Water-soluble Antioxidant Activity Research Articles

Influence of drying methods on total phenolics, total flavonoids and antioxidant activities in the gurmar leaf (Gymnema inodorum (Lour.) Decne.) powder

The effect of different drying methods on moisture contents, total phenolics, flavonoids and antioxidant activities in the gurmar leaf (Gymnema inodorum (Lour.) Decne.) powder was studied. These drying methods were shade drying and hot air drying at 40 ∞C – 60 ∞C for 3 – 5 h. The percentage of moisture content in powder was 3.15 – 4.83 and the water activities were 0.302 – 0.407. Total phenolics, flavonoids, and antioxidant activities of the extract were analyzed. The powder was extracted by distilled water as extracting solvent with controlled temperature 80 ∞C for 45 min. The results indicated that the hot air-dried powder at 50 °C for 3 h had total phenolics, flavonoids, and antioxidant activities higher than that of the hot air-dried (40 °C for 5 h), hot air-dried (60 °C for 3 h) and shade dried powder, respectively. Total phenolic contents were 20.165, 19.800, 18.115, and 16.903 mg GAE g–1 powder, respectively. Total flavonoid contents were 5.241, 5.238, 5.024, and 4.454 mg CE g–1 powder, respectively. The DPPH free radical scavenging activities were 10.312, 9.684, 9.498, and 8.894 mg AAE g–1 powder, respectively. The ABTS+ radical scavenging activity were 8.929, 8.914, 8.844, and 8.819 mg TE g–1 powder, respectively. Total antioxidant capacities were 42.118, 39.639, 38.812, and 37.040 mg AAE g–1 powder, respectively. The reducing powers were 13.195, 13.110, 11.832, and 11.354 mg AAE g–1 powder, respectively. The drying temperature and time affected on the water-soluble phenolics, flavonoids and antioxidant activities in the water extracts of gurmar leaf powder from different drying methods.

Water-soluble phenolic compounds and their putative antioxidant activities in the seed coats from different lentil (Lens culinaris) genotypes

The seed coat is a major byproduct of lentil processing with potential as a sustainable source of antioxidant polyphenols. Profiles of water-soluble phenolic compounds and antioxidant activities of seven genotypes of lentil which includes both normal-tannin and low-tannin seed coats were investigated. Antioxidant activities were assessed using four antioxidant assays, and phenolic compounds were quantified using liquid chromatography mass spectrometry (LC-MS). Total phenolic content (TPC) varied significantly among genotypes and ranged between 1519 ± 140 and 6502 ± 154 μg/g. Thirty phenolic compounds were identified with kaempferol tetraglycoside, catechin-3-glucoside and procyanidins being the dominant compounds in normal-tannin seed coats. Kaempferol tetraglycoside predominated (80–90%) in low-tannin seed coats. Antioxidant activities strongly correlated with TPC (r > 0.93) with a 6–9 times higher activity in normal-tannin than that of low-tannin lentils. Without flavan-3-ols and procyanidins, low-tannin seed coat may not exert strong antioxidant potential, whereas normal-tannin seed coat contains water-extractable natural phenolic compounds with promising antioxidant potential.

Effect of drying methods on the water soluble phenolics, flavonoids and antioxidant activities in baby jackfruit leaves (Momordica cochinchinensis (Lour.) Spreng.) powder

The study of effect of drying methods on the water soluble phenolics contents and antioxidant activities in baby jackfruit leaves (Momordica cochinchinensis (Lour.) Spreng.; MC) powder were investigated. Three different drying methods were sun drying, hot air drying at 60 °C for 6 h and 8 h. The powder samples were extracted by water as extracting solvent with control 80 °C for 45 min. The extract samples had phytochemicals such as saponin, tannin and terpenoid, phenolics and flavonoids which were analyzed the total phenolics and flavonoids contents. The results found that total phenolics contents were 12.03, 7.78, and 7.08 mg GAE g–1 powder and total flavonoids contents were 6.41, 3.49, and 3.35 mg CE g–1 powder, respectively. Then, DPPH free radical scavenging activities, ABTS free radical scavenging activities, total antioxidant capacities and reducing powers were investigated. The results showed that DPPH free radical scavenging activities were 6.40, 3.23, and 2.56 mg AAE g–1 powder, respectively. ABTS free radical scavenging activities were 17.76, 13.46, and 12.42 mg AAE g–1 powder, respectively. Total antioxidant capacities were 28.58, 26.87, and 26.23 mg AAE g–1 powder and reducing powers were 5.02, 2.72, and 2.43 mg AAE g–1 powder, respectively. The results indicated that the sun dried MC powder showed the values of phytochemicals, phenolics, flavonoids and antioxidant activities higher than the hot air dried MC powder at 60 °C 6 h and 8 h. The drying temperature and time were effect on the water soluble effective compounds and antioxidant activities in baby jackfruit leaves (Momordica cochinchinensis (Lour.) Spreng.) powder. HIGHLIGHTS The study of effect of drying methods on the water soluble phenolics contents and antioxidant activities in baby jackfruit leaves (Momordica cochinchinensis (Lour.) Spreng.; MC) powder were investigated. GRAPHICAL ABSTRACT

Optimization of Fermentation Process for Water-soluble Polysaccharides and Antioxidant Activity of Polygonatum odoratum Fermentated by Bacillus subtilis LY-05

Optimization of Fermentation Process for Water-soluble Polysaccharides and Antioxidant Activity of Polygonatum odoratum Fermentated by Bacillus subtilis LY-05

Effects of temperature-controlled ultrasound treatment on sensory properties, physical characteristics and antioxidant activity of cloudy apple juice

Cloudy apple juice were subjected to ultrasound treatments at various power levels (525, 975, and 1125 W) and temperatures (50, 60, and 70 °C). The effects of temperature-controlled ultrasound treatment (TCUT) on the microbial load, color, sensory evaluation, total soluble solids, water soluble pectin (WSP), rheological properties, stability, and antioxidant activity of cloudy apple juice were investigated. Ultrasound and thermal treatment play a synergistic role in the reduction of microbial populations and could achieve microbial safety. TCUT enhanced the sensorial properties and improved the content of WSP, while reducing the particle size. TCUT significantly improved the rheological properties and suspension stability of apple juice. Moreover, the phenol content and percentage of DPPH inhibition also increased by TCUT in apple juice. The optimized TCUT conditions was at 60 °C with 1125 W power for 12min. The juice showed inactivation of microorganisms (<1 log CFU/mL), a preferable sensory property, obvious decreasing in particle size, more WSP, and better cloudy stability.

DEVELOPMENT OF DIRECT EXPANDED HIGH PROTEIN SNACK PRODUCTS FORTIFIED WITH SACHA INCHI SEED MEAL

Direct expanded or ready-to-eat (RTE) snacks fortified with Sacha inchi (Plukenetia volubilis L.) seed meal, a by-product of oil extraction process, were developed using a co-rotating twin-screw extruder. The composite blends of various amounts of Sacha inchi seed meal (20-60%), rice flour (40-80%) were prepared for extrusion cooking at 10-15% in-barrel moisture, 10.88-15.14 kg/h of feeder speed and 400 rpm of screw speed. The final products were characterized in terms of physical properties (color, texture, density, expansion ratio, water absorption index (WAI), water soluble index (WSI), proximate compositions, sensory, in-vitro digestibility and antioxidant activities, respectively. The results indicate that level of Sacha inchi seed meal significantly affected the physical characteristics by increasing hardness and density of the snack products. Expansion ratio and WAI of the snack products were decreased by increasing the level of Sacha inchi seed meal. The sensory evaluation result shows that all snack formulations were generally accepted by consumers. The snack fortified with 40% Sacha inchi seed meal was the most acceptable product based on the overall characteristics. It contained highest protein content (24.94±0.07%) with approximately 1.79±0.16% fiber, 2.09±0.00% fat, 3.42±0.02% ash, 5.61±0.14% moisture, and 62.27±0.11% carbohydrate, respectively. Total digestibility of the snack was 41.11% in which 12.36% and 28.75% were digested in stomach and small intestine, respectively. The total phenolic content (TPC) was 205.46±11.66 mg GAE/g dry weight snack and the Trolox equivalent antioxidant capacity (TEAC) was 135.40±1.10 µmol TE/g dry weight snack. The extruded product developed from Sacha inchi seed meal is protein-rich and suitable for health-conscious consumers.

Константа скорости реакции пероксильного радикала 1,4-диоксана с α-токоферолом и тролоксом

The study of the properties of water-soluble antioxidants is of practical interest. Research is hindered by the fact that such substances are poorly soluble in substrates, which are most widespread in determining the quantitative characteristics of antioxidants. Usually it is cumene, ethylbenzene, styrene. In this work, we used a method based on a model reaction of the radical chain 1,4-dioxane oxidation. This substrate is the most suitable solvent for evaluating the water-soluble substances antioxidant activity. The inhibitory activity of α-tocopherol (vitamin E) and trolox (a water-soluble analogue of α-tocopherol) was studied in a model system of radical chain 1,4-dioxane oxidation. Air oxygen served as the oxidizing agent. The experiments were carried out at 333 K. Initiation was carried out with 2,2'-azo-bis-isobutyronitrile. The reaction kinetics was monitored by the rate of oxygen uptake using a manometric setup. In this work to measure the initiation rate, the inhibitors method is used. The standard α-tocopherol inhibitor was used for this purpose. α-Tocopherol is an effective inhibitor with a known stoichiometric inhibition ratio of two. The method used in our study makes it possible to measure correct the length of the induction period using the kinetics of oxygen absorption. The induction period was determined by graphical and integral methods. The initiation rate was calculated based on the induction period values. The resulting value is in satisfactory agreement with the data based on the literary value of the decay rate constant 2,2'-azo-bis-isobutyronitrile. The rate constant of the reaction of the 1,4-dioxane peroxyl radical with α-tocopherol and trolox (fk7, L mol-1s-1, 333 K) was measured: (1.6 ± 0.1)∙106, (1.2 ± 0.1)∙106. The stoichiometric inhibition coefficient for trolox in the system of radical chain 1,4-dioxane oxidation was determined: f = 2.4 ± 0.2.

Ultrasound Treatment of Buckwheat Grains Impacts Important Functional Properties of Resulting Flour.

The benefit of not containing the gluten complex protein also provides problems with the achievement of typical and proper texture, especially in bakery products. Ultrasound (US) treatment has been previously studied on buckwheat as assistance treatment facilitating the release of antioxidant compounds. However, there is no study regarding the changes occurring in US-treated buckwheat grains regarding the structure-creating capacity, like water absorption, gelling, and pasting. The aim of this study is to the impact of US-treatment of buckwheat grains at 1:10, 1:5, and 1:2.5 solid:liquid ratio (in water). The particle size distribution, water absorption index (WAI), water solubility index (WSI), swelling power (SP), pasting characteristics, color, soluble, insoluble and total polyphenols content (SPC, IPC, TPC) and antioxidant activity (DPPH) were assessed in resulting flours. US-treatment caused specific agglomeration, resulting in bigger particles for 1:5, and 1:2.5 ratio treated samples, while higher dilution (1:10) increased smaller particle size fractions. The WAI and SP were the highest for the1:5 solid:liquid ratio sample, and the same sample revealed the highest peak viscosity, breakdown, and setback values. The ultrasound treatment increased the WSI, which was positively correlated with insoluble polyphenols content. The soluble polyphenols content decreased, and insoluble polyphenols content increased in all ultrasound treated samples. The DPPH scavenging activity remaining in grain after US treatment was lowered compared to the control sample. The relocation of pigments resulted in a redness and yellowish increase in all treated samples, while lightness was also increased but was most pronounced for a 1:10 ratio treated sample. The results suggest that ultrasound treatment of grain can improve the essential functional properties of buckwheat flour.

Отходы чайного производства как дополнительный ресурс биологически активных веществ

Листья чая являются уникальным источником разнообразных биологически активных веществ, особенно из группы полифенолов. На предприятиях по упаковке чая остаются отходы – чайная пыль. Эта порошкообразная масса состоит из мелких частиц сухого листового чая. В настоящее время она практически не используется. Можно предположить, что по составу и содержанию биологически активных веществ чайная пыль приближается к листовому чаю, следовательно, может быть дополнительным ресурсом биологически активных веществ. Целью работы является изучение химического состава и биологической активности чайной пыли, образующейся на предприятиях по упаковке чая, определение возможности использования чайной пыли для получения биологически активных веществ. Проведен сравнительный анализ среднего, составленного из точечных проб, образца чайной пыли, образцов черного листового и зеленого листового чаев, полученных с одного предприятия. Методами лабораторного анализа определены: содержание водорастворимых экстрактивных веществ, общее содержание водорастворимых полифенолов, содержание белка, суммарная антиоксидантная активность водорастворимых веществ чая и другие показатели. Содержание водорастворимых полифенолов и антиоксидантную активность определяли методами, разработанными авторами данной публикации, методы зарегистрированы как изобретения РФ. Органолептическим и химическими анализами установили, что в составе чайной пыли преобладают частицы листьев черного чая, что соответствует доле этого сорта чая в продукции предприятия. При кратковременном режиме экстракции, соответствующим условиям дегустационного заваривания чая (5 мин, 950С), содержание экстрактивных веществ в образце чайной пыли составило 35,64%, в черном чае – 32,47%, содержание полифенолов в чайной пыли – 7,76%, в черном чае – 7,95%. В чайной пыли определено высокое содержание белка – на уровне 17,44%. Общая антиоксидантная активность водного экстракта чайной пыли в пересчете на кверцетин составила 29 мг/г. что ниже по сравнению с черным и, особенно, зеленым чаем. Проведена оптимизация режимов экстракции водорастворимых веществ из чайной пыли, позволившая увеличить выход полифенолов и антиоксидантную активность экстрактов. Результаты исследования дают основание считать, что отходы чайного производства могут быть использованы как сырье для получения биологически активных веществ таких, как полифенолы, а также являются ресурсом белка.

Chemical and thermal properties of flours from germinated amaranth seeds

Modification of the chemical composition of amaranth flours from Amaranth caudatus L. seeds with germination was studied. Seeds were sprouted at 30 °C for 0, 18, 24, and 48 h. Proximal composition, total phenolic content and antioxidant activity were evaluated. Further, changes in fatty acid and protein profiles and in amino acid composition due to germination were analyzed. In addition, modification in thermal properties of starch and proteins of amaranth flours were studied. Germination process increased protein, ash, water soluble carbohydrates, phenols contents and antioxidant activity, while reduced the amount of lipids. Proportion of P-globulins and 11S (62 kDa) decreased while the A-11S polypeptide (34 kDa) increased with germination. After 18 h of germination, respect to the control flour, lysine and aromatic amino acids and essential fatty acids content of flour significantly increased. Therefore, germination improved nutritional characteristics of amaranth flour turning it into a high nutritional food ingredient.

Miniature cheeses made with blends of chymosin and a vegetable rennet from flowers of Silybum marianum: Enzymatic characterization of the flower-coagulant peptidase

Binary blends of S. marianum–flower extract and chymosin, as coagulant preparations, enabled the manufacture of miniature cheeses with distinctive characteristics compared to those of chymosin-renneted cheeses. The physicochemical parameters, sensory attributes of the cheeses, and in-vitro water-soluble antioxidant activity were analyzed and compared to those properties obtained from control chymosin-renneted cheeses. The preponderant proteolytic constituent in the flower extract was isolated in a two-step-purification protocol. The thus purified aspartic peptidase was maximally active at acidic pHs and exhibited a preference for peptide bonds between hydrophobic residues. Enzymologic characterization revealed differences in the kinetic parameters and specificity compared to other enzymes employed, such as rennet. S. marianum–flower extract, as a source of peptidase with distinctive characteristics, is a suitable substitute for chymosin in miniature-cheese production. The addition of vegetable rennet contributed to the development of an intense aroma and conferred antioxidant activity to the cheeses and wheys.

Geographic variation in water-soluble polysaccharide content and antioxidant activities of Cyclocarya paliurus leaves

Cyclocarya paliurus is a multiple function woody plant. To reveal the geographic variation pattern of water-soluble polysaccharide content in the leaves and its antioxidant activities, the leaf samples were collected and analyzed from 29 geographic locations of natural C. paliurus populations throughout the distribution areas. Significant differences in the water-soluble polysaccharide content and antioxidant activities were detected among the C. paliurus populations. The water-soluble polysaccharide content in the leaves of different populations ranged from 18.72 to 53.59 mg g−1, and the 29 populations could be classified into four distinct groups. There was a significant correlation between the water-soluble polysaccharide content and scavenging activities for the leaves of C. paliurus (p < 0.01). Multivariable nonlinear regression analysis showed that no clear geographic variation pattern in water-soluble polysaccharide content was detected for the leaves sampled. However, Pearson correlation analysis indicated that the average annual precipitation was significantly correlated to the leaf polysaccharide content (r = 0.428, p < 0.05), and its scavenging activities on DPPH radical (r = 0.386, p < 0.05) and superoxide radical (r = 0.446, p < 0.05). Based on the water-soluble polysaccharide contents of all populations studied, leaves from the Wufeng, Muchuan and Liping were recommended for food and medical use in the future. Results from this study not only demonstrated that the polysaccharide content in C. paliurus leaves could be used either as nutriments, food additives, or antioxidant supplements, but also provided a basis for optimizing cultivation strategies of C. paliurus plantations.

Synthesis, characterization, solubilization, cytotoxicity and antioxidant activity of aminomethylated dihydroquercetin.

A dihydroquercetin derivative (DHQA) was prepared through aminomethylation to overcome the low water solubility and bioavailability of dihydroquercetin (DHQ). DHQA was characterized through HPLC, nuclear magnetic resonance, scanning electron microscopy, X-ray diffraction, and thermogravimetric analyses. DHQA was converted into the amorphous form, but the major structure of DHQ remained unchanged. Solubilization and dissolution tests were also performed. Results showed that the solubility and dissolution rates of DHQA were approximately 16.28 and 6.31 times higher than those of DHQ, respectively. The MTT assay of DHQA showed a non-toxic effect against non-cancerous HEK-293T cells (EC50 = 820.00 μM), and potent inhibitory activity against cancerous Hela cells (EC50 = 138.17 μM). Finally, the antioxidant activity of DHQA was confirmed in vitro through DPPH and ABTS radical scavenging activity assays. DHQA displayed high antioxidant activities with low IC50 values (0.043 and 0.042 mM, respectively). Reducing Fe3+ power assay indicated that DHQA exhibited higher reducing power than DHQ and ascorbic acid.

Effects of Different Cooking Methods on Improving Total Antioxidant Activity in Selected Vegetables

The present study compares Water-soluble Phenolic Content (WPC) and antioxidant activities in eggplant, kidney bean, bitter gourd and spinachprior to and after subjecting to boiling, microwaving and pressure cooking. The total antioxidant activity was increased in cooked spinach, eggplant and bitter gourd, estimated based on the ferric reducing antioxidant power, the Troloxequivalent antioxidant capacity and 2, 2-diphenyl-1-picryl-hydrazyl radical scavenging activity. Pressure cooking did not cause any significant decline in the antioxidant property. Boiling generally improved the overall antioxidant activity in all the vegetables. Correlation analysis suggests that WPC contributed to significant antioxidant activities in these vegetables. Thus, prudence in selecting an appropriate cooking method for different vegetables may improve or preserve their nutritional value.

Exploration of Three Solanum Species for Improvement of Antioxidant Traits in Tomato

Wild tomato species have been widely used for improvement of tomato disease resistance but have not been extensively explored for health-related traits. In this work, three interspecific populations derived from backcrosses between cultivated tomato and Solanum pimpinellifolium (LA1589), S. habrochaites (LA1223), and S. peruvianum (LA2172) were analyzed for water-soluble antioxidant activity, phenolic content, vitamin C content, and basic agronomic traits including fruit weight, shape, and color. The wild species accessions significantly exceeded S. lycopersicum for all three antioxidant traits with only one exception: vitamin C content in S. habrochaites LA1223. Several populations and traits showed transgressive segregation indicating that the backcross populations contained individuals with allele combinations that allowed antioxidant activity/content to exceed that of both parents. The S. habrochaites LA1223 population provided the best starting material for improvement of water-soluble antioxidant activity and phenolics content with 20% and 15% of the population, respectively, significantly exceeding the parental values for these traits. Moreover, the S. habrochaites population contained individuals that had nearly 2-fold more water-soluble antioxidant activity and phenolic content than cultivated tomato. The S. peruvianum LA2172 population was best for improvement of vitamin C content with 3-fold variation for the trait and individuals, which had twice as much vitamin C as cultivated tomato.

Effect of pre-harvest methyl jasmonate treatments on ethylene production, water-soluble phenolic compounds and fruit quality of Japanese plums.

The effects of pre-harvest methyl jasmonate (MJ) treatments on ethylene production, respiration rate, bioactive compounds and physico-chemical parameters of plum fruits (Prunus salicina Lindell cv. 'Fortune' and 'Friar') were investigated. Whole trees were sprayed once with an aqueous solution containing MJ (0, 1120 and 2240 mg L(-1)) 2 weeks before the anticipated commercial harvest for each cultivar. In both plum cultivars, 1120 mg L(-1) MJ significantly increased hue angle of fruits. The fruit mass and geometric mean diameter were lower in MJ treatments while flesh firmness was higher, except at initial harvest date. Soluble solids concentration increased and titratable acidity decreased with MJ treatments. MJ-treated fruits exhibited higher levels of ethylene production and respiration rate. MJ was more effective in increasing water-soluble antioxidant activity, water-soluble phenolics and individual phenolics. Chlorogenic acid, caffeic acid, rutin, ferulic acid, naringenin and kaempferol contents significantly increased with 2240 mg L(-1) MJ. This study revealed that pre-harvest MJ treatments were effective in delaying softening of late-harvested fruits and increasing bioactive compounds of plum fruits.

Heterosis and antioxidant compounds of sweet corn breeding lines and their F1 hybrid

In this research, the mid-parent heterosis and the levels of phenolic, flavonoids compounds and antioxidants activity among two selected sweet corn parental lines and their F1 hybrid Zaharina were evaluated. Substantial positive mid-parent heterosis (MPH) was found for parent-hybrid triplet for ear weight and for plant height. Among all other traits, insertion height had the greatest heterosis and ear diameter had the lowest. Negative mid-parent heterosis exhibited only the trait 1000-kernel weight. Data analysis indicated significant differences in the contents of total phenolic content, total flavonoids content, water-soluble antioxidant capacity, lipid-soluble antioxidant capacity, and antioxidant activity among parent-hybrid triplet. The results suggest that F1 hybrid Zaharina can be considered as good source of natural antioxidants since it extracts were found to possess high antioxidant activity.

Optimization of UF-Feta cheese preparation, enriched by peppermint extract.

Strong antioxidant activity, antimicrobial, antiviral, antitumor, and some antiallergenic potential actions have been reported in peppermint. For daily acceptance of the benefits of this plant, UF-Feta cheese, enriched by whole peppermint extract, was prepared with different levels of Peppermint Extract (PE) (220-660μg/g cheese), starter (1.3-2.7g/100Kg retentate), rennet (1.3-2.5g/100Kg retentate), and Ripening Time (RT) (10-50days). Simultaneous effects of the considered variables were also investigated on Water-soluble Phenolic Content (WSPC), Antioxidant Activity (AOA), and Sensory Score (SS) by means of Response surface methodology. The results showed that although rennet concentration had a little positive effect on WSPC, its effect on AOA was significantly negative. It was determined that PE had a crucial role in acceptance of cheese samples and showed a negative effect on SS. More maturation of produced cheese samples effectively increased AOA. It was found that for producing cheese with maximum SS and AOA, the optimum values of variables should be applied as follows: PE, 227μg/g cheese; starter, 2.7g/100Kg retentate; rennet, 1.3g/100Kg retentate; RT, 41.7days.

Customized cooking method improves total antioxidant activity in selected vegetables

The present study compares water-soluble phenolic content (WPC) and antioxidant activities in Chinese long bean (Vigna unguiculata), bitter gourd (Momordica charantia), water convolvulus (Ipomoea aquatica) and broccoli (Brassica olearacea) prior to and after subjecting to boiling, microwaving and pressure cooking. The total antioxidant activity was increased in cooked water convolvulus, broccoli and bitter gourd, estimated based on the ferric reducing antioxidant power, the Trolox equivalent antioxidant capacity and 2,2-diphenyl-1-picryl-hydrazyl radical scavenging activity. Pressure cooking did not cause any significant decline in the antioxidant property. Boiling generally improved the overall antioxidant activity in all the vegetables. Correlation analysis suggests that WPC contributed to significant antioxidant activities in these vegetables. Thus, prudence in selecting an appropriate cooking method for different vegetables may improve or preserve their nutritional value.

Salt tolerance in Solanum pennellii: antioxidant response and related QTL

BackgroundExcessive soil salinity is an important problem for agriculture, however, salt tolerance is a complex trait that is not easily bred into plants. Exposure of cultivated tomato to salt stress has been reported to result in increased antioxidant content and activity. Salt tolerance of the related wild species, Solanum pennellii, has also been associated with similar changes in antioxidants. In this work, S. lycopersicum M82, S. pennellii LA716 and a S. pennellii introgression line (IL) population were evaluated for growth and their levels of antioxidant activity (total water-soluble antioxidant activity), major antioxidant compounds (phenolic and flavonoid contents) and antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase and peroxidase) under both control and salt stress (150 mM NaCl) conditions. These data were then used to identify quantitative trait loci (QTL) responsible for controlling the antioxidant parameters under both stress and nonstress conditions.ResultsUnder control conditions, cultivated tomato had higher levels of all antioxidants (except superoxide dismutase) than S. pennellii. However, under salt stress, the wild species showed greater induction of all antioxidants except peroxidase. The ILs showed diverse responses to salinity and proved very useful for the identification of QTL. Thus, 125 loci for antioxidant content under control and salt conditions were detected. Eleven of the total antioxidant activity and phenolic content QTL matched loci identified in an independent study using the same population, thereby reinforcing the validity of the loci. In addition, the growth responses of the ILs were evaluated to identify lines with favorable growth and antioxidant profiles.ConclusionsPlants have a complex antioxidant response when placed under salt stress. Some loci control antioxidant content under all conditions while others are responsible for antioxidant content only under saline or nonsaline conditions. The localization of QTL for these traits and the identification of lines with specific antioxidant and growth responses may be useful for breeding potentially salt tolerant tomato cultivars having higher antioxidant levels under nonstress and salt stress conditions.