O processo respiratório e diversas reações oxidativas das células aeróbicas levam à formação de radicais livres, que contribuem para o aparecimento de diversas doenças. As células humanas dependem de sua capacidade antioxidante para fornecer proteção contra os efeitos prejudiciais de radicais livres e espécies reativas do oxigênio, que são conseqüências inevitáveis da vida aeróbica. Vários estudos epidemiológicos indicam que a alta ingestão de produtos vegetais está associada com uma redução no risco de uma variedade de doenças crônicas como aterosclerose e câncer, efeitos que têm sido particularmente atribuídos aos compostos que possuem atividade antioxidante nos vegetais: vitaminas C e E, os compostos fenólicos, especialmente os flavonóides, e os carotenóides. Compostos fenólicos agem como antioxidantes, não somente por sua habilidade em doar hidrogênio ou elétrons, mas também em virtude de seus radicais intermediários estáveis, que impedem a oxidação de vários ingredientes do alimento, particularmente de lipídios. Carotenóides são constituídos de cadeias de polienos, em um longo sistema de duplas ligações conjugadas, rico em elétrons, responsável pela atividade antioxidante desses compostos: tanto na absorção do oxigênio singlet quanto de radicais livres, para interromper as reações em cadeia onde eles estão envolvidos. Este trabalho teve por finalidade revisar as diferentes formas de avaliação qualitativa e quantitativa dos principais componentes não-nutrientes antioxidantes em alimentos de origem vegetal: compostos fenólicos e carotenóides.The respiratory process and several aerobic cells oxidative reactions lead to the formation of free radicals which contribute to the appearance of different diseases. The human cells depend on their antioxidant ability to provide protection against the prejudicial effects of free radical and reactive oxygen species that are inevitable consequences of aerobic life. Several epidemiologic studies indicate that high plant products ingestion is associated to a reduction in the hazard of a variety of cronical diseases such as arteriosclerosis and cancer. These effects have been specifically attributed to the plant compounds that have antioxidant activity: vitamin C and E, phenolic compounds, specially flavonoids, and carotenoids. Phenolic compounds act as antioxidants, not only for their ability to donate hydrogen atoms or electrons, but also because of their stable intermediary radicals, that prevent the oxidation of many food ingredients, especially lipids. Carotenoids are built by polyene chains in a long conjugated double bonds system, electron rich, which is responsible for the antioxidant activity of these compounds, by the absorption of singlet oxygen and free radicals, to interrupt the chain reaction they are involved in. This paper had as a goal to review the different qualitative and quantitative evaluation methods of the main non-nutrient antioxidants in plant originated foods: phenolic compounds and carotenoids.

The aim of this study was to assess the total carotenoid, a- and B-carotene, and 9 and 13-Z- B-carotene isomer contents in C. moschata after different cooking processes.201

The almond cake is a protein-rich residue generated by the mechanical expression of the almond oil. The effects of the aqueous (AEP) and enzyme-assisted aqueous extraction processes (EAEP) on the biological properties of the almond cake protein were evaluated. Total phenolic content (TPC), antioxidant capacity, inhibitory effects against crucial enzymes related to metabolic syndrome, antimicrobial potential, and in vitro protein digestibility profile were assessed. EAEP provided the best results for antioxidant capacity by both ORAC (397.2 µmol TE per g) and ABTS (650.5 µmol TE per g) methods and also showed a high (~ 98%) potential for α-glucosidase inhibition. The AEP resulted in protein extracts with the highest lipase inhibition (~ 70%) in a dose-dependent way. Enzymatic kinetic analyses revealed that EAEP generated uncompetitive inhibitors against α-glucosidase, while EAEP, AEP, and HEX-AEP (used as control) generated the same kind of inhibitors against lipase. No protein extract was effective against any of the bacteria strains tested at antimicrobial assays. An in silico theoretical hydrolysis of amandin subunits corroborated with the results found for antioxidant capacity, enzyme inhibitory experiments, and antimicrobial activity. Digestibility results indicated that the digestive proteases used were efficient in hydrolyzing almond proteins, regardless of the extraction applied and that HEX-AEP presented the highest digestibility (85%). In summary, EAEP and AEP skim proteins have the potential to be used as a nutraceutical ingredient. The biological properties observed in these extracts could help mitigate the development of metabolic syndrome where EAEP and AEP skim proteins could be potentially used as a prophylactic therapy for diabetes and obesity, respectively.