Soluble Phenolic Content Research Articles

Analysis of the nutritional properties and flavor profile of sweetpotato residue fermented with Rhizopus oligosporus

Sweetpotato residue, a by-product generated after starch extraction in the food industry, has not been effectively utilized. In this study, fermentation with Rhizopus oligosporus RT-3 was carried out to improve the nutritional properties and flavor profile of sweetpotato residue. The contents of soluble dietary fiber, protein, phenolics and flavonoids and the antioxidant activities of sweetpotato residue significantly increased during fermentation. The analysis of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and sensory evaluation indicated that fermentation enhanced the aroma of sweetpotato residue due to the increased levels of alcohols, esters, ketones, and alkenes. Metabolite analysis further revealed that fermentation remarkably improved the nutritional composition of the sweetpotato residue. The potential metabolic pathways triggered during fermentation demonstrated that the improved nutritional composition of sweetpotato residue was attributed to the biochemical reactions driven by microbial enzymes.

The Effects of Fixation Methods on the Composition and Activity of Sea Buckthorn (Hippophae rhamnoides L.) Leaf Tea

Fixation is the key step to improve the quality of sea buckthorn leaf tea. Composition and activity are important indexes to evaluate the quality of sea buckthorn leaf tea. Comparing the effects of fixation methods on components and activities provides a theoretical basis for the contemporary, controllable, and continuous production of sea buckthorn leaf tea. The effects of six different fixed methods, pan-firing fixed (PF), steaming fixed (SF), boiling water fixed (BF), hot air fixed (HF), microwave fixed (MWF), and infrared fixed (IRF) for sea buckthorn leaf tea in terms of α-glucosidase inhibitory activity, lipase inhibitory ability, and the antioxidant capacity were studied. The total flavonoids (TF) content, total soluble phenolics (TP) content, water-soluble carbohydrate (WSC) content, the inhibitory activity of α-glucosidase, lipase inhibitory ability, and the antioxidant capacity of fixed sea buckthorn leaf tea were significantly higher ( p ≤ 0.05 ) compared with sea buckthorn leaf. IRF and MWF samples had higher ( p ≤ 0.05 ) contents of TF (92.48 mg RE/g and 79.20 mg RE/g), TP (115.37 mg GA/g and 135.18 mg GA/g) and WSC (4.24% and 4.39%). The DPPH radical scavenging activity of the SF sample was the strongest one, followed by the MWF sample and IRF sample ( p ≤ 0.05 ). The hydroxyl radical scavenging ability and reducing power of IRF were the strongest one, followed by the MWF sample ( p ≤ 0.05 ). The IRF sample had the strongest α-glucosidase inhibitory activity ( p ≤ 0.05 ), and the MWF sample had the strongest lipase inhibitory ability while samples contained the same amount of total polyphenols ( p ≤ 0.05 ). Principal component analysis results showed that the IRF sample, MWF sample, and SF sample had higher comprehensive principal component values. MWF takes less time than IRF, which operated at 2,450 MHz (full power of 700 W) for 2 min. Therefore, MWF was the most suitable fixation method for sea buckthorn leaf tea. Practical Applications. Leaf tea is the main product of sea buckthorn leaf. However, at present, the quality of sea buckthorn leaf tea in the market is uneven, the processing methods are diverse, and there is no certain quality standard. This paper provides some data support and theoretical support for the production, processing, and purchase of sea buckthorn leaf tea.

Drying Characteristics and Quality Analysis of Medicinal Herbs Dried by an Indirect Solar Dryer.

Considering the solar radiation status in Oman, a low-cost, indirect, stand-alone, forced-convective solar dryer was developed to dry medicinal herbs, which are sensitive to direct sun. The hot air flow was obtained using a solar-panel-powered blower and air passing through a black-body solar collector. This drying process could extend the shelf life of herbs while preserving their medicinal and nutritional (physicochemical) properties and adhering to food safety and hygiene practices. This study investigated the benefits of an indirect solar drying technique on the retention of quality attributes of mint and basil used in medicinal applications. Herbs used during drying could be subjected to changes in their physicochemical properties such as color, water activity (Aw), total soluble solids (TSS), phenol content, antioxidant capacity, and moisture content (MC), and, thus, results were compared with fresh herb samples. The dryer chamber-maintained temperature and relative humidity regimes of 30-50 °C and 21-95% and the expected final moisture content (wet basis) was 10%. The dryer showed improved physicochemical quality parameters and the retention of green color with parameter ranges of Aw 0.44-0.63, phenol content (increase) 1705-8994 mg/100 g DM, and antioxidant capacity (increase) 0.61-0.67 µmol/g DM, respectively. This study showed the ability of developed solar dryers to preserve the physicochemical properties of medicinal herbs during drying and can extend to other food products.

Assessment of nitrogen-fixing endophytic and mineral solubilizing rhizospheric bacteria as multifunctional microbial consortium for growth promotion of wheat and wild wheat relative Aegilops kotschyi

Microbes play crucial functions in maintaining the health and growth of the plants directly or indirectly by supplying nutrients. These microbes could be used as biofertilizers for the enhancement of soil health and growth of crops. In preset investigation, potential microbes from endophytic and rhizospheric region of Aegilops kotschyi growing in green slopes of Shivaliks, Himachal Pradesh were sorted out and screened for plant growth promoting attributes including phosphorus and potassium solubilization. The potential bacterial strains were identified through 16S rRNA gene sequencing and developed as microbial consortium for the plant growth of wheat and wild wheat relative Aegilops kotschyi. A total 125 isolates of bacteria were sorted out and among them 36 were found as P-solubilizers and 19 showed K-solubilization attribute and two highly potential bacterial strain were identified as Bacillus tropicus EU-ARP-44 (P-solubilizer; 270.5 ± 0.00 mg L−1) and B. megaterium EU-ARK-23 (K-Solubilizer; 51.3 ± 1.7 mg mL−1). The microbial consortium of Rahnella sp. strain EU-A3SNfb (N-fixer; MN294545), B. tropicus EU-ARP-44 (P-solubilizer) and B. megaterium EU-ARK-23 (K-solubilizer) evaluation in Aegilops kotschyi and wheat crop resulted in the enhancement of growth as well as physiological parameter including shoot/root length, fresh/dry weight and chlorophyll, carotenoid, total soluble sugar content, phenolic and flavonoid content as compared to un-inoculated control. Microbial consortium consisting of potential plant growth promoting (PGP) bacterial strains could be used as biofertilizer and bioinoculants in cereals crop growing in hilly region.

The effect of popping, soaking, boiling and roasting processes on antinutritional factors in chickpeas and red kidney beans

SummaryThis study was conducted to determine the effect that a popping head (like a rice cake machine), a low‐shear and low‐water processing technology, has on the concentration of antinutritional factors in chickpeas and red kidney beans. Seeds were popped under several parameters (popping time, sample format and equipment type) and analysed against soaking (1:5 w/v in reverse osmosis water for 24 h), roasting (100 g at 180 °C for 20 min) and boiling (1:5 w/v in reverse osmosis water at 100 ± 1 °C for 1 h) processes. Popping and roasting significantly reduced phytic acid content in chickpeas (6%–22%) and red kidney beans (16%–39%). In contrast, phytic acid content after soaking and boiling was not significantly different to raw seeds. Condensed tannins were significantly reduced in red kidney beans after soaking (74%), boiling (100%) and 4 s popping (28%–42%) treatments and increased in both pulses after roasting (137%) and 8 s popping (21%–47%). Further analysis showed that the soluble phenolic content increased with popping, but total and bound phenolic content was reduced. These results demonstrate that the high temperatures and pressures applied during the popping process effectively reduce antinutritional factors in pulses, compared to conventional processing methods.

Ultrasonic washing as an abiotic elicitor to induce the accumulation of phenolics of fresh-cut red cabbages: Effects on storage quality and microbial safety.

Ultrasonic washing has been proved to be an abiotic elicitor to induce the accumulation of phenolics in some fruit and vegetables. However, the feasibility of ultrasonic washing on the accumulation of phenolics in fresh-cut red cabbages has not yet been reported. Therefore, the effects of ultrasonic washing on the phenolics and related phenolic metabolism enzymes of fresh-cut red cabbages, as well as quality and microbial safety during cold storage, were investigated. Firstly, the single-factor tests were used to optimize the ultrasonic processing parameters, including frequency mode, frequency amplitude, power density, frequency cycle time, and ultrasonic washing. Then the activities of the enzymes related to phenolic metabolisms after optimal ultrasound treatment were investigated, including phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD). Additionally, the quality and microbial safety of fresh-cut red cabbages stored at 4°C under the optimal ultrasound treatment were evaluated. The results showed that the content of soluble phenolics (SPs) in fresh-cut red cabbages increased significantly during storage under the optimal conditions (28 ± 2 kHz, 60 W/L, 400 ms, and 20 min) compared with the control (P < 0.05). The PAL activity was activated and the PPO and POD activities were inhibited after ultrasonic washing, which contributed to the increase in the content of SPs. Meanwhile, the storage quality and microbial safety of fresh-cut red cabbages were improved. Ultrasonic washing reduced the weight loss and respiration rate and improved the color and texture characteristics. Additionally, the fresh-cut red cabbages after ultrasonic washing showed more retention of ascorbic acid (AA), total soluble proteins (TSPs), total soluble sugars (TSSs), and total soluble solids (SSs) compared with the control. Finally, ultrasonic washing effectively inhibited the growth of bacteria, molds and yeasts, which is beneficial to the extension of the shelf-life of fresh-cut red cabbages. Therefore, ultrasonic washing can be used as a tool to increase the content of SPs in fresh-cut red cabbages while retaining quality attributes and microbial safety.

Zinc oxide nanoparticles (ZnONPs) influenced seed development, grain quality, and remobilization by affecting the transcription of microRNA 171 (miR171), miR156, NAM, and SUT genes in wheat (Triticum aestivum): a biological advantage and risk assessment study.

Limited studies have been conducted on the role of microRNAs (miRs) and transcription factors in regulating plant cell responses to nanoparticles. This study attempted to address whether the foliar application of zinc oxide nanoparticles (ZnONPs; 0, 10, 25, and 50 mgL-1) can affect miRs, gene expression, and wheat grain quality. The seedlings were sprayed with ZnONPs (0, 10, 25, and 50 mgL-1) or bulk counterpart (BZnO) five times at 72h intervals. The application of ZnONPs at 10 mgL-1 increased the number of spikelets and seed weight, while the nano-supplement at 50 mgL-1 was accompanied by severe restriction on developing spikes and grains. ZnONPs, in a dose-dependent manner, transcriptionally influenced miR156 and miR171. The expression of miR171 showed a similar trend to that of miR156. The ZnONPs at optimum concentration upregulated the NAM transcription factor and sucrose transporter (SUT) at transcriptional levels. However, the transcription of bothNAMandSUTgenes displayed a downward trend in response to the toxic dose of ZnONPs (50 mgL-1). Utilization of ZnONPs increased proline and total soluble phenolic content. Monitoring the accumulation of carbohydrates, including fructan, glucose, fructose, and sucrose, revealed that ZnONPs at 10 mgL-1 modified the source/sink communication and nutrient remobilization. The molecular and physiological data revealed that the expression of miR156 and miR171 is tightly linked to seed grain development, remobilization of carbohydrates, and genes involved in nutrient transportation. This study establishes a novel strategy for obtaining higher yields in crops. This biological risk assessment investigation also displays the potential hazard of applying ZnONPs at the flowering developmental phase.

Silicon amendment improves wheat defence against Fusarium graminearum and complements the control by fungicide of Fusarium head blight

AbstractA three‐year field experiment with two wheat cultivars evaluated the effect of soil‐applied silicon (Si), with and without fungicide spraying, on Fusarium head blight (FHB) control. Silicon treatment alone reduced FHB severity and the percentage of damaged wheat kernels, regardless of the cultivar. The best disease control was obtained for the cultivar with moderate disease resistance (MR), supplied with silicon and treated with fungicide during flowering. Silicon treatment alone promoted an increase in deoxynivalenol (DON) concentration in the disease‐susceptible cultivar; however, in the MR cultivar, silicon amendment associated with fungicide treatment led to a reduction in DON concentration. Greenhouse experiments evaluated the effect of silicon combined with different timings of fungicide application on wheat defences against Fusarium graminearum. Plants supplied with silicon had a longer pathogen incubation period, lower FHB severity and lower DON concentration when compared to plants without silicon. In addition, silicon‐supplied plants had higher soluble phenolic content and altered antioxidant enzyme activities (SOD, CAT, POX and PPO) that favoured early accumulation of hydrogen peroxide when compared to plants without silicon. Greater control of FHB and lower DON concentration in plants treated with silicon and fungicide before inoculation and up to 1 day after inoculation was associated with increased levels of defence‐associated metabolites. Silicon contributed to the reduction of FHB and DON concentration in wheat, especially for the MR cultivar and, when combined with fungicide spraying, both MR and disease‐susceptible cultivars had enhanced performances upon silicon amendment.

Pulse type and extrusion conditions affect phenolic profile and physical properties of extruded products

The suitability of chickpea, red lentil and green pea for the production of extruded products (i.e., snacks and pasta) was studied. Besides starch and technological properties, the impact of processing on some bioactive compounds was evaluated. The best results were obtained for lentil: the snacks showed the lowest porosity (21 %), the highest average pore radius (18.8 µm), and high expansion (section area: 310 mm2; inner area: 114 mm2), while pasta exhibited low cooking loss (5.7 g 100 g−1) and high firmness (924 N). Extrusion-cooking reduced the soluble phenolic acid content (−45 %) and flavonoids (−41 %), but increased the cell-wall bound phenolic acids and antioxidant activity. The different pulses did not lead to a marked difference in the antioxidant activity of the extruded products, although the lentil maintained the highest flavonoid content after both processes.

Sprouting and Hydrolysis as Biotechnological Tools for Development of Nutraceutical Ingredients from Oat Grain and Hull

Oat consumption has increased during the last decade because of the health benefits associated with its soluble dietary fiber (β-glucan), functional proteins, lipids, and the presence of specific phytochemicals, such as avenanthramides. Oat is consumed mainly as whole grain, and the hull (seed coat), comprising 25–35% of the entire grain, is removed, generating a large amount of waste/by-product from the milling industry. The objective of this study was to evaluate the use of biotechnological strategies, such as sprouting for oat grain (OG) and hydrolysis for oat hull (OH), to enhance antioxidant and anti-inflammatory properties and lower the glycemic index (GI). Sprouting produced significant (p ≤ 0.05) increases in free (32.10 to 76.62 mg GAE (100 g)−1) and bound phenols (60.45 to 124.36 mg GAE (100 g)−1), increasing significantly (p ≤ 0.05) the avenanthramide (2c, 2p and 2f) soluble phenolic alkaloid content and anti-inflammatory properties of OG. On the other hand, the hydrolysis of OH using Viscoferm (EH2-OH) and Ultraflo XL (EH21-OH) increased by 4.5 and 5-fold the release of bound phenols, respectively; meanwhile, the use of Viscoferm increased the 4.55-fold soluble β-glucan content in OH, reaching values close to those of OG (4.04 vs. 4.46 g (100 g)−1). The study shows the potential of both strategies to enhance the nutritional and bioactive properties of OG and OH and describes these processes as feasible for the industry to obtain an ingredient with high antioxidant and anti-inflammatory activities. Single or combined biotechnological tools can be used on oat grains and hulls to provide nutraceutical ingredients.

Solid-state fermentation with Rhizopus oligosporus RT-3 enhanced the nutritional properties of soybeans.

Fermented soybean products are favorite foods worldwide because of their nutritional value and health effects. In this study, solid-state fermentation (SSF) of soybeans with Rhizopus oligosporus RT-3 was performed to investigate its nutraceutical potential. A rich enzyme system was released during SSF. Proteins were effectively transformed into small peptides and amino acids. The small peptide content increased by 13.64 times after SSF for 60 h. The antioxidant activity of soybeans was enhanced due to the release of phenolic compounds. The soluble phenolic content increased from 2.55 to 9.28 gallic acid equivalent (GAE) mg/g after SSF for 60 h and exhibited high correlations with microbial enzyme activities during SSF. The potential metabolic pathways being triggered during SSF indicated that the improved nutritional composition of soybean attributed to the biochemical reactions catalyzed by microbial enzymes. These findings demonstrated that SSF could evidently improve the nutritional value and prebiotic potential of soybeans.

Comparison of wheatgrass juices from colored wheat (white, black, blue, and purple) for health promoting phytochemicals

Wheatgrass juice is a low-acid functional drink extracted from white wheat seedlings. It is cherished by consumers due to its potent health benefits. The present study was conducted to develop and analyze wheatgrass juice from colored wheat lines to meet consumers increasing demand for a novel functional drink. The conventional lyophilized wheatgrass juice powder (WJLP) was found to contain significant chlorophyll content (0.3%), soluble phenolic content (0.6%), protein content (20%), moderate essential amino acid index (EAAI; 86%), high K (RDA; 11.6%) and antioxidant activity. Whereas, black WJLP had 564.2% higher anthocyanins, 30.5% higher chlorophyll, 87.5% higher soluble phenolic content, 10.2% higher proteins, 31.5% higher EAAI, and 112.5% higher antioxidant activity compared to white WJLP. Overall, the biochemical parameters of WJLP were increased in the order of white < blue < purple < black. The findings indicate that a proper cultivar selection can improve the nutritional value of wheatgrass juice.

The gene LpBCP increased NaHCO3 resistance by enhancing lignin or ROS scavenging in the Nicotiana benthamiana.

Lilium pumilum is an excellent wildflower germplasm resource with high resistance to salinity stress. The gene LpBCP plays an important role in salinity tolerance of L. pumilum. Studying the molecular mechanism of salinity resistance in L. pumilum will provide insights into multiple aspects, including breeding better varieties, environmental protection, improving soil conditions, etc. Conventional methods were used to determine different physiological indicators of Nicotiana benthamiana after NaHCO3 treatment, i.e. chlorophyll content, soluble phenol content and lignin content. RT-qPCR was carried out to find expression of LpBCP in different organs and under abiotic stresses. DAB was used to detect H2 O2 in leaves in situ. A yeast two-hybrid system was used to screen for LpBCP interacting proteins. LpBCP was cloned from bulbs of L. pumilum. The highest expression of LpBCP was in roots and bulbs of transgenic plants. LpBCP-overexpressed plants showed less wilting, compared to WT plants. LpBCP transgenic plants have higher chlorophyll, soluble phenol and lignin content, and lower relative conductivity under 500 mM NaHCO3 stress. In addition, H2 O2 scavenging in transgenic plants was much improved, indicating increased resistance to NaHCO3 stress. Thirteen LpBCP-interacting proteins were screened using the yeast two-hybrid method and five were associated with salt stress. Based on our findings, LPBCP could be a key gene that can be used to improve L. pumilum salt tolerance.

Impact of extrusion on the content and bioaccessibility of fat soluble nutraceuticals, phenolics and antioxidants activity in whole maize

The present study investigated the changes in fat soluble nutraceuticals, phenolics and antioxidant activity in extrudates of whole maize flour processed at 20 %, 25 % and 30 % feed moisture (M). Bioaccessibility of them in extrudates was also investigated at 20 % M. Extrusion resulted in a significant reduction in the content of components and antioxidant activity. Retention of phytosterols was more (77 %–100 %) followed by phenolics and flavonoids in extrudates. Reducing power decreased more than threefold, while DPPH radical scavenging activity and total antioxidant activity were half of its activity observed in raw. In bioaccessible fraction, the content of stigmasterol, β-sitosterol and flavonoids was higher than in raw while phenolics and antioxidant activity were unchanged. Bioaccessibility of carotenoids, phytosterols, phenolics, and flavonoids, as well as antioxidant activity was high, except tocopherols and tocotrienols. Overall, extrusion of maize flour with 20 % M enhanced bioaccessibility most of fat solubles, phenolics and antioxidants activity.

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

Similar structural complexity of phenols in plant morphotypes with contrasting soluble phenol concentration and richness in arid rangelands of Patagonia

Phenols can play a significant role in plant tolerance of drought and herbivory. We assessed the concentration, richness and structural complexity of soluble phenols (hereafter phenols) in leaves of different species representing different plant morphotypes of arid ecosystems. We selected seven species representative of the three main plant morphotypes of the Patagonia Monte (Argentina): tall evergreen shrubs (TES), medium evergreen shrubs (MES), and perennial grasses (PG). These morphotypes differed in plant height, rooting depth, proportion of photosynthetic tissues, specific leaf area, and concentration of phenols and N in leaves. We found 48 compounds belonging to six types of phenols differing in structural complexity (low complexity: simple phenols, phenolic acids and phenolic esters; medium complexity: hydroxycinnamic acids and phenylpropenes; and high complexity: quinones, flavonols and flavones). Phenols of low and medium complexity were the most abundant in all morphotypes, while those of high complexity, probably the most costly for plants, were nearly exclusive of some tall evergreen shrubs. In general, PG, MES and TES had low, intermediate and high phenol concentration (8.5, 27.2, 202.5 mg g−1DW, respectively) and richness (15, 25, 37 compounds, respectively) in leaves. The richness of phenols was significantly and positively related to phenol concentration. However, we did not find distinctive phenol compound patterns among morphotypes. Our results suggest that drought and, to some extent, herbivory have exerted selective selection pressure on richness and phenol concentration in leaves of contrasting morphotypes but the type of phenols accumulated probably depends on intrinsic species attributes within each morphotype.

Exploring the Potential of Moringa Leaf Extract for Mitigation of Cadmium Stress in Triticum aestivum L.

Cadmium (Cd) is one of the most toxic metals accumulated in wheat grains. Daily intake of Cd through food is posing serious health problems. There is an urgent need to reduce the uptake and accumulation of Cd in wheat and other cereal crops. In this study, we investigated the potential of moringa leaf extract (MLE) in decreasing the Cd toxic effects in wheat (Triticum aestivum L.) cv. A.S. 2002. Sowing was carried out in pots under shade and natural light conditions. Two Cd concentrations (500 µM and 1000 µM) were applied with and without MLE (0 and 3%). Results revealed that plant growth parameters viz diameter of stem, number of leaves, leaf area, photosynthetic pigments were improved with MLE application under Cd stress. Moreover, biochemical attributes and osmolytes such as total soluble sugars, and soluble proteins, phenolic content and flavonoids were negatively effected by Cd stress and were improved under MLE treatment. Moreover, Cd stress enhanced phytotoxicity as higher ROS accumulation is observed under both stress conditions, whereas after MLE application MDA and H2O2 accumulation was significantly decreased. Based on current observations, MLE was effective in mitigating the biological and toxic effects of Cd by promoting the growth attributes and mineral contents in wheat. Further experiments are needed for discovering the molecular mechanisms underlying MLE and host plant interactions involved in Cd stress mitigation.

BIOCHEMICAL CHANGES IN LEAVES OF RESISTANT AND SUSCEPTIBLE URDBEAN GENOTYPES INFECTED WITH URDBEAN LEAF CRINKLE VIRUS (ULCV)

Urdbean leaf crinkle virus (ULCV) is a widespread and most destructive virus that causes leaf crinkle disease in black gram. Virus infection causes alteration in physiological and biochemical processes within the plant. In present study, effect of viral infection was investigated on chlorophyll content, total soluble sugar, total protein, phenolic contents, sodium dismutase (SOD) and nitrate reductase activities in the leaves of susceptible and resistant genotypes of urdbean at 30 days after virus inoculation. Disease symptoms were mild (6.7% to 10%) in resistant genotypes and severe (36% to 43%) in susceptible genotypes. ULCV infection resulted in a significant decrease in chlorophyll content in infected plants of all genotypes over control plants; however, magnitude of reduction was more in susceptible genotypes (41%) as compared to the resistant genotypes (14.35%). The total sugar and protein contents were significantly higher in the inoculated susceptible (210.26 % and 68.67%, respectively) as compared to the resistant genotypes (183.87% and 25.89%, respectively). Also, the total phenolic content was significantly higher in inoculated resistant genotypes (83.91%) over the susceptible genotypes (25.89%). There was significant decrease in the activity of superoxide dismutase enzyme in resistant genotypes as compared to susceptible inoculated genotypes. Similarly, a reduction in nitrate reductase activity was more in inoculated plants of resistant genotypes. Our results indicate that post-infection significant increases in total sugars and proteins in susceptible genotypes and phenols in resistant genotypes may have a role in disease resistance and development. Changes in enzymatic activities in resistant and susceptible genotypes might also have some role in resistance against ULCV.

Defense Response to Fusarium Infection in Winter Wheat Varieties, Varying in FHB Susceptibility, Grown under Different Nitrogen Levels

Fusarium head blight and inadequate nitrogen fertilization can cause numerous biochemical changes in wheat. The main aim of this study was to determine the effects of Fusarium inoculation and a broader range of different nitrogen fertilization on the defense response in the spikes of four wheat varieties, varying in FHB susceptibility. Total soluble phenolics content, activities of enzymes involved in phenol metabolism (PAL and PPO), and total antioxidant capacity were determined as indicators of defense response. In both growing seasons, Fusarium inoculation altered PHE content in wheat spikes, indicating involvement of PHE in the defense response to Fusarium attack. Increased PHE content in the partially resistant varieties (Apache and Graindor) indicates involvement of PHE in the defense response and better disease tolerance in the more resistant varieties. Breeding wheat varieties with enhanced PHE synthesis could be a promising strategy to control FHB. To the best of our knowledge, this is the first study that emphasizes the effects of Fusarium infection and a broader range of different nitrogen fertilization on PHE and enzymes involved in PHE metabolism. In addition, this is the first study using the FRAP method to determine the antioxidant capacity of wheat tissues under the influence of Fusarium infection and different nitrogen fertilization.

Efficacy of plant-based natural preservatives in extending shelf life of sugarcane juice: Formulation optimization by MOGA and correlation study by principal component analysis

Sugarcane juice spoils quickly as a result of microbial contamination and enzymatic reactions. To maintain its quality during storage, synthetic preservatives are generally employed. However, their use has been linked to potential health hazards. In this regard, some plant based natural preservatives can be utilized as safe alternatives. Lemon juice (LJ), basil leaf extract (BE), mint leaf extract (ME), and lemongrass essential oil (LGEO) were used in this study. LJ, BE and ME were varied from 2 to 8% (v/v) and LGEO was ranged between 1 and 3% (v/v). The concentrations of these natural preservatives were optimized by multi-objective genetic algorithm (MOGA) based on contrasting goals of maximizing soluble solids, phenolic content (PhC) and sensory acceptability score while minimizing pH, polyphenoloxidase (PPO) activity and bacterial count. The LGEO followed by LJ inhibited the microorganisms and oxidative enzymes at an appreciable level and ME was the least effective among all. At the same time, LJ offered more preferable sensory scores than others. The optimized concentration suggested by MOGA was 6.84% LJ and 1.05% LGEO which resulted in 10.3% rise in PhC, 49.3% PPO inactivation, 2 log cycle bacterial reduction and 3.5% sensory improvement in the raw juice. The changes in quality parameters during storage and correlations among them were effectively illustrated by principal component analysis. It was revealed from microbial safety analysis that sugarcane juice with storage stability of 26 days at 4 ºC could be prepared by addition of natural preservatives.