Total Lycopene Content Research Articles

Vigorous rootstocks improve yields and increase fruit sizes in grafted fresh market tomatoes

Grafting high yielding tomato cultivars (Solanum lycopersicum L.) onto vigorous rootstocks can increase marketable yields, but questions remain regarding optimal cultural and growing conditions such as pinching and plant spacing. This study addressed some of the dynamics between grafted plants and cultural practices. Two scions, ‘Tasti-Lee’ (TL) and ‘Mountain Fresh Plus’ (MFP) were grafted onto each of three rootstocks, ‘Beaufort’, ‘Arnold’, and ‘Shield’. Plants were pinched (removal of main shoot to induce both axillary shoots to grow) or non-pinched, and spaced at 56 or 61 cm. All 32 grafted treatments were compared to the grower standard: non-grafted TL and MFP spaced at 46 cm, which were non-pinched. Fruit quality traits including soluble solids content, pH, lycopene concentration, and titratable acidity were recorded for fruit harvested from tomatoes grafted onto ‘Arnold’, ‘Beaufort’, ‘Shield’ and non-grafted TL. The overall effect of grafting TL and MFP onto vigorous rootstocks ‘Arnold’, ‘Beaufort’, and ‘Fortamino’ increased marketable yields per hectare by 24-35% compared to non-grafted grower standards. The rootstock ‘Shield’ did not significantly increase yields with either scion. TL had a more positive response to grafting than MFP. ‘Arnold’, ‘Beaufort’, and ‘Fortamino’ significantly increased TL fruit size, but the fruit size results were not as significantly impacted by graft treatments for MFP. Plants spaced at 56 compared to 61 cm generated similar yields. Pinched plants significantly increased yields over non-pinched plants by 15% in 2018 but did not impact yield in 2017. No consistent difference was observed between pinched and non-pinched plants with regard to fruit size, only plants grafted with ‘Shield’ benefited significantly from being pinched. Soluble solids content, pH, total lycopene concentration, and titratable acidity differed slightly between grafted and non-grafted plants but was unlikely to positively or negatively affect overall perception of fruit quality in tomatoes. A partial budget analysis revealed that grafting with ‘Arnold’ or ‘Beaufort’ consistently increased profits in this low-disease field.

Effect of UV-LED irradiation processing on pectolytic activity and quality in tomato (Solanum lycopersicum) juice

The aim of this research was to analyze pectolytic activities (pectinmethylesterase “PME” and polygalacturonase “PG”) and physical qualities in tomato juice treated by UV-LED, Hot Break (HB), and Cold Break (CB) processing. Tomato juice treated by UV-LED (117 mJ/cm2) obtained a residual PME activity similar to that of CB, and tomato juice treated by UV-LED (351 mJ / cm2) had a residual PME activity 28.3% lower than HB (p < 0.05). The effect of UV-LED on PG activity was similar to HB and 49% lower than CB (p < 0.05). Furthermore, UV-LED processing caused a decrease in pH and total acidity and a significant increase in total lycopene content. Antioxidant activity and viscosity for UV-LED processing were similar to CB, total polyphenol content and °Brix were similar to HB (p > 0.05). Therefore, this study provides a promising application of UV-LED technology for controlling enzymatic activity in tomato juice, and an alternative to heat treatment. Industrial relevanceNowadays, the tomato industry uses heat treatments to inactivate pectolytic enzymes. UV-LED technology could have an industrial appreciation, as it was efficient in decrease the activity of these enzymes, in addition, preserved and increased some bioactive compounds. Therfore, it is proposed as an efficient method for processing fruit and vegetable juices. Nevertheless, further studies are needed to clarify the effect of this technology on pectolytic enzymes and quality parameters in liquid fruit and vegetable foods.

Non-volatile and volatile metabolic profiling of tomato juice processed by high-hydrostatic-pressure and high-temperature short-time

High hydrostatic pressure (HHP) processing has become a commercial success in fruit and vegetable processing. Herein, the effects of HHP and high-temperature short-time (HTST) processing on metabolic profiling in tomato juice was evaluated by UPLC–MS/MS, HPLC, and GC–MS; a total of 425 metabolites, 14 carotenoids, and 56 volatile compounds were identified in tomato juice. HHP processing affects the composition of the juice less than HTST processing, considering 4 and 33 differential metabolites discriminated after HHP and HTST processing, respectively. The total lycopene and carotenoid contents in tomato juice increased after HHP processing, while the β-carotene and lycopene contents decreased after HTST processing. Further, more volatile compounds and higher contents of aldehydes that contribute to green aroma and lower contents of alcohols were observed after HHP and HTST processing, respectively. These findings provide a comprehensive understanding of the advantages of HHP processing on metabolite profiles in tomato juice.

Postharvest spraying of zinc oxide nanoparticles enhances shelf life qualities and zinc concentration of tomato fruits

Plant growth relies on the bioavailability of essential nutrients in the growth environment. Access to mineral nutrients is particularly challenging for crops cultivated in alkaline soil, and in these environments, postharvest application may be effective. Advancements in nanotechnology have provided approaches to improve the essential nutrient content of plants and shelf life of produce. Mineralisation by nanoparticles is a promising postharvest technique that can fortify the essential minerals of plants. This study investigated the role of zinc oxide nanoparticles (ZnO-NPs) as a potential nano-agent to enhance Zn content in tomato (Solanum lycopersicum L.), with ZnO-NPs at 100 mg L–1 applied externally to tomatoes postharvest for 4 weeks. The assimilation of Zn into the tomato tissues was quantified by inductively coupled plasma-mass spectrometry. The main shelf life factors affecting tomato quality, including microbial spoilage, water loss and colour change, were studied. All experimental data were incorporated through the neural networks model to simulate microbial involvement in fruit spoilage. The biological spoilage factor in the shelf life of tomatoes was projected with high accuracy and a relative error of 3%. Application of ZnO-NPs was associated with 47% inhibition of microbial growth on tomatoes, which may enhance the total lycopene content by up to 6%. In addition, the Zn content of tomatoes was significantly enhanced by 17%. The results also shed light on the thermal conductivity of Zn metal, which increased the dehydration of tomatoes and improved colour maturation. This study provides vital information about the beneficial application of ZnO-NPs and their role in mineralisation to enhance the shelf life of tomatoes.

Preliminary Investigation on the Physicochemical and Functional Properties of Commercial Salmorejo Found in Spanish Supermarkets.

Salmorejo is a traditional Spanish food made of raw tomatoes, bread, garlic, and virgin olive oil. The food industry aims to satisfy consumer demand for ready-to-eat salmorejo while trying to maintain characteristics of the homemade product. In this work, we have assessed physical-chemical and color parameters, radical scavenging activity, and total polyphenol, lycopene, and β-carotene contents of raw and pasteurized commercial salmorejo, as well as homemade (raw) salmorejo samples. Our results showed that heat treatment had a significant influence on color parameters of salmorejo, with pasteurized samples being less red and exhibiting an increase in the degree of browning. Pasteurized samples also showed the highest radical scavenging activity when expressing the results per dry weight. However, when water content was considered, radical scavenging activity was superior in homemade samples when analyzing non-polar molecules extracted with acetone. Results were similar for polyphenol content. It was also observed that heat treatment affected lycopene but not β-carotene content. When acquiring commercial salmorejo at the supermarket, consumers have the option to choose between already prepared pasteurized or raw salmorejo. According to the results obtained in this work, physicochemical and functional properties of commercial raw salmorejo were comparable to a larger extent than pasteurized salmorejo compared to those exhibited by homemade salmorejo samples.

Tomato growth, yield, and quality response to mixed chemical–organic fertilizers and grafting treatments in a high tunnel environment

Tomato (Solanum lycopersicum L.) is a major vegetable crop world-wide and grown in high tunnels in many regions. This study investigates the use of two fertilizer sources, chemical and integrated (composted poultry manure plus urea) fertilizers, and grafting on growth, nitrate-N content, yield, and fruit quality of tomato grown in high tunnels in northwestern Washington. Grafting treatments consisted of ‘Panzer’ tomato grafted on one of three tomato rootstocks ‘Estamino’, Maxifort’, ‘DRO138TX’, or non-grafted (control). Application of chemical fertilizer increased number of leaves per plant, plant height, and cumulative fresh biomass of pruned suckers relative to tomato plants grown with the integrated fertilizer treatment. Grafted tomato plants had greater plant growth than non-grafted plants throughout the growing season. There was no significant difference between fertilizer treatments on nitrate-N concentration in plant tissue or fresh petiole sap; however, grafted plants contained higher levels of nitrate-N than non-grafted plants. Total and marketable fruit weight and number did not differ due to fertilizer source, but total and marketable fruit weight was higher for grafted plants than for non-grafted plants in 2016. There was no significant effect due to fertilizer source on fruit firmness, water content, pH, titratable acidity, and β-carotene; however, total soluble solids (TSS) and lycopene content were higher for fruit grown with integrated fertilizer in 2016. Grafting enhanced water content of tomato fruit in 2015, and TSS (°Brix) in 2016.

Composition and Antioxidant Activity, Supercritical Carbon Dioxide Extraction Extracts, and Residue after Extraction of Biologically Active Compounds from Freeze-Dried Tomato Matrix

Supercritical carbon dioxide extraction (SCE-CO2) is an attractive, green technology that is used for the recovery of biologically active compounds from plant material. The antioxidant potential of lipophilic fractions (extract obtained with SCE-CO2) and hydrophilic fractions (extracts obtained from the residue after extraction) obtained from a matrix of freeze-dried tomatoes (cvs. “Admiro” F1, “Jurgiai”, “Vilina”, “Pirmutis”, and “Skariai”) was assessed via different antioxidant activity methods. The total amount of polyphenols, carotenoids, and carotenoid isomers before and after SCE-CO2 extraction was also determined. To investigate the effect of the SCE-CO2 extract on the viability of cancer cells, rat glioblastoma C6 cells were chosen. The SCE-CO2 yielded an average of 800 mg of lipophilic fraction per 100 g of freeze-dried tomatoes. The ABTS•+ scavenging activity of the extract was 251 ± 3.4 µmol TE/g. After SCE-CO2 extraction, the DPPH•-RSA of the freeze-dried tomato matrix was 7 to 12% higher. There was a strong positive correlation (R = 0.84) between the total polyphenolics content and the DPPH•-RSA of the tomato samples. The SCE-CO2 increased the radical scavenging activity of the extraction residue, indicating that a considerable fraction of the hydrophilic compounds with particular antioxidant capacity remain unextracted from the tomato matrix. Our results reveal the cytotoxic effect of lycopene extract rich in cis-isomers (62% cis-isomers of the total lycopene content) on rat glioblastoma C6 cells. The viability of the glioblastoma C6 cells significantly decreased (−42%) at a total lycopene concentration of 2.4 µM after 24 h of incubation.

Yield, Quality and Nutrient Content of Tomato in Response to Soil Drenching of Silicic Acid

Although the role of silicon (Si) in enhancing crop performance has been proven in many field crops including rice, wheat, sugarcane and soybean, its influence on Si non-accumulator crops like tomato is very much limited. In order to evaluate the effect of silicic acid on tomato, a field experiment was conducted during summer 2018. The experiment consisted of with and without silicic acid treatments to test the efficacy of silicic acid soil drenching on yield, quality and nutrient content of tomato. The results revealed that soil drenching of silicic acid @ 4 ml L−1 at 15, 30 and 45 days after planting significantly increased the yield attributes, viz. number of fruits per plant (41.42 ± 2.77), fruit yield per plant (2.34 ± 0.05 kg) and fruit yield per hectare (86.66 ± 1.74 t) over control. Silicic acid soil drenching significantly enhanced the quality parameters in tomato. The total soluble solids (TSS) and lycopene content of tomato significantly improved with drenching of silicic acid @ 4 ml L−1 over control from 3.55 ± 0.23 to 4.23 ± 0.21 Brix and 4.65 ± 0.66 to 6.34 ± 0.22 mg 100 g−1 fruit, respectively, but significantly decreased the titratable acidity (0.45 ± 0.08 per cent) of tomato over control (0.63 ± 0.03 per cent) and enhanced major and micronutrients contents apart from Si. Thus, soil drenching of silicic acid @ 4 ml L−1 has found to be a novel way to enhance yield, quality and nutrient content of tomato.

Biocontrol efficacy of Trichoderma asperellum-enriched coconut fibre against Fusarium wilts of cherry tomato.

Agro-based wastes were evaluated as a medium for mass micropropagule production and optimal efficacy of Trichoderma asperellum B1092 in controlling Fusarium oxysporum f. sp. lycopersici and promoting tomato growth. This study focused on biological control because pathogen persistence in the soil makes the disease difficult to control. Rice bran, biochar, empty fruit bunches, coconut fibres, compost, top soil and mixed soil were evaluated as media for mass multiplication of T. asperellum, which is effective in controlling plant pathogens. Yielding the most colony forming units (CFU) among the media, coconut fibre was deemed most suitable for promoting sporulation. After 120days on the medium, T. asperellum B1902 produced 9·053×105 CFU per gram coconut fibre; oil palm empty fruit bunches was second highest (7·406×105 CFU per gram). In field tests of T. asperellum B1092 against F. oxysporum f. sp lycopersici (causing Fusarium wilt of cherry tomato), B1092 significantly promoted plant growth compared to the control. The efficacy of this formulation resulted in increased growth of roots and shoots tomato plants and total lycopene, sugar, K, N, Ca, P and Mg content after 120days. Trichoderma asperellum B1092 showed great field potential for improving productivity and quality of tomatoes and in controlling Fusarium wilt of cherry tomato. This innovative approach using a cheap agro-waste to control the persistent soil-borne Fusarium pathogen of cherry tomato should increase soil survival rate of Trichoderma and has potential for upscaling in the field for other crops.

Z-Isomers of lycopene exhibit greater liver accumulation than the all-E-isomer in mice.

The effect of oral administration of all-E-isomer-rich and Z-isomer-rich lycopene on liver accumulation in mice was investigated. When a diet rich in the Z-isomers was administered for 4 weeks, the total lycopene concentration in the liver was more than 3 times higher than that of all-E-isomer administration. This result clearly indicates that lycopene Z-isomers show greater bioavailability and/or liver accumulation than the all-E-isomer in mice.

Phytochemical analysis, antioxidant, antibacterial and antidiarrheal activities of Limnophila repens

The study was carried out to determine the phytochemical content, antioxidant, antibacterial and antidiarrheal activity of methanolic extract of whole plant of Limnophila repens . The total phenolic, flavonoids, flavonols, tannins, β-carotene, lycopene, chlorophyll-α, and chlorophyll-β contents were found to be 65.21 ± 0.004 mg GAE/g , 44.83 ± 0.003 mg QE/g , 17.21 ± 0.002 mg QE/g, 56.27 ± 0.002 mg GAE/g , 1.32 ± 0.01 µg/g, 0.93 ± 0.012 µg/g, 11.85 ± 0.04 mg/g and 9.69 ± 0.037 mg/g, respectively. In vitro antioxidant potential of L. repens was assessed using various methods like by 2,2-diphenyl-1 picrylhydrazyl (DPPH), hydroxyl radical scavenging assay, reducing power assay, FRAP assay and thiobarbituric acid assay. IC 50 values of the aforesaid tests were found to be 2.33 mg/ml, 442.31 µg/ml, 374 µg/ml, 55.09 µg/ml, and 4.30 mg/ml, respectively. The total antioxidant capacity was observed 140.7 ± 0.004 mg/g AAE. Aantibacterial activity of the methanolic extracts of whole plant of L. repens was evaluated using the disk diffusion method. The plant extract didn’t show any activity against Gram-positive (except Staphylococcus aureus ) and Gram-negative bacteria. Finally, castor oil induced method was conducted to investigate the antidiarrheal activity of L. repens . At the dose of 400 mg/kg, the plant extract (35.62% inhibition of diarrhea) exhibited stronger effect compared to standard drug, loperamide (27.4% inhibition of diarrhea).

High pressure homogenization versus ultrasound treatment of tomato juice: Effects on stability and in vitro bioaccessibility of carotenoids

The effect of high pressure homogenization (HPH) and ultrasound treatments on the stability and bioaccessibility of tomato juice were investigated. Maximum total lycopene content (777 μg/100 g) was achieved at pressure of 200 bar after HPH treatment, and severe lycopene degradation (48%) was observed as the pressure increased to 500 bar. Meanwhile, ultrasound increased total lycopene to 921 μg/100 g fresh weight at power of 400 W. Both HPH and ultrasound treatments changed the bioaccessibility of total lycopene (1.43 folds and 1.76 folds, respectively) and ζ-carotene (1.06 folds and 0.95 folds, respectively). The increase in lycopene bioaccessibility was attributed to the isomerization of all-trans lycopene and cell breakage induced by HPH and ultrasound treatments. Additionally, the antioxidant activities of tomato juice and digesta were slightly influenced by HPH and ultrasound process. The HPH and ultrasound treatments caused significantly difference to the quality of tomato juice and ultrasound treatment could be a promising technology for obtaining tomato juice with higher bioaccessibility and carotenoid content.

Heterosis for growth, yield and fruit quality traits in papaya

An experiment was conducted during 2016–2017 to determine the magnitude of heterosis in papaya for growth, yield and fruit quality traits. A total of eight genotypes consisting three hybrids along with their five parents were evaluated in a Randomized Block Design with three replications. Appreciable heterosis was found over better over mid parent in traits like days to fruit maturity, number of fruits per plant, fruit yield, fruit shelf life, fruit firmness, antioxidant activity of fruit, total carotenoid content and lycopene content in desirable direction. A hybrid, of progeny of Red Lady (Self) × Pusa Nanha (14.57%) showed significant relative heterosis for yield, whereas none of the hybrids were recorded with better parent heterosis. Two hybrids, Red Lady (Self) × Pusa Nanha (2.93%) and Pune Selection 3 × P-7-9 (22.13%) was observed with high heterosis for number of fruits per plant. All three hybrids exhibited heterosis in negative direction for days to fruit maturity. For fruit shelf life at ambient temperature, hybrid Red Lady (Self) × P-9-5 (3.12%) exhibited better parent heterosis, whereas all three hybrids showed positive mid parent heterosis for the same trait. All three hybrids showed positive mid-parent heterosis for traits like number of fruits per plant, shelf-life, total phenolic content and antioxidant activity. The hybrid Red Lady (Self) × Pusa Nanha exhibited better parent and mid parent heterosis for total carotenoid and lycopene content along with total phenolic content and antioxidant activity. Moreover, none of the hybrids showed positive heterosis for TSS, leaf length, fruit weight, fruit diameter and fruit length. However, hybrid Red Lady (Self) × Pusa Nanha has shown moderate heterosis for important economic traits and same may be exploited further to develop a commercial hybrid of papaya.

Quality parameters of tomatoes submitted to different doses of gamma radiation

Abstract Ionizing radiation can be used for different purposes in the food industry. In this study, the effect of irradiation doses (0, 0.5, 1.0 and 1.5 kGy) on the quality parameters of long life tomatoes (Lycopersicon esculentum Mill.), was evaluated during 4 storage periods (1, 7, 14 and 21 days). The different treatments were evaluated by analysing for colour, pH, total soluble solids (TSS), total titratable acidity (TTA), ratio (TSS/TTA), hardness, total lycopene and ascorbic acid contents, weight loss and maturation stage (O2 /CO2 ratio) for all the storage periods. The tomato samples were irradiated in a Co60 irradiator and maintained at 22 °C ± 1 °C. The quality of the tomato fruits was influenced by the gamma radiation basically by making the fruits softer and not degrading the ascorbic acid and lycopene contents at the doses evaluated. The irradiation process used in the doses evaluated was promising with respect to maintaining the quality parameters of long life tomatoes.

Optimization of drum drying parameters for gac powder

Gac (Momordica cochinchinensis Spreng.) is a tropical fruit which contains a rich nutrient source, especially lycopene. However, fresh gac fruit can spoil rapidly due to its high moisture content. Drum drying is a process to remove moisture from food in order to preserve nutrients and extend shelf life. In this study, gac fruit powder was produced by using drum drying technique. The present research was aimed to determine the optimum drum drying condition for gac powder. Response Surface Methodology was employed with three processing variables, including drum surface drying temperature (115, 125, 135˚C) maltodextrin content (100, 150, 200%) and gum arabic content (10, 20, 30%). The response variables were moisture content, solubility, hygroscopicity, total phenolic content and lycopene content of gac fruit powder. Regression analysis was then performed to obtain the mathematical relation between the processing variables and the responses in the form of second-order polynomial equations.. The results showed that optimum conditions for drum drying of gac fruit was at 135˚C of drum surface drying temperature, 138% of added maltodextrin and 10% of added gum arabic, which provided the highest amount of total phenolic and lycopene content.

Physiological characterization of SUB1 trait in rice under subsequent submergence and re-aeration with interaction of chemical elicitors

In the present study, the sensitivity of two chemical elicitors: polyamine (PA) and salicylic (SA) acid were exercised for submergence sensitivity in Swarna Sub1A rice variety. Under 5 days of submergence, the antioxidation responses were more distinguished in plants against control. Along with the anti-oxidation modules, significant changes in biomolecule loss were registered through lipid and protein oxidation by 1.91 and 1.46 -fold respectively. PA and SA treated plants were the reliever to recover the membrane potential. Total carbohydrate and reducing sugars were varied under submergence by down regulation of 36.66 and 44.44% as compared to control. This was also supported by regulation of ?-amylase activity under submergence that also recovered significantly with PA and SA treatments against submergence. In association with carbohydrate metabolism, Under submergence Swarna Sub1A recorded to be prone with oxidative stress through O2.- (1.55 fold) and peroxide (1.70-fold) over-accumulation but recovered as PA and SA applied. In both cases, sustenance of non-enzymatic anti-oxidant like total carotenoid and lycopene content were also contributory through down-regulation. The enzymatic anti-oxidation paths like SOD, GPX, CAT and GR were regulated by 11.11, 19.54, 13.65, 10.03% declined respectively and thoroughly discussed with reference to PA and SA interactions.

Proximate analysis and total lycopene content of some tomato cultivars obtained from Kano State, Nigeria

Standard analytical techniques were employed to determine the proximate composition and lycopene content of three tomato cultivars namely: Roma VF, Ronita and UTC grown in six local government areas of Kano state, Nigeria. Results indicated mean values of 0.15±0.03, 0.16±0.01, 0.15±0.01% titratable acidity; 8.36±0.01, 8.14±0.02, 8.25±0.03% total soluble solids; 1.19±0.04, 1.25±0.03, 1.12±0.01% crude fiber; 2.26±0.05, 2.32±0.02, 2.60±0.02% crude protein; 0.18±0.01, 0.14±0.01, 0.14±0.02% ash content; 90.75±0.03, 88.43±0.04, 84.15±0.01% moisture content; 3.73±0.09, 4.59±0.09, 4.34±0.18 mg/100g vitamin C and 6.88±0.06, 6.88±0.02, 7.83±0.04 mg/100g lycopene content for Roma VF, Ronita and UTC respectively. The levels of the proximate parameters and lycopene contents have shown that the cultivars were of high nutritional quality and can be good sources of raw material for industrial use due to their high total soluble solids which are twice the minimum level recommended for tomato to be employed for industrial processing. Keywords: Antioxidant, lycopene content, proximate composition, tomato cultivars

Recovery and Isomerization of Carotenoids from Tomato Processing By-products

Industrial tomato processing by-products are intended mainly for animal feed or fertilizer, though they can be used for the recovery of valuable constituents. Carotenoids constitute an important component of these by-products, well credited with important health-promoting functions. This study examined the effect of several organic solvents (hexane, ethanol, acetone, ethyl acetate, ethyl lactate and their mixtures), and extraction temperature on the recovery and isomerization of carotenoids from tomato processing by-products. Another area under investigation was the stability of carotenoids, as affected by drying and storage conditions of tomato by-products. HPLC–DAD analysis was applied for the efficient separation and analysis of the carotenoids and their cis-isomers. The highest extraction yield was obtained with ethyl lactate (203.6 μg/g dry by-product) followed by hexane–ethyl acetate mixture with a considerably lower yield (36.1 μg/g dry by-product). The identified carotenoids in all solvent extracts followed the order: lycopene ≫ β-carotene > lutein, in their predominant trans-configuration. Among the identified isomers, 5-cis lycopene and 15-cis-β-carotene were the most abundant in all extracts. The increase of extraction temperature increased the total lycopene concentration in all extracts, whereas cis-isomers remained lower than 8 % in most solvents. A steadily high percentage of cis-isomer (≈30 %) was observed in ethyl lactate extracts, independent of temperature. Conversely, the increase of extraction temperature induced a reduction in total β-carotene and total lutein concentration in all solvents, while cis-isomers were not detected. Drying or even cold storage of the raw material led to decreased yields, and affected lycopene isomerization with a considerable increase of cis-isomers.

Antioxidant, Total Lycopene, Ascorbic Acid and Microbial Load Estimation in Powdered Tomato Varieties Sold in Dutsin-Ma Market

Tomato varieties sold in Dutsin-Ma market namely, UTC, Rukuta and Dan-Aka were subjected to drying in a laboratory oven, solar drier and under direct sunlight then, powdered. The antioxidant and total lycopene contents were examined and found to be unaffected by the three drying procedures, with values ranging between 68.46% ± 0.90% to 80.77% ± 1.11% and 123.63 to 161.98 mg/kg, respectively. The ascorbic acid was also tested and values were significantly lower in all the samples subjected to sun-drying with values ranging from 17.78 ± 1.78 μg/ml to 28.44 ± 1.78 μg/ml as against 100.15 ± 1.03 μg/ml to 164.74 ± 2.06 μg/ml for oven and solar dried tomato samples (p < 0.05), respectively. Total microbial load, yeast/mould, and coliform counts were then investigated. They were too numerous to count (TNTC) in the sun-dried samples. Although, also found among samples that were oven and solar dried, counts of the microorganisms were within the acceptable standards of <105 for bacteria and 103 - 104 for fungi. While solar and oven drying presented better preservation of the tomato samples, the former offers most incentive in terms of cost and quality to farmers and the people, considering its free availability and abundance in processing dry tomato powders.

Home processing of tomatoes (Solanum lycopersicum): effects onin vitrobioaccessibility of total lycopene, phenolics, flavonoids, and antioxidant capacity

In order to investigate the effect of home processing on the bioaccessibility of health-related constituents of tomatoes, total lycopene, phenolics, flavonoids and antioxidant capacity were determined from seven different tomato products using an in vitro gastrointestinal digestion model. Additionally, the changes in the contents of the major tomato phenolics were determined and compared for these different tomato products using HPLC. The results revealed that paste processing and drying significantly increased the bioaccessible total lycopene content (2.2- and 3.8-fold, respectively), total phenolic content (2.3- and 2.0-fold, respectively), total flavonoid content (9.0- and 2.5-fold, respectively) and total antioxidant capacity (6.3- and 8.0-fold for the DPPH assay, 26- and 33-fold for the CUPRAC assay, respectively) (P < 0.05) compared to fresh tomatoes. HPLC analysis revealed significantly lower (P < 0.05) rutin content in puree and juice. The loss of naringenin chalcone in some tomato products, as well as its conversion into naringenin in heat-treated products was observed. The current study provided valuable insights into the changes in the content and bioaccessibility of tomato antioxidants as a result of home processing.