The aim of this study was to determine the effect of chitosan (CH)-based
nanocomposite coating applications [chitosan+TiO
2
(CHT) and
chitosan+TiO
2
+rosmarinic acid (CHTRA)] on changes in quality
attributes of rainbow trout fillets during cold storage (4°C). Fish
fillets were randomly divided into four groups and subjected to treatments (CH,
CHT, CHTRA, and control). After treatments, the groups were packaged under a
modified atmosphere (40% CO
2
+30% O
2
+30% N
2
) and
stored at 4°C for 18 days. During cold storage, the samples were
subjected to physico-chemical and microbiological analyses. During storage, CH,
CHT, and CHTRA treatments showed lower aerobic mesophilic and psychrotrophic
bacteria counts than the control. However, the differences between coating
treatments were not significant. The highest mean pH value was determined in the
control group. As the storage time increased, the thiobarbituric acid reactive
substances value increased. At the end of the storage period, no significant
differences were observed between the treatments, including in the control
group. The total volatile basic nitrogen (TVB-N) level in the control group was
above 25 mg/100 g on day 15 of storage. However, the TVB-N level in the
treatment groups was below 20 mg/100 g on day 18. It was also determined that
coating application×storage period interaction had a significant effect
on all color parameters (p<0.01). At the end of storage, the highest CIE
L* was observed in CHTRA treatment. However, the value of this treatment did not
differ from that of the CH treatment.