Development and Quality Assewssment of low fat Mozzarella Cheese

Abstract

study was planned to explore fat mimetic potential of different hydrocolloids (guar gum, xanthan gum, gum acacia and corn starch) in Mozzarella cheese and to investigate combined impact of hydrocolloids and homogenization as fat reduction strategies on the low fat Mozzarella cheeses (LFMCs) quality. Research project was conducted in three phases. In phase-I best levels while in phase-II best combinations of different hydrocolloids were selected on the basis of cheese functionality and yield. In phase-III, LFMCs were manufactured by using selected levels (Phase-I) and combinations (Phase-II) of hydrocolloids with and without cheese milk homogenization (2000 psi at 45°C). Non-homogenized (NH) and homogenized (H) milk Mozzarella cheeses (FF= Control and LFMCs included HF= Negative control; GG= 0.15% guar gum; XG= 0.15% xanthan gum; GA= 0.30% gum acacia; CS= 0.50% corn starch; G:C= 50% of the selected level of guar gum and corn starch; C:G:G= 33% of the selected levels of corn starch, guar gum and gum acacia) were analyzed for physicochemical parameters, functional attributes, texture profile, expressible serum, water activity, proteolysis, microstructure, baking performance and sensory properties during 90 days ripening. Results showed that use of hydrocolloids as fat replacer significantly (p<0.01) affected the fat, moisture, protein, ash and Ca contents in LFMCs. Cheese milk homogenization significantly (p<0.01) increased the fat contents but decreased the moisture, protein and Ca. Fat content in FF was 18.50% (NH) and 19.12% (NH) whereas it ranged between 8.20 to 10.40% in non-homogenized and 8.83 to 10.80% in homogenized milk LFMCs. Cheese ripening significantly (p<0.01) decreased the moisture and pH value but increased the protein, acidity and Ca. Highest meltability was found in FF (58.6 mm for NH and 59.8 mm for H) followed by GG (52.1 mm for NH and 53.1 mm for H) which increased significantly (p<0.01) during ripening. Addition of hydrocolloids and homogenization significantly (p<0.01) improved the cheese stretchability as all hydrocolloids containing LFMCs exhibited higher stretchability (39.8 to 43.1 cm for NH and 39.9 to 44.1 cm for H) as compared to HF (36.6 cm for NH and 36.8 cm for H). Cheese stretchability increased during ripening only up to 60 days after that significant (p<0.01) decrease was observed in all treatments. The texture profile of LFMCs differed significantly (p<0.01) due to addition of hydrocolloids and cheese ripening. FF cheese showed lower values for all textural parameters (hardness, cohesiveness, springiness, gumminess, chewiness) as compared to LFMCs. Increase in ripening period decreased the values of all textural parameters of LFMCs. Homogenization of cheese milk produces LFMCs which were soft, less in springiness, gumminess and chewiness when compared with their corresponding non-homogenized milk LFMCs. Expressible serum (ES) in LFMCs was significantly (p<0.01) affected by all variables. Addition of hydrocolloids improved the ES level in LFMCs as among all hydrocolloids containing LFMCs GG exhibited the highest ES values (18.68 g/100g for NH and 19.85 g/100g for H). The pH 4.6 and TCA soluble N increased significantly (p<0.01) with cheese ripening. Electrophoresis and reverse phase HPLC results indicated that level of intact casein in LFMCs decreased with increase in ripening period. Micrographs obtained from Electron microscopy indicated that the size of serum channels reduced and cheese structure becomes more homogenous with ripening and cheese milk homogenization. Color L* value in LFMCs increased with the addition of hydrocolloids when compared with HF and homogenization of cheese milk significantly improved the LFMCs appearance (L* value) before and after baking. Sensory evaluation based on cheese flavor, texture and appearance showed that GG, GA and G:C were very similar to FF. Homogenization of cheese milk improved all sensory attributes and cheese ripening improved the flavor and texture upto 60 days. In conclusion, use of guar gum (GG), gum acacia (GA) and combnation of guar gum and corn starch (G:C) along with cheese milk homogenization offers a perspective to reduce fat in Mozzarella cheese without compromising its quality.