Effects of hydrocolloid coatings containing transglutaminase on the shelf-life of different vegetable foods

摘要: Overall quality and shelf life of fruits and vegetables is reduced by several factors including water loss, enzymatic browning, texture deterioration, senescence processes and microbial growth. Edible films applied by dip-coating technique allow to create a layer on food surfaces counteracting possible deleterious modifications. The aim of this study was to evaluate the effect of whey protein/pectin edible films, prepared in the absence or presence of the enzyme transglutaminase, to extend the shelf-life of apples, potatoes and carrots. Therefore, slices of 2.5 cm3 of the selected foods were cut and coated with film forming solutions having different composition. Our results demonstrated that whey protein/pectin-based coatings were able to protect the minimally-processed fruits and vegetables tested from degradative processes, storing their characteristic parameters, such as water content and sensorial properties, preventing oxidative processes and, consequently, increasing the shelf-life of the products. In particular, the presence in the coating solution of transglutaminase determined a significant improvement of the film barrier properties. In fact, samples of apples, carrots and potatoes treated with the film forming solution containing the enzyme showed a significant reduction in the loss of water and, in parallel, a reduced bacterial proliferation compared to the control foods.