INFUSÃO DE Aloysia triphylla: EFEITOS OPOSTOS EM UM TESTE DE ATIVIDADE ANTIOXIDANTE IN VITRO E NA ESTABILIDADE OXIDATIVA DE PATÊS DE PESCADO REFRIGERADOS

O objetivo deste trabalho foi avaliar o efeito da infusão de Aloysia triphylla (IAT) sobre os valores de pH e a estabilidade oxidativa de patês de carne de jundiá (Rhamdia quelen) armazenados refrigerados. A IAT apresentou 1,8 mg de fenólicos totais/mL e teve boa capacidade antioxidante no ensaio de remoção do radical 2,2-difenil-1-picrilhidrazila (DPPH) (equivalente a uma solução 3,2 mM de trolox). As formulações de patês, sendo uma controle (água) e três formulações com quantidades crescentes de IAT (18 mg, 45 mg e 90 mg de fenólicos totais/kg de patê) foram armazenadas a 5°C e avaliadas ao longo de 28 dias quanto ao pH, oxidação lipídica (substâncias reativas ao ácido tiobarbitúrico, TBARS) e proteica (carbonilação de proteínas) e cor instrumental (CIELab). Os valores de pH reduziram ao longo da armazenagem, enquanto os de TBARS aumentaram até o 9º dia e depois reduziram (p<0.05), mas nenhuma dessas medidas foi influenciada pela IAT (p<0,05). A oxidação proteica aumentou ao longo do armazenamento (p<0.05) e as formulações com 45 mg e 90 mg de fenólicos/kg tiveram maior carbonilação proteica que o controle nos dias 21 e 28 de armazenagem, respectivamente (p<0,05). Comparadas ao controle, as formulações com IAT tiveram maiores valores de L* no início da armazenagem e menores valores de a* e croma a partir do 15º dia de armazenagem (p<0,05). A IAT não foi efetiva como antioxidante em patês de jundiá, ainda que tenha apresentado boa atividade antioxidante no ensaio de remoção do radical DPPH in vitro.

Conditions of enzyme-assisted extraction to increase the recovery of flavanone aglycones from pectin waste

The citrus pectin by-product (CPB), generated from pectin industry, is a rich-source of flavanones, but not explored until now. As most of these compounds are inside vacuoles or bound to cell wall matrix, enzymatic hydrolysis was applied on their recovery, followed by hydroalcoholic and ultrasound extraction. Different parameters were studied: enzymes (β-glucosidase, tannase, and cellulase), their concentration (5, 10, and 20 U g−1 CPB), and reaction time (6, 12, and 24 h). Extracts were characterized in total phenolic content (TPC), antioxidant capacity (ORAC and DPPH assays), and polyphenolic profile (HPLC–DAD). All enzymatic treatments significantly improved CPB antioxidant capacity and TPC, compared with hydroalcoholic and ultrasound extraction. β-glucosidase (5 U) for 24 h was the most effective in polyphenol extraction and bioconversion, followed by β-glucosidase (5 U) for 12 h and tannase (5 U) for 24 h. Thus, the concentration of these enzymes was increased (10 and 20 U) to improve flavanones extraction. β-glucosidase at 20 U offered the highest amount of naringenin (77.63 mg 100 g−1 of CPB) and hesperetin (766.44 mg 100 g−1) obtained so far by biological processes. According to Person’s correlation analysis, TPC and antioxidant activity were highly correlated with CPB contents of hesperetin and naringenin. The aglycone flavanones are rarely found in natural sources and have higher biological potential than their glycosylated forms. Our results indicated enzyme-assisted extraction as a good choice for recovering aglycone flavanones from CPB, and increased knowledge on the biological activity of this agroindustrial waste, amplifying their application in food and pharmaceutical fieldCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão tem2015/04555-

Antioxidant potential of barley extract in rats subjected to a high-fat diet

Antioxidants have the ability to neutralize free radicals produced in the body during lipid oxidation. The objective in this article was to study the effect of the barley extract on lipid oxidation in rats subjected to a high-fat diet. The experiment lasted 67 days. The animals were separated into three experimental groups: standard (P), high-fat diet group (L), and group with high-fat diet supplemented with barley extract (C). The feed intake of L and C groups was the lowest (p < 0.05). The treatments did not influence weight gain, organ weight, and the blood parameters measured. However, the levels of malondialdehyde present in the liver tissue were higher in the L group and lower in the P and C groups. Therefore, the results indicated an increased level of lipid peroxidation in the liver of rats subjected to high-fat diet, which was reduced by the consumption of barley

Antioxidant potential of barley extract in rats subjected to a high-fat diet Potencial antioxidante de extrato de cevada em ratos submetidos à dieta hiperlipídica

Antioxidants have the ability to neutralize free radicals produced in the body during lipid oxidation. The objective in this article was to study the effect of the barley extract on lipid oxidation in rats subjected to a high-fat diet. The experiment lasted 67 days. The animals were separated into three experimental groups: standard (P), high-fat diet group (L), and group with high-fat diet supplemented with barley extract (C). The feed intake of L and C groups was the lowest (p < 0.05). The treatments did not influence weight gain, organ weight, and the blood parameters measured. However, the levels of malondialdehyde present in the liver tissue were higher in the L group and lower in the P and C groups. Therefore, the results indicated an increased level of lipid peroxidation in the liver of rats subjected to high-fat diet, which was reduced by the consumption of barley.<br>Os antioxidantes têm a capacidade de neutralizar os radicais livres gerados no organismo durante a oxidação lipídica. O objetivo deste artigo foi estudar o efeito do extrato de cevada na oxidação lipídica em ratos submetidos a uma dieta rica em gordura. O experimento durou 67 dias. Os animais foram separados em três grupos experimentais: grupo padrão (P), grupo de dieta rica em gordura (L) e grupo com dieta rica em gordura suplementada com extrato de cevada (C). O consumo de ração dos grupos L e C foi mais baixa (p < 0,05). Os tratamentos não influenciaram no ganho de peso, no peso dos órgãos e nos parâmetros sanguíneos avaliados. No entanto, os níveis de malondialdeído presentes no tecido hepático foram maiores no grupo L e menores nos grupos P e C. Portanto, os resultados indicaram um aumento do nível de peroxidação lipídica no fígado de ratos submetidos à dieta rica em gordura, a qual foi reduzida com o consumo de cevada

Aglycone-rich extracts from citrus by-products induced endothelium-independent relaxation in isolated arteries

Citrus by-products are rich in flavanone aglycons which have lower bioactivity than aglycone forms. Based on this, the study evaluated the effects of enzyme biotransformation on antioxidant and vasorelaxant capacity of polyphenolic rich-extracts from citrus waste. Enzymatic treatment produced extracts with high hesperetin concentrations and higher antioxidant capacity than non-treated extracts. At the highest concentration tested (3 mg mL−1), citrus juice by-products exhibited only a partial vasorelaxant effect. After the enzymatic treatment, the extract had a maximal effect of 100% relaxation and enhanced their pEC50. The relaxation promoted by citrus pectin by-products was potentiated in the presence of ODQ, suggesting that vasorelaxant effects of these extracts may occur even when sGC is oxidized because of vascular oxidative stress. Thus, the enzyme-assisted extraction appears to enhance antioxidant and vasorelaxant properties of citrus extracts, which could be used to develop new products with antihypertensive properties23CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP140537/2015-52015/04555-

Estabilidade lipídica de filés de carpa húngara congelados tratados com extratos de Lippia Alba

O objetivo do presente estudo foi avaliar o efeito da aspersão de extratos de Lippia alba na estabilidade lipídica de filés de carpa húngara armazenados a -18±2°C. Filés não tratados (controle sem aspersão) ou aspergidos (1mL 10g-1 de filé) com água destilada (controle água destilada) ou com extratos de L. alba (0,10g mL-1) hidrometanólico ou aquoso foram analisados durante o armazenamento nos dias zero, 90 e 180. Independente do tempo de congelamento, o extrato hidrometanólico reduziu os valores de dienos conjugados (DC) dos filés em relação aos demais tratamentos, além de reduzir os valores de ácidos graxos livres aos 90 dias (P<0,05). O extrato aquoso resultou em maior teor de peróxidos após 180 dias de congelamento comparado aos demais tratamentos (P<0,05). Os extratos hidrometanólico e aquoso reduziram os valores de substâncias reativas ao ácido tiobarbitúrico (TBARS) após 180 dias, comparados aos filés tratados com água destilada e sem aspersão (P<0,05). Ambos os extratos de L. alba retardaram a oxidação lipídica, sendo que o extrato aquoso retardou a degradação de produtos primários da oxidação lipídica (peróxidos) em produtos secundários (TBARS), enquanto o extrato hidrometanólico parece ser mais eficiente, pois inibiu de forma similar tanto a formação de DC e peróxidos, quanto a sua degradação em produtos secundários (TBARS

Oxidative stability of refrigerated fish pates containing loquat seed extract

This study investigated the effects of hydroethanolic E. japonica seed extracts (EJSE) as inhibitors of lipid and protein oxidation on fish pates subjected to refrigerated storage. Five fish pate formulations were developed. These formulations included two control pates (water-control and ascorbic acid-control) and three pates with added EJSE (0.1, 0.2 and 0.4g of seed 100g-1 product, equivalent to 3.4, 6.8 or 13.6mg phenolic compounds kg-1 product), which were then stored under refrigeration for 35 days. Conjugated dienes (CD) and peroxide (PV) values increased along with the storage time; however, these values decreased and were similar among all samples at the end of 35 days of analysis (P<0.05). However, the thiobarbituric acid reactive substances levels (TBARS) did not change along the storage and were not affected by the EJSE. Additionally, there was a linear increase in the protein carbonyl content of fish pates over the storage period (P<0.05), but no effect of EJSE on protein oxidation. The results show that, at the concentrations evaluated, hydroethanolic E. japonica seed extract was unable to inhibit or reduce lipid and protein oxidation in fish pates, but the observed phenolic content emphasizes the need for further studies on the wastes of this fruit