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Tomato (Solanum lycopersicum) is one of the most important vegetable plants in the world used in cooking foods. In Ghana, at peak seasons of harvesting tomato, high postharvest loses are incurred because of the absence of industrial tomato processing facilities for value addition into other convenient forms to extend shelf-life. Solar drying is a m...
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... tomato slices (4 kg) were uniformly spread on rectangular mesh trays (87 cm x 53 cm) and placed in the drying chamber of the solar dryer over three-day period till moisture content of 13-14 %. In order to compare the performance of the cabinet dryer with that of open sun drying, 4 kg of sliced tomatoes were placed on drying trays and sun-dried ( Figure 2). Triplicate sun drying experiments were carried out alongside the solar dryer. ...
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... Vol. 7, No. 6; Figure 2. Distribution of tomato powder particle high-sensitivity (HS) circularity SA-sundried tomato powder pre-treated with Ascorbic acid; SK-sundried tomato powder pre-treated with potassium metabisulfite; SC-sundried tomato powder with no pre-treatment; DA-solar dried tomato powder pre-treated with Ascorbic acid; DK-solar dried tomato powder pre-treated with potassium metabisulfite; DC- solar dried tomato powder with no pre-treatment Even with the same milling process, the HS-circularity (Figure 2) and convexity (Figure 3) of tomato powder were highly different. The circularity of 10 % of the particles of solar dried tomato powder pre-treated with KMS were 0.92 % making up the highest proportion of the shape of the samples. ...
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Citations
... The drying process creates a hard outerlayer which prevents micro-organisms from entering into the food product and therefore conserves the food for a long time. Solar dryer has been reported to be better preservers and produce items of higher quality than sun drying because they are free of microbial contamination [7]. ...
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... Sun drying application(Mavis, O.A,2018). ...
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Since ancient times, vegetables have been preserved in oil, to be consumed throughout the year, and not just during the period in which they were harvested. Dried tomato slices in Extra Virgin Olive Oil (EVOO) are one of the most famous Italian preserves. This is the first study which aimed to investigate the shelf-life parameters of this preserve during the 12 months of storage in both light and dark conditions. For this purpose, quality and CIELab color parameters were analysed in EVOO alone and as preserving liquid; total phenols and carotenoids content as well as β-carotene and lycopene content, a fatty acids profile, and antioxidant activities were examined. Results showed that samples stored in the dark are protected against degradative processes. Moreover, after 6 months of storage, the EVOO used as preserving liquid is enriched by the phytochemicals contained in dried tomato slices. This enrichment of EVOO by tomato bioactive compounds is reflected in the increase in the antioxidant activity of the oil independently by the presence of light during storage.
Tomatoes, a highly perishable agricultural product, are commonly dried to extend their shelf life. They serve as raw materials in various domains, including direct consumption and as key ingredients in processed foods, functional foods, and nutraceuticals. However, producing dried tomato products with quality attributes equivalent to fresh tomatoes, such as nutrient content, appearance, flavor, texture, and reconstitution properties, poses significant challenges. Several research attempts have been made to evaluate the feasibility of different drying methods for tomatoes. Solar drying, hot air drying, and spray drying are commonly employed techniques, each with its own set of advantages and disadvantages. Conventional solar drying practices often result in extended drying times and undesirable quality parameters. Hence, it is imperative to adopt enhanced solar drying techniques for the large‐scale production of dried tomato products. Additionally, hybrid‐drying approaches can be explored to achieve better quality products with reduced drying times. Pretreatments before drying can also enhance overall drying performance. Combining conventional drying with novel drying methods, precise selection of drying parameters and pretreatments are demonstrated as efficient ways to improve the drying rate while preserving food quality. Modeling the drying process is also critical for designing large‐scale dryers, selecting appropriate drying conditions, maintaining product quality, and process optimization. Therefore, this article aims to provide detailed insight into existing drying methods with their unique features and modeling approaches, which may enable professionals and scientists to choose better and optimized tomato drying method to deliver the highest quality product to consumers.
Practical Applications
Processing tomatoes as dried products is a potential area to explore to minimize their postharvest loss. Lack of awareness regarding how to process, what parameters to consider, and which method to employ are hurdles in adopting and popularizing dried tomato products. Hence, it is crucial to consolidate the key findings pertaining to tomato drying from various methods into a unified platform. This will provide valuable guidance to future researchers and enable consumers to make informed decisions when selecting the most suitable drying method. Therefore, this comprehensive review aims to elucidate the current practices in tomato drying, highlighting their potential benefits and limitations.
Drying fruits and vegetables is a long-established preservation method. For tomatoes, sun-drying is preferred. Semi-drying is a new application aimed to preserve better the original tomato properties. We have assessed the effects of different drying methods on the phytochemical variation in tomato products using untargeted metabolomics and targeted analyses of key compounds. An LC-MS approach enabled the relative quantification of 890 mostly semi-polar secondary metabolites and GC-MS analysis in the relative quantification of 270 polar, mostly primary metabolites. Metabolite profiles of sun-dried and oven-dried samples were clearly distinct and temperature-dependent. Both treatments caused drastic changes in lycopene and vitamins with losses up to > 99% compared to freeze-dried controls. Semi-drying had less impact on these compounds. In vitro bioaccessibility analyses of total phenolic compounds and antioxidants in a gastrointestinal digestion protocol revealed the highest recovery rates with semi-dried fruits. Semi-drying is a better way of preservation of tomato phytochemicals, based on both composition and bioaccessibility results.
An exploration was conducted in the year 2017-2018 at College of Horticulture, Bagalkot, Karnataka, India to evaluate nutritional quality of dehydrated spine gourd (Momordica dioica Roxb.) slices as influenced by different pre-treatments. Spine gourd is a high value underexploited vegetable which is rich in nutrition, medicinal value and also having potential to cure many diseases and disorders with good cultivation potential. In order to enhance its availability in the offseason along with proper retention of nutritional property dehydration was carried out with different pretreatments as a preservative method. The effect of pretreatments on nutritional attributes was observed in the present study. The treatment T2 which include blanching of spine gourd slices for 3 min. and steeping in 0.2 per cent KMS and 2 per cent salt solution for 10 min. showed significantly best results with respect to protein (1.93%), ash (8.11%), total phenols (831.20 mg GAE/100g) and L*(78.32), a*(0.68), except b* (32.28) values and carbohydrate per cent (p>0.01). The effect of pre-treatments showed non-significant results for moisture, water activity, fat, crude fibre and calorific value (kcal/100g). It was concluded form the study that the pretreatment with KMS (0.2 %) and salt (2%) solution along with blanching for 3 min. was considered best with respect to nutritional quality retention.
to evaluate nutritional quality of dehydrated spine gourd (Momordica dioica Roxb.) slices as influenced by different pre-treatments. Spine gourd is a high value underexploited vegetable which is rich in nutrition, medicinal value and also having potential to cure many diseases and disorders with good cultivation potential. In order to enhance its availability in the offseason along with proper retention of nutritional property dehydration was carried out with different pretreatments as a preservative method. The effect of pretreatments on nutritional attributes was observed in the present study. The treatment T 2 which include blanching of spine gourd slices for 3 min. and steeping in 0.2 per cent KMS and 2 per cent salt solution for 10 min. showed significantly best results with respect to protein (1.93%), ash (8.11%), total phenols (831.20 mg GAE/100g) and L*(78.32), a*(0.68), except b* (32.28) values and carbohydrate per cent (p>0.01). The effect of pre-treatments showed non-significant results for moisture, water activity, fat, crude fibre and calorific value (kcal/100g). It was concluded form the study that the pretreatment with KMS (0.2 %) and salt (2%) solution along with blanching for 3 min. was considered best with respect to nutritional quality retention.
BACKGROUND
Tomato (Lycopersicon esculentum) is an important vegetable in Ghana, with high post‐harvest losses due to absence of facilities to store, process and extend the shelf life of fresh tomatoes. Solar drying has been proven to be a more efficient and low‐cost method of enhancing quality and adding value to tomato and other vegetables. However, there are concerns about sensory appeal of the dried products. In this study a natural mixed mode solar dryer was developed to dry pre‐treated fresh Roma tomatoes. The sensory characteristics of the solar dried product was profiled and compared to the sensory properties of similar commercial dried tomato on the market using quantitative descriptive analysis methodology. Consumer testing using qualitative methods provided consumer feedback on the appeal of the solar dried tomatoes.
RESULTS
Results showed that the solar dried tomato powder had a stronger tomato aroma intensity (scoring 127 on a 150 mm intensity scale) than the market products (0.7 on the same 150 mm intensity scale). When reconstituted, the solar dried tomato powder had a coarse appearance and texture, and a strong cooked tomato aroma compared to tomato paste. Consumers indicated that tomato powder was used as a thickener because it was highly viscous and when reconstituted imparted a desirable cooked tomato aroma and flavor.
CONCLUSION
Considering the positions of the tomato products in the sensory space, although tomato powder had its own unique sensory properties, it also exhibited some sensory characteristics found in tomato paste. From this study, high‐quality tomato powder has great potential for commercialization. © 2021 Society of Chemical Industry.
