Biodegradable and biodesintegrable films employed for the storage of long keeping tomatoes

摘要

The aim of this work was to test the behaviour of biodegradable and/or biodesintegrable films as protective wraps for tomatoes type "long keeping" to be consumed "fresh". The films were tested both under refrigerated storage and retailing conditions. For the experimental work, we used tomatoes cv R-190 (Graziella), harvested at USDA six ripening stage, and placed them in containers having four tomatoes each. Each container was covered with a given film. The following films were used: Ecostar 5, 10 and 15 p. 100 (biodisintegrable) and Mater-bi (biodegradable). To compare such novel films with current commercial ones, we also used PVC and RD-10~6 films (both non-degradable). Tomatoes were stored at 12 deg C. Samples were extracted every seven days, being some of these transferred to 20 deg C for additional seven days, so as to test their shelf-life. To characterize tomato quality, we regularly determined weight loss, surface color, titratable acidity, composition of the afmosphere inside the package, etc. We observed that up to 14 storage days at 12 deg C, tomato quality kept between excellent and very good in all films. In contrast, after 28 days at 12 deg C, only those PVC-covered tomatoes kept commercial quality. In all films, the passage to 20 deg C led to a noticeable quality decrease. Tomato wrapped with Mater-bi films experienced the greatest weight loss. In addition, the atmosphere developed inside those packages had the highest CO_2 proportion.