Volatile compounds of acerola (Malpighia emarginata) obtained by HS-SPME at two ripening stages

O aroma é uma das principais características dos alimentos e é determinado por uma combinação de moléculas voláteis presentes na matriz, sendo um dos seus atributos mais atraentes para o consumidor. Neste trabalho foram identificados compostos voláteis presentes em dois estágios de maturação da acerola. Para a análise, utilizou-se a técnica da microextração em fase sólida por headspace (HS-SPME – HeadSpace Solid Phase MicroExtraction) associada com a cromatografia gasosa de alta resolução acoplada a espectrômetro de massa (GC-MS – Gas Chromatography - Mass Spectrometry). A influência das fibras na extração dos voláteis via SPME (CAR/PDMS e DVB/CAR/PDMS) foi avaliada. Os efeitos da temperatura de extração, concentração do meio de extração (cloreto de sódio - NaCl) e quantidade de amostra foram estudados usando-se o Delineamento Central Composto (DCC) para avaliar a maior eficiência de extração. Observou-se que, na acerola madura (vermelha) e semimadura (amarela) os compostos predominantes foram os ésteres, dentre eles o etil hexanoato o 4-pentenil-butanoato foram os que apresentaram maior concentração relativa. Esta identificação é uma informação importante para a indústria de aromas, que utilizam diferentes compostos aromáticos para a formulação de fragrâncias e aromas para serem usados em alimentos, cosméticos e perfumes.Flavor is one of the main characteristics of food identified as a combination of volatile molecules present in the matrix and is one of its most attractive attributes to the consumer. In this research have been identified volatile compounds present in two stages of acerola maturation. For the analysis, have been used the following techniques and equipment: Headspace (HS-SPME) Solid Phase Microextraction Technique associated with High-Resolution Gas Chromatography coupled to mass spectrometer (GC-MS). The influence of SPME fibers (CAR / PDMS and DVB / CAR / PDMS) was evaluated on the volatiles extraction. The effects of extraction temperature, extraction medium concentration (NaCl) and amount of sample were studied using the Composite Central Delineation (CCD) to achieve the highest extraction efficiency. In mature (red) and semi-yellow (yellow) acerola the dominant compounds were esters; among them, ethylhexanoate and 4-pentenyl butanoate were the ones with the highest relative concentration. This identification is essential information for the flavors industry which use different aromatic compounds for the formulation of fragrances and aromas to be used in food, cosmetics, and perfumes.Revisión por paresCampus Arequip

HS-SPME-GC-MS detection of volatile compounds in Myrciaria jabuticaba Fruit

This study was performed to investigate the volatile compounds for the characteristic aroma in jabuticaba fruit distributed in southern and central regions of Brazil. The present work combines headspace solid phase microextraction (HS-SPME) and high resolution gas chromatography-mass spectrometry (GC-MS) techniques to identify and quantify the volatile compounds. The influence of different SPME fibers (CAR/PDMS and DVB/CAR/PDMS) in extraction of volatile compounds was evaluated. The effects of extraction temperature and salt concentration (NaCl) in the extraction medium were studied using the response surface methodology in order to achieve the highest extraction efficiency. The better extraction of volatile compounds was achieved by using a CAR/PDMS fiber and the optimum adsorption conditions were at 42 °C for 30 min and 5% NaCl concentration. A total of 71 compounds were identified, among these, 57% were terpenes which was the most representative class of compounds, followed by esters (19%), aldehydes (10%), alcohols (5.5%) and aromatics compounds (4.4%) and other organic compounds 2.8%. Limonene and ethyl acetate were the volatile compounds that showed highest relative concentration and these could contribute to the characteristic aroma of the jabuticaba fruit along with other compounds such as ?-pinene, d-cadinene, linalool, ?-guaiene, and a-caryophyllene.Revisión por paresCampus Arequip

The physical, chemical and functional characterization of starches from Andean tubers: oca (Oxalis tuberosa Molina), olluco (Ullucus tuberosus Caldas) and mashua (Tropaeolum tuberosum Ruiz & Pavón)

As propriedades físicas, químicas e funcionais de amidos isolados das tuberosas andinas, oca (Oxalis tuberosa M.), olluco (Ullucus tuberosus C.) e mashua (Tropaeolum tuberosum R. & P.), obtidas no comércio local, foram estudadas. A morfologia dos grânulos de amido foi avaliada por microscopia eletrônica de varredura (SEM) revelando formas elipsoidais, ovais, cônicas, periformes e prismáticas: grânulos elipsoides e ovais com dimensões de até 54,30 µm de comprimento para a oca, de até 32,09 µm para o amido de olluco, e com formas predominantemente esféricas ou ovais truncadas, de menores dimensões de até 16,29 µm para grânulos de amido de mashua. Os conteúdos de amilose foram similares entre as amostras: 27,60% (oca), 26,49% (olluco) e 27,44% (mashua). O amido de olluco teve menor poder de intumescimento, formando géis opacos e menos resistentes. Os géis dos três amidos mostraram a mesma estabilidade sob refrigeração e apresentaram alta sinérese após congelamento, com variação de 40,28 a 74,42% para amido de olluco. Os amidos tiveram cocção rápida com alto pico de viscosidade. A baixa temperatura de gelatinização e alta estabilidade durante a refrigeração fazem destes amidos matérias-primas adequadas para formulações que requeiram temperaturas brandas de processamento e que dispensem conservação por congelamento.The physical, chemical, and functional properties of starches isolated from the Andean tubers oca (Oxalis tuberosa M.), olluco (Ullucus tuberosus C.) and mashua (Tropaeolum tuberosum R. & P.) were studied. The tubers were obtained from a local grocery. The morphology of the starch granules (size and shape) was studied with scanning electron microscopy (SEM), which revealed ellipsoid, oval, conical, pear-shaped and prismatic forms: ellipsoids and oval granules with lengths up to 54.30 µm in oca; with lengths up to 32.09 µm for olluco starch granules; and with predominantly truncated spherical or oval forms and smaller dimensions (up to 16.29 um) for mashua starch granules. Amylose contents were similar among the samples: 27.60% (oca), 26.49% (olluco) and 27.44% (mashua). Olluco starch had less swelling power, forming opaque, less firm gels. All three starch gels showed the same stability on refrigeration and presented high syneresis under freezing temperatures, with a variation of 40.28 to 74.42% for olluco starch. The starches cooked easily, with high peak viscosity. The low gelatinization temperatures and high stability during cooling make these starches suitable feedstock for use in formulations that require milder processing temperatures and dispense freezing storage

HS-SPME-GC-MS detection of volatile compounds in Myrciaria jabuticaba Fruit

This study was performed to investigate the volatile compounds for the characteristic aroma in jabuticaba fruit distributed in southern and central regions of Brazil. The present work combines headspace solid phase microextraction (HS-SPME) and high resolution gas chromatography-mass spectrometry (GC-MS) techniques to identify and quantify the volatile compounds. The influence of different SPME fibers (CAR/PDMS and DVB/CAR/PDMS) in extraction of volatile compounds was evaluated. The effects of extraction temperature and salt concentration (NaCl) in the extraction medium were studied using the response surface methodology in order to achieve the highest extraction efficiency. The better extraction of volatile compounds was achieved by using a CAR/PDMS fiber and the optimum adsorption conditions were at 42 °C for 30 min and 5% NaCl concentration. A total of 71 compounds were identified, among these, 57% were terpenes which was the most representative class of compounds, followed by esters (19%), aldehydes (10%), alcohols (5.5%) and aromatics compounds (4.4%) and other organic compounds 2.8%. Limonene and ethyl acetate were the volatile compounds that showed highest relative concentration and these could contribute to the characteristic aroma of the jabuticaba fruit along with other compounds such as b-pinene, δ-cadinene, linalool, b-guaiene, and α-caryophyllene

Impact of mining on surface waters of the region Puno – Perú

El objetivo del presente estudio es evaluar las condiciones físicas y químicas de las aguas superficiales derivadas de los deshielos del nevado Riticucho en la Rinconada- Puno, los cuales evidentemente son afectados por la actividad minera informal desarrollada en esa localidad. El trabajo evalúa el efecto de esta actividad en sedimentos y agua de las lagunas Lunar y Cumunni, las cuales fueron evaluadas en temporada seca y temporada de lluvias en 2018. El análisis físicoquímico incluyó: pH, conductividad, OD, DBO5 , DQO, dureza, cloruros y sólidos en suspensión. También incluyó metales (As, Cd, Cu, Fe, Hg, Ni, Pb y Zn) en agua y sedimentos. El diseño de investigación es descriptiva, ya que se describen y analizan los datos encontrados, observándolos sin influenciar en ninguna variable del estudio. La metodología desarrollada fue la propuesta en los Métodos Estandarizados para el Agua: APHA, AWWA 2012, que incluye técnicas nefelométricas, fotométricas y colorimétricas. Los resultados fueron comparados con normas de calidad ambiental peruanas, canadienses y niveles de referencia para los Estados Unidos de América. Los resultados muestran valores fuera de las normas establecidas, principalmente el pH ácido y aguas duras. Los metales Cd, Ni, Pb, Fe y Zn también exceden los límites de los estándares. La concentración de Hg en sedimentos alcanzó valores altos de 20,13 y 33,32 mg/Kg en época de lluvias y seca respectivamente.This work evaluates the effect of mining activity on sediments and water from the Lunar and Cumunni lagoons, in Puno. Surface waters were evaluated in the dry season and rainy season in 2018. The physical-chemical analysis included: pH, conductivity, DO, BOD5, COD, hardness, chlorides and suspended solids. It also included metals (As, Cd, Cu, Fe, Hg, Ni, Pb and Zn) in water and sediments. The results were compared with Peruvian and Canadian environmental quality standards and reference levels for the United States of America. The results show values outside the established norms, mainly acid pH and hard water. The metals Cd, Ni, Pb, Fe and Zn also exceed the limits of the standards. The concentration of Hg in sediments reached high values of 20.13 and 33.32 mg / Kg in the rainy and dry season respectively.Campus Arequip

Partial characterization of carbohydrases, morphology of starch granules and chemical composition from roots of maca (Lepidium meyenii Walpers)

A maca é uma raiz aromática com 52 a 76% de carboidratos e seu período de conservação pós-colheita é bastante longo, sem demonstrar sinais de deterioração. O mecanismo de degradação do amido e dos componentes da parede celular via ação enzimática não eram ainda conhecidos. O objetivo do trabalho foi caracterizar a ação de enzimas amilolíticas e pectinolíticas nessas raízes, bem como a morfologia do grânulo de amido e a composição centesimal. Os resultados mostraram que foi obtida a purificação parcial de β-amilase com peso molecular aproximado de 57 kDa, com atividade máxima a 40,7 ºC e pH de 5,1. A pectinesterase foi extraída a pH 6,0 com maior atividade a 49,4ºC e pH 6,6 a maior atividade da poligalacturonase foi a 46 ºC e pH 5,4, quando extraída a pH 8,5.O teor de amido total foi de 8,92%, os grânulos apresentaram morfologia oval em observados em microscopia eletrônica de varredura (MEV).Maca is an aromatic root that contends 52 to 76 per cent of carbohydrates and is very stable for a long period without signals of deterioration. The degradation mechanisms of the reserve carbohydrates and the cell wall components by enzymatic way had not been described yet. The main objective of this study was the identification of inner enzymes which degrades the starch and the pectins; the others objectives were the analysis and the morphology of the starch grains as well as the root\'s contend composition. The results showed that was obtained the partial purification of a β- amylase, characterized by the molecular mass of 57 kDa, with a highest activity at 40.7 °C and pH 5.1. The pectinesterease was extracted with a pH of 6.0 and its maximum activity was at 49.4 °C and pH 6.6; the polygalacturonase was extracted with a pH of 8.5 and its top activity was achieved at 46 °C and pH 5.4. The total contend of starch was 8.92 % and the grains had an oval morphology observed by SEM

Partial characterization of carbohydrases, morphology of starch granules and chemical composition from roots of maca (Lepidium meyenii Walpers)

A maca é uma raiz aromática com 52 a 76% de carboidratos e seu período de conservação pós-colheita é bastante longo, sem demonstrar sinais de deterioração. O mecanismo de degradação do amido e dos componentes da parede celular via ação enzimática não eram ainda conhecidos. O objetivo do trabalho foi caracterizar a ação de enzimas amilolíticas e pectinolíticas nessas raízes, bem como a morfologia do grânulo de amido e a composição centesimal. Os resultados mostraram que foi obtida a purificação parcial de β-amilase com peso molecular aproximado de 57 kDa, com atividade máxima a 40,7 ºC e pH de 5,1. A pectinesterase foi extraída a pH 6,0 com maior atividade a 49,4ºC e pH 6,6 a maior atividade da poligalacturonase foi a 46 ºC e pH 5,4, quando extraída a pH 8,5.O teor de amido total foi de 8,92%, os grânulos apresentaram morfologia oval em observados em microscopia eletrônica de varredura (MEV).Maca is an aromatic root that contends 52 to 76 per cent of carbohydrates and is very stable for a long period without signals of deterioration. The degradation mechanisms of the reserve carbohydrates and the cell wall components by enzymatic way had not been described yet. The main objective of this study was the identification of inner enzymes which degrades the starch and the pectins; the others objectives were the analysis and the morphology of the starch grains as well as the root\'s contend composition. The results showed that was obtained the partial purification of a β- amylase, characterized by the molecular mass of 57 kDa, with a highest activity at 40.7 °C and pH 5.1. The pectinesterease was extracted with a pH of 6.0 and its maximum activity was at 49.4 °C and pH 6.6; the polygalacturonase was extracted with a pH of 8.5 and its top activity was achieved at 46 °C and pH 5.4. The total contend of starch was 8.92 % and the grains had an oval morphology observed by SEM

Physico-chemical properties of isolated starch, enzymatic parameters during storage, and characterization of amylolytic enzymes of maca (Lepidium meyenii Walp.) root

A maca (Lepidium meyenii Walpers) é uma planta herbácea bienal da família Brassicae, cultivada principalmente na região dos Andes da América do Sul. A parte subterrânea vem sendo consumida por muito tempo devido a seu valor nutricional e energético, mas é mais conhecida no mercado peruano e internacional por alegadas propriedades terapêuticas. Esta raiz apresenta até 76% de carboidratos, dos quais 30% é amido. Este trabalho teve como objetivos estudar: as propriedades físico-químicas e funcionais do amido isolado; os parâmetros enzimáticos durante o armazenamento e a purificação parcial de enzimas amilolíticas. Em relação às propriedades do amido, este apresentou um teor de amilose de 20% valor semelhante aos encontrados em raízes e tubérculos similares. A turbidez das suspensões de amido apresentou estabilidade durante o armazenamento. A temperatura de gelatinização e a viscosidade da pasta foram a 45,7° e 46°C, respectivamente. Com base nos dados obtidos, o amido de maca seria indicado para alimentos que requeiram temperaturas moderadas no processamento, não sendo apropriado para o emprego em alimentos congelados. Os parâmetros enzimáticos medidos tais como teor de amido total, teor de açúcares solúveis, atividade amilolítica total, atividade de α e β amilases, não mostraram diferenças significativas entre as medidas durante um período de armazenamento de 16 dias. As microscopias eletrônicas de varredura (MEV) dos grânulos de amido mostraram grãos íntegros com superfícies lisas, com algumas depressões ao redor dos grânulos os quais poderiam indicar o inicio de ataque enzimático, ou fraturas na purificação. Em relação à purificação de enzimas amilolíticas, foi possível separar uma fração ativa com a carboximetilcelulose (CMC) seguida de cromatografia liquida de alta resolução (CLAE) que permitiu a separação de duas frações protéicas, analisadas por eletroforese SDS-PAGE e eletroforese bidimensional (2D). Os polipeptídeos identificados no gel 2D apresentaram massa molecular semelhante entre 22 a 27 kDa, e os pontos isoelétricos entre 4,8 e 7,3.Maca (Lepidium meyenii Walpers) is a biennial herbaceous plant from Brassicae family, grown mainly in the Andes of South America. The underground part has been consumed for a long time due to its nutritional value and energy, but is best known in the Peruvian and international market for alleged therapeutic properties. This root has up to 76% carbohydrates, of which 30% is starch. This work aimed to study: the physico-chemical properties of isolated starch, the enzymatic parameters during storage and partial purification of amylases. In relation to the properties of starch, the amylose content showed a 20% value similar to those found in roots and tubers alike. The turbidity of starch suspensions was stable during storage. The gelatinization temperature and viscosity of the paste were 45.7 ° and 46 ° C, respectively. Based on data obtained from the starch of litter would be given to foods that require moderate temperatures in processing and is not suitable for use in frozen foods. The enzymatic parameters measured such as total starch content, soluble sugars, total amylolytic activity, activity of α and β amylases, showed no significant differences between the measures over a storage period of 16 days. Electronic microscopy (SEM) of starch granules showed grains with smooth surfaces, with some depressions around the granules which could indicate the beginning of enzymatic attack, or fractures in the purification. Regarding the purification of amylases was possible to separate an active fraction with carboxymethylcellulose (CMC) followed by high-resolution liquid chromatography (HPLC) which allowed the separation of two protein fractions, analyzed by SDS-PAGE and two-dimensional electrophoresis (2D ). The polypeptides had a molecular mass between 22 and 27 kDa and isoelectric points ranging from 4.8 to 7.3

Effects on starch and amylolytic enzymes during Lepidium meyenii Walpers root storage

The high water content in maca (Lepidium meyenii W.) roots combined with the damage produced during or after harvest makes them vulnerable to attack by enzymes and microorganisms. Although starch degradation has been extensively studied, in maca roots there is a paucity of research regarding the starch reserves. In this paper, parameters of starch degradation are shown to be related to the action of amylolytic enzymes during storage at room temperature. Over the course of three weeks, the starch and protein content, soluble sugar, total amylolytic activity, and alpha- and beta-amylase activity were measured. In addition, the integrity of starch granules was observed by scanning electron microscopy. Despite the evidence of dehydration, there were no significant differences (p <= 0.5) in the total starch content or in the activities of alpha- and beta-amylase. After the third week the roots remained suitable for consumption. The results indicate a postharvest latency that can lead to sprout or to senescence, depending on the environmental conditions. (C) 2012 Elsevier Ltd. All rights reserved.CNPqCNPqCAPESCAPE

The physical, chemical and functional characterization of starches from Andean tubers: oca (Oxalis tuberosa Molina), olluco (Ullucus tuberosus Caldas) and mashua (Tropaeolum tuberosum Ruiz & Pavón)

The physical, chemical, and functional properties of starches isolated from the Andean tubers oca (Oxalis tuberosa M.), olluco (Ullucus tuberosus C.) and mashua (Tropaeolum tuberosum R. & P.) were studied. The tubers were obtained from a local grocery. The morphology of the starch granules (size and shape) was studied with scanning electron microscopy (SEM), which revealed ellipsoid, oval, conical, pear-shaped and prismatic forms: ellipsoids and oval granules with lengths up to 54.30 µm in oca; with lengths up to 32.09 µm for olluco starch granules; and with predominantly truncated spherical or oval forms and smaller dimensions (up to 16.29 um) for mashua starch granules. Amylose contents were similar among the samples: 27.60% (oca), 26.49% (olluco) and 27.44% (mashua). Olluco starch had less swelling power, forming opaque, less firm gels. All three starch gels showed the same stability on refrigeration and presented high syneresis under freezing temperatures, with a variation of 40.28 to 74.42% for olluco starch. The starches cooked easily, with high peak viscosity. The low gelatinization temperatures and high stability during cooling make these starches suitable feedstock for use in formulations that require milder processing temperatures and dispense freezing storage