Naimeh Khazaei1, Mohsen Esmaiili1, Zahra Emam-Djomeh2. 1. Department of Food Science and Technology, Faculty of Agricultural Engineering, Urmia University, Iran. 2. Department of Food Science, Engineering and Technology, Campus of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Abstract
BACKGROUND: To improve the quality of Pacific white shrimp (Litopenaeus vannamei), active coating solutions were prepared by dissolving 10 g L-1 of basil seed gum (BSG) and adding various levels of thymol (6%, 8% and 10% w/w based on gum weight) and glycerol (3.5 g L-1 ) as plasticizer. The effects of coating solutions (CS1-4) on the quality changes of shrimps during refrigerated storage over 20 days were investigated. RESULTS: The total volatile basic nitrogen (TVB-N) value in shrimps coated with CS4 (containing 10% w/w thymol) was slightly higher than the upper threshold of 300 mg kg-1 on day 18, whereas that of uncoated shrimps increased to, or over, the threshold value on day 7. Active coatings significantly reduced (P < 0.05) microbial growth in shrimps during the cold storage without a negative impact on the organoleptic properties. Using CS4 on the shrimp samples immediately reduced total viable count and psychrotrophic bacteria count by 2 and 1 log colony forming units g-1 , respectively, compared to controls. CONCLUSION: The results of the present study revealed that the active edible coatings based on BSG activated with thymol had good potential to be used in the production of active packaging for various food applications.
BACKGROUND: To improve the quality of Pacific white shrimp (Litopenaeus vannamei), active coating solutions were prepared by dissolving 10 g L-1 of basil seed gum (BSG) and adding various levels of thymol (6%, 8% and 10% w/w based on gum weight) and glycerol (3.5 g L-1 ) as plasticizer. The effects of coating solutions (CS1-4) on the quality changes of shrimps during refrigerated storage over 20 days were investigated. RESULTS: The total volatile basic nitrogen (TVB-N) value in shrimps coated with CS4 (containing 10% w/w thymol) was slightly higher than the upper threshold of 300 mg kg-1 on day 18, whereas that of uncoated shrimps increased to, or over, the threshold value on day 7. Active coatings significantly reduced (P < 0.05) microbial growth in shrimps during the cold storage without a negative impact on the organoleptic properties. Using CS4 on the shrimp samples immediately reduced total viable count and psychrotrophic bacteria count by 2 and 1 log colony forming units g-1 , respectively, compared to controls. CONCLUSION: The results of the present study revealed that the active edible coatings based on BSG activated with thymol had good potential to be used in the production of active packaging for various food applications.