Effects of pretreatment during drying on the antioxidant properties and color of selected tomato varieties

Mwende, Rosemary; Owino, Willis; Imathiu, Samuel

doi:10.1002/fsn3.581

Cited by 28 publications

(27 citation statements)

References 25 publications

(39 reference statements)

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“…Similar observation was reported by Mwende et al. () and Demiray, Tulek, and Yilmaz () in the drying of tomatoes. On the other hand, carotenoid retention has been shown to decrease with longer processing time, higher processing temperature, and cutting or puréeing of the food regardless of the processing method.…”

Section: Discussionsupporting

confidence: 91%

“…The beta‐carotene content of manyire green (29 mg/100 g db) is comparable to tomato as reported by Mwende et al. (). On the other hand, the beta‐carotene content reported in this study (Table ) is higher compared to previous reports by Chepngeno, Owino, Kinyuru, and Nenguwo () and Msogoya, Majubwa, and Maerere () on African eggplants.…”

Section: Discussionsupporting

confidence: 82%

“…This may be attributed to its larger surface area due to its semi-long shape. Studies have shown that most phenolic compounds are concentrated in the skin surface of fruits (Dadalı, Kılıç Apar, & Özbek, 2007 as reported by Mwende et al (2018). On the other hand, the betacarotene content reported in this study (Table 2) is higher compared to previous reports by Chepngeno, Owino, Kinyuru, and Nenguwo (2016) and Msogoya, Majubwa, and Maerere (2014) on African eggplants.…”

Section: Discussioncontrasting

confidence: 69%

“…Therefore, the choice of the drying method and optimization of the drying process are important for bioactive compound retention (Akdaş & Başlar, ). Several studies have described the drying characteristics of various vegetable products such as tomato (Kingsly, Singh, Goyal, & Singh, ; Movagharnejad & Nikzad, ; Mwende, Owino, & Imathiu, ), red chilli (Hossain, Woods, & Bala, ), sweet pepper (Vengaiah & Pandey, ), okra (Doymaz, ), carrot (Zielinska & Markowski, ), and common eggplant (Doymaz & Göl, ). However, information on drying of African eggplant is scanty.…”

Section: Introductionmentioning

confidence: 99%

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Effect of drying methods on the retention of bioactive compounds in African eggplant

Mbondo

Owino

Ambuko

et al. 2018

Food Science & Nutrition

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African eggplants (Solanum aethiopicum L.) are a rich source of bioactive compounds and functional constituents that are beneficial to human health. However, the short shelf life of these vegetables can be a major cause of postharvest losses especially during peak harvesting season. Drying is one of the most convenient technologies for the production of shelf stable food products. However, drying can lead to considerable loss of the available bioactive compounds due to thermal degradation depending on the drying method and temperature conditions. This study investigated the effect of four drying methods (solar, oven, vacuum, and freeze) on the retention of total phenolics, beta‐carotene, antioxidant capacity, and lycopene in five African eggplant (S. aethiopicum) accessions (sangawili, manyire green, S00047A, AB2, and aubergine blanche). Samples were dried up to ~10% moisture content. The fresh and dried samples were analyzed for total phenolic content, antioxidant capacity, beta‐carotene content, and the lycopene content. In the fresh state, beta‐carotene, total phenolic content, and free radical scavenging activity ranged between 14.75 ± 0.50 and 29.50 ± 0.77 mg/100 g db, 751.21 ± 1.73 and 1,363.95 ± 2.56 mg/100 g GAE db, and 99.58 and 325.61 mg/ml db IC 50 value, respectively. The accession S00047 showed highest total phenolic content and lowest IC 50 value in the fresh samples. The results also showed that total phenolic content, antioxidant capacity, and beta‐carotene contents were significantly (p < .05) affected by drying method and drying temperature with freeze‐drying presenting the highest retention. Overall, 36.26%s–95.05% (total phenolics) and 31.44%–99.27% (beta‐carotene) were retained during freeze‐drying. Lycopene was only detected in the dried samples of the accession manyire green but absent in all the fresh samples of all the accessions. This study demonstrates that freeze‐drying was the most effective in retaining the highest bioactive compounds in African eggplants.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionsupporting

confidence: 82%

Section: Discussioncontrasting

confidence: 69%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of drying methods on the retention of bioactive compounds in African eggplant

Mbondo

Owino

Ambuko

et al. 2018

Food Science & Nutrition

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“…All collected leaf samples were oven dried for 1–2 days at 75 °C, ground to a fine powder with mortar and pestle, and further dried for 1–2 days at 75 °C. 28 Between 1.5 and 1.9 mg of each leaf sample were packed into a Costech Analytical 3.5 × 5 mm 2 tin capsule. Soil samples were oven dried for 3–4 days at 70 °C, ground to a powder, and oven dried again for another 1–2 days at 70 °C.…”

Section: Materials and Methodsmentioning

confidence: 99%

Nitrogen Isotope Composition, Nitrogen Amount, and Fruit Yield of Tomato Plants Affected by the Soil–Fertilizer Types

et al. 2018

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Tomatoes (Solanum lycopersicum) are heavy nutrient feeding crops and require high amounts of nitrogen to maximize fruit production. The type of nitrogen applied and timing of fertilizer applications are important to reduce losses due to volatilization and leaching. Previous research suggested that nitrogen stable isotopes are a useful fingerprinting system for indicating if a crop has been grown with synthetic or organic nitrogen applications. To study the effects of fertilization systems on nitrogen isotopic patterns, “Better Bush” tomatoes were grown in a 2 year greenhouse experiment to analyze nitrogen isotopic composition, nitrogen content, and fruit yield. Three main soil fertility treatments were evaluated, and the results were compared to those obtained on plants grown in unfertilized soil: conventional inorganic (synthetic Miracle Grow (MG)), organic (bonemeal and bloodmeal (BB), BB with liquid Earth Juice (BBL), BB with 25% vermicompost (VC), BBL with 25% VC, and 25% VC), and mixed (MG with 25% VC). The soil fertilizers, treated and untreated soil, immature and mature leaflets tomato fruit peels, and fruit juices were analyzed for both nitrogen isotope ratios and nitrogen concentrations. Plant δ15Nair decreased in the order organic treatment-no fertilizer-mixed treatment-conventional treatment. The average δ15Nair values in leaves, fruit peels, and juice from plants grown with organic treatments ranged from 4.5 to 11.9, 5.4 to 10.1, and 6.1 to 11.1‰, respectively, whereas in the case of the inorganic treatment, the average δ15Nair values varied between −3.0 and 0.4, −1.1 and 0.4, and −0.9 and 1.9‰, respectively. Plant nitrogen concentrations in tomato decreased in the following order (from highest to lowest): inorganic soil fertility treatment, mixed treatments, and organic and control (no fertilizer) treatment. The average weight %N values in leaves and fruit peels from plants grown with organic treatments ranged from 1.3 to 4.2 and 1.1 to 2.3%, respectively, whereas in the case of the inorganic treatment, the average weight %N values varied between 3.7 and 5 and 1.3 and 2.8%, respectively. Plants grown under organic treatments have higher δ15Nair, lower weight %N, and are enriched in 15N compared with the original soil than plants grown with inorganic fertilizer, suggesting that the synthetic nitrogen sources are more readily available for plant uptake than the organic ones. The addition of vermicompost increases both δ15Nair and weight %N in plants. Tomato fruit yields did not differ between cluster 1 and cluster 2 harvest, however, total tomato fruit yields differed indicating that synthetically fertilized plants produced the highest total yields (g) (P ≤ 0.05). However, all treatments with VC soil applications indicated an increase in the amount of plant nitrogen, fruit yield, soil cation exchange capacity, soil organic matter content, and released soil nitrogen. Nitrogen isotope ratios of tomatoes can be used to distinguish among various soil fertility treatments, therefore fingerprinting the organ...

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Effect of packaging materials on lycopene vitamin C and water activity of dried tomato (Lycopersicon esculentum Mill.) powder during storage

Dufera

Hofäcker

Esper³

et al. 2023

Food Science & Nutrition

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In this work, a storage study was conducted to find suitable packaging material for tomato powder storage. Experiments were laid out in a single factor completely randomized design (CRD) to study the effect of packaging materials on lycopene, vitamin C moisture content, and water activity of tomato powder; The factor (packaging materials) has three levels (low‐density polyethylene bag, polypropylene bottle, wrapped with aluminum foils, and packed in low‐density polyethylene bag) and is replicated three times. During the study, a twin layer solar tunnel dried tomato slices of var. Galilea was used. The dried tomato slices were then ground and packed (40 g each) in the packaging materials and stored at room temperature. Samples were drawn from the packages at 2‐month interval for quality analysis and SAS (version 9.2) software was used for statistical analysis. From the result, higher retention of lycopene (80.13%) and vitamin C (49.32%) and a nonsignificant increase in moisture content and water activity were observed for tomato powder packed in polypropylene bottles after 6 months of storage. For low‐density polyethylene packed samples and samples wrapped with aluminum foil and packed in a low‐density polyethylene bag, 57.06% and 60.45% lycopene retention and 42.9% and 49.23% Vitamin C retention were observed, respectively, after 6 months of storage. Considering the results found, it can be concluded that lycopene and vitamin C content of twin layer solar tunnel dried tomato powder can be preserved at ambient temperature storage by packing in a polypropylene bottle with a safe range of moisture content and water activity levels for 6 months.

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Effects of pretreatment during drying on the antioxidant properties and color of selected tomato varieties

Cited by 28 publications

References 25 publications

Effect of drying methods on the retention of bioactive compounds in African eggplant

Effect of drying methods on the retention of bioactive compounds in African eggplant

Nitrogen Isotope Composition, Nitrogen Amount, and Fruit Yield of Tomato Plants Affected by the Soil–Fertilizer Types

Effect of packaging materials on lycopene vitamin C and water activity of dried tomato (Lycopersicon esculentum Mill.) powder during storage

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