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Background@#Gold nanoparticles have been studied extensively for their potential application in the detection of important analytes. Their relative ease of synthesis through numerous procedures makes possible their implementation in a variety of assays. Cysteine (cys), a thiol-containing amino acid implicated in numerous pathologies such as obstructive sleep apnea (OSA), has been routinely detected through expensive fluorometric assay kits. @*Objectives@#As such, this study aimed to develop a carbohydrate-based gold nanoparticle colorimetric assay for the convenient and straightforward detection of cys. @*Methodology@#Carbohydrate-based gold nanoparticles (c-AuNPs) were synthesized following a microwaveassisted procedure. The as-prepared c-AuNPs were used to detect cys by plotting the ratio of the absorbances of the aggregated and dispersed gold nanoparticles against the concentration of cys. @*Results@#The c-AuNP solutions were able to detect cys in the micromolar range, with the glucose-based AuNPs (glc-AuNPs) showing the widest linear range (16.7 μm to 167 μm), and the fructose-based gold nanoparticles (frc-AuNPs) exhibiting the lowest detection limit (9.0 μm) for cys. Aside from being able to detect cys, the c-AuNPs were also responsive to tyr and lys.@*Conclusion@#This study demonstrates that carbohydrate-based gold nanoparticles prepared following a microwave-assisted procedure using sugars as reducing agents and capping agents can be used successfully in the detection of cysteine.
Subject(s)
Cysteine , Carbohydrates , StarchABSTRACT
PURPOSE: This study examined the status and needs of school-based nutritional education programs for reducing sugars intake in elementary schools. METHODS: A total of 230 elementary nutrition teachers participated in this study through an online survey in July 2017. RESULTS: Approximately one-third of the schools conducted nutrition education on reducing sugars intake as a main topic. The most frequent educated grade and education period were 4th and 3rd grade, and once a year. Most of the nutrition teachers answered that nutrition education related to reducing sugars intake for children was necessary. The nutrition teachers answered that first graders were the recipients in most need of nutrition education for reducing sugars but, realistically, third graders were the most suitable for nutrition education. The appropriate education topics were limited to the lower grades, such as sugars consumption related health problems, foods containing high sugars, and behaviors to reduce sugars intake; however, a wider variety of topics were selected for the upper grades. The experiment was considered to be an effective educational method for both the lower and upper grades. The most appropriate nutrition education media appeared to be a mock-up in the lower grades, and an experiment kit in the upper grades. Games and videos were highly considered to be effective media to educate students in reducing sugars consumption by voluntary participation in free time in the classroom in both the lower and upper grades. CONCLUSION: Nutrition education programs focusing on sugars intake reduction were conducted in some elementary schools, but the training time was short and the types of activities were limited. The perception and demand for nutrition education was very high. Therefore, the development and dissemination of elementary school-based nutritional education programs for sugars intake reduction is urgently needed. Moreover, to develop an effective nutrition education program, the education environment and demand in the field should be fully considered.
Subject(s)
Child , Humans , Carbohydrates , Education , MethodsABSTRACT
Abstract The aim of this study was to characterize and perform enzymatic hydrolysis of cassava peeling residue (peel and inner peel), mainly composed of peels and small pieces. Residue was sanitized, dried at 55 °C for 24 hours and ground. The obtained flour showed pH of 4.85; 72.53 g 100 g-1 moisture; 5.18 mL 1M NaOH 100 g-1 acidity; 60.68 g 100 g-1 starch; 1.08 g 100 g-1 reducing sugar; 1.63 g 100g-1 ash; 0.86 g 100 g-1 lipid and 3.97 g 100 g-1 protein. Enzymatic hydrolysis was carried out by means of rotational central composite design, analyzing the effects of concentrations of α-amylase enzyme (10 to 50 U g starch-1), and the amyloglucosidase enzyme (80 to 400 U g starch-1) on variable responses: percent conversion of starch into reducing sugars (RSC) and soluble solid content (SS). Highest values of RSC (110%) and SS (12 °Brix) were observed when using the maximum concentration of amyloglucosidase and throughout the concentration range of α-amylase. Enzymatic hydrolysis of cassava peel is feasible and allows the use of hydrolysate in fermentation processes for the production of various products, such as alcoholic drinks, vinegar, among others.
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To evaluate the influence of phosphorus (P) fertilization on the potato tuber quality of the cultivar 'Atlantic' experiments were conducted in soils with medium (36 mg dm-3) and high (70 mg dm-3) P availability. The treatments consisted of five P2O5 rates (0, 125, 250, 500, and 1,000 kg ha-1). The experiments were conducted in a randomized block design, with four replications. Only in soil with medium P availability, the phosphorus fertilization decreases protein, but increases starch content of the tubers until rate of 595 kg ha-1 P2O5. Phosphorus fertilization increases the tuber size and marketable yield, but in a more expressive and until higher rates in soil with medium P concentration, in which the influence of tuber size on marketable yield is higher. In two conditions of P availability, the phosphorus fertilization has greater influence on the tuber size and the production of processed material (dry matter yield of tubers) than on the quality characteristics of tubers that influence in the quality frying.
Para avaliar a influência da adubação fosfatada sobre a qualidade dos tubérculos de batata da cultivar 'Atlantic' foram conduzidos experimentos em solos com médio (36 mg dm-3) e alto (70 mg dm-3) teor de P disponível. Os tratamentos foram constituídos por cinco doses de P2O5 (0, 125, 250, 500 e 1.000 kg ha-1). Os experimentos foram conduzidos no delineamento experimental de blocos casualizados, com quatro repetições. Apenas no solo com média disponibilidade de P a adubação fosfatada diminui os teores de proteína, mas aumenta o teor de amido dos tubérculos até a dose de 595 kg ha-1 de P2O5. A adubação fosfatada aumenta o tamanho dos tubérculos e a produtividade comercial, porém de forma mais expressiva e até maiores doses em solo com médio teor de P, em que a influência do tamanho do tubérculo sobre a produtividade comercial é maior. Nas duas condições de disponibilidade inicial de P, a adubação fosfatada tem maior influência sobre o tamanho dos tubérculos e a produção de material processado (produtividade de matéria seca de tubérculos), do que sobre as características de qualidade dos tubérculos, que podem influenciar na qualidade da fritura.
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INTRODUCCIÓN: las plantas que crecen en el desierto requieren de características especiales para adaptarse a las condiciones adversas de esta región. Dentro de estos se destacan los géneros Pergularia, Hammada y Rhus, al poseer estructuras y mecanismos que les confieren una gran versatilidad en cuanto a sus usos medicinales. Las investigaciones encaminadas al estudio de su composición química y actividad biológica son limitadas. OBJETIVO: determinar la composición química preliminar de extractos de diferente polaridad de las especies Pergularia tomentosa L. (Apocynaceae), Hammada scoparia I. (Amaranthaceae) y Rhus tripartita L. (Anarcadiaceae). MÉTODOS: los materiales vegetales empleados fueron las hojas y las ramas de las especies. En el momento de la colecta no existía ni floración, ni fructificación en estas especies vegetales. Se realizó un proceso de extracción por maceración, se empleó etanol. A partir de éste extracto se efectuó un fraccionamiento preliminar y se usó disolventes de diferente polaridad; el hexano, acetato de etilo, metanol y butanol. A todas estas fracciones se le realizó un tamizaje fitoquímico. RESULTADOS: los metabolitos secundarios encontrados en la identificación preliminar de las tres especies fueron; los alcaloides, azúcares reductores, compuestos con agrupamientos lactónicos y compuestos fenólicos. CONCLUSIONES: en las tres especies, las fracciones metanólicas fueron las que mostraron una mayor variedad de metabolitos secundarios.
INTRODUCTION: plants growing in deserts require special characteristics to survive under the extreme conditions of these regions. Inside these groups of plants are the genus Pergularia, Hammada and Rhus having a great versatility of medical uses. Investigations about chemical composition and biological activities of these genuses are limited. OBJECTIVE: to determine the preliminary chemical composition of extracts from different polarity of Pergularia tomentosa L. (Apocynaceae), Hammada scoparia (Amaranthaceae) and Rhus tripartita L. (Anarcadiaceae). METHODS: plant materials used were the leaves and branches of the species. At the time of collection there was not flowering or fruiting in these plants. Extraction procedure was carried out by maceration with methanol. From this extract preliminary fractionation was done using solvents with different polarity: hexane, ethyl acetate, methanol and buthanol. All these fractions were phytochemical screened. RESULTS: the secondary metabolites found in the preliminary identification of the three species were: alkaloids, reducing sugars, compounds with lactone groups and phenolic compounds. CONCLUSIONS: in the three species, the methanolics fractions showed the most variety of secondary metabolites.
Subject(s)
Humans , Rhus/drug effects , Plant Preparations/therapeutic use , Reference DrugsABSTRACT
The profiles of amylase activity, soluble sugars and proteins in unripe plantain (Musa paradisiaca) and for a comparison, unripe banana (Musa sapientum), from harvest to ripening were investigated to provide basic information about their nutritional status at the different stages of the ripening process. Unripe plantain contained about a quarter of the soluble sugars found in ripe plantain. Conversion of the insoluble sugar (starch) to soluble sugar by amylase during ripening was an almost linear process. And as such, activity of amylase in plantain was highest at the ripe stage (2400 ± 120 Units/mg protein) and lowest immediately after harvest when it was still green (700±100 Units/mg protein). The soluble proteins increased from first day when it was harvested, at maximum around the third day and began to decline gradually. In contrast, amylase activity was highest in unripe banana (3900 ± 310 Units/mg protein) and decreased rapidly to a very low value (100 ±15 Units/mg protein) when it was fully ripened. The soluble sugar level in unripe banana was 3.8 ±0.5 mg/ml and around 6.0 ±1.0 mg/ml of extract when fully ripened. The soluble protein was 3 ± 1.0 mg/ml of extract when unripe and increased nine folds to a value of 27± 3.0 mg/ml of extract when fully ripened. The overall results suggest that the highest amount of starch, and the lowest amount of soluble sugars were present on the day when the mature plantain was just harvested.
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Mealey bug (Maconellicoccus hirsutus) causes dreadful infection in Hibiscus rosa sinensis.Infections are highly virulent and alters biochemical componenets of the species. Therefore an attempt has been made to evaluate the alteration of biochemical components in Hibiscus stem at various stages of infection. The results reveal that partial infected stem had shown 14.2% increase in its total soluble sugars whereas highly infected had shown 40% decrease.The results also show that total soluble sugars had increased significantly(14%) in highly infected stem and noticeable increase (3%) in partial infected.
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In this study, forty-two fungi from soil were isolated and tested for their carboxymethyl cellulase (CMCase) and xylanase activities. From all isolates, the fungal isolate FR60, which was identified as Aspergillus aculeatus Iizuka, showed high activities in both CMCase and xylanase with 517 mU/mg protein and 550 mU/mg protein, respectively. The crude enzyme from A. aculeatus Iizuka FR60 could hydrolyze several agricultural residues such as corncob, and sweet sorghum leaf and stalk at comparable rates with respect to the tested commercial enzymes and with a maximum rate in rice hull hydrolysis (29 μg sugar g-1 dry weight substrate mg-1 enzyme hr-1). The highest amount of glucose was obtained from corncob by using the crude enzyme from A. aculeatus Iizuka FR60 (10.1 g/100 g dry substrate). From overall enzymatic treatment results, the lowest sugar yield was from rice hulls treatment (1.6 g/100 g dry weight) and the highest amount of reducing sugar was obtained from rice straw treatment (15.3 g/100 g dry weight). Among tested agricultural wastes, rice hull could not be effectively hydrolyzed by enzymes, whereas sugarcane leaf and stalk, and peanut shell could be effectively hydrolyzed (30-31% total sugar comparing with total sugar yield from acid treatment).
Subject(s)
Aspergillus/enzymology , Aspergillus/isolation & purification , Cellulose, Oxidized/analysis , Cellulose, Oxidized/isolation & purification , Food , Oryza , Zea mays , Biomass , Enzyme Activation , Food Samples , Hydrolysis , Methods , Waste ProductsABSTRACT
Developing cold sweetening resistant processing varieties is one of the frontal areas of research all over the world. In India, first potato processing variety was released in the year 1998 and till 2005 three varieties have been developed. But, there is no information available regarding sugar accumulation response of Indian varieties to low temperature storage. Therefore, it is imperative to generate basic information on cold sweetening development in Indian processing varieties for the use of potato breeders. Development of cold-induced sweetening and its relation to phenolic content of the tuber was studied in three Indian potato varieties viz., Kufri Chipsona-1, Kufri Chipsona-3 and Kufri Jyoti. The reducing sugars decreased in initial phase of storage, followed by continuous increase to unacceptably higher levels after around two weeks of storage. The increase in reducing sugar contents took place subsequent to increase in sucrose content. The changes in phenol content were not in a fixed trend. The degree or number of folds increase in reducing sugar content was relatively less in Kufri Jyoti which contained highest phenol content among the three varieties investigated. It is suggested that development of processing varieties with higher anti-oxidant content and lower invertase activity may provide better cold-induced sweetening resistance.
Subject(s)
Carbohydrate Metabolism , Cold Temperature , Food Handling/methods , Phenols/metabolism , Solanum tuberosum/metabolism , Sucrose/metabolism , TasteABSTRACT
A pesar de nuestra profesión, cuando cocinamos no reflexionamos demasiado acerca de lo complejas que resultan las operaciones culinarias desde el punto de vista químico. Nuestra condición humana requiere alimentarnos con productos que además de nutrirnos, sorprendan nuestros sentidos y nos satisfagan espiritualmente. Para introducirnos en la complejidad de los alimentos es necesario comprender la diferencia entre gusto y sabor y relacionarlos con los alimentos resultantes de la combinación de diversas biomoléculas. Debemos a ciertas reacciones químicas la generación de una enorme variedad de compuestos aromáticos, que combinados en forma adecuada, producen alimentos de los cuales disfrutamos diariamente. Mucho de este tema gira alrededor de Louis Camille Maillard, un médico que a principios del siglo XX estudió la combinación de los azúcares con las proteínas. Su principal aporte fue relacionar los procesos culinarios con los que ocurren en el organismo. Las reacciones de Maillard -la llamada glucosilación no enzimática- modifican profundamente las biomoléculas, como se ha comprobado en muchos trabajos científicos. En el organismo las reacciones de Maillard son similares a las que ocurren en la cocina, pero transcurren más lentamente y se relacionan con la enfermedad y el envejecimiento.
In spite of our profession, when we cook we do not think too much about the complex processes that take place in culinary operations from the chemical point of view. Our human nature makes us desire not only a meal that nourishes us, but also surprises our senses and satisfies us spiritually. In order to introduce ourselves in the complexity of food, it is necessary to understand the difference between taste and flavor, and to relate them to food as an outcome of a diverse combination of biomolecules. We owe to certain chemical reactions the generation of an enormous variety of aromatic compounds that combined in a suitable way, produce the meals which we enjoy daily. Most of this subject revolves around Louis Camille Maillard, a French physician who, at the beginning of XX century, studied the combination of sugars with proteins. His main contribution was that he related culinary processes to those which take place in our body. It has been broadly verified scientifically that the Maillard reaction -also known as nonenzymatic glycosylation- modifies biomolecules deeply. In the organism, Maillard reactions are similar to those which happen in the kitchen but they occur more slowly and are associated with disease and aging.