scholarly journals ASPECTOS FÍSICO-QUÍMICOS E FISIOLÓGICOS DO AMIDO RESISTENTE

Author(s):  
SILVANA MAGALHÃES SALGADO ◽  
ZELYTA PINHEIRO DE FARO ◽  
NONETE BARBOSA GUERRA ◽  
ALDA VERÔNICA SOUZA LIVERA

A presente revisão teve por objetivo estudar os fatores que influem na formação do amido resistente (AR) e sua proporção nos alimentos, visando auxiliar os profissionais da área de saúde no estabelecimento de recomendações dietéticas. O termo amido resistente é definido como a soma do amido e produtos da sua degradação que não são digeridos pelas enzimas humanas de indivíduos saudáveis. O amido resistente foi abordado quanto a sua classificação e formação, bem como seus efeitos fisiológicos sobre o metabolismo intestinal, glicídico e lipídico. Verificou-se que não obstante comprovação das propriedades prebióticas do AR, os mecanismos sistêmicos dos ácidos graxos de cadeia curtos produzidos durante a fermentação e os efeitos sobre as respostas glicêmicas e lipídicas ainda são conflitantes. PHYSICAL-CHEMICAL AND PHYSIOLOGICAL ASPECTS OF RESISTANT STARCH Abstract The present revision had as objective: to study the factors, which have influence on resistant starch (RS) formation, and their content on foodstuffs, aiming to subsidies health professionals on dietary recommendations. The expression resistant starch refers to the sum of starch and its degradation products not digested by gastrointestinal tract enzymes from healthy human beings. Resistant Starch was approached according to its classification and formation and also according to its physiological effects on intestinal sugar and lipids metabolisms. It was observed RS prebiotics properties confirmation, although the systemic mechanisms of low chain fatty acids produced during fermentation and the effects on glycemic and lipidic responses are still conflicting.

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 177-177
Author(s):  
Gabriela E Martinez Padilla ◽  
Rajesh Jha ◽  
Vivek Fellner ◽  
Eric van Heugten

Abstract This study evaluated short-chain fatty acid (SCFA) production from purified fiber sources when fermented in vitro using pig cecal contents as an inoculum. Fiber sources of interest were inulin from chicory root (native and long-chain inulin with 90 and 98% fiber, respectively), pectin from citrus peel (high methoxyl pectin), resistant starch (native starch), potato starch (commercial grade), and β-glucan (β-1,3;β-1,6 yeast-derived). Cellulose and cornstarch were used as indigestible and highly digestible carbohydrates, respectively. Triplicate samples of substrates (2 g) were subjected to enzymatic hydrolysis with pepsin and pancreatin for 6 h. Subsequently, hydrolyzed residues (200 mg) were incubated under anaerobic conditions at 39°C with 30 mL solution of cecal inoculum collected from 3 sows fed a standard commercial diet and buffered mineral solution. After 48 h of incubation, solutions from fermented samples were analyzed for pH, SCFA, and branched-chain fatty acids (BCFA) using gas-liquid chromatography. Enzymatic hydrolysis had no effect on digestion of β-glucan, but total SCFA concentration after fermentation was highest (26.13 mmol/g) followed by resistant starch (22.61 mmol/g) and potato starch (22.20 mmol/g) and was lowest for cellulose (13.91 mmol/g). In contrast, native inulin was highly digested during enzymatic hydrolysis, resulting in the lowest substrate available for fermentation (11.84% DM) and the highest pH (5.98). Enzymatic hydrolysis and fermentation of resistant starch increased (P< 0.001) concentrations of acetate (0.60 mg/g), whereas potato starch and β-glucan yielded more butyrate (0.60 and 0.54 mg/g respectively), and β-glucan resulted in greater (P< 0.001) propionate concentrations (0.69 mg/g). Pectin resulted in the highest fermentation (82.38% DM disappearance) and the lowest pH (4.03) compared to the other fiber sources (P< 0.001) and yielded the lowest BCFA concentration (1.89 mM, P< 0.001). Results suggest that fermentation of resistant starch, potato starch, and β-glucan produced higher SCFA concentrations, while pectin resulted in a decreased pH of fermentation solution.


2020 ◽  
pp. 110032
Author(s):  
Tânia B. Ribeiro ◽  
Débora Campos ◽  
Ana Oliveira ◽  
João Nunes ◽  
António A. Vicente ◽  
...  

1989 ◽  
Vol 70 (1) ◽  
pp. 189-191 ◽  
Author(s):  
R. L. Lochmiller ◽  
E. C. Hellgren ◽  
J. F. Gallagher ◽  
L. W. Varner ◽  
W. E. Grant

2012 ◽  
Vol 9 (7) ◽  
pp. 2407-2418 ◽  
Author(s):  
D. Rush ◽  
E. C. Hopmans ◽  
S. G. Wakeham ◽  
S. Schouten ◽  
J. S. Sinninghe Damsté

Abstract. Ladderane fatty acids are commonly used as biomarkers for bacteria involved in anaerobic ammonium oxidation (anammox). These lipids have been experimentally shown to undergo aerobic microbial degradation to form short chain ladderane fatty acids. However, nothing is known of the production or the distribution of these oxic biodegradation products in the natural environment. In this study, we analysed marine water column particulate matter and sediment from three different oceanic regimes for the presence of ladderane oxidation products (C14 ladderane fatty acids) and of original ladderane fatty acids (C18 and C20 ladderane fatty acids). We found that ladderane oxidation products, i.e. C14 ladderane fatty acids, are already produced within the water column of the Arabian Sea oxygen minimum zone (OMZ) and thus only low amounts of oxygen (< 3 μM) are needed for the β-oxidation of original ladderane fatty acids to proceed. However, no short chain ladderane fatty acids were detected in the Cariaco Basin water column, where oxygen concentrations were below detection limit, suggesting that the β-oxidation pathway is inhibited by the absence of molecular oxygen, or that the microbes performing the degradation are not proliferating under these conditions. Comparison of distributions of ladderane fatty acids indicates that short chain ladderane fatty acids are mostly produced in the water column and at the sediment surface, before being preserved deeper in the sediments. Short chain ladderane fatty acids were abundant in Arabian Sea and Peru Margin sediments (ODP Leg 201), often in higher concentrations than the original ladderane fatty acids. In a sediment core taken from within the Arabian Sea OMZ, short chain ladderanes made up more than 90% of the total ladderanes at depths greater than 5 cm below sea floor. We also found short chain ladderanes in higher concentrations in hydrolysed sediment residues compared to those freely occurring in lipid extracts, suggesting that they had become bound to the sediment matrix. Furthermore, these matrix-bound short chain ladderanes were found at greater sediment depths than short chain ladderanes in the lipid extract, suggesting that binding to the sediment matrix aids the preservation of these lipids. Though sedimentary degradation of short chain ladderane fatty acids did occur, it appeared to be at a slower rate than that of the original ladderane fatty acids, and short chain ladderane fatty acids were found in sediments from the Late Pleistocene (~ 100 kyr). Together these results suggest that the oxic degradation products of ladderane fatty acids may be suitable biomarkers for past anammox activity in OMZs.


1997 ◽  
Vol 75 (10) ◽  
pp. 2697 ◽  
Author(s):  
J van der Meulen ◽  
G C Bakker ◽  
J G Bakker ◽  
H de Visser ◽  
A W Jongbloed ◽  
...  

2018 ◽  
pp. 5-12
Author(s):  
Hendricks

Alimentation Influence in the characteristics of compounds related with fat of ham from iberic pigs. Alimentation influence (acorn, acorn-bait mixed, bait) over characteristics fat and their degradation products, that are in part, responsible of the aroma of ham, has been studied. Influence over the naturation degree has been observed. Relation oleic/ linoleic+linolenic acids are different In the three types of hams. Also water activity, salinity index and redox potential show differences that affect to the relative percentage of satured and unsatured free fatty acids. Fat of bait hams suffer more oxidation. Acorn and mixed acornbait hams offer a higher level of pentanal and acetaldehyde. Whereas bait hams have higher level of hexanal, heptanal and octanal. The percentage of cetonic compounds are similar in all then.


2009 ◽  
Vol 72 (9) ◽  
pp. 2006-2016 ◽  
Author(s):  
BULENT KABAK ◽  
ALAN D. W. DOBSON

Mycotoxins are fungal secondary metabolites that if ingested can cause a variety of adverse effects on both humans and animals, ranging from allergic responses to death. Therefore, exposure to mycotoxins should be minimized. A variety of physical, chemical, and biological methods have been developed for decontamination and/or detoxification of mycotoxins from contaminated foods and feeds. This overview details the latest developments in the biological control of both fungal infection and mycotoxin formation and describes the detoxification of many of the most important mycotoxins by microorganisms. This review also addresses the potential for use of microorganisms as mycotoxin binders in the gastrointestinal tract of both humans and animals, thereby reducing the potential deleterious effects of exposure to these toxins.


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