Quality and microbial safety of 'Fuji' apples coated with carnauba-shellac wax containing lemongrass oil

A carnauba-shellac wax (CSW)-based nanoemulsion containing lemongrass oil (LO) was prepared using high pressure homogenization. 'Fuji' apples were coated with the CSW/LO nanoemulsion and the coated apple samples were compared with uncoated apple samples with respect to quality and microbial safety for 5 months. During storage, the hardness of the uncoated apples decreased by 3.3 N, and the weight loss was 7.7%. In contrast, the hardness of the coated apples did not change, and the weight loss was 5.2%. Titratable acidity and total soluble solids were not significantly different between coated and uncoated apples. The apples coated with the CSW/LO solution had the best sensory appreciations. After 5 months of storage, the population of total aerobic bacteria on the coated apples was decreased by 1.4 log CFU/g compared with the uncoated apples. In addition, the population of yeast and molds on the uncoated apples was 2.2 log CFU/g after 5 months of storage, whereas yeast and molds were not detected on the coated apples. The CSW/LO coating can improve the quality of 'Fuji' apples during storage. (C) 2013 Elsevier Ltd. All rights reserved.