions, within the ranges studied, to obtain lycopene loaded microparticles were a biopolymer concentration of 10 wt % for both materials and an inlet temperature of 200 and 160 °C for arabic gum and inulin, respectively. Arabic gum and inulin possessed a good performance in the encapsulation of tomato pomace extract by spray drying. It is envisaged that the capsules produced have good potential to be incorporated in foods systems with diverse chemical and physical properties.

Shifts in Soil Bacterial Communities as a Function of Carbon Source Used During Anaerobic Soil Disinfestation

Anaerobic soil disinfestation (ASD) is an organic amendment-based management practice for controlling soil-borne plant pathogens. Pathogen suppression appears to be carbon source-dependent and mediated by bacteria that proliferate and produce volatile organic compounds, as well as physico-chemical changes (i.e., elevated temperature, lowered redox potential and pH, release of metal ions) in soil. ASD is under study for adoption in tree crops as a replacement for chemical-fumigation, but its widespread use is limited by incomplete understanding of its suppression mechanisms and high economic costs. The carbon substrate is one component of the ASD process that can be optimized to enhance effectiveness and affordability. While rice bran is currently the standard carbon source used for ASD, we identified three alternative substrates (molasses, mustard seed meal, and tomato pomace) that are similar in efficacy to rice bran at generating and sustaining soil anoxia and reducing populations of introduced plant pathogens. Here, we used replicated ASD field trials to determine if rice bran and the alternative carbon substrates would elicit similar soil bacterial communities (characterized via amplicon sequencing of the 16S rRNA gene v4 region) and to assess if any observed community shifts were consistent across repeated trials. We found significant, but minimal differences in community composition between ASD carbon treatments (F4,30 = 2.80, P 5 log2 fold change) in all ASD treatments compared to untreated controls. A group of shared core genera belonging to the Clostridiales and Selenomonadales were identified in both trials and constituted 22.6% and 21.5% of the communities. Bacterial taxa that were most responsive to ASD treatments had the genomic potential for denitrification, nitrogen fixation, and fermentation reactions that produce organic acids (such as acetate and butyrate) known to inhibit in vitro growth of plant pathogens based on predicted metagenomes. Together, these results indicate that reproducible and effective implementation of ASD is achievable with alternative carbon substrates to rice bran.

Effects of fibrolytic enzymes and lactic acid bacteria on fermentation quality and in vitro digestibility of Napier grass silage

An experiment was conducted to evaluate the effect of xylanase and cellulase derived from dried tomato pomace treated with Aspergillus niger and fermented juice of epiphytic of lactic acid bacteria (FJLB) on fermentative quality and in vitro digestibility of Napier grass silages. Thus, we treated Napier grass silage with or without fibrolytic enzymes (ENZ) in combination with or without FJLB. The pH values of silages treated with FJLB, but not ENZ, were found to be lower than the other silages during the ensiling process. The content of water soluble carbohydrates (WSC) of all silages was likely to decrease during fermentation in all silages. However, after 30 days of ensiling, the addition of ENZ resulted in higher WSC content when compared to the other treatments. At 30 day of ensiling, the crude protein of silage was higher in silage treated with FJLB. The gas production related to the soluble fraction was higher in silage treated with ENZ but total gas production was similar between treatments. The latter is in line the observation that the degradability of organic matter also was not different between treatments. It is concluded that neither the fermentation quality nor the in vitro digestibility of organic matter is improved when Napier grass is ensiled with both FJLB and fibrolytic enzymes compared with FJLB alone.HighlightsEnsiling Napier grass, which contains high water soluble carbohydrates, without additives results in an acceptable fermentation quality.A combination of fermented juice of epiphytic lactic acid bacteria (FJLB) and fibrolytic enzymes has no effect on quality of Napier grass silage.

Antiplatelet protocol: Effects of ingesting a tomato pomace extract on human platelet aggregation

Consumption of tomato and tomato-based products is associated with risk reduction of cardiovascular disease (CVD). Protective effect of tomato is not clearly understood, but there is an interest in its ability to affect platelet aggregation (coagulation). Therefore, the aim of the present study is to describe the protocol of a single blind, parallel design (3-groups), placebo controlled trial, which will assess acute and “acute upon 5-day repeated dose” effects of ingesting a tomato pomace extract on platelet aggregation. Participants will be randomized to receive a flavoured water either with 1 g tomato pomace extract, 2.5 g tomato pomace extract or placebo negative control. A total of 99 people are required to complete (n = 33/group). Each group will ingest either a treatment or placebo once daily, for 5-days and blood samples will be taken to analyze platelet aggregation. For 14-days preceding the baseline assessment day and for the 5-day period of intervention, participants will have to exclude some foods/beverages from their diet, which are known to affect platelet function. The present study is expected to generate significant information about the effect of tomato pomace extract consumption on platelet function of volunteers.

Influence of Dried Tomato Pomace as a Source of Polyphenols on the Performance of Growing Rabbit

This study was carried out to determine the effects of dried tomato pomace (DTP) feeding on the performance and apparent digestibility of growing rabbits. A total 54, 6-week old rabbits were divided into three equal groups and fed isonitrogenous and isoenergetic diets containing 0 (CON), 10 (DTP-10) and 20 (DTP-20) per cent DTP for a period of 6 weeks. A digestibility trial carried out in the second week of the growth trial indicated that the digestibility of DM and EE remained similar among the three groups. However, rabbits fed DTP-containing diets showed higher (P 0.05) differences between experimental groups in terms of weight gain, average daily gain, feed intake and feed conversion ratio. Interestingly, the highest level of DTP (i.e. at 20%) resulted in the lowest mortality. Moreover, supplementing the diet of rabbits with DTP decreased the cost of production and increased relative net revenue. It is concluded that the incorporation of dried tomato pomace rich in polyphenols up to 20% in the rabbitdiet contributes to improved protein digestibility.

Sustainable polycondensation of multifunctional fatty acids from tomato pomace agro-waste catalyzed by tin (II) 2-ethylhexanoate

Bioplastics were prepared from the fatty fraction (i.e., unsaturated and polyhydroxylated fatty acids) of tomato pomace agro-wastes. Aliphatic polyesters were synthesized at different temperatures (125, 150, and 175 °C), reaction times (0.25, 0.5, 0.75, 1, 3, 5, and 7 h), and amounts of tin (II) 2-ethylhexanoate (0, 0.02, 0.05, and 0.10 mmol) used as a catalyst. The rate constants and activation energies were calculated from infrared spectra. The right combination of reaction temperature and amount of catalyst improved the reaction kinetics (apparent k from ∼1 to ∼8.5 h−1), whereas the activation energy was reduced from ∼39 without catalyst to ∼28 kJ/mol when tin (II) 2-ethylhexanoate was present. Glass transitions between ca. −25 and ∼0 °C were measured by differential scanning calorimetry, strictly depending on the degree of polymerization. The amorphous character of the samples was confirmed by X-ray diffraction. Young's modulus and hardness were calculated from indentation tests and were typical of soft materials, although increased as the polycondensation reaction progressed. High water-contact angles (maximum value ∼109°) and low water uptakes (minimum value ∼2.1%) were determined. Physical properties were compared with those of common man-made plastics and polymers, finding that these tomato pomace bioplastics could be their realistic alternatives.

Interactions between fecal bacteria, bile acids and components of tomato pomace

The tomato pomace obtained during processing as a residue of tomato processing from large industry. The interactions between tomato pomace and fecal bacteria, bile acids during in vitro digestion were studied. Digestion was carried out by using bioreactor in anaerobic conditions. Tomato pomace can significantly affect the count of fecal bacteria and the solubility of bile acids in in vitro digestion due to bonding ability of their proteins/peptides. The availability and use of bile acids does not only depend on the interactions between bile acids and bacteria, but also the interactions of bile acids with digested food components. Tomato pomace characterized high dietary fiber content and its fractions: 17.64–21.53% for cellulose and 13.48–18.63% for lignin. Given our results we supposed that fecal bacteria can use primary bile acids, as their source of energy in an environment where carbon availability is limited.

Valorization of Tomato Processing by-Products: Fatty Acid Extraction and Production of Bio-Based Materials.

A method consisting of the alkaline hydrolysis of tomato pomace by-products has been optimized to obtain a mixture of unsaturated and polyhydroxylated fatty acids as well as a non-hydrolysable secondary residue. Reaction rates and the activation energy of the hydrolysis were calculated to reduce costs associated with chemicals and energy consumption. Lipid and non-hydrolysable fractions were chemically (infrared (IR) spectroscopy, gas chromatography/mass spectrometry (GC-MS)) and thermally (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)) characterized. In addition, the fatty acid mixture was used to produce cutin-based polyesters. Freestanding films were prepared by non-catalyzed melt-polycondensation and characterized by Attenuated Total Reflected-Fourier Transform Infrared (ATR-FTIR) spectroscopy, solid-state nuclear magnetic resonance (NMR), DSC, TGA, Water Contact Angles (WCA), and tensile tests. These bio-based polymers were hydrophobic, insoluble, infusible, and thermally stable, their physical properties being tunable by controlling the presence of unsaturated fatty acids and oxygen in the reaction. The participation of an oxidative crosslinking side reaction is proposed to be responsible for such modifications.

Tomato pomace powder as a raw material for ketchup production

A value-added ketchup from tomato pomace powder was developed and compared to a previously developed ketchup from fresh tomato pomace. The total dietary fiber content of tomato pomace powder ketchup was higher than fresh tomato pomace ketchup due to the production process in which no seeds were removed. Differences in processing led to larger specific surface area of rehydrated tomato pomace powder particles when compared to fresh tomato pomace particles and consequently their larger bonding affinity to polysaccharides. The pomace powder ketchup had a significantly higher yield stress and pronounced thixotropy in comparison with fresh tomato pomace ketchup that could not be packed into tubes. Additionally, improved thermal stability of ketchup prepared from tomato pomace powder suggested its possible application as a bakery filling. However, this promising procedure requires more expensive processing equipment and higher energy consumption than fresh tomato pomace processing.