Improving storage quality of refrigerated steamed buns by mung bean starch composite coating enriched with nano-emulsified essential oils

In this study, the edible antimicrobial coating was prepared from mung bean starch and soluble soybean polysaccharide (MBS-SSPS) enriched with different concentrations (0%, 0.3%, 0.6%, 0.9%, and 1.2%) of nano-emulsified clove and cinnamon oil (CCO). Then MBS-SSPS incorporated CCO coating (MSC) was applied on steamed buns at 10 degrees C, 50% RH and the microbiological attributes (total viable count and the mold and yeast counts), hardness, and organoleptic attributes were assessed. The use of CCO in MBS-SSPS coating solution reduced viscosity of final coating and increased antimicrobial activity. Also, compared with the uncoated sample, MSC0.6 and MSC0.9 under no adverse effect on flavor quality, reduced the aerobic plate count by 38.5 and 42% and decreased mold and yeast counts by 32 and 37%, respectively. Meanwhile, the coated samples obtained acceptable sensory qualities and lower hardness than the uncoated ones. Practical Applications The objective of the study was to develop and characterize the MBS-SSPS coating enriched with nano-emulsified CCO (the mixture of cinnamon and clove essential oil), then evaluate the effectiveness of antimicrobial coating on the storage quality of steamed buns. MSC0.6 and MSC0.9 improved the storage quality without sacrificing flavor while compared with uncoated samples. Therefore, it was feasible to apply this new edible antimicrobial coating on the surface of the steamed buns.