Este trabalho avaliou o efeito do processamento e do tempo de armazenamento sobre o potencial antioxidante e atividade de enzimas antioxidantes de polpa congelada de frutos de seis clones de aceroleira. Foram colhidas acerolas maduras dos clones BRS 235, BRS 236, BRS 237, BRS 238, II47/1 e BRS 152; a polpa foi processada, acondicionada em sacos plásticos de polietileno selados à vácuo e armazenada em freezer doméstico à -18 °C por 11 meses. Amostras de cada clone foram analisadas no dia colheita/processamento e a cada 30 dias quanto aos compostos bioativos antioxidantes, a atividade de enzimas antioxidantes e a atividade antioxidante total. As polpas de acerola apresentaram uma diminuição dos antioxidantes não enzimáticos e um aumento da atividade das enzimas antioxidantes, indicativo de um mecanismo compensatório entre antioxidantes enzimático e não enzimático. Na polpa de acerola, antocianinas e polifenóis estão fortemente correlacionados com o conteúdo de sólidos solúveis e de vitamina C, destacando os polifenóis como o principal contribuinte para a atividade antioxidante total. A polpa do clone II47/1 teve um excelente desempenho em relação ao potencial antioxidante e o melhor período de armazenamento à -18 °C seria de 150 dias, para todos os clones estudados.

This study evaluated the effect of the processing and long-term storage on the antioxidant potential and activity of antioxidant enzymes of frozen purées from six acerola clones. Ripe acerolas from clones BRS 235, BRS 236, BRS 237, BRS 238, II47/1 and BRS 152 were harvested; the pulp was processed, packed in sealed polyethylene plastic bags and stored in a domestic freezer at -18°C for 11 months. Samples of each clone were analyzed on harvest/processing day and every 30 days after for bioactive antioxidant compounds, antioxidant enzyme activity and total antioxidant activity. Acerola purées presented a decrease of non-enzyme antioxidants and an increase of antioxidant enzymes activities, indicatives of a compensatory mechanism between enzymatic and non-enzymatic antioxidants. In acerola purée, anthocyanin and polyphenols are strongly correlated to soluble solids content and vitamin C seems a major contributor to total antioxidant activity. Clone II47/1 had an outstanding performance regarding the antioxidant potential of its purée and the best storage period at -18ºC would be 150 days, for all clones studied.

In this study, proteins extracted from laticifer cells of three plants were examined by electrophoresis, mass spectrometry (MALDI-TOF) and characterized in respect of proteolytic, chitinolytic and anti-oxidative activities by means of zymography and colorimetric assays. Acidic proteins with molecular masses between 12.5 and 74.5 kDa predominated in laticifers of P. rubra. This profile was not found in laticifers of C. grandiflora and E. tirucalli. The later was poor in respect of proteins. Strong anti-oxidative activity of superoxide dismutase (E.C. 1.15.1.1) was detected in P. rubra and C. grandiflora latices, and to a lesser extent ascorbate peroxidase (E.C. 1.11.1.1) and isoforms of peroxidase were seen. Catalase (E.C. 1.11.1.6) was detected only in laticifer cells of C. grandiflora. Chitinase (E.C. 3.2.1.14) was the sole activity found in laticifer cells of E. tirucalli, but was also detected in the other latices. The strong proteolytic activity of C. grandiflora was shown to be shared by at least three distinct cysteine proteinases (E.C. 3.4.22.16). Serine, aspartic and metaloproteinases were not detected. In laticifer cells of P. rubra, four proteinases were detected, including cysteine and serine types. This study reports new protein data of laticifers from plants that have been poorly investigated in this respect and contributes to the understanding of biochemical and functional aspects of laticifers in plants.