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Evaluation of PLA nanocomposite films on physicochemical and microbiological properties of refrigerated cottage cheese
Author(s) -
Li Wenhui,
Li Lin,
Zhang Heng,
Yuan Minglong,
Qin Yuyue
Publication year - 2018
Publication title -
journal of food processing and preservation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.511
H-Index - 48
eISSN - 1745-4549
pISSN - 0145-8892
DOI - 10.1111/jfpp.13362
Subject(s) - shelf life , food science , lactic acid , low density polyethylene , antimicrobial , food packaging , chemistry , polyethylene , nanocomposite , materials science , bacteria , composite material , organic chemistry , genetics , biology
A novel antimicrobial packaging system was prepared by incorporating TiO 2 or Ag nanoparticles into poly(lactic acid) (PLA) matrix. The effect of PLA, PLA/TiO 2 , and PLA/TiO 2 + Ag film on the physicochemical and microbiological properties of Yunnan cottage cheese stored at 5 ± 1 °C for 25 days was investigated. The low density polyethylene (LDPE) film was used as the control. The weight loss, pH value, lactic acid bacteria count (LAB), texture, sensory quality, and antimicrobial activity were determined. Cheeses packed by PLA/TiO 2 and PLA/TiO 2 +Ag film provided better retention in pH value, LAB, sensory quality, and antimicrobial activity compared with those packed by PLA and LDPE film. Migration of Ti and Ag nanoparticles was lower than the limit of 10 mg/kg as defined by EFSA for food contact materials. The results indicated that the incorporation of TiO 2 or Ag nanoparticles into PLA matrix could maintain cheese quality and prolong its shelf life to 25 days. Practical applications Yunnan cottage cheese is one of the most popular cheeses in China. However, the shelf life of unpacked Yunnan cottage cheese is only 5–7 days under refrigerated condition. PLA film incorporated with antimicrobial TiO 2 or Ag nanoparticles has great potential to prolong cheese shelf life. The novel packaging material may be an effective alternative for cheese preservation.