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1.
J Sci Food Agric ; 101(15): 6347-6354, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33969893

RESUMO

BACKGROUND: Vacuum package storage is commonly applied to reduce postharvest deterioration in minimally processed cassava roots. However, the influence of vacuum packaging conditions on root end-use quality is poorly understood. Hence, the effects of vacuum packaged storage at ambient, refrigerated and freezing temperatures on microflora, cassava tissue structure and starch extraction by wet milling were studied. RESULTS: Vacuum packaged storage temperature strongly affected cassava root quality. Minimal adverse effects were obtained with frozen storage. With refrigerated storage, there was negligible microbial growth but some disruption of the parenchyma cell wall structure suggestive of chilling injury. With ambient temperature storage, there was considerable Lactobacilli dominated fermentation. This caused substantial cell degradation, probably due to the production of extracellular cellulolytic and other cell wall degrading enzymes. A benefit of this cell wall breakdown was that it substantially improved starch extraction with wet milling from the stored cassava pieces; by 18% with pieces that had been ambient vacuum packaged and wet milled using a 2000 µm opening screen. However, ambient temperature storage resulted in some starch granule pitting due to the action of extracellular amylases from the fermenting microorganisms. CONCLUSION: The best vacuum packaging storage conditions for minimally processed cassava depends on application and cost. For short-term storage, refrigeration would be best for vegetable-type products. For several months storage, freezing is best. For wet milling applications, this could be combined with subsequent short-term ambient temperature storage as it improves starch extraction efficiency and could reduce distribution energy costs. © 2021 Society of Chemical Industry.


Assuntos
Embalagem de Alimentos/métodos , Manihot/química , Tubérculos/química , Amido/isolamento & purificação , Manipulação de Alimentos , Embalagem de Alimentos/economia , Embalagem de Alimentos/instrumentação , Armazenamento de Alimentos , Amido/análise , Temperatura , Vácuo
2.
Ann Pharm Fr ; 79(1): 28-35, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32853574

RESUMO

OBJECTIVES: The aim of the current study was to compare the physicochemical and disintegrant properties of pearl millet starch with other starches using paracetamol as model drug. METHODOLOGY: Determination of percentage yield, Physicochemical, micrometrics characteristics of starch/granules, drug excipients compatibility studies and evaluation of prepared paracetamol tablets were measured using official techniques. RESULTS: The yield of the millet starch ranged from 30 to 40%. Moisture content 8.77%, pH 5.7, Swelling capacity 1.2, Hydration capacity 1.748, Moisture uptake 11.8%, Amylose 24.6%, with poor flowability and compressibility. No significant difference in hardness, friability% & disintegration times for formulations containing millet starch to that containing potato and maize starch (P>0.05). CONCLUSION: From the study, Millet seeds locally cultivated in Sudan gave a high yield of starch, has same physicochemical properties as maize and potato starch so can be used as an alternative to those starches.


Assuntos
Acetaminofen/química , Excipientes/análise , Milhetes/química , Sementes/química , Solanum tuberosum/química , Amido/análise , Zea mays/química , Acetaminofen/administração & dosagem , Química Farmacêutica , Composição de Medicamentos , Custos de Medicamentos , Incompatibilidade de Medicamentos , Excipientes/economia , Concentração de Íons de Hidrogênio , Pós , Solubilidade , Sudão , Comprimidos
3.
J Sci Food Agric ; 99(3): 1351-1357, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30094850

RESUMO

BACKGROUND: The development of new products with a focus on nutrition, rather than other technical aspects, is essential to improve the quality of celiac diets. Nutritional attributes of white and brown sorghum gluten-free pasta developed in a previous work were analyzed. The extent and kinetics of starch in vitro digestion, estimated glycemic index (eGI), potentially bioaccessible and dialyzable polyphenols, and antioxidant activity were evaluated and compared with commercial products. RESULTS: Sorghum flour samples were used to obtain pasta with high protein (≈170 g kg-1 ), dietary fiber (≈80 g kg-1 ), polyphenols (2.6 g GA kg-1 pasta), and antioxidant activity. This sorghum pasta showed slower starch in vitro digestion than the other gluten-free pasta, with a high level of protein hydrolysis (76%). The highest eGI was observed in a rice sample (69.8) followed by a corn-based pasta (66.4). White and brown sorghum gluten-free pasta showed 2.9 and 2.4 times, respectively, higher potentially bioaccessible polyphenol content compared to that in cooked pasta. No significant variation in antioxidant activity was found in sorghum pasta after digestion and around 48% and 36% of activity was detected in dialysate. CONCLUSION: Both types of sorghum gluten-free pasta have demonstrated their nutritional value and represent a good potential alternative to current commercial pasta. © 2018 Society of Chemical Industry.


Assuntos
Antioxidantes/metabolismo , Dieta Livre de Glúten/economia , Digestão , Sorghum/metabolismo , Amido/metabolismo , Antioxidantes/química , Culinária , Farinha/análise , Farinha/economia , Glutens/análise , Glutens/economia , Valor Nutritivo , Sorghum/química , Amido/análise
4.
J Sci Food Agric ; 98(12): 4403-4410, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29435988

RESUMO

BACKGROUND: Staling of maize tortillas is a major drawback affecting their manufacture, commercialization and consumption. The development of methods that may help retard staling of maize tortillas is an ongoing research topic. In this work, a novel, simple, economic and effective method is proposed, based on adding completely gelatinized nixtamalized maize flour (GMF) dispersion to the basic masa formulation recipe (water, 600 g kg-1 ; nixtamalized maize flour, 400 g kg-1 ) in substitution of 50, 100 and 150 g kg-1 of water. RESULTS: Masa added with GMF showed increased water retention capacity, reduced freezable water content and improved flow and dynamic rheological properties and produced tortillas with decreased firmness. The infrared 1047/1022 cm-1 spectral ratio indicated that a more disordered starch granule arrangement was formed, while enthalpy peaks associated with starch retrogradation decreased. All the above indicators were more pronounced the higher was the GMF content. CONCLUSION: This work showed that GMF can play the role of a self-hydrocolloid anti-staling agent by retarding the retrogradation of maize starch and deterring the loss of water and rheological properties of masa and the increase in undesirable sensory characteristics of tortilla such as increased firmness. © 2018 Society of Chemical Industry.


Assuntos
Pão/análise , Farinha/análise , Manipulação de Alimentos/ética , Manipulação de Alimentos/métodos , Zea mays/química , Humanos , Reologia , Amido/análise , Paladar , Água/análise
5.
J Sci Food Agric ; 97(13): 4343-4352, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28485024

RESUMO

BACKGROUND: Cowpea is traditionally cultivated in some regions of southern Europe for its dried seeds; however, there is a scarcity of information on the quality and dietary characteristics of fresh pods, which are occasionally used in folk diets. This paper aims at covering this gap in knowledge, thereby contributing to the dissemination of fresh cowpea pods as a novel product for the market. The quality and dietary characteristics of pods from 37 accessions (Vigna unguiculata ssp. unguiculata and ssp. sesquipedalis) grown in southern Europe were assessed in an attempt to provide information on pod quality and nutritional properties and to identify relationships between quality traits and accession origin. RESULTS: Pods from the sesquipedalis accessions were heavier and larger, and reached commercial maturity 2 days later, than those from the unguiculata accessions. There were also large differences in the quality and dietary characteristics of the accessions. The pods of most accessions were rich in proteins, chlorophylls, carotenoids and phenolics, and showed high antioxidant activity and low concentrations of nitrates and raffinose-family oligosaccharides. Cluster analysis based on quality, dietary or antinutritional traits did not reveal any apparent grouping among the accessions. All the quality characteristics were independent of accession origin and subspecies. CONCLUSION: Most of the accessions produced fresh pods of good quality and high dietary value, suitable for introduction in the market and/or for use as valuable genetic material for the development of new improved varieties. © 2017 Society of Chemical Industry.


Assuntos
Sementes/química , Vigna/química , Clorofila/análise , Dieta , Europa (Continente) , Humanos , Valor Nutritivo , Proteínas de Plantas/análise , Sementes/classificação , Sementes/crescimento & desenvolvimento , Amido/análise , Paladar , Vigna/classificação , Vigna/crescimento & desenvolvimento
6.
Plant Physiol Biochem ; 110: 100-107, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27117792

RESUMO

Little is known about the effects of surface modification on the interaction of nanoparticles (NPs) with plants. Tomato (Solanum lycopersicum L.) plants were cultivated in potting soil amended with bare and citric acid coated nanoceria (nCeO2, nCeO2+CA), cerium acetate (CeAc), bulk cerium oxide (bCeO2) and citric acid (CA) at 0-500 mg kg-1. Fruits were collected year-round until the harvesting time (210 days). Results showed that nCeO2+CA at 62.5, 250 and 500 mg kg-1 reduced dry weight by 54, 57, and 64% and total sugar by 84, 78, and 81%. At 62.5, 125, and 500 mg kg-1 nCeO2+CA decreased reducing sugar by 63, 75, and 52%, respectively and at 125 mg kg-1 reduced starch by 78%, compared to control. The bCeO2 at 250 and 500 mg kg-1, increased reducing sugar by 67 and 58%. In addition, when compared to controls, nCeO2 at 500 mg kg-1 reduced B (28%), Fe (78%), Mn (33%), and Ca (59%). At 125 mg kg-1 decreased Al by 24%; while nCeO2+CA at 125 and 500 mg kg-1 increased B by 33%. On the other hand, bCeO2 at 62.5 mg kg-1 increased Ca (267%), but at 250 mg kg-1 reduced Cu (52%), Mn (33%), and Mg (58%). Fruit macromolecules were mainly affected by nCeO2+CA, while nutritional elements by nCeO2; however, all Ce treatments altered, in some way, the nutritional quality of tomato fruit. To our knowledge, this is the first study comparing effects of uncoated and coated nanoceria on tomato fruit quality.


Assuntos
Acetatos/farmacologia , Cério/farmacologia , Ácido Cítrico/farmacologia , Frutas/efeitos dos fármacos , Nanopartículas Metálicas/administração & dosagem , Solanum lycopersicum/efeitos dos fármacos , Acetatos/química , Boro/análise , Cálcio/análise , Carboidratos/análise , Carotenoides/análise , Carotenoides/metabolismo , Cério/química , Ácido Cítrico/química , Análise de Alimentos/métodos , Frutas/química , Ferro/análise , Licopeno , Solanum lycopersicum/química , Manganês/análise , Nanopartículas Metálicas/química , Valor Nutritivo , Amido/análise , Propriedades de Superfície
7.
Food Chem ; 159: 287-92, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-24767057

RESUMO

Using gas chromatography-mass spectrometry (GC-MS) as a system for the detection of amino acids, organic acids, sugars, sugar alcohols, and fatty acids, we characterised six commercial potato cultivars (Hópehely, Katica, Lorett, Somogyi kifli, Vénusz Gold, and White Lady) with different pedigrees, starch contents, cooking types, and dormancy periods, in five developmental stages from harvest to sprouting. The tubers were stored at 20-22°C in the dark. The metabolite data were subjected to principal component analysis. No correlation between metabolite contents of freshly harvested tubers and starch content or cooking type of the cultivars was detected. The storage decreased the fructose and sucrose and increased the proline concentrations of tubers. Irrespective of the length of dormancy a substantial difference in metabolite composition at each time point upon storage was detected in each cultivar except Somogyi kifli, the only cultivar amongst those tested with a pure Solanum tuberosum origin and A cooking type.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Metabolômica/métodos , Tubérculos/química , Solanum tuberosum/química , Aminoácidos/análise , Aminoácidos/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Armazenamento de Alimentos , Frutose/análise , Frutose/metabolismo , Tubérculos/metabolismo , Solanum tuberosum/economia , Solanum tuberosum/metabolismo , Amido/análise , Amido/metabolismo , Sacarose/análise , Sacarose/metabolismo
8.
J Sci Food Agric ; 94(5): 857-65, 2014 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-23893794

RESUMO

BACKGROUND: The acceptability of frozen green peas depends on their sensory quality. There is a need to relate physico-chemical parameters to sensory quality. In this research, six brands of frozen green peas representing product sold for retail and caterer's markets were purchased and subjected to descriptive sensory evaluation and physico-chemical analyses (including dry matter content, alcohol insoluble solids content, starch content, °Brix, residual peroxidase activity, size sorting, hardness using texture analysis and colour measurements) to assess and explain product quality. RESULTS: The sensory quality of frozen green peas, particularly texture properties, were well explained using physico-chemical methods of analysis notably alcohol insoluble solids, starch content, hardness and °Brix. Generally, retail class peas were of superior sensory quality to caterer's class peas although one caterer's brand was comparable to the retail brands. Retail class peas were sweeter, smaller, greener, more moist and more tender than the caterer's peas. Retail class peas also had higher °Brix, a(*) , hue and chroma values; lower starch, alcohol insoluble solids, dry matter content and hardness measured. CONCLUSIONS: The sensory quality of frozen green peas can be partially predicted by measuring physico-chemical parameters particularly °Brix and to a lesser extent hardness by texture analyser, alcohol insoluble solids, dry matter and starch content.


Assuntos
Inspeção de Alimentos/métodos , Qualidade dos Alimentos , Alimentos Congelados/análise , Pisum sativum/química , Sementes/química , Fenômenos Químicos , Culinária , Carboidratos da Dieta/análise , Manipulação de Alimentos , Alimentos Congelados/economia , Dureza , Humanos , Fenômenos Mecânicos , Pisum sativum/economia , Pigmentação , Controle de Qualidade , Sensação , África do Sul , Amido/análise , Propriedades de Superfície , Água/análise
9.
Eur J Nutr ; 51(8): 947-54, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22072067

RESUMO

PURPOSE: To evaluate whether the modification of ingredients of two bakery products, muffins and bread, reduces their glycemic index, by means of in vitro and in vivo procedures. METHODS: In vitro and in vivo glycemic index were evaluated for two types of bread and two types of muffins including one standard product for each category. For the in vitro determination, kinetics of starch digestion method was used. For the in vivo procedure, postprandial glucose measured as IAUC was obtained in a group of eighteen healthy volunteers (ten did the test with muffins and eight with breads). RESULTS: In in vitro, a reduction in the expected glycemic index regarding the control muffin was achieved with the partial substitution of wheat flour by a mixture of resistant starch, dextrin and lentil flour. In breads, with the partial substitution of wheat flour by a mixture of resistant starch and dextrins, a decrease in the expected glycemic index was also observed. In in vivo, a reduction in GI was also achieved both in muffin and in bread. All the obtained GI was higher in in vitro method. CONCLUSIONS: Despite the fact that in vitro overestimate in vivo method, the trend in the reduction in GI seems to be similar in both methods. With the substitution assayed, a reduction in the expected glycemic index and the glycemic index were obtained both in muffins and in breads.


Assuntos
Pão/análise , Farinha/análise , Análise de Alimentos , Índice Glicêmico , Adolescente , Adulto , Área Sob a Curva , Glicemia/análise , Feminino , Humanos , Cinética , Masculino , Dinâmica não Linear , Período Pós-Prandial , Espanha , Amido/análise , Triticum/química , Adulto Jovem
10.
Ceylon Med J ; 56(2): 54-8, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21789865

RESUMO

OBJECTIVES: The mature jackfruit (Artocarpus heterophyllus) is consumed in Sri Lanka either as a main meal or a meal accompaniment. However, there is no scientific data on the nutrient compositions of cooked jackfruit meals. Thus, the objective of the study was to carry out a nutritional assessment of a composite jackfruit breakfast meal comprising seeds and flesh. DESIGN: A jackfruit meal comprising of flesh (80% available carbohydrate) and seeds (20% available carbohydrate) was included in the study. The study was carried out in a random cross over design. Setting University of Sri Jayewardenepura. Study participants Healthy individuals (n=10, age: 20-30 yrs). MEASUREMENTS: The macronutrient contents, rapidly and slowly available glucose (SAG) contents, water solubility index of the jackfruit meal were determined according to standard methods. The GI of the meal was calculated according to FAO/WHO guidelines. RESULTS: The moisture content of the boiled jackfruit flesh was high (82% FW). Jack seeds contained 4.7% protein (FW), 11.1% total dietary fibre (FW) and 8% resistant starch (FW). Jackfruit meal elicited a GI of 75. The Glycaemic Load (GL) of the normal serving size of the meal is medium. The slowly available glucose (SAG) percentage of jackfruit meal (30%) was twice that of the standard. The boiled jackfruit flesh contained disintegrated starch granules while seeds contained intact swollen and disintegrated granules. CONCLUSIONS: The jackfruit seeds are a good source of starch (22%) and dietary fibre. The meal is categorized as a low GI meal. The low GI could be dueto the collective contributions from dietary fibre, slowly available glucose and un-gelatinised (intact) starch granules in the seeds.


Assuntos
Artocarpus/química , Adulto , Carboidratos da Dieta/análise , Fibras na Dieta/análise , Índice Glicêmico , Humanos , Valor Nutritivo , Período Pós-Prandial , Sementes/química , Amido/análise , Adulto Jovem
11.
Int J Pharm ; 411(1-2): 27-35, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21419207

RESUMO

The inclusion of hyperspectral imaging systems in the manufacturing and development of pharmaceutical products is allowing a successful improvement in the quality control of solid dosage forms. The correct distribution not only of active pharmaceutical ingredient (API) but also of the rest of excipients is essential to assure the correct behavior of the tablet when ingested. This is especially relevant in tablets with low content of potent APIs, in which the prescribed intake dosage frequently corresponds to half-a-tablet. Therefore, the aim of this work is to study the surface distribution of the compounds in tablets with low API content. The proposed procedure includes the scanning of the tablet surface using near infrared hyperspectral spectroscopy in association with multivariate curve resolution (MCR) techniques to obtain selective pictures for each individual compound and to allow the fast assessment of their distribution in the measured surface. As an example, a set of commercial Lorazepam tablets (approximately 1% mass fraction of API, and four excipients) were analyzed. The results obtained show the capacity of the proposed methodology as an expedite approach to evaluate the uniformity of the contents between and within tablets. A method to estimate the homogeneity distribution of API in the two halves of the tablet is also proposed.


Assuntos
Ansiolíticos/química , Excipientes/química , Lorazepam/química , Preparações Farmacêuticas/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Ansiolíticos/análise , Celulose/análise , Celulose/química , Simulação por Computador , Excipientes/análise , Excipientes/síntese química , Lactose/análise , Lactose/química , Lorazepam/análise , Teste de Materiais , Amido/análogos & derivados , Amido/análise , Amido/síntese química , Amido/química , Ácidos Esteáricos/análise , Ácidos Esteáricos/síntese química , Ácidos Esteáricos/química , Propriedades de Superfície , Comprimidos
12.
Phytochemistry ; 71(17-18): 1940-51, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20943239

RESUMO

The present state of knowledge of the phytochemistry of small molecules isolated from the roots and leaves of cassava, Manihot esculenta Crantz (Euphorbiaceae), is reviewed. Cassava roots are an important source of dietary and industrial carbohydrates, mainly eaten as a source of starch, forming the staple food to over 500 million; additionally, the roots have value as a raw material for industrial starch production and for animal feed giving the crop high economic value, but it suffers markedly from post-harvest physiological deterioration (PPD). The hydroxycoumarins scopoletin and its glucoside scopolin as well as trace quantities of esculetin and its glucoside esculin are identified from cassava roots during PPD. The biotechnological prospects for cassava are also reviewed including a critical appraisal of transgenic approaches for crop improvement, together with its use for bioethanol production, due to cassava's efficient ability to fix carbon dioxide into carbohydrate.


Assuntos
Produtos Biológicos , Manihot/química , Plantas Comestíveis/química , Produtos Biológicos/química , Produtos Biológicos/economia , Produtos Biológicos/isolamento & purificação , Biotecnologia , Cumarínicos/química , Cumarínicos/isolamento & purificação , Glucosídeos/química , Glucosídeos/isolamento & purificação , Estrutura Molecular , Nitrilas/química , Folhas de Planta/química , Raízes de Plantas/química , Escopoletina/química , Escopoletina/isolamento & purificação , Amido/análise , Terpenos , Umbeliferonas/química , Umbeliferonas/isolamento & purificação
13.
Br J Nutr ; 103(10): 1485-92, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19995473

RESUMO

Nutritional recommendations call for balanced, diversified consumption of starchy foods and increased whole-grain food intake. Their efficiency may depend on sociodemographic and socioeconomic factors, for which little information is available. The aim of the present study was to investigate the relationship between sociodemographic and socioeconomic characteristics and starchy food consumption in a large general population of French adults. Dietary intake was assessed using at least six 24-h dietary records collected, during a 2-year period, from 4574 men and women aged 45-60 years who participated in the Supplémentation en VItamines Minéraux et AntioXydants cohort study in 1995-7. Compliance with the recommendation ( > or = 3 and < 6 servings/d), non-consumption of whole-grain products, variety and daily cost were compared across sociodemographic and socioeconomic categories using logistic regression and covariance analyses. About 55 % of subjects complied with the starchy food recommendation, with little variation across sociodemographic characteristics. Consumption of whole-grain products was less likely in men (P = 0.001), in subjects with a lower education level (P-trend = 0.01) and in those belonging to intermediate occupational categories (P = 0.02). The variety of starchy food intake increased with education level (P-trend = 0.0002) and was lowest for manual workers (P = 0.03). The proportion of daily food cost spent on starchy foods decreased with occupational category (P < 0.0001), and was higher in rural areas (P = 0.0004). The starchy food budget spent on potatoes decreased with the educational level (P-trend = 0.007), whereas it increased for rice and unsweetened breakfast cereals (P-trend = 0.001 for both). Public recommendations concerning starchy food variety and whole-grain intake should specifically target subjects with a lower education level and/or occupational category.


Assuntos
Carboidratos da Dieta/administração & dosagem , Comportamento Alimentar , Análise de Alimentos , Amido/análise , Dieta , Carboidratos da Dieta/classificação , Carboidratos da Dieta/economia , Escolaridade , Feminino , Alimentos/economia , França , Humanos , Masculino , Pessoa de Meia-Idade , Ocupações , Fatores Socioeconômicos
14.
Interciencia ; 31(9): 686-689, sept. 2006. tab, graf
Artigo em Espanhol | LILACS | ID: lil-449307

RESUMO

Con una historia de más de cinco décadas, los beneficios del cultivo de tejidos vegetales (CTV) no han llegado a los agricultores de las regiones más necesitadas. El problema radica en la complejidad y costo de aplicación de la técnica. En Venezuela, la yuca (Manihot esculenta Crantz) es cultivada en suelos marginales por agricultores de escasos recursos. Las limitaciones del cultivo son la carencia de semilla sana y los bajos niveles de rendimiento. Esta situación puede superarse mediante el uso del CTV para la producción de semilla vegetativa de alta calidad. Un primer paso para lograr la transferencia tecnológica es la sustitución de los componentes de los medios de cultivo convencionales por otros más económicos y accesibles. En el presente trabajo se evaluó el crecimiento de plantas de yuca in vitro, al sustituir el agente solidificante del medio con diferentes almidones modificados de yuca producidos en el país. Para ello fueron sembrados microesquejes en medio Murashige y Skoog (MS) y diferentes agentes solidificantes (Phytagel, AIM TF-351, AIM TF-352 y AIM TP-212). El crecimiento de las plantas fue comparado de acuerdo al peso seco, peso fresco, número de nudos, raíces y altura. Los resultados no mostraron diferencias significativas en el crecimiento y la tasa de multiplicación de plantas crecidas en Phytagel® y AIM TF-351. El almidón AIM TF-351 puede ser utilizado en medios de micropropagación clonal de yuca como una alternativa económica, de fácil manejo y disponibilidad en programas nacionales de producción de semilla


Assuntos
Produção Agrícola , Amido/análise , Manihot , Agricultura , Venezuela
15.
Ann Chim ; 92(4): 457-67, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12073892

RESUMO

Cereal starch occurs as two types of micrometer-sized granules, large and small. Large starch granules are more susceptible to enzymatic hydrolysis. When cereal starch is used for fermentation processes, as in brewing of barley malt, the barley strains with the highest content of large starch granules should be preferred. Gravitational field-flow fractionation (GFFF) is a separation method able to fractionate starch samples at low cost and short analysis time. In this work, the search for the best GFFF conditions for the analytical separation of barley starch within an inter-laboratory approach is presented. For different barley strains cultivated under monitored conditions the size distributions of starch granules is here quickly monitored and characterized by GFFF. As a consequence, dimensional characterization of barley starch can allow for the selection of the most suitable strains with the lowest content of non-degradable starch.


Assuntos
Fracionamento por Campo e Fluxo , Hordeum/química , Amido/química , Fermentação , Hordeum/fisiologia , Tamanho da Partícula , Amido/análise
16.
J Dent Educ ; 63(11): 814-20, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10608927

RESUMO

Cornstarch powder on latex examination gloves acts as an airborne carrier of natural latex allergens resulting in cutaneous, conjunctival, and/or respiratory responses to latex, a particular concern in a dental school environment where concentrated use of latex examination gloves occurs. This study measured airborne powder levels associated with a trial substitution of powder-free latex examination gloves for powdered latex examination gloves in a dental school clinic. Secondary aims of the study were to assess user acceptance of powder-free gloves during the trial and to assess the financial impact of converting the entire dental school to a powder-free environment. Air was sampled from two areas (dispensary and treatment room) of a student clinic fifteen to thirty minutes before the beginning of normal clinic sessions and again about 1.5 hours into the clinic session. The samples were microscopically analyzed for particulate counts of cornstarch powder. A written survey instrument assessed user acceptance of the two types of gloves. Historical financial data were used to estimate the cost of converting the entire dental school to a powder-free environment. Both the dispensary and the treatment room showed significant reductions in airborne powder counts during use of powder-free latex gloves and a return to high powder counts with resumption of powdered glove use. During the weeks of powdered glove use, the powder counts were also significantly lower before the beginning of the clinic session and higher during the clinic session. User acceptance of the powder-free latex gloves was high. The increased cost per year to convert the entire dental school to a powder-free environment was estimated to be $13,943.


Assuntos
Poluentes Ocupacionais do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Clínicas Odontológicas , Luvas Cirúrgicas , Látex , Poluição do Ar em Ambientes Fechados/prevenção & controle , Alérgenos/análise , Atitude do Pessoal de Saúde , Custos e Análise de Custo , Docentes de Odontologia , Luvas Cirúrgicas/economia , Humanos , Látex/análise , Hipersensibilidade ao Látex/prevenção & controle , Pós , Faculdades de Odontologia , Amido/análise , Estudantes de Odontologia , Tensoativos/análise
17.
J AOAC Int ; 77(5): 1197-202, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7950419

RESUMO

Dried beans (kidney and great northern) and dried peas (chick, green, and yellow) were cooked according to package instructions. Total dietary fiber (TDF) was measured by the Mongeau (AOAC 992.16), Prosky (AOAC 985.29), and Lee (AOAC 991.43) methods (A, B, and C, respectively). Nonstarch polysaccharides (NSP) were measured by the Englyst gas-chromatographic method that included dimethyl sulfoxide treatment, and the lignin measured separately was added to NSP (method D). TDF was also measured by the Li method (E). TDF values ranged from 7 to 48 g/100 g dry weight. Methods B and C gave similar TDF values, which were higher than those from other methods. For kidney beans I, TDF values by methods B and C were up to 2.5 times higher because of the inclusion of starch. The fiber residues from methods A and C contained the same amounts of arabinose, xylose, mannose, galactose, and uronic acid, but glucose was 4 times higher in residue C than in residue A. When alpha-amylase from porcine pancreas was incorporated in methods B or C for 5 samples, the discrepancies among methods A, B, and C were reduced by 60-98%.


Assuntos
Fibras na Dieta , Fabaceae/química , Temperatura Alta , Plantas Medicinais , Arabinose/análise , Cromatografia Gasosa , Dimetil Sulfóxido , Galactose/análise , Glucose/análise , Lignina/análise , Manose/análise , Polissacarídeos/análise , Amido/análise , Ácidos Urônicos/análise , Xilose/análise
18.
Plant Foods Hum Nutr ; 46(1): 33-9, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7971785

RESUMO

The nutrient and antinutrient components of tubers from seven cultivars of Dioscorea alata were determined. The average crude protein content of D. alata tubers was 7.4%. Starch (75.6-84.3%) was the predominant fraction of the tuber dry matter. Significant differences in crude protein and starch contents were observed among cultivars. Vitamin C content of the yam tubers ranged from 13.0 to 24.7 mg/100 g fresh weight. The results showed yams to be reasonably good sources of minerals. Phytic acid contents of the yams were low, with values ranging from 58.6 to 198.0 mg/100 g dry matter. Total oxalate levels in yam tubers were found to be in the range of 486-781 mg/100 g dry matter, but may not constitute a nutritional concern since 50-75% of the oxalates were in the water-soluble form. The overall results are suggestive of the nutritional superiority of yams compared to other tropical root crops.


Assuntos
Valor Nutritivo , Plantas Comestíveis/química , Minerais/análise , Oxalatos/análise , Ácido Fítico/análise , Proteínas de Plantas/análise , Raízes de Plantas/química , Sri Lanka , Amido/análise
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