The effect of edible coatings on physical and chemical characteristics of fruit bars

Functional and textural properties of fruit bars are susceptible to environmental conditions such as temperature, humidity and oxygen. This study aimed to prevent these changes by the edible coating of fruit bars using sodium alginate (SA), carboxymethyl cellulose (CMC) and whey protein isolate (WPI) during storage at two different temperatures. The color, textural properties, moisture content (12.44-17.14 g/100 g), total phenolic content (2200.4-3141.9 mg GAE/kg dm), radical scavenging activity (1118.8-1477.0 mg TEAA/kg dm) and ascorbic acid content (60.90-162.72 mg/kg dm) of the bars were determined. Edible coating using different biopolymers did not cause a significant effect on the chemical properties of bars. All tested coating materials limited moisture loss during storage compared to control samples. SA coated bars maintained their textural properties throughout the storage. All three coating materials prevented the loss of total phenolic content and radical scavenging activity during storage. On the other hand, coating with CMC caused some undesired alterations in colour and textural properties. Coating with WPI provided the best protection on ascorbic acid. According to obtained results in the study, coating with SA or WPI can be suggested for coating fruit bars.