Impact of edible coatings and packaging on quality of white asparagus (Asparagus officinalis, L.) during cold storage

The effects of edible coatings and plastic packaging on quality aspects of refrigerated white asparagus spears were studied using two different experimental protocols. The first included four coating formulations based on carboxymethyl-cellulose and sucrose fatty acid esters, whey protein isolate alone and in combination with stearic acid, and pullulan and sucrose fatty acid esters, and an uncoated sample serving as a control. The second set consisted of four treatments; uncoated asparagus spears (control), coated with a carboxymethyl-cellulose formulation, packaged in plastic packaging and combination of coated and packaged asparagus spears. All products were stored at 4 degrees C and the quality parameters such as weight loss, texture, visual appearance, lignin and anthocyanins concentration, and colour were evaluated during their storage. Edible coatings exhibited a beneficial impact on the quality of asparagus by retarding moisture loss, reducing hardening in their basal part and slowing down the purple colour development. The plastic packaging had a remarkable influence in reducing weight loss and retarding hardening but its impact to the rest of the quality parameters was similar to that of the edible coatings. The combination of packaging and edible coating did not seem to offer any additional advantage on asparagus spears apart from the fact that the product had a brighter appearance at the middle part of the stem compared to the packaged spears alone. (C) 2009 Elsevier Ltd. All rights reserved.