Navegando por Assunto "Enzyme"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Estudo do processo de extração aquosa enzimática do óleo da polpa de tucumã-ída várzea(Astrocaryum giganteum Barb. Rodr.)
(Universidade Federal do Pará, 2022-06-30) SANTOS, Wanessa Oliveira dos; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170
The objective of the present work was to study the process of enzymatic aqueous extraction and to characterize the oily and aqueous fractions obtained from the pulp of tucumã-í-da-várzea (Astrocaryum giganteum Barb. Rodr.). The fruits collected in different months of the year (March, April, May, June and October) were characterized in terms of physicochemical properties (total lipids, soluble solids and instrumental color) and bioactive properties (total carotenoids, total phenolic compounds and antioxidant activity). , and the month of collection was defined based on the evaluation of these properties. The aqueous enzymatic extraction assays were carried out using a full 22-factorial experimental design, with three repetitions at the central point and four axial points (totaling eleven assays). The type of pre-treatment used and the conditions applied for the aqueous enzymatic extraction tests (enzyme, solute:solvent ratio, temperature and pH) were defined from preliminary tests evaluating different conditions, and the effect of such variables was evaluated. in the yield of extracted oil. The oil obtained in the tests of the experimental design of aqueous enzymatic extraction was characterized in terms of its chemical properties (acidity index, peroxide value, oxidative stability and total carotenoids). The bioactive properties of the two fractions (oily and aqueous) obtained in the aqueous enzymatic extraction process were evaluated by determining the content of total phenolic compounds (CFT) and antioxidant activity. In addition, the characterization of tucumã-í-da-várzea oil, obtained in the test with the best conditions for extraction, was carried out in terms of fatty acid composition, nutritional quality indices, iodine and saponification indices, and melting point. . The aqueous enzymatic extraction applied to the extraction of tucumã-í-da-várzea oil made it possible to obtain yields equivalent to conventional extraction methods, with oxidative stability comparable to traditional commercial oils, in addition to high values of total carotenoids, CFT and antioxidant activity. . In addition, the aqueous extracts obtained showed excellent chemical quality, demonstrated by the high values of CFT and antioxidant activity obtained, which indicates the great potential of application of the polar phase obtained in these processes in several uses. The tucumã-í-da-várzea oil presented a fatty acid composition rich in unsaturated fatty acids, especially oleic and linoleic acid. In addition, it showed excellent nutritional quality indices (AI and TI), being considered an oil of high nutritional value and that can be used for food purposes to replace traditional oils, such as olive oil. Based on the results of this study, the aqueous enzymatic extraction methodology is potentially viable for obtaining excellent quality tucumã-í-da-várzea oil and is environmentally friendly, as it does not produce volatile organic compounds such as atmospheric pollutants, and 2 the by-product obtained (aqueous extract) through extraction has high quality functional properties and is free from toxic products.
Acesso aberto (Open Access)
Hidrólise da quitosana: obtenção de um extrato enzimático e caracterização do produto hidrolisado
(Universidade Federal do Pará, 2022-08-09) GONÇALVES, Cleidiane Gonçalves e; FERREIRA, Nelson Rosa; http://lattes.cnpq.br/3482762086356570; https://orcid.org/0000-0001-6821-6199; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; https://orcid.org/0000-0001-5009-8235
Chitin, extensively found in crustaceans exoskeletons, insects, and microorganisms, has limited usage due to its low solubility in aqueous solution, requiring its partial deacetylation to obtain chitosan. Chitosan's depolymerization has attracted considerable attention, as its oligomers have high water solubility, biocompatibility, and non-toxicity, as well as beneficial properties such as antimicrobial, antioxidant, and antitumor properties. For this reason, in this research, a review article was produced (Chapter I) based on the main methods of chitosan hydrolysis, besides analyzing the parameters that influence the acquisition, and characteristics of hydrolysis results, effectively and at a lower cost. Among the approaches studied, enzymatic hydrolysis excels due to its control ease and performance under milder conditions, making it possible to use low-cost enzymes belonging to the glycoside hydrolases group. Thus, enzymatic hydrolysis was defined as a technique for various sizes of chitosan acquisition (Chapter II) through the production of an enzymatic extract (integral enzymatic extract - IEE) from a filamentous fungus strain. The enzyme identification present in the IEE showed exo-chitinases, endo-chitinase, and cellobiohydrolase. Considering the same reaction conditions, the IEE showed greater efficiency than the commercial enzyme (Celluclast 1.5 L®), which was used as a parameter because it is an enzyme capable of cleaving the β-1,4-glycosidic bond of chitosan - similar to chitosanase, besides presenting a lower cost. The IEE reduced the molecular weight of chitosan by 47.80; 75.24 and 93.26% at 2.0; 5.0, and 24 h, respectively. Through the FTIR analysis, a lower absorbance of the spectral signals of chitosan oligomers was detected, and the crystallinity reduced after 3.0 h of hydrolysis. Based on this study, we can infer that enzymatic hydrolysis, under established conditions, is effective at obtaining lower molecular weight chitosan using unpurified crude extract.
Acesso aberto (Open Access)
Uso combinado de técnicas não convencionais na recuperação de astaxantina do coproduto gerado no processamento de camarão-rosa (farfantepenaeus subtilis)
(Universidade Federal do Pará, 2021-08-31) SILVA, Aline Kazumi Nakata da; RODRIGUES, Antonio Manoel da Cruz; http://lattes.cnpq.br/7524720020580309
The large amount of co-products generated in the production chain of shrimp processing has created a discussion about their use for the manufacture of high-added value ingredients. Regarding this subject, the use is both an attempt to minimize the pollution caused by the inadequate disposal of industrial waste in nature, and a way to generate income through the extraction of substances of economic interest. For this, knowing the amount of carotenoids and polyunsaturated fatty acids of the pink shrimp (Farfantepenaeus subtilis), which is the main species of marine shrimp produced by capture fisheries in the state of Pará, is essential since it is recognized as a source of these substances by the specialized literature. In the present work, two ways of using the pink shrimp co-product were studied, the first through drying in a spouted fluidized bed and the second through the extraction of the astaxanthin (ASX) carotenoid through enzymatic hydrolysis combined with ultrasound-assisted extraction (UAE). For drying the co-product, the spouted bed is a good alternative due to its low operating cost and high efficiency in removing moisture from the material. The co-product (pink shrimp cephalothorax) was ground in a food processor and then dehydrated at temperatures of 70, 80 and 90 °C, and later, conducted to an ASX extraction step using palm olein as a solvent at temperatures of 50, 60 and 70 °C. In carrying out the ASX extraction with enzymatic hydrolysis and UAE, the effects of the enzyme type (alcalase, flavourzyme and a mixture of alcalase and flavourzyme in a ratio of 1:1, v/v), enzyme concentration (0.2; 0.4; 0.6 and 0.8 % relative to the sample mass) and hydrolysis time (0, 60, 90 and 120 minutes). Alcalase was the most efficient enzyme, whose action culminated in the extraction of almost 70 % of the relative content of ASX of the sample. The ASX content was significantly and positively affected by the enzyme concentration (p<0.05) for all the enzymes, but the hydrolysis time was only partially significant.