100g Dry Weight Research Articles

High productivity of fucoxanthin and eicosapentaenoic acid in a marine diatom Chaetoceros gracilis by perfusion culture under high irradiance

For a high production rate of microalgae, a high-cell-density culture is an effective strategy for reducing the light intensity per dry weight in the culture to avoid photoinhibition under high light conditions. However, under high cell density microalgae are exposed to nutrient-deficient conditions, resulting in a reduced biomass production rate. To enhance the production rate of high-value bioactives such as fucoxanthin and eicosatetraenoic acid (EPA) by the diatom Chaetoceros gracilis, a perfusion culture was operated at harvesting rates of 10–40 % under light intensities of 300–2000 μmol m−2 s−1. At a harvesting rate of 20 % under a high light intensity of 2000 μmol m−2 s−1, the dry weight increased, and the areal productivity reached 15.6 ± 1.3 g-dry weight (dw) m−2 d−1, which is comparable to the maximum value previously reported in diatoms. The high biomass production, even at a low harvesting rate of 20 %, could result from sufficient nutrient supply by perfusion culture. At a harvesting rate of 20 %, the EPA areal productivity achieved 183 mg-dw m−2 d−1 even under 2000 μmol m−2 s−1 due to the increase in the dry weight using the perfusion culture. However, the fucoxanthin content decreased under 2000 μmol m−2 s−1. A strong relationship was observed between the specific light intensity per dry weight and fucoxanthin content in C. gracilis. This relationship indicates that the fucoxanthin content does not increase unless the specific light intensity per dry weight is adjusted below 20 μmol g-dw−1 s−1. Thus, perfusion culture proved to be useful to control the biomass-specific light intensity for the effective production of EPA and fucoxanthin in C. gracilis under high light conditions expected for outdoor culture.

Functional biscuits enriched with potato peel powder: Physical, chemical, rheological, and antioxidants properties

This research aimed to replace wheat flour with potato peel powder (PPP) at different levels (3, 5, 7, 10, 30, and 50%). An effect of PPP on physical, chemical, rheological, and antioxidant properties of biscuit samples was investigated. The results show that the PPP sample had a significantly higher content of total sugar, protein and ash, and a lower content of moisture (15.68g/100g dry weight, 15.32 g/100g dry weight, 9.11%, 8.35%, respectively) compared with the wheat flour sample. Also, a higher total phenolic content and antioxidant activity (71.12 mg Gallic acid equivalent / 100g dry weight and 68.39%, respectively) was observed in the PPP sample. The highest percentage of PPP addition (50%) exerted the greatest significant effect on the content of total sugar, protein, moisture, ash, total phenols, and antioxidant activity compared with the control sample and other biscuit samples leading to their increase to 50.90 g/100g dry weight, 12.74 g/100g dry weight, 5.56%, 2.39%, 41.71 mg Gallic acid equivalent / 100g dry weight, 59.72%, respectively. A decrease in the L*, a*, b*, C*, h and BI values, and an increase in ∆E values were observed with replacing wheat flour with PPP. The 3% and 5% replacement rates contributed to improving most organoleptic characteristics (general acceptability, color, taste) compared to the samples with the highest studied percentages (30% and 50%). Although the highest percentages of PPP addition led to lower scores for sensory characteristics, all studied samples were acceptable from the sensory point of view, except the samples with the 50% replacement rate in terms of their taste and color.

Comammox Nitrospira and Ammonia-Oxidizing Archaea Are Dominant Ammonia Oxidizers in Sediments of an Acid Mine Lake Containing High Ammonium Concentrations.

Exploring nitrifiers in extreme environments is vital to expanding our understanding of nitrogen cycle and microbial diversity. This study presents that complete ammonia oxidation (comammox) Nitrospira, together with acidophilic ammonia-oxidizing archaea (AOA), dominate in the nitrifying guild in sediments of an acid mine lake (AML). The lake water was characterized by acidic pH below 5 with a high ammonium concentration of 175 mg-N/liter, which is rare on the earth. Nitrification was active in sediments with a maximum nitrate production potential of 70.5 μg-N/(g-dry weight [dw] day) for mixed sediments. Quantitative PCR assays determined that in AML sediments, comammox Nitrospira and AOA amoA genes had relative abundances of 52% and 41%, respectively, among the total amoA genes. Further assays with 16S rRNA and amoA gene amplicon sequencing and metagenomics confirmed their dominance and revealed that the comammox Nitrospira found in sediments belonged to comammox Nitrospira clade A.2. Metagenomic binning retrieved a metagenome-assembled genome (MAG) of the comammox Nitrospira from sediments (completeness = 96.76%), and phylogenomic analysis suggested that it was a novel comammox Nitrospira. Comparative genomic investigation revealed that this comammox Nitrospira contained diverse metal resistance genes and an acidophile-affiliated F-type ATPase. Moreover, it had a more diverse genomic characteristic on nitrogen metabolism than the AOA in sediments and canonical AOB did. The results suggest that comammox Nitrospira is a versatile nitrifier that can adapt to acidic environments even with high ammonium concentrations. IMPORTANCE Ammonia-oxidizing archaea (AOA) was previously considered the sole dominant ammonia oxidizer in acidic environments. This study, however, found that complete ammonia oxidation (comammox) Nitrospira was also a dominant ammonia oxidizer in the sediments of an acidic mine lake, which had an acidic pH < 5 and a high ammonium concentration of 175 mg-N/liter. In combination with average nucleotide identity analysis, phylogenomic analysis suggested it is a novel strain of comammox Nitrospira. Moreover, the adaption of comammox Nitrospira to the acidic lake had been comprehensively investigated based on genome-centric metagenomic approaches. The outcomes of this study significantly expand our understanding of the diversity and adaptability of ammonia oxidizers in the acidic environments.

Effect of pH on Rhodomonas salina growth, biochemical composition, and taste, produced in semi-large scale under sunlight conditions

Rhodomonas salina is a microalgal species, belonging to the cryptophytes, and is widely used as aquaculture feed because of its high nutritional profile and phycoerythrin content. This study investigated the effect of pH on the growth, biochemical composition, and taste of R. salina when cultivated on a semi-large scale under natural light conditions. Two tubular photobioreactors (200 L) were used for the cultivation of R. salina with sunlight as the only illumination source. Two different pH setpoints were applied, 7 and 8.5. Optimal temperature and nutrient conditions were applied, according to previous research findings. The results demonstrated that the productivity of R. salina was higher at pH 7, 0.06–0.14 gdry weight L−1 day−1, compared to pH 8.5, 0.03–0.12 gdry weight L−1 day−1. It was found that protein and total fatty acid concentrations were higher in the biomass that was produced at pH 8.5, 33.7% and 12.3% of dry weight, respectively, while at pH 7, the protein content was 31.9% and the total fatty acids 8.8% of dry weight. The phycoerythrin concentration, like protein, was higher at pH 8.5, 2.7% of dry weight, compared to pH 7, 1% of dry weight. The free amino acid and nucleotide profile of R. salina was affected by the pH, resulting in increased equivalent umami concentration at pH 7. For the sensory evaluation, an expert panel on algae flavors evaluated the effect of pH on the taste of R. salina, reporting that the biomass that was produced at pH 7 had more umami flavor than the biomass that was produced at pH 8.5, which was evaluated as more bitter.

Mycochemical contents, Free-radical scavenging capacity and anti-microbial activity of wild edible mushroom from Algeria

Edible fungal species like desert truffles are often considered a healthy food source, contributing to high antioxidant and antimicrobial effects which have been used as functional foods for health promotion and disease prevention, and as treatments for a variety of diseases since antiquity. The use of desert truffles in traditional medicine has led to modern scientific investigation into their bioactive properties. This study is part of this perspective and consists of doing in a first time the determination of the nutritional value of Terfezia boudieri harvested from North-western of Algeria, Secondly, we have evalu-ated the antioxidant capacity using two complementary test systems, name-ly DPPH free radical scavenging and iron reduction (FRAP) , and finely the antimicrobial properties were screened against seventeen Gram positive and Gram negative pathogenic bacterial strains; and two strains of yeast using agar well diffusion method. The quantitative estimate of nutritional value shows that T. boudieri showed a preponderance of proteins and minerals with12.57 ± 0.13 and 15 ± 3g / 100g dry weight respectively; In addition, the methanolic extract of the ascocarps contains a high content of total phenols estimated at 44.68 ± 0.22 mg GAE / g, vitamin c and carotenoids are also present in large quantities. The methanolic extract has good capacity re-duction with iron. The free radical scavenging capacity DPPH is very inte-resting with an IC50 = 0.30 mg / ml; this last remains greater than the radical trapping capacity DPPH of ascorbic acid, whose IC50 = 0.08 mg / ml. Results of antimicrobial activity in particular against Gram (+) bacteria, the diameter of which varies from 10 ± 0.01 to 30 ± 0.57 mm where Bacillus subtilis ap-pears to be the most sensitive. On the other hand, they have moderate activ-ity against Gram (-) bacteria where Enterobacter cleacae, and Actinobacter baumannii, are the only Gram (-) bacteria that show hyper-sensitivity, our methanolic extract did not show anticandidal activity against Candida albi-cans. Therefore, the current results have demonstrated that this mushroom is nutritious and contain multiple antioxidants and has confirmed that desert truffle extracts have antimicrobial properties that are effective against com-mon pathogens that cause disease in humans, which can be further exploit-ed for clinical use.

Development of large-scale microalgae production in the Middle East

Microalgae in the Middle East can theoretically address food security without competing for arable land, but concerns exist around scalability and durability of production systems under the extreme heat. Large-scale Chlorella sorokiniana production was developed in outdoor raceway ponds in Oman and monitored for 2 years to gather data for commercial production. Biological and technical challenges included construction, indoor/outdoor preculturing, upscaling, relating productivity to water temperature and meteorological conditions, harvesting, drying, and quality control. Small cultivation systems required cooling for initial scale-up, but, despite maximum temperatures of 49.7 °C, water temperatures were at acceptable levels by evaporative cooling in larger raceway ponds. Contamination with Vampirovibrio chlorellavorus was identified by 16S rDNA amplicon sequencing and addressed by culture replacement. Productivities ranged from 8 to 30 g-dry weight m-2d-1, with estimated annual productivity of 16 g-dry weight m-2d-1 as functions of solar intensity and water temperature, confirming that the region is suitable for commercial microalgae production.

COMPARATIVE ASSESSMENT OF PHYTOCHEMICALS, ANTIOXIDANT ACTIVITY AND ANTIMICROBIAL ACTIVITY OF Cola acuminata, Garcinia kola and Vernonia amygdalina

Folin Ciocalteu’ s method was employed to screen Vernonia amygdalina leaf and the seeds of Garcinia kola and Cola accuminata for total polyphenols. The in vitro antioxidant activities of the extracts were evaluated by 1, 1 -diphenyl-2-picryl-hydrazyl (DPPH) assay. The result of the total polyphenol content indicated 3211.6, 1826.2 and 892.8mg (GAE)/100g dry weight of sample and the antioxidant activity ranged from 50.80, 46.00 to 36.32 for C. acuminata, G. kola and V amygdalia respectively. A high level of correlation (r2 = 0.927) was observed for total polyphenols and antioxidant activity. The methanol, chloroform and ethyl acetate extracts were also assessed for antimicrobial activity using agar well diffusion method. Screening for major classes of phytochemicals was done using standard chemical tests. The preliminary phytochemical test revealed the presence of flavonoids, tannins, saponins, phenols, alkaloids and steroids as the major chemical groups in these plant extracts. The plant extracts showed antibacterial activity against the test organisms. However, the highest spectrum of activity was indicated by Garcinia Kola as it was active against B. subtilis and S. mutans at a low concentration of 1.25mg/mi (l4 &amp; l2mm). The results obtained in the present investigation showed that the use of these plants as nutraceuticals may reduce the risk of microbial infections and diseases associated with oxidative stress.

Comparison between the Physicochemical Properties, Bioactive Compounds and Antioxidant Activities of Thai and Chinese Garlics

Garlic (Allium sativum L.) is an economically important vegetable that contains bioactive compounds and has high levels of antioxidant activity. Thus, it is commonly used in traditional medicine and culinary contexts. The aim of the present work was to compare the physiochemical and antioxidant properties and the bioactive compounds of three commonly used garlic cultivars in Thailand, the ‘Srisaket’, ‘Chiangmai’ and ‘Chinese’ cultivars. The results revealed that Srisaket garlic contained the highest amount of protein (32.96±0.51% dry weight), while Chiangmai garlic contained the highest amount of carbohydrate (73.81±0.44% dry weight). Chinese garlic contained the highest amounts of fiber (3.29±0.05% dry weight) and ash (6.03±0.07% dry weight) and the lowest amount of fat (0.15±0.01% dry weight). Antioxidative measurements indicated that Chinese garlic had the largest total phenolic content (543.8±13.4 mg gallic acid equivalent per 100g dry weight). However, Srisaket garlic contained the highest amounts of allicin (100.8±2.7 mg per 100 g dry weight) and total flavonoids (95.0±2.0 mg of quercetin equivalents), as well as the highest antioxidant activity (161.6±24.9 and 348.9±1.0 mg of trolox equivalents based on the DPPH and the ABTS assays, respectively). These results suggests that the Srisaket cultivar might confer greater health benefits than the Chiangmai and the Chinese cultivars. From the consumer acceptance test of fresh garlics (n=30), Thai consumers accepted all three cultivars with nonsignificant differences. The Srisaket cultivar was rated at 5.47±1.36 for overall liking because of its pungent flavor.

Combined cellulolytic and pectinolytic enzymes to increase the polyphenol extractability of coffee husks

Coffee husks (CHs) is a high biological activity by-product of the coffee bean industry, but currently, in Vietnam, it has not been used properly in the food industry. This study was conducted to investigate the combined cellulolytic and pectinolytic enzymes to increase the polyphenol extractability of coffee husks. The red ripe Robusta coffee cherries from Dăklak province, Vietnam were blanched, peeled and the coffee husks was then extracted. The effects of pectinase content (from 0 to 800 U/gCHs), cellulase content (from 0 to 800 U/gCHs), pH (from 3.0 to 5.0), temperature (from 40◦C to 60◦C), CHs: solvent ratio (from 1: 6 to 1:12) and extracted time (from 60 minutes to 120 minutes) on soluble solid content (SSC), total polyphenol content (TPC) and antioxidant activity were investigated. The appropriate conditions for the treatment were pectinase dosage of 600 U/gCHs, cellulase dosage of 400 U/gCHs, pH 4.0, temperature 50◦C, CHs:soluble ratio = 1:10 and incubation time of 60 min under which the SSC, TPC and antioxidant activity of extract were highest by 60.60.4 g/100g dry weight of CHs, 200.5 gGAE /100g dry weight of CHs, 1.5 +/- 0.1 mMTE/g dry weight of extract (according to DPPH assay) and 1.5 +/- 0.1 mMTE/g dry weight of extract (according to DPPH assay). From this result, it can be seen that the extracted solution from coffee husk is a potential source for the production of soft drinks with high antioxidant activity.

Antioxidant activity of water extract from bamboo by high-temperature and high-pressure steam treatment

The antioxidant activity of water extract from bamboo by high-temperature and high-pressure steam treatment was analyzed. Bamboo was decomposed by high-temperature and high-pressure steam treatment, and more decomposition products were extracted with water extraction. The maximum antioxidant activity, i.e., EC50 = 0.127 mg/mL, and the maximum flavonoid content, i.e., 3.94 mg-quercetin equiv./g-dry weight bamboo, of water extract were obtained at a treatment pressure of 30 atm for a steaming time of 5 min. Compared with the untreated sample, they showed about 4.16 times higher of antioxidant activity and 6.02 times higher of flavonoid content. The maximum total polyphenol content, i.e., 35.7 mg-catechin equiv./g-dry weight bamboo, of water extract was obtained at 25 atm for 5 min. Compared with the untreated sample, it showed 6.69 times higher of total polyphenol content. The water extract from bamboo by high-temperature and high-pressure steam treatment was fractionated by high-performance liquid chromatography (HPLC). The structure of the fraction showing the highest antioxidant activity in the fractionated extract was determined. It had a structure having two highly reactive phenolic hydroxyl groups. The two phenolic hydroxyl groups reacted with reactive oxygen species (ROS) to cause a reduction reaction, thereby exhibiting antioxidant activity.

Effect of light quality and quantity on productivity and phycoerythrin concentration in the cryptophyte Rhodomonas sp.

The cryptophyte Rhodomonas sp. is a potential feed source for aquaculture live feed and resource for phycoerythrin (PE) production. This research investigates the influence of light, both quality and quantity, on the biomass productivity, composition and growth rate of Rhodomonas sp. The incident light intensity used in the experiments was 50 μmolphotons m−2 s−1, irrespective of the colour of the light, and cultivation took place in lab-scale flat-panel photobioreactors in turbidostat mode. The highest productivity in volumetric biomass (0.20 gdry weight L−1 day−1), measured under continuous illumination, was observed under green light conditions. Blue and red light illumination resulted in lower productivities, 0.11 gdry weight L−1 day−1 and 0.02 g L−1 day−1 respectively. The differences in production are ascribed to increased absorption of green and blue wavelength by phycoerythrin, chlorophyll and carotenoids, causing higher photosynthetically usable radiation (PUR) from equal photosynthetically absorbed irradiance (PAR). Moreover, phycoerythrin concentration (281.16 mg gDW−1) was stimulated under red light illumination. Because photosystem II (PSII) absorbs poorly red light, the algae had to induce more pigments in order to negate the lower absorption per unit pigment of the incident available photons. The results of this study indicate that green light can be used in the initial growth of Rhodomonas sp. to produce more biomass and, at a later stage, red light could be implemented to stimulate the synthesis of PE. Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated a significant difference between the cells under different light quality, with higher contents of proteins for samples of Rhodomonas sp. cultivated under green light conditions. In comparison, higher carbohydrate contents were observed for cells that were grown under red and blue light.

Exploring Antioxidant Activity, Organic Acid, and Phenolic Composition in Strawberry Tree Fruits (Arbutus unedo L.) Growing in Morocco.

This study aimed to explore the main biochemical components and the antioxidant capacity of five strawberry tree fruits using three antioxidant essays within the ecotypic comparison scheme, to find out the most valuable fruit presenting disease-preventing properties. Total phenols, total flavonoids, total anthocyanins, antioxidant activity (DPPH, ABTS, and β-Carotene bleaching assays), pH, titratable acidity, soluble solids, and moisture content were investigated in five strawberry tree genotypes belonging to several areas in Morocco. Phenolic compounds were also identified using high performance chromatography (HPLC), with a diode array detector (DAD). High significant differences (p ˂ 0.05) were revealed among the examined genotypes regarding their total phenols (25.37–39.06 mg gallic acid equivalents (GAE)/g Dry weight (DW), total flavonoids (3.30–7.07 mg RE/g Dry weight (DW), total anthocyanins (0.15–0.64 mg cya-3-glu/100g Dry weight (DW), pH (2.44–3.92), titratable acidity (0.65–1.01 g malic acid/100g Fresh weight (FW), and soluble solids (14.83–18.53%). The average radical scavenging capacity, assessed using three methods, exhibited the following concentration ranges: 3.33–21.08, 2.25–19.58, and 1.08–13 mg Ascorbic Equivalent (AAE/g Dry weight(DW) for the DPPH scavenging test, ABTS, and β-carotene bleaching, respectively. Seventeen phenolic compounds were identified in sampled cultivars. Gallocatechol and catechin were found to be the major phenolic compounds. The correlation matrix revealed significant correlations among investigated variables, particularly ABTS and DPPH. The principal component analysis showed that the first three components formed 90.25% of the total variance. The following variables: chlorogenic acid, ellagic acid derivative, ellagic acid, rutin, and cyanidin−30.5-diglucoside, were the most involved in the total variance. The results revealed highly promising physico-biochemical profiles within the studied strawberry tree genotypes.

Towards the Utilization of Date Palm (&lt;i&gt;Phoenix dactylifera&lt;/i&gt;) Leaves as a Rich Source of Antioxidants

Three varieties of date palm (Phoenix dactylifera) leaves (DPL) namely: Sagaie, Khalas, and Nabtat Alsaif were examined for their antioxidant activities. DPL extracts showed a total phenolic content ranged between 1498.14 ± 100.52 - 4374.76 ± 657.64 mg gallic acid equivalent (GAE)/100g dry weight (DW) and a total flavonoid ranged between 134.70 ± 16.24 - 224.62 ± 22.35 mg quercetin (QE)/100g (DW). The IC50s for scavenging ABTS radical were ranged between 71.87 ± 14.37- 217.87 ± 27.40µg Trolox equivalent, whereas that required for scavenging DPPH were ranged between 197.86 ± 17.60-693.32 ± 25.44 µg ascorbic acid equivalent. DPL extracts potentially scavenged hydroxyl and superoxide anion radicals, IC50s values were ranged between 208.04 ± 12.76-719.63 ± 24.38 and 825.92 ± 19.40 -1193.20 ± 28.74µg GAE respectively. DPL extracts showed a good activity against ferric reducing antioxidant power (FRAP) ranged between 7.69 ± 0.47- 22.13 ± 1.36 mmol ascorbic acid equivalent/100g. DPL extracts showed a considerable antioxidant activity, therefore, DPL could be effectively used as natural source of antioxidant in food and pharmaceutical industries.

Influence of the Maturity Stage on the Phytochemical Composition and the Antioxidant Activity of Four Andean Blackberry Cultivars (Rubus glaucus Benth) from Ecuador.

Andean blackberries (Rubus glaucus Benth) are fruits rich in phytocomponents with high antioxidant activity. In this work, the changes in the total polyphenol content (TPC), the total flavonoid content (TFC), and the total anthocyanin content (TAC) of four blackberry varieties at three maturity stages (E1-25%, E2-50%, and E3-100%) were measured. The antioxidant activity (AA) was evaluated using the 2,2’azinobis-(3-ethylbenzthiazolin 6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) methods. TPC and TFC content decreased with the increase in the maturity stage. The blackberry Brazos cultivar presented TPC values of 51.26, 38.16, and 31.59 mg of gallic acid equivalents (GAE)/g dry weight (DW) at E1, E2, and E3, respectively. The TAC and soluble solids increased with the increase in the maturity stage of the fruits. The Andimora variety at E3 presented a high TPC content, and the Colombiana variety presented a high TFC content. The blackberry Colombiana cultivar presented TAC values of 1.40, 2.95, and 12.26 mg cy-3-glu/100g DW at E1, E2, and E3, respectively. The blackberry Colombiana cultivar presented a high AA value at 1278.63 µmol TE/g DW according to the ABTS method and 1284.55 µmol TE/g DW according to the FRAP method. The TPC and TFC showed a high correlation with the AA according to the ABTS and the FRAP methods. The Pearson correlation between the TFC and AA/ABTS has a value of r = 0.92. The TFC and AA/FRAP present a value of r = 0.94.

Non-destructive determination of the main chemical components of red dragon fruit peel flour by using Near-Infrared Reflectance Spectroscopy (NIRS)

Red dragon fruit peel is still not optimally utilized and only becomes waste. According to previous research, it is known that red dragon fruit peel contains 72.1% carbohydrate, 0.7% fat, 3.2% protein, and 46.7% food fiber and contains betacyanin of 186.90 mg / 100g dry weight and 53.71% antioxidant. One of the solutions to use red dragon fruit peel is to process it into flour. The accurate and efficient determination of the chemical content of red dragon fruit peel flour can be realized through the development of the Near-Infrared Reflectance Spectroscopy (NIRS) technology. The sample that used was made directly from the waste of red dragon fruit peel with a process of flouring, then measured the spectra with NIRS and the chemical content of the sample destructively. The reflectance spectra as output were transformed into absorbance spectra. Data calibration uses a partial least squares (PLS) method with several variations in the number of factors and pretreatment data in the form of normalization and smoothing Savitzky-Golay smoothing (SGs), resulting in the best calibration regression model in estimating water, ash, carbohydrate, and protein content. In contrast, the estimation of fat cannot be done non-destructively by using the NIRS method.

Accumulation of polyphenols and flavonoids in Atriplex canescens (Pursh) Nutt stressed by heavy metals (zinc, lead and cadmium)

Pollution of the environment and soils by heavy metals is one of the major problems of our time. Our study was to determine the effect of five doses for : zinc, lead and cadmium (0, 2500, 5000, 7500, and 10000 ppm) applied to the Atriplex canescens after 60 days for two weeks. The results showed an increase in the total polyphenols and flavonoids, depending on the increasing concentration of heavy metals at the leaf and root levels. The leaves have total polyphenols and flavonoids higher than those of the roots. The highest levels of total polyphenols and flavonoids in the leaves (3.47 mg EAG/ gdry weight of total polyphenols and 3.70 mg EQ/g dry weight of flavonoids) were obtained at a dose of 10000 ppm (cadmium, lead) respectively. On the other hand, the highest levels of total polyphenols and flavonoids in the roots were obtained at the metallic dose of 10000 ppm for cadmium (3.38 mg EAG/ gdry weight of total polyphenols and 0.61 mg EQ/g dry weight of flavonoids). These results also underlined the important role of secondary metabolites (total polyphenols and flavonoids) in the defense against oxidative stress caused by metallic stress.

Effect of Gibberellic Acid on Production of Biomass, Polyphenolics and Steviol Glycosides in Adventitious Root Cultures of Stevia rebaudiana (Bert.).

In current study, the effect of gibberellic acid was tested for production of biomass, polyphenolics and Steviol glycosides in adventitious root cultures of Stevia rebaudiana. Adventitious cultures were induced from the roots of in vitro grown plantlets on Murashige and Skoog (MS) medium containing combination of gibberellic acid (GA3; 0.5, 1.0, 1.5 and 2.0 mg/L) and naphthalene acetic acid (NAA; 0.5 mg/L). Initially, a known mass of inoculum roots were shifted into suspension media augmented with various GA3 concentrations. The growth behavior of adventitious roots was recorded every 3 days for a period of 30 days. Maximum biomass biosynthesis (13.12 g/flask) was noticed in exponential phase on 27th day in the suspension containing 2.0 mg/L of GA3. Other GA3 concentrations also displayed optimum patterns of biomass accumulation as compared to the control. Adventitious roots were investigated for total phenolic content (TPC) and production (TPP), total flavonoid content (TFC) and production (TFP), and 1, 1-diphenyl-2-picrylhydrazyl (DPPH)-based antioxidant potential. Maximum phenolics (TPC 9.84 mg gallic acid equivalent (GAE)/g-dry weight (DW)) and TPP (147.6 mg/L), TFC (5.12 mg Quercitin equivalent (QE)/g-DW) and TFP (76.91 mg/L) were observed in 2.0 mg/L GA3 treated cultures. The same concentration of gibberellic acid enhanced antioxidant activity (77.2%). Furthermore, maximum stevioside (7.13 mg/g-DW), rebaudioside-A (0.27 mg/g-DW) and dulcoside-A (0.001 mg/g-DW) were observed in roots exposed to 2.0 mg/L GA3. This is the first report on the application of GA3 on biomass accumulation and secondary metabolite production in S. rebaudiana. The current study will be helpful to scale up the adventitious root cultures in bioreactors for the production of biomass and pharmaceutically important secondary metabolites.

Impact of Thermal, Agitation and Microwave Assisted Extraction on Flavonoids from Red Beet (Beta vulgaris L)

In recent years, there has been a growing interest in the biological activity of red beet and its potential utility as one of the health promoting and disease preventing functional food. The objective of the study was to investigate the influence of extraction techniques such as Thermal, Agitation assisted extraction (AAE) and Microwave assisted extraction (MAE) on flavonoid content of red beet using different solvent compositions viz., T1 Distilled water ii) T2-Distilled water + 0.5% citric acid, iii)T3- 20% Ethanol, iv) T4–20% Ethanol+ 0.5% citric acid, v)T5–50% Ethanol, vi)T6- 50% Ethanol +0.5% citric acid. The impact of solvent systems and extraction techniques were evaluated at different temperatures (40, 50 and 60°C), agitation speeds (150, 170 and 190 rpm) and microwave power levels (160, 320 and 480 W). It was found that highest flavonoid content was observed in AAE at 190 rpm as 11.62 mg quercetin equivalent (QE)/100g dry weight (DW)in T4 followed by 8.00 mg QE/100g DWat 480 W in T5 through MAE and 7.16 mg QE/100g DW in thermal extraction at 40°C in T5. The effect of solvent composition on extraction methods was found significant and MAE evolved as efficient process for the extraction of flavonoids from red beet.

Effects of nitrogen source heterogeneity on nutrient removal and biodiesel production of mono- and mix-cultured microalgae

Effects of nitrogen source inhomogeneity on nutrient removal and biodiesel production of mono- and mix-cultured microalgae were investigated in this study. The microalgal growth characteristics, lipid accumulation, biodiesel production and nutrient removal were determined by mono- or co-culturing microalgae Chlorella vulgaris and Scenedesmus dimorphus in media with different nitrogen sources. The results showed that microalgae cultivated in media with different nitrogen sources indicated higher nitrogen removal, biomass increase and productivities of biomass, lipids and biodiesel than media with the sole nitrogen source. As for the microalgae grown in media with the same nitrogen source, the pattern for the lipid content was in the relationship C. vulgaris > mixed culture > S. dimorphus. The fatty acids of microalgae mainly consisted of C16:0, C16:1, C18:0, C18:2 and C18:3, accounting for 79.6–90.6% of the total. The biodiesel production in this study ranged from 8.5 to 11.2 g-biodiesel/100 g-dry weight. This study presents one of the few studies, suggesting that nitrogen source itself can influence the nutrient removal and biodiesel production of mono- and mix-cultured microalgae.

Phytochemical Content, Radical Scavenging Ability &amp;amp; Enzyme Inhibiting Activities of Selected Spices (Cinnamon, Cardamom and Cloves)

Cinnamon, cardamom and cloves have been widely used for medicinal purposes as well as essential cooking ingredients for flavor. The objective of the research was to investigate the antioxidant content, antioxidant capacity, and inhibition of lipid and carbohydrate metabolizing enzyme activities of selected spices (cinnamon, cardamom & cloves) methanol (ME) and water extracts (WE). The phytochemical content was determined by total phenolic and total flavanoid content. The antioxidant potential was determined by measuring 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and Ferric Reducing Antioxidant Power (FRAP) in spice’s (ME) and (WE) extracts. Total phenolic (GAE mg/100g dry weight) and flavonoid (mg CE/100g dry weight) content were the highest in Cloves (ME) 174.4 and 101.06. The lowest values for phenolic content were seen in ME and WE of Cardamom at 31.24 and 7.55. The DPPH IC50 values ranged from 0.22mg/mL (Cloves ME) to 0.60mg/mL (Cardamom ME). FRAP (μmol Fe2+/100g dry weight) for Cinnamon, Cardamom (ME) was 2438.5 and 325. Clove (ME) had a significantly higher reducing potential of 6888.5 which might have been attributed by the high amounts of phenolics and flavonoids in the spice. FRAP in spice extracts (WE) was lower with values of 2296.5 and 218.5 and 2310.5, respectively. The highest inhibition of the α-glucosidase was observed by Clove (ME) 86.5%, which also had the highest amylase enzyme inhibition at 71%. However, inhibition of the lipase enzyme was highest by the Cinnamon (WE) extracts 44.3%. The potential of phytochemicals in spices was studied and if consumed in high amounts could offer antioxidative properties and regulate key digestive enzymes which may lead to prevention or decreased progression of diseases such as Cancer, Diabetes and Cardiovascular diseases.