We investigate the impact of fermion vacuum fluctuations on the thermodynamic properties of quark matter within the finite-volume Polyakov chiral SU(3) quark mean-field (PCQMF) model at finite temperature and chemical potential. A lower momentum cutoff introduces finite-size effects, modifying scaled thermodynamic quantities such as pressure, energy density, entropy density, and trace anomaly. Additionally, we analyze the influence on the speed of sound and specific heat. Our results show that including fermion vacuum fluctuations leads to a reduction in effective quark masses and enhances thermodynamic quantities in smaller system sizes.