76C-24 |
Influence of water stress, minimal processing and storage on bioactive amines profile in American lettuce |
M. B. A. GLÓRIA1, A. F. S. Coelho, and S. Motta. (1) Departamento de Alimentos, Universidade Federal de Minas Gerais, R. Zilah Correa Araujo 416 B. Ouro Preto, Belo Horizonte, 31310-450, Brazil Lettuce, specially American lettuce, is one of the most important vegetable in the Brazilian diet. Lettuce production and quality is highly affected by water stress. It is also highly perishable, showing fast and irreversible changes. Minimally processed vegetables are becoming popular due to easiness of preparation. It also adds value to the product, increasing competitiveness and providing better commercialization opportunities. The quality of vegetables is evaluated by visual and microbiological aspects, however these methods are subjective and time consuming, respectively. Several investigators have proposed the use of bioactive amines as a quality control index for vegetables. The objective of this work was to investigate the types and levels of bioactive amines in American lettuce as affected by water stress, part of plant, processing and storage. Lucy Brown lettuce was cultivated for 93 days in a green house. Plants were submitted to droplet irrigation using 4 levels of water layer (25, 50, 75 and 100%). Samples were minimally processed and stored at 4°C. The microbial quality and levels of bioactive amines were determined. Four amines were detected in lettuce with a total level of 0.76 mg/100 g. Spermidine was the prevalent amine, followed by putrescine, cadaverine and agmatine. There was no significant difference on the levels of amines among inner, intermediate and outer leaves of lettuce cultivated under ideal conditions. Samples cultivated under water deficiency showed accumulation of spermidine and putrescine. However significant difference was only observed between control and the sample submitted to 25% water layer. During processing, enzymatic browning was prevented with sodium metabisulfite 0.2%. During storage of minimally processed lettuce, there was an increase on cadaverine levels. This amine could be used as quality control criterion of minimally processes lettuce.
Session 76C, Fruit & Vegetable Product: Fresh Fruits and Vegetables
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