Application of Starch Foams Containing Plant Essential Oils to Prevent Mold Growth and Improve Shelf Life of Packaged Bread

Abstract

In the recent years, considerable attention has been allocated in the area of using natural preservatives in foods, especially vegetable oils. Starch foams prepared from high amylose starch are useful for encapsulation of substances such as chemicals, liquids or solids, including flavor compounds, pharmaceuticals and essential oils. The foams have the ability to trap the active material and subsequently release the activity. Cinnamon oil is absorbed to foam starch microparticles and acts as an antimicrobial agent. This study was designed and implemented to evaluate the use of starch foam containing vegetable oil to prevent mold growth and improve packaged bread shelf life. For this purpose, first cinnamon essential oil was extracted with water by distillation method then, 250 groups of bread were prepared within polypropylene plastic bags. Various amounts of cinnamon essential oil (500, 750, 1000and1500ppm) with 1 g of starch foam powder inside sterilized filter paper were added to these packages.The obtained results of multi-way and intergroup repeated tests indicated that there was a significant difference (P <0/05) between the control groups and various groups containing cinnamon essential oil in terms of microbial load. In the groups containing essential oils, less increase was showed in microbial load and with increasing concentrations of cinnamon essential oil, mold and yeast growth rate decreased. It concluded that by using starch foam containing cinnamon essential oil in bulky bread packing at ambient temperature (25°C), the spoilage process of bulky bread can be postponed 3 to 6 days, and it can be used as an appropriate natural and antifungal preservative in packaging of bread.