Total phenolic content,in vitro antioxidant activity and chemical composition of plant extracts from semiarid Mexican region

Objective:To determine the extraction suitable conditions of total phenolic content(TPC) by heat-reflux system,antioxidant activities and HPLC characterization of the aqueous-ethanolic extracts of Jatropha dioica(J.dioica)(Dragon's blood).Flourensia cernua(F.cernua)(Tar bush).Eucalyptus camaldulensis(E.camaldulensis)(Eucalyptus) and Turnera diffusa(T.diffusa)(Damiana).Methods:TPC was evaluated by the well-known colorimetric assay using FolinCiocalteu reagent.The antioxidant activities were assayed by three methods based on scavenging of DPPH,ABTS and by lipid oxidation inhibition.The chemical composition of the extracts obtained was subject to HPLC analysis.Results:TPC in the plant extracts ranged from 2.3 to14.12 mg gallic acid equivalents/g for J.dioica and E.camaldulensis,respectively.The plant extracts of F.cernua,E.camaldulensis and T.diffusa showed similar strong antioxidant activities on scavenging of DPPH and lipid oxidation inhibition.In contrast,J.dioica extracts had lowest potential antioxidant in three assays used.HPLC assay showed the presence of several phenolic compounds in the extracts used.Conclusions:The results obtained suggest that F.cernua,E.camaldulensis and T.diffusa are potential sources to obtain bioactive phenolic compounds with high antioxidant properties which can be used in the factories as antioxidant agents or for treatments in diseases.

Isolation and pathogenicity of fungi associated to ambrosia borer (<i>Euplatypus segnis</i>) found injuring pecan (<i>Carya illinoensis</i>) wood

Euplatypus segnis is an insect pest of economic importance in pecan (Carya illinoensis) trees grown at Parras, General Cepeda and Torreón Coahuila, Mexico. The objectives in this study-were to identify the fungal strains associated to ambrosia borer body and diseased pecan wood and determine their pathogenicity. The results showed that the associated fungi to Euplatypus segnis and damaging the pecan wood were identified as: Helminthosporium sp., Aspergillus sp., Penicillium sp., Phoma sp., Ascochyta sp., Phaecylomices sp., Umbeliopsis sp., Torula sp., Fusarium solani, Alternaria alternata, Fusarum oxysporum, and Lasiodiplodia theobromae. The pathogenicity tests on healthy 3 year old pecan trees cv. western using Fusarium oxysporum, Fusarium solani, Alternaria alternata and Lasiodiplodia theobromae suspension conidia shown die back tree branches after 84 days inoculation. The insect in combination with the fungal invasion eventually cause the death of trees. Additionally, the insect contributes to the spread of fungi in pecan nut orchards.

Embryo and Endosperm Phytochemicals from Polyembryonic Maize Kernels and Their Relationship with Seed Germination

Because of the growing worldwide demand for maize grain,new alternatives have been sought for breeding of this cereal,e.g.,development of polyembryonic varieties,which agronomic performance could positively impact the grain yield per unit area,and nutritional quality.The objectives of this study were to(1)determine the phytochemicals present in the embryo and endosperm of grain from maize families with high,low,and null polyembryony frequency,which were planted at different locations,and(2)state the relationship between these compounds and seed germination.The extracted phytochemicals from corn were identified by HPLC-MS.The results showed that the genotype with the highest presence of phytochemicals was the brachytic population with high polyembryony called“BAP”,which also required less water during the germination process.The number of phytochemicals in both embryo and endosperm tissues was not related to the sowing location where they came from or the type of polyembryony.The number of different phytochemicals depended on the grain tissue from where they were extracted.The chemical compounds found in the different maize tissues were related to the development of the plant,either in roots or nibs because these are mainly associated with the lignin synthesis.

Development and characterization of whey protein films incorporated with tarbush polyphenols and candelilla wax

Edible films were prepared with whey protein incorporating candelilla wax,and glycerol in aqueous solution.Tarbush polyphenols were added as bioactive agent.An optimization based on the water vapor permeability(WVP)of the formulation was performed using a Box-Behnken design.The films were characterized by the determination of WVP,moisture,solubility,color,antioxidant and antifungal activity.Scanning electron microscopy(SEM)was also performed to observe the surface and cross-section micrographs.The lowest permeability values were found with concentrations of 1.27,0.3 and 0.5% of protein,wax and glycerol respectively.It was proved that the addition of polyphenols into films causes a significant effect only on solubility and transparency characteristics.Edible films have suitable properties as a barrier for the goods they could be applied on.It is proposed for use in foods such as fresh or minimally processed fruits and vegetables.