Chlorophyll stability in yerba maté leaves in controlled atmospheres

• Autor(a) principal: Morawicki,Rubén O.
• Data de Publicação: 1999
• Outros Autores: Schmalko,Miguel E., Känzig,Rodolfo G.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Archives of Biology and Technology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000100012
• topic: yerba maté; chlorophyll stability; controlled atmosphere

The objective of this research was to investigate the stability of chlorophyll in yerba maté leaves in controlled atmospheres of CO2/air mixtures and different water activities at 25°C.Two levels of water activity were selected corresponding to saturated salt solutions of LiCl (a w=0.113) and MgCl2(a w=0.330) and three levels of CO2/air mixtures (0/100,20/80 and 40/60). The chlorophyll content was evaluated using a liquid chromatography HPLC technique. Experimental values varied between 2.16 and 0.61 mg/g of dry matter. For each sample, 5 determination were made during 58 days. Experimental values were fitted to an equation describing a first order reaction. In all cases, the agreement was good with P<3 10-3. The initial concentration of chlorophyll dropped, in average, to 30.5% after 58 days. However, after comparing the velocity constants, no differences were found between them.