Tomato Paste Production Research Articles

Treatment of tomato paste wastewater by electrochemical and membrane processes: process optimization and cost calculation.

This study investigated the treatment of wastewater from tomato paste (TP) production using electrocoagulation (EC) and electrooxidation (EO). The effectiveness of water recovery from the pretreated water was then investigated using the membrane process. For this purpose, the effects of independent control variables, including electrode type (aluminum, iron, graphite, and stainless steel), current density (25-75 A/m2), and electrolysis time (15-120 min) on chemical oxygen demand (COD) and color removal were investigated. The results showed that 81.0% of COD and 100% of the color removal were achieved by EC at a current density of 75 A/m2, a pH of 6.84 and a reaction time of 120 min aluminum electrodes. In comparison, EO with graphite electrodes achieved 55.6% of COD and 100% of the color removal under similar conditions. The operating cost was calculated to be in the range of $0.56-30.62/m3. Overall, the results indicate that EO with graphite electrodes is a promising pretreatment process for the removal of various organics. In the membrane process, NP030, NP010, and NF90 membranes were used at a volume of 250 mL and 5 bar. A significant COD removal rate of 94% was achieved with the membrane. The combination of EC and the membrane process demonstrated the feasibility of water recovery from TP wastewater.

Spatial Procurement of Farm Products and the Supply of Processed Foods: Application to the Tomato Processing Industry

AbstractIncreased transportation and logistical costs in agricultural markets have affected the spatial allocation of production in the agricultural and food sectors of the economy. We develop a spatial model of farm product procurement by a food processor, which is designed to capture the effects of supply-chain disruptions on the spatial procurement of farm products in the processed food sector. We use detailed data on production and procurement from a large California tomato processor to estimate the key parameters of the model, which allow us to calculate the price elasticity of supply for California tomato paste production and describe how changes in energy prices and transportation costs for primary agricultural products affect the supply of processed food.

Life cycle assessment of tomato paste production: a case study

Life cycle assessment of tomato paste production: a case study

Productivity and quality of different tomato cultivars under intercropping system with maize and dry farming conditions in Southern Italy

This research, carried out in a typical Mediterranean environment of Southern Italy, reports some quantitative and qualitative traits of three local tomato cultivars (‘Arsicolo’, ‘Crovarese’, and ‘San Marzano’) plus a commercial one (‘Datterino’) cultivated without irrigation and intercropped with maize. For each cultivar, in addition to the determination of fruit production, tomato paste and “conserva” paste were prepared using a traditional technique of the Tanagro Valley (province of Salerno, Southern Italy). Results highlighted that ‘Arsicolo’ showed the best fruit yield (32.2 metric tons ha-1) and tomato paste production (92.9% paste return by tomato fruits weight) due to its ancient peculiar adaptability to cultivation in dry conditions, while ‘Datterino’, ‘Crovarese’, and ‘San Marzano’ had 19, 16.7, 10.5 tons ha-1 of fruit yield and 85.7, 83.9, 76.2% of tomato paste return, respectively. Conversely, for the qualitative traits, such as total solids, soluble solids, titratable acidity, and ascorbic acid, ‘Crovarese’ showed the best results (9.1%, 6.6 °Brix, 0.93%, and 39.7 mg per 100 g of fresh weight, respectively). The two components extracted by the principal components analysis (PCA) explained 84.9% of the total variance in the morphological, quantitative and qualitative traits and the dendrogram obtained by hierarchical cluster analysis allowed to divide the cultivars into three groups. Our findings highlighted that local tomato cultivars, intercropped with maize, can be cultivated adopting only few sustainable field operations and with no irrigation.

Drying of tomato pomace in daylight simulated photovoltaic‐assisted drying system: Effects of daylight intensity and application mode

AbstractIt was aimed to dry a by‐product of tomato paste production (tomato pomace) by minimizing the losses valuable components and reducing energy consumption. In this concept, a daylight simulated photovoltaic‐assisted dryer (DPVD) applying the daylight in different modes and intensities during drying was custom‐designed. The effects of daylight applications on the change of some quality characteristics of tomato pomace and system performance characteristics were investigated, and the optimum drying condition was determined. The process conditions included the combination of three different daylight application modes (UV‐blocked daylight via solar tube‐DLST, DLST + LED, and LED) and three different daylight intensities (2,500, 7,500, and 10,000 lux). The drying was applied for 240 min at constant air temperature (60°C) with an air velocity of 2 m/s. The moisture content and the water activity values of dried tomato pomace were 8.86 ± 2.00% and 0.57 ± 0.10%, respectively. The lycopene and β‐carotene losses after drying were determined as 68.36 ± 4.32% and 65.66 ± 4.33%, respectively. The energy and exergy efficiencies of the system were in the range of 19.56%–35.73% and 5.10%–17.05%, respectively. The optimum condition meeting the criteria of superior quality and high‐performance characteristics was obtained by applying DLST at 7,500 lux (desirability 0.728). In the performance improvement studies, it has been concluded that all the energy required for the process could have been fulfilled as 100% from solar energy with the support of photovoltaic panels. In other words, it was demonstrated that the developed DPVD system could be used to dry the tomato pomace not only in terms of providing high food quality and safety, but also in terms of having high energy efficiency.Practical applicationsExposure to the daylight is important to dry some foods. Especially in north countries, products are dried in artificial dryers, but it requires high energy consumption. In this study, the daylight transfer system was integrated into the artificial dryer for the purpose of using daylight effect in addition to the photovoltaic (PV) assistance for using solar energy. During periods when the solar thermal effect is not intense or in countries where the sun effect is limited, it will be possible to dry food products with the daylight effects via using the DPVD system in suitable microbiological conditions.In this study, tomato pomace samples, which are the byproduct of tomato paste production, could be dried in daylight simulated PV‐assisted drying system in high quality and with low energy consumption. It is concluded that it can be possible to obtain valuable components from a byproduct having no economical value.

Tarhana Üretiminde Kullanılan Buğday Unu Alternatifleri

The aim of this study was to investigate the possibilities of using various flour substitutes instead of wheat flour in the production of tarhana, which is a fermented food. In the studies examined for this purpose, various legume and cereal flours (oats, quinoa, lupine, wheat germ, chickpeas, beans, corn, rice, buckwheat and lentil flours), tomato paste production waste (tomato seed, tomato pulp, pepper seed, pepper pulp), potato starch, chestnut flour, carob flour, hazelnut pulp, almond pulp, and fish meat were substituted for wheat flour. With these substitutions used instead of wheat flour in the production of tarhana, it was aimed to increase the nutritional properties of the tarhana, improve its sensory properties and quality features. Alternative flours used in the production of tarhana were investigated in this study. According to the results obtained from the compiled studies, tarhana produced with the use of substitute flour will be an alternative to demand of consumers with high functional, natural and nutritional quality.

Application of the HACCP System during the Production of Tomato Paste

Food Safety is a fundamental public health concern, and achieving a safe supply poses major challenges for organisations involved in the food chain. A vide number of food borne hazards, both familiar and new, pose risks to health and obstructions to international trade in foods. These hazards must be properly analysed, assessed and managed to meet growing and increasingly complex sets of global food chain. Proper implementation of food hygiene principles across the food chain in conjunction with Hazard Analysis and Critical Control Points system will ensure food safety. In this study, microbiological, pesticide residuals and heavy metals qualities of a tomato (Lycopersicon esculentum) paste (36-38%) production line (ripe tomato, washing, sorting, crushing, refining, concentrating, sterilization and aseptic filling) and its preservation in UCI company was studied using the HACCP method. Samples generated during the steps described previously were analyzed by determining microbiological characteristics. Samples were analyzed for total aerobic bacterial count, coliform count and yeast & mould count . The microorganisms involved in spoilage of products were E. Coli, Bacillus, Staphylococcus, Salmonella and Clostridium bacteria . Results of the critical control points (CCPs) of tomato paste processing line. The analysis of selected microbiological parameters during production tomato paste that was down gradually until get the finally product within agreement for theEgyptian Standards. The preserved tomato paste exhibited a pesticide residue was lower than those presented in theEgyptian and the EU Standards. On the other hand, Results of heavy metals was not detected for finaly proudeted .

Investigation of Tomato, Quince and Grapefruit Waste; Compositions and Functional Properties

The food industry constantly growing with increasing population and food diversity. In addition to production, the formation of food waste is also increasing. These wastes cause environmental pollution, economical problems and the loss of valuable chemical com-ponents. Tomato is used for tomato paste, sauce and other food production; especially the skin and seed part of tomato is waste. Grapefruit and quince have a significant amount of waste, especially in the beverage industry. The reuse of these wastes can reduce the exposu-re of solid waste, the environmental problem and the recovery of the bioactive components. In this study, some physicochemical, functional and thermal properties of quince, grapef-ruit and tomato waste were determined and their reuse potential was revealed. All three samples showed high hydration properties. According to the dietary fiber analysis, TDF of quince, grapefruit and tomato were 87.90%, 90.34%, and 63.76% respectively. DTG and TGA chromatograms were obtained for the thermal decomposition of the samples. Tomato waste signaled lycopene and its derivatives as distinct from the other samples in the FT-IR spectrum. Based on the results of the study; the use of these wastes in many food products as hydrocolloid, filler, fat replacer is possible, also cost reduction may be possible with the recovery of these samples.

Antiplatelet Effects of Bioactive Compounds Present in Tomato Pomace.

Cardiovascular diseases (CVD) currently account for nearly half of non-communicable diseases. Epidemiological studies have demonstrated the cardiovascular protective role of a diet rich in vegetables and fruits. In this context, our research outcomes have demonstrated the antiplatelet activities of fruits and vegetable extracts widely consumed, among which tomato was highlighted in our lab work. Tomato pomace, a major byproduct of tomato paste production, consists of skin and seeds and is a rich source of bioactive compounds. Tomato pomace has potent antithrombotic effects, even greater than the tomato. Given the large volumes of an industrial generation of tomato pomace, there is an opportunity to use this by-product to obtain a functional product with antiaggregant and antithrombotic properties that could be useful as an additive in health foods and thus prevent CVD. This review will focus on the platelet as the target for the antithrombotic actions exerted by the different bioactive compounds present in tomato pomace.

Platelet Anti-Aggregant Activity and Bioactive Compounds of Ultrasound-Assisted Extracts from Whole and Seedless Tomato Pomace

Tomato paste production generates a residue known as tomato pomace, which corresponds to peels and seeds separated during tomato processing. Currently, there is an opportunity to use tomato pomace to obtain a functional extract with antithrombotic properties, such as platelet anti-aggregant activity. The aim of this study was to evaluate the yield and inhibitory activity of different extracts of tomato pomace on in vitro platelet aggregation, comparing this activity with commercial cardioprotective products, and quantify bioactive compounds. Aqueous or ethanolic/water (1:1) extracts of whole tomato pomace, seedless tomato pomace, tomato pomace supplemented with seeds (50% and 20%), and only seeds were obtained with different ultrasound-assisted extraction times. The inhibition of platelet aggregation was evaluated using a lumi-aggregometer. The quantification of bioactive compounds was determined by HPLC-MS. From 5 g of each type of tomato pomace sample, 0.023–0.22 g of a dry extract was obtained for the platelet aggregation assay. The time of sonication and extraction solvent had a significant role in platelet anti-aggregant activity of some extracts respect the control. Thus, the most active extracts decreased adenosine diphosphate (ADP)-induced platelet aggregation from 87 ± 6% (control) to values between 26 ± 6% and 34 ± 2% (p < 0.05). Furthermore, different ultrasound-assisted extraction conditions of tomato pomace fractions had varied concentration of flavonoids and nucleosides, and had an effect on extract yield.

EFEK TEGANGAN SEARAH (DC) TERHADAP DEWATERING PASTA TOMAT MENGGUNAKAN METODE ELECTROOSMOSIS DEWATERING

Tomat merupakan buah yang mengandung sejumlah nutrisi penting untuk tubuh seperti, karbohidrat, vitamin C, vitamin A, vitamin B1, vitamin B2, likopen, zat besi, serat, mineral, dan lain sebagainya. Disisi lain, tomat termasuk buah klimaterik, sehingga buah ini akan membusuk jika tidak segera dikonsumsi. Berdasarkan kondisi tersebut perlu dilakukan pengolahan buah tomat menjadi produk potensial, salah satunya yaitu pasta tomat. Umumnya pembuatan pasta tomat dilakukan dengan proses evaporasi untuk menghilangkan sebagian kadar air. Namun pemberian panas pada evaporasi dapat merusak kandungan nutrisi pasta. Electroosmosis dewatering (EOD) merupakan metode dalam pengurangan kadar air dengan menempatkan suspensi koloid diantara dua elektroda. Metode ini menjadi hal yang menarik untuk memekatkan suspensi pasta buah yang peka terhadap panas. Berdasarkan hal tersebut, diperlukan penelitian untuk mengetahui pengaruh elektroosmosis terhadap pengurangan kadar air pada pasta buah tomat. Dalam penelitian ini variasi tegangan DC yang digunakan adalah 0 V, 4.5 V, 9 V, 18 V dan 36 V dengan waktu proses 100 menit. Parameter yang diukur berdasarkan variasi tersebut adalah perubahan arus DC selama proses EOD dan kadar air pasta tomat. Hasil penelitian menunjukkan bahwa arus listrik DC semakin menurun dengan semakin lama waktu proses, dan semakin meningkat dengan adanya peningkatan tegangan yang diberikan. Aliran arus listrik pada variasi tegangan terendah, yaitu 4.5 V DC adalah di antara 41.40 mA – 59.7 mA, sedangkan arus listrik pada variasi tegangan tertinggi yaitu 36 V DC mencapai 231.86 mA – 776.67 mA. Semakin meningkatnya tegangan DC, maka kadar air pasta tomat semakin berkurang, sehingga tegangan terbaik untuk proses dewatering adalah 36 V.

Optimization of enzyme assisted extraction of lycopene from industrial tomato waste

The present study aimed to (i) select the most suitable solvent system for extraction of lycopene from industrial tomato waste; (ii) apply enzymatic pretreatment before extraction to improve lycopene recovery; and (iii) to optimize the process conditions for the selected enzyme and solvent combination using response surface methodology. Lycopene-rich oleoresins obtained through pretreatment of waste by a combination of cellulolytic and pectinolytic enzymes followed by ethyl acetate extraction had the highest phenolic compound concentration and improved antioxidant properties, as well as the highest lycopene recovery and one of the highest red color intensity. Optimized conditions were chosen to be as follows: enzymatic reaction temperature = 40 °C, enzymatic reaction time = 5 h, enzyme:substrate ratio = 0.2 ml/g, solvent:substrate ratio = 5 ml/g, extraction time = 1 h, enzyme:enzyme ratio = 1. Oleoresin with a concentration of 11.5 mg lycopene/g was obtained at the optimum conditions. Tomato paste production waste could be valorized to produce lycopene, a valuable ingredient for food and nutraceutical industries, by combined enzymatic and solvent extraction of the waste.

Application of inductive forced heating as a new approach to food industry heat exchangers

Heat exchangers are one of the main equipment used in food industry because of their convenience to transfer energy to both auxiliary facilities and various food products. In food industry, there are several reasons for heat transfer such as pre-heating, pasteurizing and sterilizing in which heat exchangers require high amount of energy. On the other hand, as being a unique quality assurance unit heat exchangers should be cleaned easily and extensively. Having high operating costs due to energy consumption and requiring high investment cost due to ensure a reliable hygienic design make heat transfer units an expensive and energy-consuming unit. Therefore, developing new approaches to generate energy and transferring it hygienically with minimum loses will be an opportunity for the food industry. With the view of developing new equipment for industry, induction-driven heating system was investigated in this study and energy and exergy efficiencies were calculated and compared with conventional heat exchanger system. Selected food system was the tomato paste sterilization/pasteurization which is a part of tomato paste production line. After assumptions and theoretical calculations for both conventional application and inductive heating, it was found that inductive heating system has 95.00% energy efficiency and 46.56% second law efficiency while the conventional heating system with electric boiler has 75.43% energy efficiency and 16.63% exergy efficiency. As a consequence, inductive method was found more beneficial compared to a commercial method having higher energy and exergy efficiencies.

Valorization of tomato pomace by sequential lycopene extraction and anaerobic digestion

Tomato pomace, a major byproduct of tomato paste production, is an abundant solid waste stream from food processing in California. Tomato pomace is a rich source of lycopene, a red carotenoid and antioxidant, and lignocellulose, the recalcitrant but energy-rich polysaccharide matrix that comprises plant cell walls. Harvesting both of these co-products could add substantial value to the pomace and potentially reduce waste. In this study, lycopene was extracted from tomato pomace using a mixed organic solvent approach. Yields of lycopene from the tomato pomace tended to be higher than most literature values reported for raw tomatoes, and consistent with many reported values for lycopene in tomato pomace and other products. However, review of the current literature indicates that reported lycopene content of tomatoes products varies by roughly two orders of magnitude, which suggests a need for investigation of the factors responsible for this unusually wide range. After lycopene extraction, direct bioconversion to methane via anaerobic digestion and pretreatment with the ionic liquid 1-ethyl-3-methylimidazolium acetate ahead of anaerobic digestion were explored. Under certain conditions, especially 100 °C for 1 h, pretreatment was beneficial to enzymatic digestion of cellulose. Extraction resulted in a statistically significant reduction in methane yield compared to raw pomace after 90 days of anaerobic digestion. However, supplementation of extracted pomace with the non-lycopene-containing aqueous fraction from the extraction is expected to restore the methane yield to that of raw pomace based on measured values for chemical and biochemical oxygen demand. Ionic liquid pretreatment decreased methane production of extracted pomace.

Energy Analysis and Current Value Stream Map Applied to a Typical Triple Concentrate Tomato Paste Production Plant with an Average Production Capacity of 500 ton/day

Energy Analysis and Current Value Stream Map Applied to a Typical Triple Concentrate Tomato Paste Production Plant with an Average Production Capacity of 500 ton/day

Industrial water demand for agro-processing and beverage industries in Rwanda

Abstract Background Water play important role in industrial operation of food processing, such ingredient of the product, operation of equipment such as boilers, cooling towers, cleaning purposes to ensure a sufficient level of hygiene and food safety etc. Rwanda is rapidly developing and this development is associated with increase in population, urbanization, industrialization, modification of agricultural practices including rise in area of irrigated land etc. All these could cause increase in water uses and modification of water demand. Assessing future water demand of the country requires the understanding of specific water demand of different sectors mentioned above and its variation within those sectors. Growth of industrial sector is expected to rise in Rwanda especially because of the created enabling environment; this of cause will cause the rise in industrial water demand. In order to understand industrial water demand and be able to project it for the future it is necessary to know specific water demand of different type of industries in the country. However, there is no published evidence of this information country wide. It is therefore necessary to conduct industrial water demand assessment in the country. The main of this study is to quantify industrial water demand for different types of industries in Rwanda. Methods The data used for this study were obtained from records of various food processing industries and breweries, interviews and from relevant organizations such as Rwanda Development Board (RDB), Water and Sanitation Corporation (WASAC), Ministry of Trade (MINICOM), and National Institute of Statistics of Rwanda (NISR). Specific water demand for various products was estimated taking into consideration the amount of water used and quantity of product produced. Correlation method in MATHLAB was used to determine the relationship between water used and production. Results and discussion The results show that industrial water used for some industrial production in Rwanda is within the recommend limit example maize flour 2m3/ton and breweries such as beer production industry 4 to 4.5 m3/m3 and carbonate soft drink industries 4m3/m3, as against internationally recommended water of 2m3/ton, and 6.5 m3/m3 respectively. However water uses for of the following, Sugar making industry 29/m3/t, Meat processing industry 5/m3/t and Tomato paste production industry 6 m3/ton exceeded the internationally recommended which are 25/m3/t, 2/m3/t, 3.58 m3/ton. Tomato Paste production industry shown strong relationship because as water demand is increasing also production is increasing. Thus from this linear model, about 98% of the variation in water demand can be explained by variation of tomato paste production due to high relationship between water demand and tomato paste production. Conclusions The quantity of water consumption differs between types of industries. It was revealed that the brewing industries uses more water than any other kind of industries in Rwanda this could related the amount of production and demand for the product. There is wide difference in specific water consumption between various industries. Brewery industries in Rwanda have shown best practice of water demand with specific water demand of 4 to 4.5 m3/m3 of final product in which is less than the global bench mark of 6.5 m3/m3. Improvements need to be made in order to achieve the recommended best practice of three cubic meters of raw water for every cubic meter of carbonate soft drinks and four cubic meters of raw water for every cubic meter of beer produced.

Bioactive compounds and antioxidant potential in tomato pastes as affected by hot and cold break process.

The effects of hot and cold break industrial tomato paste production steps on phenolic compounds, carotenoids, organic acids, hydroxy methyl furfural (HMF) and other quality parameters of tomato pastes were investigated in this study. Phenolic compounds, carotenoids, organic acids, and HMF analyses were performed with LC-DAD-ESI-MS/MS and LC-DAD-RID was used for the sugar analyses. Furthermore, the antioxidant capacities of tomato pastes were assessed via the DPPH and ABTS methods. The increase of phenol acids at the processing steps of cold break production method was higher than the hot break production method. According to PCA analyses, phenolic acids characterized cold break tomato pastes while hot break tomato pastes were characterized by flavanols and flavanones. The total amount of organic acids decreased with processing and the loss of organic acids was lower in cold break pastes. Heating and evaporation were determined as the most important processing steps in which the amount of different quality parameters change.

Comprehensive exergy analysis of a commercial tomato paste plant with a double-effect evaporator

In this study, a detailed exergy evaluation of a commercial tomato paste plant with a double-effect evaporator was conducted in order to provide information on the system thermodynamic inefficiencies. Using energy and exergy balance equations, all components of the plant were analyzed individually and their exergetic parameters were calculated on the basis of actual operational data. The required data were obtained from Nazchin tomato paste factory located in Tehran, Iran. In addition, it was attempted to quantify the exergy utilized for processing a given amount of the tomato paste. The results showed that over 82% of the total destroyed exergy in the plant occurred in the boiler combination as the main component wasting exergy. Furthermore, exergy analysis introduced this combination as the main equipment rejecting exergy to the ambient where 4.79% of its total exergy input was lost. The rational exergy efficiency of the first- and second-effect evaporative units was found to be 65.33% and 56.60%, respectively. The specific exergy consumption of the tomato paste production was also determined as 16.83 MJ/kg. Generally, exergy concept and its extensions could be served as a powerful assessment technique to optimize the design and performance of multiple-effect evaporation systems employed in food industry.

Tomato (Solanum LycopersicumL.) Processing Main Product (Juice) and By-Product (Pomace) Bioactivity Potential Measured as Antioxidant Activity and Angiotensin-Converting Enzyme Inhibition

Bioactivity potential of tomato (Solanum lycopersicum L.) juice and pomace was explored by performing four different antioxidant in vitro assays and angiotensin-converting enzyme (ACE) inhibition assay on their lipophilic and hydrophilic extracts. The content of major phytochemicals responsible for bioactivity was determined using HPLC-DAD and HPLC/UV-PAD/ESI-MSn. Rutin was found in higher quantity in pomace, while juice was richer in caffeoyl-hexosides. Ferric ion reducing ability (FRAP) of both pomace extracts was significantly higher than those of juice, while juice hydrophilic extract showed higher nitric oxide radical scavenging capacity. Tomato carotenoids were shown to be more efficient superoxide anion scavengers than phenolic compounds which, in turn, showed higher activity in FRAP assay. ACE inhibitory activity of pomace hydrophilic extract was significantly higher than that of juice at extract concentration of 10 mg/mL. This gives the tomato pomace a new possible utilization for economic and eco-friendly tomato juice and paste production. Practical Applications During industrial processing of tomato into juice, a by-product – tomato pomace is formed, consisting mainly of skin and seeds. Tomato pomace could be extracted consecutively with hexane and ethanol as environmentally preferable solvents, giving extracts which contain carotenoids and phenolic compounds. These extracts possess bioactivity potential and could be used as ingredients for value added food products.

Assessment of tomato and wine processing solid wastes as soil amendments for biosolarization

Pomaces from tomato paste and wine production are the most abundant fruit processing residues in California. These residues were examined as soil amendments for solarization to promote conditions conducive to soil disinfestation (biosolarization). Simulated biosolarization studies were performed in both aerobic and anaerobic soil environments and soil temperature elevation, pH, and evolution of CO2, H2 and CH4 gases were measured as metrics of soil microbial activity. Tomato pomace amendment induced conditions associated with soil pest inactivation, including elevation of soil temperature by up to 2°C for a duration of 4days under aerobic conditions and a reduction of soil pH from 6.5 to 4.68 under anaerobic conditions. White wine grape pomace amendment showed similar trends but to a lesser extent. Red wine grape pomace was generally less suitable for biosolarization due to significantly lower soil temperature elevations, reduced acidification relative to the other pomaces and induction of methanogenesis in the soil.