Biopolymer films based on furcellaran-whey protein isolate (FUR/WPI) and furcellaran-whey protein isolate incorporated with yerba mate extract (FUR/WPI + YM) and with white tea extract (FUR/WPI + WT) were successfully developed and investigated as active packaging materials for fresh soft rennet-curd cheese. YM improved water vapour permeability, water content, solubility, modulus elasticity, puncture strength and thermal stability of film. Water content and water activity decreased (P ≤ .05) during storage in cheese packed in each kind of the biopolymer films. These parameters did not change (P > .05) in control wrapped in linear low-density polyethylene (LLDPE). Likewise, pH decreased with the exception of the application of LLDPE and FUR/WPI + YM. In those cheese samples pH did not differ (P > .05) during storage. Total bacteria count decreased (P ≤ .05) in the cheese samples wrapped in edible films during storage. However, their levels were not significantly lower than control samples when compared within the storage week. The yeast and mould counts did not differ (P > .05) during storage for the cheese packed in FUR/WPI + WT, whereas it increased in other cheese samples. The coliform bacteria count decreased (P ≤ .05) during storage in all examined cheese samples. Overall organoleptic quality was more often rated as desirable and very desirable in cheese packed in edible films than in LLDPE.
Keywords: Active packaging; Biopolymer film; Shelf life; Soft rennet-curd cheese.
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