Extra-virgin olive oil enriched with lycopene: From industrial tomato by-products to consumer.

Lycopene is usually extracted from the by-product of the tomato industry using organic solvents (OS) in combination with a physical technique. An emerging physical technique is high-pressure processing (HPP). This study aims to find a method by applying a green solvent (edible vegetable oils) in an HPP-assisted solid-liquid extraction. Three dosages of tomato by-product (10%, 20%, and 40%, w/v) were tested using OS, sunflower oil (RSO), and extra-virgin olive oil (EVOO). Lycopene recovery increased with the ratio of by-product to oil, particularly when using EVOO. In another stage of the study, consumers evaluated EVOO that contained two doses of tomato by-product (10% and 20%, w/v). Consumers preferred the EVOO from 10% tomato by-product ratio over that with 20%. Additionally, 83.8% of consumers stated that enriched oil could be deemed beneficial for health. The proposed method considers the fundamental principles of the circular economy and practical industrial scenario to recover lycopene from tomato by-product.

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.

Stabilization of microbial network by co-digestion of swine manure and organic wastes.

The production of biogas from organic waste has attracted considerable interest as a solution to current energy and waste management challenges. This study explored the methane (CH4) production potential of swine manure (SM), food waste (FW), and tomato waste (TW) and the changes in the microbial community involved in the anaerobic digestion process. The results revealed that the CH4 production potentials of the four kinds of SM samples were influenced by the characteristics of SM (e.g., age and storage period). Among the four kinds of SM samples, the CH4 yield from the manure directly sampled from primiparous sows (SM3) was the highest. The CH4 yield was significantly improved when SM3 was co-digested with FW, but not with TW. The addition of SM fostered a stable CH4 production community by enhancing the interaction between methanogens and syntrophic bacteria. Furthermore, the addition of FW as a co-substrate may improve the functional redundancy structure of the methanogenesis-associated network. Overall, the characteristics of SM must be considered to achieve consistent CH4 yield efficiency from anaerobic digestion since CH4 production potentials of SM can be different. Also, the contribution of co-substrate to the synergistic relationship between methanogens and syntrophic bacteria can be considered when a co-substrate is selected in order to enhace CH4 yield from SM.

Use of High-Protein and High-Dietary-Fibre Vegetable Processing Waste from Bell Pepper and Tomato for Pasta Fortification.

There is worldwide wastage of 1.3 billion tons of food annually. It is recommended that food waste should be reduced at every phase of production. By-products from food processing have high nutritional value so their use in new products is advisable. The aim of the study was to enrich the nutritional value of pasta using waste from the food industry. By-products from tomato processing (tomato waste-TW) and pepper (defatted pepper seeds-DPS, pepper placenta-PP) were used at a level of 10-30% to produce pasta. The farinographic characteristics, chemical composition, cooking quality, and colour of the pasta were studied. The results show a significant (p < 0.05), up to 27%, increase in the protein content of the TW30 samples, compared with the control (16.16% d.m. vs. 20.61% d.m.). The TDF content increased over five times in DPS30 and TW30 (27.99% d.m. and 25.44% d.m.). The amino acid composition of the pasta improved with the fortification but failed to achieve complete protein by FAO. The DPS30, PP20, PP30 and all TW samples can be considered high-protein products according to the EU definition (a minimum of 20% energy from protein). Vegetable waste can be a valuable additive for the improvement of the nutritional value of food.

Tomato waste biochar in the framework of circular economy.

Tomato pomace was slowly pyrolyzed at 350 and 550 °C (under an N2 flow of 50 L/h) at a rate of 6 °C/min and a residence time of 1:30 h to produce two biochars named B350 and B550, respectively. In addition, the two biochars were chemically activated with ΚΟΗ (at a ratio of 1:10 w/v) at 800 °C to produce two new materials named BA350 and BA550. The four biochars produced were characterized physically and chemically (pH, yield, calorific value). They were also analyzed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (B.E.T), elemental analysis (EA), and thermogravimetric analysis (TGA). The results showed that as the pyrolysis temperature increased (350 to 550 °C), the specific surface area (SSA) increased. The latter was also significantly increased by the activation process. EA showed a variation in the mineral content of the produced biochars, resulting in a different content of the biochars after activation. The parameters studied showed that biochars from tomato waste could be used as an organic amendment to improve soil fertility in agricultural. In addition, because of their ability to absorb water, they could be used as a water reservoir in soils in arid areas.

Yellow laccase produced by Trametes versicolor K1 on tomato waste: A comparative study with the blue one produced on semi-synthetic medium.

Laccase production by fungal growth on agrifood waste is still poorly studied. Trametes versicolor K1 isolated from palm bark produced a yellow non glycosylated laccase from tomato waste based medium (TMT) and a blue glycosylated laccase on glucose medium (GLU). Lignocellulosic biomass, such as pinecones (PIN), palm leaves (PLM), olive pomace (OLV), and alfa stems (ALF) have also been used as growth medium for T. versicolor K1. In these conditions, very low or no laccase production was observed. When peptone was supplied in TMT medium, the laccase activity increased from 4170 U/L to 8618 U/L. By increasing the culture volume up to 1 L, laccase production on TMT was 9929 U/L. The yellow laccase (TmtLac) was purified from the supernatant TMT medium and has shown similar characteristics with the blue laccase (GluLac) purified from the GLU medium. Their apparent protein size was 63 kDa. Catalytic activities of the yellow form were not very different from those of the blue form, but specific activity of the purified yellow laccase produced on tomato waste was much higher. The Km and Vm values for four substrates, ABTS, DMP, guaiacol, and pyrogallol were almost similar for both isoenzymes. The optimum pH and temperature were respectively 4.0 and 50 °C. Although the level of glycosylation is clearly different, the thermostability of TmtLac and GluLac are quite similar. TmtLac is even slightly more tolerant at 60 °C for 24 h than GluLac. Moreover TmtLac showed greater stability at alkaline pH after 24 h compared to that of GluLac.We demonstrate that activity of the yellow TmtLac is not significantly affected compared to the blue laccase and that tomato waste is a simple and interesting lignocellulosic substrate to the laccase producer Trametes sp.

The Effect of High-Intensity Ultrasound and Natural Oils on the Extraction and Antioxidant Activity of Lycopene from Tomato (Solanum lycopersicum) Waste.

The extraction of lycopene was carried out with three types of vegetable oils (grape, extra virgin olive, and peanut) by means of two methods: agitation and high-intensity ultrasound with a frequency of 20 kHz at an amplitude of 80% with periods of 40 s of sonication for 20 min at a temperature of 40 °C. The antioxidant determination by inhibition of ABTS and DPPH radicals showed no significant differences (p > 0.05) for inhibition of the ABTS radical in native oils and oils with lycopene. However, the radical DPPH showed that the native oils presented significant differences (p ≤ 0.05) compared to the samples with lycopene. FTIR spectra revealed the characteristic functional groups of lycopene exhibiting two characteristic peaks at 2923 cm−1 and 2957 cm−1. The DSC thermograms showed that the higher the degree of oil unsaturation, the lower the melting temperatures. Olive oil was the least unsaturated with the highest amount of oleic fatty acid. Grapeseed oil reported the lowest melting temperature at around −24.64 °C. Extra virgin olive oil showed the lightest values (L* = 41.08 ± 0.45) of brightness, and the peanut oil with lycopene was the darkest (L* = 16.72 ± 0.05). The extraction of lycopene from organic wastes treated with agitation and ultrasound was satisfactory reducing the use of conventional solvents. However, extraction with olive oil under agitation showed the best results.

Valorization of Greenhouse Horticulture Waste from a Biorefinery Perspective.

Greenhouse cultivation and harvesting generate considerable amounts of organic waste, including vegetal waste from plants and discarded products. This study evaluated the residues derived from tomato cultivation practices in Almería (Spain) as sugar-rich raw materials for biorefineries. First, lignocellulose-based residues were subjected to an alkali-catalyzed extrusion process in a twin-screw extruder (100 °C and 6-12% (w/w) NaOH) to assess maximum sugar recovery during the subsequent enzymatic hydrolysis step. A high saccharification yield was reached when using an alkali concentration of 12% (w/w), releasing up to 81% of the initial glucan. Second, the discarded tomato residue was crushed and centrifuged to collect both the juice and the pulp fractions. The juice contained 39.4 g of sugars per 100 g of dry culled tomato, while the pulp yielded an extra 9.1 g of sugars per 100 g of dry culled tomato after an enzymatic hydrolysis process. The results presented herein show the potential of using horticulture waste as an attractive sugar source for biorefineries, including lignocellulose-based residues when effective fractionation processes, such as reactive extrusion technology, are available.

Effect of dietary phytochemicals from tomato peels and rosehip meal on the lipid peroxidation of eggs from laying hens.

The aim of the present study was to evaluate the effects of dietary supplementation with tomato peels (TP) and rosehip meal (RM) on their phytochemicals transfer to the egg, the antioxidant profile and the markers of lipid peroxidation in stored eggs. The experiment was conducted on 42-week-old TETRA SL laying hens, which were assigned to three dietary treatments with 30 birds each: the Control group (CON) received a corn-soybean diet containing 6% flaxseed meal without any by-product addition. Groups TP and RM received Diet CON with additionally 2% TP and 2% RM, respectively. Average daily feed intake, feed conversion ratio and laying percentage were not significantly changed by the dietary treatments. Compared to the other groups, the inclusion of dietary TP led to a significant increase in egg weight (p < 0.05) and vitamin E content in eggs (p < 0.05). The dietary inclusion of RM generated a higher vitamin A content in eggs compared to Groups CON and TP (p < 0.10). After 40 d of storage, in Groups CON, TP and RM the vitamin E contents of eggs deceased by 10.1%, 14.2% and 13.3%, respectively, whereas the reduction of the lutein and zeaxanthin concentration in eggs was more pronounced (by 24.8%, 21.8% and 25.5%, respectively). For the most primary as well as for secondary oxidation products, storage time had a significant influence (p < 0.05) on the degradation process of the eggs. After 40 d of storage, the most distinct reduction in the formation rate of secondary oxidation products was observed in Group RM (by more than 30%), while the reduction for Group TP amounted from 15% to 25%, when compared with Group CON. Therefore, the results of the present study showed a significantly positive effect of RM in retarding the lipid peroxidation process during storage.

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.

Flaxseed and dried tomato waste used together in laying hens diet.

The aim of this study was to investigate the effects of simultaneous supplementation of laying hens with dietary sources of n-3 polyunsaturated fatty acids (PUFA) and carotenoids on egg quality, fatty acids and carotenoid profile of the egg yolk and on feed and yolk lipid peroxidation. A 6-week experiment was carried out with 53-week old laying hens (96 Tetra SL) assigned to a control and three treatment groups supplemented with 5% flaxseeds and different levels of dried tomato waste (DTW, 2.5%, 5.0% and 10.0%). Hens from the groups supplemented with 5% and 7.5% DTW had a significantly lower average daily feed intake and laying percentage as compared to the control. Increased doses of dietary DTW enhanced yolk Roche colour score in direct correlation with the enrichment of egg yolk in carotenoids but decreased their transfer efficiency from feed to egg. After 4 weeks, egg yolk from hens fed with 5% flaxseeds and 7.5% DTW had increased lutein and zeaxanthin levels (by 29% and 24%, respectively) and the colour score was 3.5 fold higher compared to the control group. As a result of the dietary supplementation with flaxseed, the n-3 fatty acid content was 3.1-3.7-fold higher in egg yolk compared with the control and the n-6/n-3 ratio decreased from 18.3 (control) to 4.1-5.4 in supplemented diets. Dietary supplementation with 5% DTW effectively prevented lipid oxidation of eggs enriched with n-3 PUFA, but the increase in DTW content depressed the absorption and deposition of n-3 PUFA in egg yolk.

Tunisian tomato waste pyrolysis: thermogravimetry analysis and kinetic study.

This paper aims to set up viable units of thermal processing of numerous agricultural wastes in a sustainable development and eco-friendly approach that could create new economic profitable circuits in an increasingly competitive context. One of the most problematic food wastes are tomato processing by-products; concentrating and canning industrial activities generate important amounts of them, particularly in the Tunisian context. As no reference was found in literature dealing with these last residues, this work intended to explore their potential as biomass fuels. Pyrolysis is then applied in thermogravimetric conditions for different heating rates (5, 10, 20, and 30 °C/min) in order to recover energy on one hand and to extract the corresponding kinetic parameters for an accurate design of reactors on the other hand. Main results include suitability of the tomato residues to a thermal valorization thanks to high contents of volatiles and fixed carbon and low ash percentage as well as an interesting heating value comparable to lignocellulosic biomass. Mass loss profiles indicate consecutive and overlapping stages of drying, active pyrolysis, and passive pyrolysis. The experimental profiles of conversion rate were well fitted by the three isoconversional methods; the best fitting is recorded by the Flynn-Wall-Ozawa associated with a first-order model for the intermediate pyrolysis and with a contracted sphere (n = 1/3) for the slowest studied pyrolysis.

Tomato-Processing By-Product Combustion: Thermal and Kinetic Analyses.

This paper is part of a sustainable development approach, the aim being to develop a thermochemical energy recovery path while reducing the amount of tomato waste issued from agro-industrial units. The thermal process may contribute to an environmentally friendly management and help tomato processing industries creating new economic profitable circuits in an increasingly competitive context. The adopted approach was to follow the operating conditions needed for a complete thermal degradation through a thermal and kinetic analyses. The results of the tomato waste characterization confirmed their suitability to a thermochemical processing with high volatiles and fixed carbon and interesting high heating values comparable to sawdust biomass. We were able to isolate of the decomposition domains and extract kinetic parameters. Three kinetic models were applied; Flynn⁻Wall⁻Ozawa (FWO) simulated the best the combustion process. Calculated curves were validated by the first order (n = 1) model except for the slow heating rate of 5 °C/min which was fitted by the contracted cylinder model. The conclusions of this paper could help in optimizing the combustion process in order to achieve high energy recovery from tomato residues. Obtained kinetic data would help in the design of combustion reactors.

Effects of Short-Term Biosolarization Using Mature Compost and Industrial Tomato Waste Amendments on the Generation and Persistence of Biocidal Soil Conditions and Subsequent Tomato Growth.

Conventional solarization and biosolarization with mature compost and tomato processing residue amendments were compared with respect to generation of pesticidal conditions and tomato ( Solanum lycopersicum L.) plant growth in treated soils. Soil oxygen depletion was examined as a response that has previously not been measured across multiple depths during biosolarization. For biosolarized soil, volatile fatty acids were found to accumulate concurrent with oxygen depletion, and the magnitude of these changes varied by soil depth. Two consecutive years of experimentation showed varying dissipation of volatile fatty acids from biosolarized soils post-treatment. When residual volatile fatty acids were detected in the biosolarized soil, fruit yield did not significantly differ from plants grown in solarized soil. However, when there was no residual volatile fatty acids in the soil at the time of planting, plants grown in biosolarized soil showed a significantly greater vegetation amount, fruit quantity, and fruit ripening than those of plants grown in solarized soil.

Effect of solvent addition sequence on lycopene extraction efficiency from membrane neutralized caustic peeled tomato waste.

Lycopene is a high value nutraceutical and its isolation from waste streams is often desirable to maximize profits. This research investigated solvent addition order and composition on lycopene extraction efficiency from a commercial tomato waste stream (pH 12.5, solids ∼5%) that was neutralized using membrane filtration. Constant volume dilution (CVD) was used to desalinate the caustic salt to neutralize the waste. Acetone, ethanol and hexane were used as direct or blended additions. Extraction efficiency was defined as the amount of lycopene extracted divided by the total lycopene in the sample. The CVD operation reduced the active alkali of the waste from 0.66 to <0.01M and the moisture content of the pulp increased from 93% to 97% (wet basis), showing the removal of caustic salts from the waste. Extraction efficiency varied from 32.5% to 94.5%. This study demonstrates a lab scale feasibility to extract lycopene efficiently from tomato processing byproducts.

Ultrasound assisted extraction and characterization of pectin from tomato waste.

Pectin was extracted from tomato waste using two different extraction methods to assess its potential utilization as an alternative source of commercial pectin production. Tomato waste was treated with ammonium oxalate/oxalic acid by conventional extraction (CE), under reflux and ultrasound assisted extraction (UAE) at 37 kHz and temperatures of 60 °C and 80 °C. The pectin obtained from these methods was analysed and compared in terms of yield, chemical properties and structure. Among examined methods, CE at 60 °C resulted with the highest yield, but UAE during 15 min of sonication produced the pectin of better quality (anhydrouronic acid, methoxy and calcium pectate contents and degree of esterification). NMR and FTIR spectroscopy of isolated pectins revealed predominantly esterified structure, irrespective of extraction conditions. The comparison of the pectin yields obtained after extraction at 80 °C, indicate that similar values were found at times of 24h and 15 min for CE and UAE, respectively. According to obtained results it can be concluded that main advantage of UAE is considerable shortening of extraction procedure with strong emphasis on environmental friendly processing approach. Therefore, these results suggested that UAE could be used as an efficient technique for the extraction of pectin from tomato waste and by-products.

Conversion of tomato-peel waste into solid fuel by hydrothermal carbonization: Influence of the processing variables.

In this work, the influence of the variables temperature, residence time, and biomass/water ratio on the hydrothermal carbonization (HTC) of tomato peel was investigated. The implementation of a Design of Experiments - Response Surface Methodology approach allowed to identify the importance of each variable, as well as their interactions, in both the reactivity (solid yield) and energy densification (increase in higher heating value). The HTC residence time and specially temperature had a major effect on the process, increasing the solid yield and promoting energy densification. Ratio had a minor effect although under certain temperature and time conditions, it was a decisive parameter. Solid yields in the range 27.6% and 87.7% with corresponding high heating values 23.6-34.6 MJ kg(-1) were obtained. From the statistical processing of the experimental data obtained pseudo-second order models were developed. It was proven that these approaches envisaged the hydrochar final characteristics successfully. From the elemental analysis and the FTIR spectra, it was possible to investigate the HTC pathway, which was defined as a combination of several processes; considering dehydration and decarboxylation reactions and especially lignin depolimerization reactions, which lead to the formation of monomeric radicals. Moreover, the surface morphology of selected hydrochars by Scanning Electron Microscopy (SEM) showed the original structure scaffold, with minor changes between hydrochars prepared under different conditions.

Windrow composting as horticultural waste management strategy - A case study in Ecuador.

In Ecuador, enormous quantities of vegetable wastes are produced annually from the horticultural industries. Composting can be a feasible treatment to stabilise horticultural wastes and, thus, to improve their properties for use as organic fertilisers. In this study, two different piles were prepared, using laying hen manure and sawdust mixed with broccoli or tomato waste, respectively, and composted by the turned windrow composting system. Throughout the composting process, the temperature of the mixtures was monitored and physico-chemical and chemical properties and the degree of maturity were determined. Also, principal component analysis was used to interpret the data set of compost characteristics. In both piles, the temperature exceeded 55°C for more than 2weeks, which ensured maximum pathogen reduction. Organic matter (OM) losses followed a first-order kinetic equation in both piles. The final composts showed a suitable degree of stability and maturity and an absence of phytotoxins, as observed in the evolution and final values of the total organic carbon/total nitrogen ratio (Corg/NT<20), water-soluble organic carbon (Cw<1.7%), germination index (GI>50%) and cation exchange capacity (CEC>67meq (100g OM)(-1)). As well, the evolution of different humification indexes during composting was a good indicator of the OM humification process. The type of vegetable waste used influenced OM and NT mineralisation and the final properties of the composts, showing the mixture with tomato waste a higher fertilising capacity and less environmental problems.

Bread enriched in lycopene and other bioactive compounds by addition of dry tomato waste.

The tomato processing industry generates high amounts of waste, mainly tomato skins and seeds, which create environmental problems. These residues are attractive sources of valuable bioactive components and pigments. A relatively simple recovery technology could consist of production of powders to be directly incorporated into foods. Tomato waste coming from a Romanian tomato processing unit were analyzed for the content of several bioactive compounds like ascorbic acid, ß-carotene, lycopene, total phenolics, mineral and trace elements. In addition, its antioxidant capacity was assayed. Results revealed that tomato waste (skins and seeds) could be successfully utilized as functional ingredient for the formulation of antioxidant rich functional foods. Dry tomato processing waste were used to supplement wheat flour at 6 and 10 % levels (w/w flour basis) and the effects on the bread's physicochemical, baking and sensorial characteristics were studied. The following changes were observed: increase in moisture content, titratable acidity and bread crumb elasticity, reduction in specific volume and bread crumb porosity. The addition of dry tomato waste at 6 % resulted in bread with good sensory characteristics and overall acceptability but as the amount of dry tomato waste increased to 10 %, bread was less acceptable.

Anaerobic digestion of tomato processing waste: Effect of alkaline pretreatment.

The objective of the work was to assess the effect of mild alkaline pretreatment on the anaerobic biodegradability of tomato processing waste (TPW). Experiments were carried out in duplicate BMP bottles using a pretreatment contact time of 4 and 24 h and a 1% and 5% NaOH dosage. The cumulative methane production during a 30 d period was recorded and modelled. The alkaline pretreatment did not significantly affect methane production in any of the treatments in comparison to the control. The average methane production for all runs was 320 NmL/gVS. Based on first order kinetic modelling, the alkaline pretreatment was found to slow down the rate of methanogenesis, mainly in the two reactors with the highest NaOH dosage. The biodegradability of the substrates ranged from 0.75 to 0.82 and from 0.66 to 0.72 based on two different approaches.