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Leaves of Psidium guajava L. (guava) have been widely used in the popular way for prevention and treatment of various diseases. Thus, the objective of this study was to evaluate the inhibitory potential of leaves aqueous extract from three cultivars of P. guajava (Pedro Sato, Paluma and Século XXI) on α-amylase, α-glycosidase, lipase, and trypsin enzymes, in the presence or not of simulated gastric fluid and to determine the content of phenolic compounds by high performance liquid chromatography. All cultivars presented the same composition in phenolic compounds, but in different proportions. The compounds identified are gallic acid, epigallocatechin gallate, syringic acid, o-coumaric acid, resveratrol, quercetin, and catechin (which was the major compound in all the cultivars evaluated). In the absence of simulated gastric fluid, it was observed different inhibitions exercised by the leaves aqueous extracts from three cultivars of P. guajava on each enzyme. In presence of simulated gastric fluid, all cultivars showed increase in the inhibition of lipase and α-glycosidase, and decrease in inhibition of α-amylase and trypsin enzymes. These results indicate that P. guajava leaves aqueous extracts from all cultivars evaluated possess potential of use as an adjuvant in the treatment of obesity and other dyslipidemias.

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Composição química e fitoquímica das farinhas da casca e da semente de lichias (Litchi chinensis Sonn) cultivar 'Bengal'. 329Ciência Rural, v.45, n.2, fev, 2015.Composição química e fitoquímica das farinhas da casca e da semente de lichias (Litchi chinensis Sonn) cultivar 'Bengal'Chemical and phytochemical composition of flours from skin and seeds of 'Bengal' lychee (Litchi chinensis Sonn)

The enzyme inhibition by natural and/ or low-cost compounds may represent a valuable adjunct to traditional serotherapy performed in cases of snakebite, mainly with a view to mitigate the local effects of envenoming. The objective of this study was to evaluate possible interactions between vitamins and enzymes that comprise Bothrops atrox and Crotalus durissus terrificus venoms, in vitro. Proteolysis inhibition assays (substrates: azocasein, collagen, gelatin and fibrinogen), hemolysis, coagulation, hemagglutination were carried out using different proportions of vitamins in face of to inhibit minimum effective dose of each venom. The vitamins were responsible for reducing 100% of breaking azocasein by C.d.t. venom, thrombolysis induced by B. atrox and fibrinogenolysis induced by both venoms. It is suggested the presence of interactions between vitamin and the active site of enzymes, for example the interactions between hydrophobic regions present in the enzymes and vitamin E, as well as the inhibitions exercised by antioxidant mechanism.

In the processing for obtaining acerola juice, a large amount of residues, which is usually discharged, is generated (seeds and bagasse). Adding value to these by-products is of great interest, since their use can enrich human food as a good source of nutrients and dietary fiber. In this study, acerola seed flours (ASF) and acerola bagasse flours (ABF) were used to develop cereal bars (CB) in different combinations with brown oats: CB 1: control -with the addition of 25% brown oats, CB 2: with the addition of 12.5% ASF and 12.5% ABF, CB 3: with the addition of 6.25% ASF and 18.75% ABF, CB 4: with the addition of 12.5% ASF and 12.5% brown oats and CB 5: with the addition of 12.5% ABF and 12.5% brown oats. These bars were sensorially evaluated and CB 1, CB 4 and CB 5 received the highest scores. We conclude that CB 4 and CB 5 can be considered as products with enhanced nutritional value, containing iron with a low energetic value and high levels of dietary fibre, besides being enriched with antioxidants.

ResumoEste trabalho tem como objetivo a caracterização de três amostras comerciais de quitosana de baixo grau de acetilação, bem como a preparação e caracterização de filmes comestíveis a partir dessas amostras, com vistas a posterior aplicação desses filmes em recobrimento de frutos. As amostras foram caracterizadas pela massa molar, grau de acetilação, análise elementar, espectroscopia de infravermelho e análise térmica, enquanto os filmes pela análise térmica, espectroscopia de infravermelho, sólidos totais e permeabilidade ao vapor de água. As amostras comerciais mostraram diferentes massas molares que variaram de 132 a 245 kDa, graus de acetilação de 5,8 a 6,3% e apresentaram análise elementar próxima a fórmula C 6 H 11 O 4 N para a unidade de repetição. Os filmes produzidos apresentaram espessuras de 3,7 a 6,8 μm, sólidos totais de 2,0 a 6,3 g m -2 e permeabilidade ao vapor de água de 170,1 a 180,2 g dia -1 m -2 . Os filmes de quitosana com maior teor de sólidos e menor massa molar foram menos permeáveis ao vapor de água. Nas análises de infravermelho e termogravimetria foram observados, respectivamente, os mesmos grupos funcionais e curvas semelhantes de decomposição, para as amostras e para os filmes produzidos. Palavras-chave: caracterização, filmes comestíveis, quitosana. AbstractThe objective of this study is to characterize three commercial samples of chitosan with low degree of acetylation, as well as the preparation and characterization of edible films from these samples, aiming the subsequent application of these films in fruit coatings. The samples were characterized by molar mass, degree of acetylation, elemental analysis, infrared spectroscopy and thermal analysis, while the film was characterized by thermal analysis, infrared spectroscopy, total solids and water vapor permeability. The commercial samples showed different molar masses, which ranged from 132 to 245 kDa, degrees of acetylation from 5.8 to 6.3% and presented an elemental analysis next to the formula C 6 H 11 O 4 N, for the repeating unit. The films produced had thicknesses from 3.7 to 6.8 μm, total solids from 2.0 to 6.3 g m -2 and water vapor permeability from 170.1 to 180.2 g day -1 m -2. The chitosan films with a higher content of solids and a lower molar mass were less permeable to water vapor. Infrared and thermogravimetric analyses showed the same functional groups and similar decomposition curves, respectively, for the samples and for the films produced.Keywords: characterization, edible films, chitosan. IntroduçãoOs polímeros quitina e quitosana têm sido bastante estudados devido ao elevado potencial de aplicações em indústrias alimentícias, farmacêuticas, cosméticas e na agricultura [1][2][3] . Esses polímeros são constituídos de cadeias lineares dos carboidratos 2-acetamido-2-deoxi-D-glicopiranose e 2-amino-2-deoxi-D-glicopiranose unidos por ligações glicosídicas β (1-4) e, podem ser distinguidos por suas solubilidades em solução aquosa de ácido acético 1%. Quitina, contendo um número ≥ 40% de N-acetil-D-glicosamina é in...