Total Soluble Phenolic Compounds Research Articles

Biochemical Studies on Curing and Fermentation Processing Periods of Different Tobacco Plant (Nicotianatabacum L.) Cultivars

Abstract We studied the changes in the activity of the enzymes polyphenol oxidase (PPO) and peroxidase (POX), the concentration of total soluble phenolic compounds and soluble protein content in different tobacco cultivars (Virginia and Burley) during curing. The curing procedure was a special combination of open-air-curing and fluecuring methods and a long fermentation period. In the curing period the changes in data suggested a combination of the biochemical processes and the direct effect of oxygen. A slight increase then a decrease in the concentrations of both total soluble phenolic compounds and the soluble protein content were detected. In this period we found no correlation between the concentration of total soluble phenolic compounds, the decreasing PPO and the increasing POX activity. In the fermentation period a deactivation of the enzymes (PPO and POX) and a decrease in the concentration of both total soluble phenolic compounds and soluble protein content were found, because the fermentation is not a biochemically-regulated process. Moreover, these results suggest that the end of curing period is the most favourable time for protein isolation from different tobacco cultivars.

CHANGES IN QUALITY ATTRIBUTES OF LONGAN JUICE DURING STORAGE IN RELATION TO EFFECTS OF THERMAL PROCESSING

ABSTRACT Longan juice is accepted gradually by consumers due to its unique succulent, sweet and aromatic flavor. The effects of thermal processing (91C, 20 min) on quality related attributes (color, translucency, total soluble solids, total acidity, reducing sugars, ascorbic acid, phenolic compounds, protein and pectin) of longan juice during storage at low temperature were investigated. The heat‐treated longan juice had a higher translucency and lower concentrations of pectin, phenolic compounds and proteins of longan juice, compared with the nonheat‐treated juice. Furthermore, the thermal processing maintained higher concentrations of total soluble solids and total acidity but a lower ascorbic acid concentration. However, the thermal processing had no significant effects on reducing sugar concentration. Overall, the thermal processing maintained effectively color appearance and nutritional attributes such as total soluble solids and total acidity of longan juice during storage at low temperature. These results suggest that the thermal processing exhibits a potential for quality maintenance of longan juice. PRACTICAL APPLICATIONSBrowning and turbidity are the major factor to influence quality of fruit juice during storage. Thermal processing is generally applied to improve quality and extend shelf life of fruit‐related products. In this study, application of thermal processing exhibited potential for quality maintenance of longan juice in terms of evaluations of color, translucency and concentrations of total soluble solids, total acidity, reducing sugars, ascorbic acid, phenolic compounds, protein and pectin. The information obtained from this study could be used as a guideline for designing thermal processing to control the quality of longan juice.

Production of phenolic compounds in callus cultures of tea plant under the effect of 2,4-D and NAA

The effect of hormone-like compounds at different concentrations: 2,4-D (2 × 10−6; 2 × 10−5; and 2 × 10−4M) and 1-NAA (2 × 10−7; 2 × 10−6; 2 × 10−5; 4 × 10−5, and 6 × 10−5 M) on the growth and production of phenolic compounds, including flavans and lignin, was investigated in callus culture of tea plant (Camellia sinensis L., a highly productive strain IFR ChS-2). The growth of the culture was vigorous, and production of phenolic compounds therein was efficient in the medium containing 2 × 10−5 M 2,4-D. Substitution of 1-NAA for 2,4-D in all the cases decelerated the growth of the culture. These changes were more pronounced when 2 × 10−7 and 2 × 10−6 M 1-NAA was used; in this case, biomass accumulation decreased by 1.5–2.0 times as compared with control material growing on the medium with 2 × 10−5 M 2,4-D. In the presence of 1-NAA, the content of total soluble phenolic compounds and flavans in the calli rose by 30% on the average as compared with control material. Accumulation of lignin remained essentially the same. Therefore, the replacement of 2,4-D with 1-NAA in the nutrient medium used for the growing of highly productive strain of tea plant callus did not induce considerable changes in its ability to produce phenolic compounds.

Potential of the biopolymer chitosan with different molecular weights to control postharvest gray mold of tomato fruit

Gray mold caused by Botrytis cinerea (Pers.) is the most economically important postharvest disease of fruit and vegetables at harvest and during storage. Therefore the current study was conducted to investigate the effectiveness of chitosan with different molecular weights on gray mold in vitro and in vivo in tomato fruit ( Solanum lycopersicum L. var. lycopersicum) stored at different temperatures. In an in vitro experiment, the results demonstrated that the antifungal activity increased as the chitosan molecular weight decreased. In an in vivo study, chitosan treatments significantly reduced fungal decay and all compounds with concentrations of 2000 and 4000 mg/L showed complete control of the fungus in wound-inoculated fruit. Chitosan with a molecular weight of 5.7 × 10 4 g/mol was the most effective compound among those tested. The results also revealed that high chitosan concentrations correlated with low disease incidence regardless of storage conditions. In addition to the antifungal activity, chitosan had the potential for the elicitation of defense markers, including total soluble phenolic compounds, polyphenoloxidase (PPO) activity and total protein content. Chitosan treatment decreased the activity of PPO and enhanced total protein and phenolic compounds in wounded tomato fruit. These findings suggest that the effects of chitosan with different molecular weights on gray mold in tomato fruit may be associated with direct fungitoxic properties against the pathogen, and the elicitation of biochemical defense responses in fruit.

Total phenolic compounds and antioxidant capacities of major fruits from Ecuador

Seventeen fruits from Ecuador were analysed for total soluble phenolic compounds content and for antioxidant capacity, using three different methods (DPPH , FRAP and ABTS + ). For the total phenolic content measured by the Folin–Ciocalteu method, three groups, having <100, 200–500 and >1000 mg GAE/100 g FW, were clearly distinguishable. Andean blackberry, capulí cherry peel and banana passion fruit were classified in the third group, with concentrations of 2167, 1494 and 1010 mg of GAE/100 g FW, respectively. Antioxidant capacity analyses revealed the same classes. FRAP and ABTS + gave comparable results and were highly correlated ( y = 0.691 x + 6.78; r 2 = 0.908). Spectrophotometric measurements showed that the Andean blackberry and capulí peel but not banana passion fruit contained high levels of anthocyanins ( λ max = 520 nm).

Preliminary biochemical studies on a model growing of different tobacco plant (Nicotiana tabacum L.) cultivars

The aim of our preliminary studies was to characterize the change in the activity of enzymes PPO and PDX, the concentration of total soluble phenolic compounds and soluble protein content of different tobacco cultivars measured in tobacco plants during cultivation. The results suggest that a shorter cultivation period (13-14 weeks) is more favourable for tobacco plants as protein source than for tobacco industrial use (16-17 weeks). We found some correlation between the concentration of total soluble phenolic compounds and PPO activity data. In the increasing and maximum period of total phenol content the PPO activity was high. But later because of decrease of substrate phenol content the activity of PPO also decreased. We found higher soluble protein concentrations in Virginia than in Burley varieties.

An aqueous suspension of Crinipellis perniciosa mycelium activates tomato defence responses against Xanthomonas vesicatoria

The efficacy of controlling bacterial spot in susceptible tomato plants by using a natural product was compared to a commercial resistance inducer. Plants were sprayed with (a) acibenzolar- S-methyl, ASM [Bion ® 50 WG (0.2 g l −1)] and (b) a heterogeneous chitosan suspension (MCp) from Crinipellis perniciosa mycelium. Plants were challenged 4 d later with a virulent strain of Xanthomonas vesicatoria, under greenhouse conditions. In assessing disease, MCp-treated plants showed significant responses, reaching 87% of ASM protection performance against X. vesicatoria leaf spot. Tomato leaves exposed to MCp and ASM were assayed for pathogenesis-related enzymes, lignin deposition and soluble phenolic compounds. Induced resistance (IR) was evidenced by the enhancement of peroxidase (POX), polyphenol oxidase (PPO), and chitinase (CHI) activities at 1–72 h after spraying. These enzymes and phenylalanine ammonia-lyase (PAL) were also observed at 6, 9 and 12 d after spraying (DAS) interval. Treated and inoculated plants showed an increase in lignin deposition. The content of total soluble phenolic compounds decreased significantly by 9 and 12 DAS. The results suggest that (IR) was characterized by increased POX and PPO activities, improving lignification and, to a less extent, by CHI activity.

Changes in Formation and Localization of Phenolic Compounds in the Tissues of European and Canadian Yew during Dedifferentiation In Vitro

Changes in formation and localizations of phenolic compounds, including flavans, were investigated in the tissues of European and Canadian yew (Taxus baccata L. and T. canadensis Marsh.) during dedifferentiation in vitro. Annual shoots of European yew had the highest capacity for synthesizing these compounds. During the summer growth period, the content of total soluble phenolic compounds and flavans in these shoots was 30–40% higher than in the winter. Cell dedifferentiation and growth in vitro was accompanied by enhanced synthesis of phenolic compounds, including flavans, the change in tissue localization of these compounds, and an increase in the number of cells containing phenolics. Significant accumulation of phenolic compounds in callus cells resulted in necroses following two subcultures in the European and Canadian yew cultures initiated from summer explants, and following seven subcultures of the European yew calli initiated from winter explants. These data allow us to suggest that a high level of phenolic compounds in yew calli could be the reason for their necrosis.

Interaction Between Nitrogen-Fertilized Peach Trees and Expression ofsyrB, a Gene Involved in Syringomycin Production inPseudomonas syringaepv.syringae

ABSTRACT The in vitro expression of the syrB gene that controls the synthesis of syringomycin, a non-host-specific phytotoxin produced by Pseudomonas syringae pv. syringae van Hall, was studied using aqueous extracts derived from bark tissues collected from nitrogen-fertilized and nonfertilized peach trees. Expression of the syrB gene was quantified as beta- galactosidase activity expressed by P. syringae pv. syringae B3AR-132 containing a syrB::lacZ fusion. Gene expression was significantly less in three of four paired comparisons using extracts derived from fertilized versus nonfertilized trees; however, canker lengths were significantly different in only one of four comparisons. Expression was negatively correlated with plant tissue nitrogen content and positively correlated with a plant carbon/nitrogen ratio. Bark tissue from ring nematodeinfested trees had significantly higher concentrations of total soluble phenolic compounds and carbon/nitrogen ratios than bark samples from trees without nematodes, and canker size was significantly greater in trees growing in ring nematode-infested soil compared with noninfested soil. Nitrogen fertilization significantly decreased the plant carbon/nitrogen ratio, which was positively correlated with the concentration of total soluble phenolic compounds. Canker size developing after bacterial inoculation was positively correlated with higher plant carbon/nitrogen ratios and total soluble phenolic compounds. These results support the hypothesis that one reason why nitrogen fertilization decreases host susceptibility to bacterial canker is by either reducing the amount of plant metabolites that can induce syrB gene expression, or producing or increasing the concentration of compounds that antagonize syrB inducing compounds.

The antiatherogenic potential of oat phenolic compounds

Avenanthramides are phenolic antioxidants, which are present in oats. Avenanthramides A, B, and C are the major constituents of the total soluble antioxidant phenolic compounds in oats. We tested the potential antiatherogenic activity of partially purified avenanthramides from oats by examining their effects on adhesion of monocytes to human aortic endothelial cell (HAEC) monolayers, expression of adhesion molecules, and production of proinflammatory cytokines and chemokines by HAEC. The oat avenanthramides mixture was prepared and partially purified by column chromatography. This avenanthramide-enriched mixture (AEM) had no toxicity to HAEC as tested up to 40 ng/ml. The pre-incubation of HAEC with 4, 20, and 40 ng/ml AEM for 24 h significantly decreased adhesion of U937 monocytic cells to interleukin (IL)-1β-stimulated HAEC in a concentration-dependent manner. Pre-incubation of HAEC with AEM at 20 and 40 μg/ml, but not at 4 μg/ml, for 24 h significantly suppressed IL-1β-stimulated expressions of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin and the secretion of proinflammatory cytokines IL-6, chemokines IL-8 and monocyte chemoattractant protein (MCP)-1. These data provide evidence for the potential anti-inflammatory and antiatherogenic effects of antioxidant avenanthramides present in oats.

Influência do genótipo e do estádio de maturação na colheita sobre a matéria fresca, qualidade e cura dos bulbos de cebola

Avaliou-se a influência do genótipo e do estádio de maturação da planta de cebola, na colheita, sobre o tamanho e qualidade, e subseqüente perda de matéria fresca na cura dos bulbos de 'Granex', 'Baia Periforme' e 'Jubileu'. A antecipação ou retardamento da colheita em 15 dias, em relação ao estalo da planta, não influenciou a matéria fresca total e o teor de açúcares solúveis totais dos bulbos, sendo estas características função do genótipo utilizado. A colheita antecipada dos bulbos em 15 dias reduziu significativamente o teor de sólidos solúveis na cultivar Baia Periforme. Os bulbos dos genótipos analisados apresentaram concentrações insignificantes de amido, inferiores a 0,16 % da matéria fresca. A média geral da concentração de açúcares solúveis totais foi de 6,8% da matéria fresca para o híbrido precoce 'Granex', 11,5% para a cultivar de ciclo médio Baia Periforme e 10,8% em bulbos da tardia 'Jubileu'. A colheita dos bulbos 15 dias após o tombamento do pseudocaule permitiu acúmulo significativo de compostos fenólicos solúveis na casca das cultivares Baia Periforme e Jubileu, de coloração amarelada. Durante a cura dos bulbos houve maior taxa de perda de matéria fresca naquelas plantas colhidas 15 dias antes do colapso do pseudocaule, independente do genótipo testado.

Foliar Content of Phenolic Compounds in Platanthera bifolia from Natural and Transformed Ecosystems at Different Stages of Orchid Development

The representatives of the family Orchidaceae Juss. are often used as a source of natural antioxidants, including phenolic compounds, which play an important role in plant resistance under stressful conditions. This study investigates the content of lipid peroxidation products and soluble phenolic compounds in flowering plants of Platanthera bifolia (L.) Rich. growing in natural (forest park) and transformed (fly ash dumps of Thermal Power Stations) ecosystems of the Middle Urals, Russia, as well as the content of flavonoids at different stages of orchid development. Research has shown that in disturbed habitats, P. bifolia is capable of forming abundant populations containing a significant portion of the flowering plants. Additionally, flowering orchids from fly ash dumps contained an average 20 % more lipid peroxidation products, which indicated a shift in the redox balance towards oxidative processes. An increase by 2.4 times on average in the content of phenolic compounds, particularly flavonoids, was observed at all developmental stages of the plants growing in the transformed ecosystems. Regardless of the growing conditions, the non-flowering mature individuals were characterized by a minimum content of flavonoids, probably due to pre-generative metabolic restructuring. Yet, in the period of orchid blooming, the flavonoid content in their leaves increased again in all study sites. At the same time, the flavonoid proportion of the total soluble phenolic compounds was 42 % in the natural habitat, increasing to 66 % on average in the transformed ecosystems. Thus, flavonoids are involved in the protective adaptive responses of P. bifolia, not only ensuring the survival of this orchid but also contributing to the implementation of its ontogenetic program

Nutritional uniformity of crude protein fractions in some tropical browse plants estimated by two in vitro methods

Twenty eight plant species consisting mainly of leaves from leguminous browse trees collected in Tanzania, Colombia and Vietnam were analysed for total crude protein (CP), total soluble phenolic compounds, neutral detergent fibre (NDF) and CP in neutral detergent fibre (NDF-CP). Two in vitro methods were used to determine digestibility of the dry matter (IVDM) and the CP. Both methods involved a 48 h incubation with rumen liquor followed either by a 16 h neutral detergent extraction (IVND) to isolate the fibre fraction or a 16 h HCl-pepsin digestion (IVPEP) to mimic abomasal digestion. True CP digestibility was estimated as the slope of the line in a Lucas test when disappearance per unit of sample DM was regressed upon sample content. Crude protein contents ranged from 105 to 309 g/kg DM with 6 to 72% bound to the NDF. The mean IVDMD and digestible CP (DCP) for the IVND method were 73.9% (SD ± 13.1) and 17.9% (SD ± 5.9), respectively and were significantly ( p < 0.05) higher than for the IVPEP method of 67.3% (SD ± 15.4) and 16.0% (SD ± 6.5), respectively. As the proportion of NDF-CP in the total CP increased, CP digestibility (CPD) decreased linearly ( p < 0.05) for both in vitro methods. There were no significant ( p > 0.05) relationships between the content of phenolic compounds and either CPD or DCP of the browse species. The Lucas test revealed that CP did not behave uniformly in either of the in vitro methods, reflected by high standard deviations of the regression slopes and regression slopes more than 100%. The estimated true digestibilities of the CP fraction were 105% (SD ± 13.6%) and 105% (SD ± 10.2%) for the IVPEP and the IVND methods, respectively. The metabolic CP fractions were 6.89 (SD ± 3.04) and 5.13 (SD ± 2.29) g/100 g DM feed for the IVPEP and IVND methods, respectively. True digestibility of NDF-CP for the IVND method estimated by the Lucas test was 40% (SD ± 9.3%) with an intercept of 0.03 (SD ± 0.71) g/100 g DM. Tannins were considered to be the main factor responsible for the non-uniformity of the CP fractions in the browse species tested. It was concluded that digestibility of CP in tropical browse may not be predicted by the content of CP or phenolic compounds.

Effects of Temperature on Ethylene-induced Phenylalanine Ammonia Lyase Activity and Russet Spotting in Harvested Iceberg Lettuce

Experiments were conducted to study the effect of temperature on the ethylene inducibility of phenylalanine ammonia lyase (PAL, EC 4.3.1.5) activity and the development of russet spotting (RS) in Iceberg lettuce (Lactucu sutiva L.). Tissue exposed to ethylene and held at 15 or 20C showed earlier hut lower peaks in PAL activity than tissue held at 5C. Accumulation of total soluble phenolic compounds, and the development of RS paralleled increases in PAL activity after a short lag period. Lettuce tissue transferred from 5 to 15C after 1 to 3 days showed later hut higher peaks in PAL activity than tissue continuously held at 15C. Transferring ethylene-exposed tissue to 0C before RS symptoms developed greatly limited further rise in PAL activity and RS development. Discontinuing ethylene exposure after 4 days resulted in a rapid decrease in PAL activity. Lettuce tissue exposed to ethylene for 4 days and then transferred from 5 to 0C after the development of moderate RS symptoms showed no difference in RS after 8 days compared to tissue stored continuously at 5C.

モモ果実のポリフェノール含量に及ぼす土壌の乾燥ならびに気温の影響

The weight of harvested fruits, and the contents of total soluble solids and phenolic compounds were determined in four peach cultivars (Prunus persica BATSCH) planted in plastic containers grown under different conditions of soil moisture and air temperature.Using the peach trees, cv.‘Takei Hakuho’grafted on P. persica, and cv.‘Sanyo Suimitsu’grafted on P. persica or P. tomentosa THUNB., soil moisture tension (pF) was maintained for each stage of fruit growth such as an early period (Stage 1), a stone-hardening period (Stage 2), and a maturation period (Stage 3) at 2.3 to 2.7 by withdrawing water. Whereas in the control pF was maintained at 1.0 to 1.5 throughout experiments. Later time of the drought treatments resulted in later maturation of fruits in either cultivar. In both‘Takei Hakuho, ’and‘Sanyo Suimitsu’grafted on P. tomentosa, the smallest fruit and the highest content of phenolic compound in the fruit were observed in the drought plot during the Stage 3. In ‘anyo Suimitsu’grafted on P. persica, the content of phenolic compound was high not only in the drought plot during the Stage 3, but also in the control one.When peach trees, cv.‘Saotome’and‘Chikuma’grafted on P. persica were grown under four different air temperatures throughout Stages 2 and 3, the content of phenolic compound in the fruit was higher in the plots of 15°C and 20°C than in those of 30°C and the control, in which plants were grown outdoors throughout experiments. In‘Sanyo Suimitsu’ peach trees on P. persica grown at 20°C and 30°C of air temperatures during Stages 2 or 3, the content of phenolic compound was higher at 20°C than at 30°C in either stage, and it was also higher in the treatments of Stage 3 than in those of Stage 2 for both temperatures. Regardless of cultivar, at any plot treated with constant air temperatures of 15°C, 20°C, and 30°C, fruit weight was small, compared to the control. Average air temperature outdoors was 22.8°C or higher throughout the treatments.From these results, it is considered that soil drought and low air temperature during the Stage 3 of fruit growth is closely related to the occurrence of astringency in peach fruits.

Variation of Soluble Phenolic Compounds in Flue‐cured Tobacco Cultivars with Stalk Position1

AbstractPhenolic levels in field‐grown flue‐cured leaves of ‘Coker 139,’ ‘NC 95,’ ‘SC 58,’ and ‘LN 38’ were compared within each cultivar according to leaf positions on the stalks and among the four cultivars. Each of the cultivars showed a significant but generally nonlinear increase in levels of total phenolics (about 2‐fold for each) and sums of chlorogenic acids and rutin (2 to 9‐fold depending on cultivar) with eight ascending leaf positions on the stalk from lower to upper leaves. However, mean values of total phenolic reducing power equivalent to a chlorogenic acid standard and averaged over all stalk positions ranged from 7.17% in Coker 139 to 7.92% in NC 95; these values were not significantly different among the cultivars. Likewise, means of the sums of chlorogenic acids and rutin averaged over all leaf positions on the stalk ranged from 120% in Coker 139 to 1.59% in NC 95, and the four cultivars were not significantly different. Total soluble phenolic compounds were estimated by their bonding to insoluble polyvinylpyrrolidone at pH 3.5. Chlorogenic acid isomers and rutin were determined by electron capture gas chromatographic analysis based upon the amount of soluble caffeic acid and quercetin moieties found. Leaf phenolic compounds affect color and quality and may contribute to the tumor‐promoting weak acid fraction of tobacco (Nicotiana tabacum L.) smoke condensate. Therefore, leaves of these cultivars from different positions on the stalk will be used for cigarette manufacture to correlate the phenolic‐stalk position findings with smoke characteristics and composition.