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Identification and Quantification of Monosaccharides in Aloe vera Gel by Acid and Enzymatic Hydrolysis and Wet Heat Treatment

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Food and Nutrition Sciences 2017年第8期8卷 840-853页

作者： Dianeli Madera Pina Carlos Hernán Herrera Méndez Lourdes Vargas y Vargas Herbert Loria Sunza jorge tamayo cortez Research and Postgraduate Division Instituto Tecnológico de MéridaMéridaMexico Agroindustrial Engineering Department Campus Celaya-SalvatierraUniversidad de GuanajuatoSalvatierraMéxico

Aloe vera (Aloe barbadensis Miller) possesses curative and therapeutic properties attributed to the polysaccharides found in its tissue. This work aimed to study hydrolyzed (chemical and enzymatical) Aloe vera gel extracts using ultrafiltration membranes with a pore size of 0.22 micron (μm). Nine chemical treatments were achieved with H2SO4 and three wet heat treatments were carried out at a pressure of 1.2 lbf/in2 for 15 minutes;in both cases, three different concentrations of Aloe vera gel juice (AGJ) were used: 1.5%, 2.5% and 3.5% w/w. The concentrations of H2SO4 were 0.10%, 0.25% and 0.40% w/w. Chemical experiments are performed over a factorial 32 design and results were analyzed using SPSS software (version 17, SPSS Inc.), finding the one labeled T7 (15 ml of AGJ 3.5% with 15 ml of H2SO4 0.10% added) the best of them, as it leaded to 0.0446 mg/ml of liberated glucose. Among the three wet heat treatments, the one labeled TC3 (15 ml of AGJ 3.5% with 15 ml of H2O added) was the best-performing one, as it leaded to 0.292 mg/ml of liberated glucose. Furthermore, an enzymatic hydrolysis was carried out using Novozymes’ Pectinex? AR and Viscozyme?. Hydrolisis with both enzymes yield to better results than acid hydrolysis: in the treatment with Pectinex? AR, 3.282 mg/ml of liberated glucose were obtained and 3.302 mg/ml in the treatment with Viscozyme?. The hydrolyzed substances obtained by acid and enzymatic hydrolysis, as well as by wet heat treatment, were subsequently analyzed by thin layer chromatography (TLC), using glucose, galactose and arabinose 1000 ppm solutions as reference patterns. Among the treatments by H2SO4, the one labeled T4 obtained an Rf value of 50, the same as on the galactose reference pattern.

关键词： Carbohydrates Enzyme Mucilage Reducing Sugars Retention Factor

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Purification and Partial Characterization of Polyphenol Oxidase from Sapodilla Plum (<i>Achras sapota</i>)

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Food and Nutrition Sciences 2013年第7期4卷 727-734页

作者： jorge tamayo cortez Carlos Hernán Herrera Méndez Enrique Sauri Duch María de Lourdes Vargas y Vargas Sara Solís Pereira Agroindustrial Engineering Department Campus Celaya-Salvatierra Universidad de Guanajuato Salvatierra Mexico. Research and Postgraduate Division Instituto Tecnológico de Mérida Merida Mexico

The browning of fruits can be considered as an enzymatic oxidation which is believed to be one of the main causes of quality loss during post-harvest handling. The enzymes responsible for this are the oxidoreductases;the polyphenol oxidase (PPO) (monophenol, o-diphenol, oxygen oxidoreductase;EC 1.***.18.1) belongs to this group. This enzyme, which is found in the sapodilla plum (Achras sapota), was purified using a phenylsepharose and a SephacrylS-200 columns. The molecular weight of the purified enzyme was estimated to be about 66 kDa by gel filtration and 29 kDa by SDS-PAGE. A single protein band was found using the latter system (SDS-PAGE), which shows that the PPO of the pulp of the sapodilla plum may be composed of two protein subunits with similar molecular weight. The optimum pH was 7.0 and the optimum temperature 60℃. The most effective inhibitors tested were ascorbic acid, sodium metabisulfite and acetic acid.

关键词： Enzymatic System Oxidation Polyphenol Oxidase Browning Process Nutritional Value

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Extraction and Stability of Anthocyanins Present in the Skin of the Dragon Fruit (<i>Hylocereus undatus</i>)

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Food and Nutrition Sciences 2013年第12期4卷 1221-1228页

作者： María de Lourdes Vargasy Vargas jorge Abraham tamayo cortez Enrique Sauri Duch Andrés Pech Lizama Carlos Hernán Herrera Méndez Agroindustrial Engineering Department Campus Celaya-Salvatierra Universidad de Guanajuato Salvatierra México Research and Postgraduate Division Instituto Tecnológico de Mérida Mérida Mexico

The extraction of anthocyanins present in the skin of the dragon fruit was performed using trifluoroacetic acid (TFA) plus a mixture of methanol, acetic acid and water;the anthocyanins were then purified with a LC-18 cartridge, using methanol acidified with TFA as eluent, reaching concentrations of 44.3865 ± 1.3125 mg/100g of sample. The extracts were put through stability tests under different storage conditions, modifying the pH of the extracts (pH of 1, 4 and 6), the temperature (4℃, 25℃ and 68℃) and the absence and presence of light for a time period of 4 days;the tests indiated that anthocyanins remain more stable at a temperature of 4℃?with a pH of 4 in the absence of light, retaining up to 80% of the pigment. Three anthocyanins were partially identified in the extracts by high performance liquid chromatography (HPLC);they were: cyanidin 3-O-glucoside, cyanidin 3,5 O-glucoside and pelargonidin 3,5 O-glucoside.

关键词： Anthocyanins Dragon Fruit Stability

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Main Polysaccharides Isolated and Quantified of Aloe vera Gel in Different Seasons of the Year

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Food and Nutrition Sciences 2016年第6期7卷 447-453页

作者： Berenice Aranda Cuevas Carlos Hernán Herrera Méndez Ignacio Islas Flores Sara Solís-Pereira Luis Cuevas-Glory Gerardo Rivera Muñoz María de Lourdes Vargas y Vargas jorge tamayo cortez Research and Postgraduate Division Instituto Tecnológico de Mérida Mérida Mexico Agroindustrial Engineering Department Universidad de Guanajuato Campus Celaya-Salvatierra Salvatierra México Centro de Investigación Científica de Yucatán Mérida México

We developed and implemented a methodology that allowed extracting and evaluating high molecular weight polysaccharides present in the gel of Aloe barbadensis Miller. One of the fractions evaluated revealed the presence of high molecular weight carbohydrates (200 kDa) with a behavior similar to that of acemannan and another fraction with compounds of molecular weights between 17 and 47 kDa. We quantified the concentration of acemannan for two different growing periods. The concentration of acemannan in the high molecular weight fraction was 99.97 ppm in the rainy season and 106.03 ppm in the dry season. The concentration of acemannan in the fraction of low molecular weight was 9.364 ppm during the season of greatest rainfall and 26.939 ppm in the dry season.

关键词： Acemannan Aloe vera Gel Polysaccharides Rainy Season Dry Season

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Abundance and harvest strategy of three species of clam (BivalviaVeneridae) located in new fishing banks in the Gulf of California

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Aquaculture and Fisheries 2021年第5期6卷 506-512页

作者： jorge A.López-Rocha Francisco J.Fernández-Rivera Melo Ernesto Gastélum-Nava Estefani Larios-Castro Laboratorio de Análisis Espacial de Zonas Costeras Unidad Multidisciplinaria de Docencia e InvestigaciónFacultad de CienciasUniversidad Nacional Autónoma de M´exicoSisal97356YucatánMexico Comunidad y Biodiversidad A.C Guaymas85448SonoraMexico Centro de Investigaciones Biológicas Del Noroeste La Paz02320BCSMexico

Clams of the family Veneridae in northwest Mexico have traditionally been exploited by small-scale *** their socioeconomic importance for coastal communities in the region,most catch zones are currently in decline due to a lack of harvest control regulations that would impede the depletion of local fishing *** Puerto Libertad,in the northern reaches of the Gulf of California,banks of commercially unexploited clam species,including Megapitaria aurantiaca,*** and Dosinia ponderosa,were *** adequate management and exploitation of these banks requires developing basic knowledge regarding the abundance of the species and establishing reference points to determine clear,simple harvest *** goal of this study was to identify population abundance in these banks and ascertain the parameters of the life history of the species found there in order to propose a harvest strategy that will allow the sustainable exploitation of this resource.A total of 288 transects were conducted in the two clam banks to identify species *** was determined using a geostatistical *** relative cohort biomass-at-length was estimated to evaluate the effect of different lengths of first capture on the remaining *** on these data,two harvest control regulations were proposed:a maximum catch(Cmax)of 10%of the total estimated biomass,and a minimum optimal catch size(Lc).The abundance estimates were ***(266,293-381,881 individuals);***(2,779,100-3,455,597);and ***(408,783-447,391).The harvest control regulations proposed are:***,Cmax=2.98 t and Lc=50.33 mm;***,Cmax=49.67 t and Lc=103.44 mm;and ***,Cmax=15.87 t and Lc=80.85 *** results are important as reference information for implementing harvest strategies in clam-fishing banks,and as a contribution to the management and sustainable exploitation of fisheries in the region.

关键词： Bivalves Fishery management Population size Sea of cortez Veneridae

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Emerging and under-recognized Chagas cardiomyopathy in non-endemic countries

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World Journal of Cardiology 2012年第7期4卷 234-239页

作者： Joana cortez Rui Providência Evelise Ramos Cristina Valente jorge Seixas Manuela Meruje António Leito-Marques António Vieira Infectious Diseases Department Coimbra's Hospital Centre and University Cardiology Department Coimbra's Hospital Centre and University Hygiene and Tropical Medicine Institute Universidade Nova de Lisboa Pathology Department Coimbra's Hospital Centre and University

Due to recent population emigration movements,an epidemic of Chagas disease is currently menacing most developed *** authors report the case of a 53-year-old Brazilian woman living in Europe for the last 10 years who developed heart failure symptoms,having a previous symptomatic sinus node disease with a pacemaker implant at age of 40 *** diagnosis was based on serology and myocardial biopsy and the patient was treated with *** authors emphasize the need of a high level of suspicion in patients with suggestive epidemiology and the needof populational screening of specific high risk *** treatment options are also discussed.

关键词： Chagas disease Chagas cardiomyopathy Dysrhythmia Emigration Non-endemic countries Benznidazole Nifurtimox

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