Effect of antibacterial nanocomposite film on the preservation of cheese

LI, Yana; CHEN, Zhiwei; WU, Kaixuan

doi:10.1590/fst.93321

Abstract

High density polyethylene (HDPE) and nano-ZnO were used to prepare nano-ZnO/HDPE composite film with a nano-ZnO content of 0.5wt%. The morphology, mechanical, barrier and antibacterial properties, as well as the preservation to cheese of the films were studied. The results showed that the ZnO nanoparticles had a good dispersion in HDPE matrix so that the improvement of the mechanical, barrier and antibacterial performances of the film was achieved after the addition of nano-ZnO to HDPE. In comparison to cheese packaged in HDPE bags, it was found that the sensory score of the cheese in nano-ZnO/HDPE bags increased from 66.6 to 73.7 and the pH of cheese was closer to the standard sample at storage time of 7d. Furthermore, nano-ZnO/HDPE inhibited effectively the increase of the total bacterial count (TBC) on cheese contrast of HDPE. That indicates the prepared nano-ZnO/HDPE is potential in cheese packaging to extend the shelf life.

Keywords:
ZnO nanoparticles; cheese; antibacterial; packaging

[1] *Corresponding author: myllyn@126.com

Rating criteria	Rating range
Rating criteria	0 points	20 points
Smell and taste	Taste musty, sour, bitter and other undesirable odors	Tastes cheesy with a characteristic flavor, no unpleasant smells
Color and appearance	Visible variation in appearance, uneven or indistinct colors	White or pale yellow in color
Histological architecture	Loose condition with cracks in the outer skin and sandy sections	Uniform and consistent texture, moderate softness, moist, fine condition
Elasticity and hardness	Too small or too large, broken after squeezing and cannot be recover	Good elasticity, does not break after squeezing and can be recovered
Melting and stringy	Poor melting properties, more grease precipitation, not stringy	Good melting fluidity, no obvious grease precipitation and stringy

	Mechanical properties			Barrier properties
Nano-ZnO/%	Tensile strength /MPa	Elongation at break /%	Tear strength /MPa	Oxygen permeability coefficient ×10^-14/(cm³.cm/cm².s.Pa)	Moisture permeability coefficient ×10^-13 /(g.cm/cm².s.Pa)
0	20.01 ± 1.2	746.63 ± 7.2	151.36 ± 10.1	8.80 ± 0.7	6.32 ± 0.2
0.5	37.50 ± 2.3	854.67 ± 5.6	160.16 ± 12.2	8.08 ± 0.8	5.29 ± 0.5

samples	sensory scores	pH	TBC(×10⁴CFU/mL)
Standard	81.5 ± 2.3	6.212 ± 0.1	0 ± 0.1
HDPE	66.6 ± 6.2	6.140 ± 0.1	8.2 ± 0.1
nano-ZnO/HDPE	73.7 ± 3.4	6.167 ± 0.1	3.2 ± 0.1

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Effect of antibacterial nanocomposite film on the preservation of cheese

Abstract