Antioxidant Properties of Extracts Obtained from Raw,Dry-roasted,and Oil-roasted US Peanuts of Commercial Importance

Raw, skinless peanut kernels from US commercial production lines were dry- and oil-roasted according to standard industrial practices. Eighty percent (v/v) methanolic extracts from the peanut cultivars were prepared and characterized by RP-HPLC: five predominant compounds were found comprising free p-coumaric acid and potential p-coumaric acid derivatives, as elucidated by DAD-UV spectra with comparisons to those of commercial standards. A Spanish high-oleic peanut possessed the greatest naturally-occurring level of p-coumaric acid and its derivatives, followed by a high-oleic Runner, a normal Runner, and a Virginia peanut. Upon thermal processing, p-coumaric acid was liberated at the expense of its derivatives according to the relationship: oil roasting > dry roasting > raw. A high-oleic Runner exhibited the greatest increase (～785%) in free p-coumaric acid levels after oil roasting. For many of the samples from the 2007 crop, processing increased the TPC and antioxidant capacities in the order of raw < dry roast < oil roast, but results were cultivar dependent. Oil-roasted peanuts were more effective at scavenging O₂ ^●- than their dry-roasted counterparts, as determined by a photochemiluminescence assay. Overall findings indicate that although thermal processing altered the composition of peanut kernel antioxidants, TPC values and radical-scavenging activities are preserved. Depending on peanut type, cultivar, and harvest date, enhanced antioxidant capacities can result.     

<Emphasis Type="Italic">Prunus persica</Emphasis> var. <Emphasis Type="Italic">platycarpa</Emphasis> (Tabacchiera Peach): Bioactive Compounds and Antioxidant Activity of Pulp,Peel and Seed Ethanolic Extracts

A comparative analysis of ethanol extracts from peel, pulp and seed of Prunus persica var. platycarpa (Tabacchiera peach) was done. The total phenol, flavonoid and carotenoid content as well as the antioxidant properties by using different in vitro assays (DPPH, ABTS, FRAP, Fe-chelating, β-carotene bleaching test) were evaluated. Pulp extract was subjected to liquid chromatography-electrospray-tandem mass spectrometry (HPLC-ESI-MS/MS). Gallic acid, protocatechuic acid, protocatechualdehyde, chlorogenic acid, p-coumaric acid, and ferulic acid were identified as main constituents. Pulp extract was characterized by the highest total phytonutrients content and exhibited the highest antioxidant activity in all in vitro assays (IC₅₀ values of 2.2 μg/mL after 60 min of incubation by using β-carotene bleaching test and 2.9 μg/mL by using Fe-chelating assay). Overall, the obtained results suggest that P. persica var. platycarpa displays a good antioxidant activity and its consumption could be promoted.     

Functional Teas from the Leaves of <Emphasis Type="Italic">Arbutus unedo</Emphasis>: Phenolic Content,Antioxidant Activity,and Detection of Efficient Radical Scavengers

The phenolic content/composition and antioxidant activity of hot/cold infusion and decoction from the leaves of Arbutus unedo were studied for the first time. 1,1-diphenyl-2-picrylhydrazyl (DPPH^●), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS^●+), crocin-bleaching, copper-reducing, and liposome accelerated oxidation assays were used for the evaluation of the activity in vitro. In vivo, the extracts were examined for their ability to protect S. cerevisiae cells from H₂O₂ induced oxidative stress. An on-line high-performance liquid chromatography-DPPH^● assay was applied to identify potent radical scavengers and comment on their contribution to the total activity. The addition of leaves to boiling water (decoction) was the most appropriate practice to apply since the highest phenol intake (220.2 mg gallic acid/cup served) was obtained. Additionally, its antioxidant activity was equal or superior to that of the other extracts. Flavonols (~51–61 mg/g dry extract) were the main phenols in all the extracts, with quercitrin accounting for ~20% of the total phenol amount. The on-line DPPH^● method verified the high potency of the decoction and indicated as the most active radical scavengers, two galloylquinic acid derivatives and myricitrin, accounting for ~28–45% and ~11–13% of the total scavenging, respectively. Present data may contribute to the future exploitation of A. unedo leaves by the food industry for health-promoting herbal tea preparations and dietary supplements.     

Anti-proliferative Effect of <Emphasis Type="Italic">Melissa officinalis</Emphasis> on Human Colon Cancer Cell Line

Melissa officinalis L. (Lamiaceae) is consumed as a traditional herbal tea in the Mediterranean region. The cytotoxic effect of the 50% ethanolic and aqueous extract, determined by the MTT and NR assays, was evaluated in vitro on Human Colon Cancer Cell Line (HCT-116), using Triton 10% as positive control. The 50% ethanolic extract showed significant differences after 72 h of treatment, reducing cell proliferation to values close to 40%, even the lowest dose tested (5 μg/ml). In the MTT assay, the same extract caused the lowest cell viability with 13% at a concentration of 1,000 μg/ml after 72 h of treatment, being a value lower than Triton 10%. The antioxidant activity was also confirmed evaluating the capacity of the extracts to scavenge ABTS and DPPH radicals, and IC₅₀ values were highly correlated with the total phenolic and flavonoid content. Bioassay guided fractionation led to the isolation of an anti-proliferative compound, rosmarinic acid. Its structural elucidation was performed by HPLC/DAD/ESI/MS analysis. High dose of rosmarinic acid (1,000 μg/ml) was clearly cytotoxic against HCT-116 cells, with a significant decrease in cell number since the earliest time point (24 h).     

Investigation of the Potential Health Benefits as Lipase Inhibitor and Antioxidant of <Emphasis Type="Italic">Leopoldia comosa</Emphasis> (L.) Parl.: Variability of Chemical Composition of Wild and Cultivated Bulbs

There is a great interest in the nutritional value of vegetables and fruits and how the habitat affects nutritive and biological properties. In vitro studies here reported were performed to evaluate the inhibitory activity of formulations from edible plant on pancreatic lipase. The aim of this study was also to evaluate the biovariability of L. comosa (L.) Parl. bulbs from Italy. The wild bulbs were compared with the same cultivated species that are commonly commercialized to identify samples with the best quality for a potential therapeutic application. Hydroalcoholic extract and polar fraction of wild bulbs showed a very important pancreatic lipase inhibitory activity, with IC₅₀ values of 0.166 ± 0.005 and 0.153 ± 0.005 mg/mL, respectively. In order to characterize the extracts, gas chromatography associated with mass spectrometry (GC/MS) analysis was performed, revealing the predominance of palmitic acid. Phenolic and flavonoid composition was also evaluated. L. comosa extract obtained from wild bulbs demonstrated both antioxidant and anti-obesity activities that might be attributed to a wide range of present phenolic compounds.     

<Emphasis Type="Italic">Limoniastrum monopetalum</Emphasis> stems as a new source of natural colorant for dyeing wool fabrics

In the present study, an attempt has been made to dye the wool fabric with Limoniastrum monopetalum stems, as a source of natural dye, which has not been exploited so far. Optimization of extraction parameters was done. Optimum results of extraction process were obtained with a dye concentration of 60 g/l, a temperature of 90 °C during 100 min. The study of different factors effecting dyeability of wool fabrics by aqueous L. monopetalum stems extract showed that the pH of dye bath and dyeing temperature and time affected considerably the color yield. The best results were obtained at the following conditions; pH 2, 100 °C, and 60 min. Metal mordants, when used in conjunction with L. monopetalum dye, allowed to obtain various shades. The determination of phenolic contents of aqueous L. monopetalum stems extract showed a high amount of phenolic components. Based on RP-HPLC, the coloring extract of L. monopetalum stems contains tannins and polyphenols. The major identified phenolic compounds were procatechuic, Trans-cinnamic and gallic acids. Hence, aqueous L. monopetalum stems extract could be successfully exploited for dyeing wool fabrics with high color yield (K/S).     

Colorimetric Analysis of <Emphasis Type="Italic">Hibiscus</Emphasis> Beverages and their Potential Antioxidant Properties

In food industry, roselle beverages and their subproducts could be functional ingredients since they are an excellent source of bioactive compounds with improved performance due to their important anthocyanins content. The aim of this study was to analyze anthocyanin content and antioxidant properties of aqueous infusions elaborated with color contrasting Hibiscus materials and design a mathematical model in order to predict color-composition relationship. Color measurements of beverages from roselle (Negra, Sudan and Rosa) were made by transmission spectrophotometry, anthocyanins quantification was determined by HPLC, and antioxidant potential was evaluated by in vitro methods (ABTS and FRAP assays). Beverages prepared with particle size minor of 250 μm presented until 4- and 2- times more anthocyanins content and antioxidant capacity respectively, in comparison to beverages prepared with powders with particle size major of 750 μm. Positive correlations among pigments composition and color parameters were found (p?<?0.05), showing that anthocyanins content, antioxidant capacity, C*_ab and h_ab values increased in relation with the smallest particle size of flours. Also, mathematical models were stablished to predict anthocyanin content (r?≥?0.97) and antioxidant capacity (r?≥?0.89) from color data; we propose equations for quick estimation of the antioxidant capacity in the Hibiscus beverages with high anthocyanin content. The obtained models could be an important tool to be used in food industry for pigment characterization or functional compounds with potential health benefits.     

Phenolic Compounds,Volatiles and Antioxidant Capacity of White Myrtle Berry Liqueurs

The aim of this research was to evaluate the antioxidant capacity and physical-chemical characteristics of commercial white myrtle berry (Myrtus communis L. var. leucocarpa DC) liqueur (WMBL). The total phenolic (TP) content was measured spectrophotometrically, applying a modified Folin-Ciocalteu’s method, and phenolic compounds were identified by high-performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry, and quantified by HPLC coupled with ultraviolet/visible detection. The antioxidant capacities were evaluated by FRAP, CUPRAC, DPPH^?, and ABTS^?+ assays. The volatiles were assessed by gas chromatography and mass spectrometry (GC-MS/FID) after headspace solid-phase microextraction (HS-SPME) and liquid-liquid extraction (LLE). WMBL showed lower TP levels (636.3 ± 39.2 mg GAE/L) than in purple myrtle berry liqueur (PMBL). Nevertheless, WMBL exhibited better antioxidant capacities, potentially due to high concentrations of gallic acid (294.2 ± 14.2 mg/L) and its derivatives (58.3 ± 2.1 mg/L). Other phenolic compounds detected by HPLC-DAD and LC-MS/MS were flavonols like myricetin and its derivatives (myricetin-3-O-galactoside and myricetin-3-O-rhamnoside) with concentrations similar to those found in PMBL. GC-MS/FID analysis revealed 44 compounds (terpenes, higher aliphatic compounds and shikimic acid pathway derivatives). 1,8-Cineole was the most abundant terpene in the liqueur (26.5% (HS-SPME) and 9.6% (LLE)).     

Hypolipidemic Activity of <Emphasis Type="Italic">Camellia euphlebia</Emphasis> Flower Extract in High–fat-fed Mice

Camellia euphlebia (family, Theaceae) has been used for the prevention and treatment of cardiovascular diseases in Southern China. However, there has been no report on the hypolipidemic activity of Camellia euphlebia flower. This study evaluated the hypolipidemic activity of different preparation of Camellia euphlebia flower extracts using in vivo models. Mice intragastrically administered aqueous extract at 400 mg/kg dose or ethanol extract at 100 and 400 mg/kg doses of Camellia euphlebia flower for 28 days exhibited significant decreases in the levels of total cholesterol, triglycerides and low-density lipoprotein cholesterol, while displaying increased level of high-density lipoprotein cholesterol in the serum. The Camellia euphlebia flower extracts also improved the antioxidant ability of hyperlipidemic mice as well as protecting the animals against liver damage by lowering the level of glutamic-pyruvic transaminase activity. Furthermore, 400 mg/kg ethanol extract effectively down-regulated the mRNA levels of fatty acid synthase, 3-hydroxy-3-methylglutaryl CoA reductase and glycerol-3-phosphate acyl transferase, suggesting that Camellia euphlebia flower extract may potentially inhibit lipid accumulation in the liver by regulating the expression of fatty acid synthase, 3-hydroxy-3-methylglutaryl CoA reductase and glycerol-3-phosphate acyl transferase. These results provided support for the potential hypolipidemic activity of Camellia euphlebia flower and could partly explain the basis of using Camellia euphlebia for the treatment of hyperlipidemia.     

The Protective Effect of Whole Honey and Phenolic Extract on Oxidative DNA Damage in Mice Lymphocytes Using Comet Assay

In this study, the antioxidant activity and the protective effect against hydrogen peroxide-induced DNA damage were assessed for five honeys of different botanical origin. Seven phenolic acids were detected in the honey samples. Ferulic acid was the most abundant phenolic acid detected in longan honey, jujube honey and buckwheat honey. Ellagic acid, p-hydroxybenzoic acid and protocatechuic acid were the main phenolic acids detected in vitex honey. Of all honey samples tested, the highest total phenolic content and antioxidant activity were found in buckwheat honey, whereas the lowest total phenolic content and antioxidant activity were found in locust honey. Treatment with hydrogen peroxide induced a 62% increase in tail DNA in mice lymphocytes, and all studied honeys significantly inhibited this effect (P < 0.05). The buckwheat honey with higher antioxidant capability also exhibited super protective effect than others. Phenolic extracts of honey displayed greater protective effects than whole honey in comet assay. The hydrogen peroxide-generated increase in 8-hydroxy-2-deoxyguanosine (8-OHdG) was effectively inhibited by the honeys studied (P < 0.05). Moreover, a dose-effect relationship between honey concentration and its protective effect was clearly observed in this study. It can be deduced that phenolic acids of honey can penetrate into lymphocytes and protect DNA from oxidative damage by scavenging hydrogen peroxide and/or chelating ferrous ions.     

<Emphasis Type="Italic">Lupinus albus</Emphasis> Conglutin Gamma Modifies the Gene Expressions of Enzymes Involved in Glucose Hepatic Production <Emphasis Type="Italic">In Vivo</Emphasis>

Lupinus albus seeds contain conglutin gamma (Cγ) protein, which exerts a hypoglycemic effect and positively modifies proteins involved in glucose homeostasis. Cγ could potentially be used to manage patients with impaired glucose metabolism, but there remains a need to evaluate its effects on hepatic glucose production. The present study aimed to analyze G6pc, Fbp1, and Pck1 gene expressions in two experimental animal models of impaired glucose metabolism. We also evaluated hepatic and renal tissue integrity following Cγ treatment. To generate an insulin resistance model, male Wistar rats were provided 30% sucrose solution ad libitum for 20 weeks. To generate a type 2 diabetes model (STZ), five-day-old rats were intraperitoneally injected with streptozotocin (150 mg/kg). Each animal model was randomized into three subgroups that received the following oral treatments daily for one week: 0.9% w/v NaCl (vehicle; IR-Ctrl and STZ-Ctrl); metformin 300 mg/kg (IR-Met and STZ-Met); and Cγ 150 mg/kg (IR-Cγ and STZ-Cγ). Biochemical parameters were assessed pre- and post-treatment using colorimetric or enzymatic methods. We also performed histological analysis of hepatic and renal tissue. G6pc, Fbp1, and Pck1 gene expressions were quantified using real-time PCR. No histological changes were observed in any group. Post-treatment G6pc gene expression was decreased in the IR-Cγ and STZ-Cγ groups. Post-treatment Fbp1 and Pck1 gene expressions were reduced in the IR-Cγ group but increased in STZ-Cγ animals. Overall, these findings suggest that Cγ is involved in reducing hepatic glucose production, mainly through G6pc inhibition in impaired glucose metabolism disorders.     

Phytochemical Properties and Antioxidant Activities of Extracts from Wild Blueberries and Lingonberries

Among Vaccinium species, blueberries (Vaccinium myrtillus L.) and lingonberries (Vaccinium vitis-idaea) are popular in the human diet. In this study, total phenolic, total flavonoid and total monomeric anthocyanin contents in the ethanol-water extracts of blueberry and lingonberry fruits grown wild in the forests in the central region of Poland were assayed. Antioxidant activities of the extracts from each plant were also evaluated for scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reducing power by cupric reducing antioxidant capacity (CUPRAC) method. Total phenolics in the blueberry extracts ranged from 4.58 to 5.28 mg GAE CE/g fw. The extracts from lingonberry fruits contained higher total contents of phenolic compounds (5.82–7.60 mg GAE/g fw) as well as total flavonoids (5.22–6.47 μmol CE/g fw) than those from blueberries (3.74–4.18 μmol CE/g fw). For the total monomeric anthocyanin contents, the blueberry extracts presented significantly higher values (3.01–3.93 mg cyanidin-3-glucoside (C3G) equivalent/g fw) in comparison to the lingonberry extracts (0.32–0.47). Blueberry extracts exhibited higher antioxidant activity measured by both assays in comparison to lingonberry extracts. Water extracts from fresh and dried fruits also exhibited significant antioxidant activities for both types of berries. Considering the health benefits that have been associated with polyphenolic consumption, these fruits could appear as a good source of this group of phytochemical compounds for their direct consumption or their use as ingredients for the design of new food products or food supplements.     

Nutrients,Antioxidant Capacity and Safety of Hot Water Extract from Sugar Maple (<Emphasis Type="Italic">Acer saccharum</Emphasis> M.) and Red Maple (<Emphasis Type="Italic">Acer rubrum</Emphasis> L.) Bark

Sugar maple (Acer saccharum M.) and red maple (Acer rubrum L.) barks were treated with hot water to extract nutrients in order to explore, for the first time, its potential as safe dietary antioxidants. The organic and inorganic nutrients of these extracts, as well as their safety on human PLB-985 cells differentiated into neutrophils-like cells, were determined. Proximate analysis showed that both bark extracts were low in moisture and fat. Sugar maple bark extract (SM-BX) showed crude protein and ash content higher than those found in red maple bark extract (RM-BX). In addition, SM-BX had total sugars higher than those evaluated in RM-BX, while complex sugars (oligo- and/or poly-saccharides) were similarly abundant in both bark extracts. Furthermore, SM-BX demonstrated a wide array of vital minerals (K, Ca, Mg, P, Na, Fe and Cu) in quantity larger than that evaluated in RM-BX, whereas RM-BX have Zn and Mn levels higher than those found in SM-BX. Phytochemical analyses showed that RM-BX exhibited total phenolic and flavonoid contents higher than those measured in SM-BX. Consequently, RM-BX presented an antioxidant activity higher than that of SM-BX: 2.85-fold ABTS radical cation scavenging capacity and 1.9-fold oxygen radical absorbance capacity. Finally, RM-BX and SM-BX were greatly safe since, at concentration up to 100 μg/ml, they did not modify the viability of neutrophils as determined by flow-cytometry assay using Annexin V-FITC/Propidum Iodide as markers. In conclusion, our in vitro studies indicate that both red and sugar maple bark extracts have a real potential as food additives.     

Rooting Characteristics of <Emphasis Type="Italic">Solanum chacoense</Emphasis> and <Emphasis Type="Italic">Solanum tuberosum in Vitro</Emphasis>

The precise level of environmental control in vitro may aid in identifying genetically superior plant germplasm for rooting characteristics (RC) linked to increased foraging for plant nitrogen (N). The objectives of this research were to determine the phenotypic variation in root morphological responses of 49 Solanum chacoense (chc), 30 Solanum tuberosum Group Phureja – Solanum tuberosum Group Stenotomum (phu-stn), and three Solanum tuberosum (tbr) genotypes to 1.0 and 0.5 N rate in vitro for 28 d, and identify genotypes with superior RC. The 0.5 N significantly increased density of root length, surface area, and tips. All RC were significantly greater in chc than in either phu-stn or tbr. Based upon clustering on root length, surface area, and volume, the cluster with the greatest rooting values consisted of eight chc genotypes that may be utilized to initiate a breeding program to improve RC in potato.     

Nutraceutical Properties of Herbal Infusions from Six Native Plants of Argentine Patagonia

Six native plants of South America traditionally consumed in the Patagonian region (southern Argentina and Chile), namely: Adesmia boronioides Hook. f., Apium australe Thouars, Buddleja globosa Hope, Drimys andina (Reiche) R. Rodr. & Quezada, Dysphania multifida L. and Solidago chilensis Meyen were investigated to determine the nutraceutical properties of infusions of their aerial parts. The infusions were characterized in terms of their antioxidant activity, phenolic and flavonoid content, profile of phenolic compounds, general toxicity and cytotoxicity on two different human cell lines: T84 (derived from colon cancer) and HTR8/SVneo (not derived from cancer). Twenty-nine compounds, mainly phenolic acids and flavonoids, were identified. This is the first analysis of phenolic compounds in infusions from native plants of Patagonia. D. andina, B. globosa and S. chilensis showed high levels of antioxidants, even higher than those of Green Tea. The content of phenolic compounds correlated significantly with the antioxidant activity of the samples analyzed. The toxicity test indicated that the use of A. australe, B. globosa and D. multifida seems safe, but a moderate consumption is suggested for A. boronioides, D. andina and S. chilensis until more exhaustive and long-term results are available. Moreover, A. boronioides and S. chilensis showed anticancer potential due to their antiproliferative activity on human cancer cell lines.     

Seasonal deviation effects foliar endophyte assemblage and diversity in <Emphasis Type="Italic">Asparagus racemosus</Emphasis> and <Emphasis Type="Italic">Hemidesmus indicus</Emphasis>

Background

Fungal endophytes are the living symbionts which cause no apparent damage to the host tissue. The distribution pattern of these endophytes within a host plant is mediated by environmental factors. This study was carried out to explore the fungal endophyte community and their distribution pattern in Asparagus racemosus and Hemidesmus indicus growing in the study area.

Results

Foliar endophytes were isolated for 2 years from A. racemosus and H. indicus at four different seasons (June–August, September–November, December–February, March–May). A total of 5400 (675/season/year) leaf segments harbored 38 fungal species belonging to 17 genera, 12 miscellaneous mycelia sterile from 968 isolates and 13 had yeast like growth. In A. racemosus, Acremonium strictum and Phomopsis sp.1, were dominant with overall relative colonization densities (RCD) of 7.11% and 5.44% respectively, followed by Colletotrichum sp.3 and Colletotrichum sp.1 of 4.89% and 4.83% respectively. In H. indicus the dominant species was A. strictum having higher overall RCD of 5.06%, followed by Fusarium moniliforme and Colletotrichum sp.2 with RCD of 3.83% and 3%, respectively. Further the overall colonization and isolation rates were higher during the wet periods (September–November) in both A. racemosus (92.22% and 95.11%) and H. indicus (82% and 77.11%).

Conclusion

Study samples treated with 0.2% HgCl₂ and 75% EtOH for 30 s and 1 min, respectively, confirmed most favorable method of isolation of the endophytes. Owing to high mean isolation and colonization rates, September–November season proved to be the optimal season for endophyte isolation in both the study plants. Assessing the bioactive potential of these endophytes, may lead to the isolation of novel natural products and metabolites.

     

<Emphasis Type="Italic">t</Emphasis>-Resveratrol Protects against Acute High Glucose Damage in Endothelial Cells

Postprandial hyperglycemia in diabetic and nondiabetic subjects is associated with endothelial dysfunction. Evidence shows that high glucose generates oxidative stress and a pro-inflammatory state promoting the development of cardiovascular diseases. trans-Resveratrol (t-RV) has been shown to reduce cardiovascular risk. To determine whether t-RV acts as a protector against acute high glucose (AHG)-induced damage, two in vitro models, rat aortic rings (RAR) and human umbilical vein endothelial cells (HUVEC) were used. RAR pretreated with AHG (25 mM D-glucose) for 3 h dramatically decreased the endothelium-dependent relaxation (EDR) induced by acetylcholine in phenylephrine (PE)-precontracted vessels. However, coincubation with t-RV significantly mitigated the damage induced by AHG on EDR. Pretreatment with AHG did not affect the vasodilation induced by sodium nitroprusside. HUVEC treated with t-RV decreased cytotoxicity and reduced radical oxygen species production induced by AHG. Taken together, these results suggest that t-RV can mitigate the AHG-induced EDR damage through a mechanism involving ROS scavenging and probably an increase in the bioavailability of NO.     

Multivariable Analysis of Gluten-Free Pasta Elaborated with Non-Conventional Flours Based on the Phenolic Profile,Antioxidant Capacity and Color

The phenolic compounds, color and antioxidant capacity of gluten-free pasta prepared with non-conventional flours such as chickpea (CHF), unripe plantain (UPF), white maize (WMF) and blue maize (BMF) were analyzed. Fifteen phenolic compounds (five anthocyanins, five hydroxybenzoic acids, three hydroxycinnamic acids, one hydroxyphenylacetic acid and one flavonol) were identified in pasta prepared with blue maize, and 10 compounds were identified for samples prepared with white maize. The principal component analysis (PCA) led to results describing 98% of the total variance establishing a clear separation for each pasta. Both the proportion (25, 50 and 75%) and type of maize flour (white and blue) affected the color parameters (L*, C _ab *, h _ab and ΔE* _ab ) and antioxidant properties (DPPH, ABTS and FRAP methods) of samples, thus producing gluten-free products with potential health benefits intended for general consumers (including the population with celiac disease).     

Water and air temperature impacts on rice (<Emphasis Type="Italic">Oryza sativa</Emphasis>) phenology

Air temperature (T_a) is commonly used for modeling rice phenology. However, since the growing point of rice is under water during the vegetative and the early part of the reproductive period, water temperature (T_w) is likely to have a greater influence on crop developmental rates than T_a during this period. To test this hypothesis, we monitored T_w, T_a, and crop phenology in three commercial irrigated rice fields in California, USA. Sampling locations were set up on along a transect from the water inlet into the field. (Water warms up as it moves into the field.) T_a averaged 22.7 °C across sampling locations within each field, but average seasonal T_w increased from 22 °C near the inlet to 23.4 °C furthest away from the inlet. Relative to T_w furthest from the inlet, low T_w near the inlet delayed time to panicle initiation (PI 5 days) and heading (HD 8 days) and the appearance of one yellow hull on the main stem panicle (R7 9 days). Using T_w instead of T_a when the active growing point is under water until booting (midway between PI and HD) in a thermal time model improved accuracy (root-mean-square error, RMSE) for predicting time to PI by 2.5 days and HD by 1.6 days and R7 by 1.8 days. This model was further validated under more typical field conditions (i.e., not close to cold water inlets) in six locations in California. Under these conditions, average T_w was 2.6 °C higher than T_a between planting and booting, primarily due to higher daily maximum T_w values. Using T_w in the model until booting improved RMSE by 1.2 days in predicting time to HD. Using T_w instead of T_a during this period could improve the accuracy of rice phenology models.     

Enhydrin Regulates Postprandial Hyperglycemia in Diabetic Rats by Inhibition of α-Glucosidase Activity

During the last few years, numerous attempts were made to identify effective α-glucosidase inhibitors from natural sources in order to develop new alternatives for diabetes management. Smallanthus sonchifolius (yacon) leaves were found to be effective in controlling postprandial hyperglycemia. Enhydrin, a constituent of yacon leaves, was noted for its significant hypoglycemic properties in diabetic rats. These properties were also demonstrated for yacon leaves decoction, which is rich in phenolic compounds such as chlorogenic acid and its derivatives. The purpose of the present study was to evaluate the potential of yacon leaves decoction and the isolated compound enhydrin to inhibit α-glucosidase enzyme, a possible mechanism of the above antihyperglycemic effect. In vitro assays showed that both 10% decoction and enhydrin significantly inhibited the activity of the yeast α-glucosidase enzyme in a dose-dependent manner, IC₅₀ values being 50.40 and 134.17 μg/ml, respectively. In vivo experiments showed a rapid decrease in the hyperglycemic peak after sucrose load (2 g/kg body weight) in normal rats treated with the 10% decoction (140 mg/kg) and enhydrin (0.8 mg/kg). Both treatments caused a significant decrease in blood glucose levels in diabetic rats after sucrose load compared to diabetic control. These results suggest that both products assayed could be effective in the management of postprandial hyperglycemia through inhibition of α-glucosidase in the small intestine.