NON-DESTRUCTIVE STUDY OF ACID MILK COAGULATION

The acid coagulation is the main processing step in the yoghurt production and has a great impact on yogurt texture, microstructure and rheology, contributing to the overall sensory and visual product perception by the consumer.  The objective of this paper was to study the different stages of acid gel formation by turbidimetric and conductivimetric methods. The non-destructive methods used allow the differentiation of three regions : latent phase( рН = 6,3 ÷ 6,0), exponential phase (рН = 5,9 ÷ 5,4) and   phase of protein structure formation of demineralized casein micelles (pH = 5,3 ÷ 4,6). The mathematical model obtained by the three-parameter sigmoid function can be used in future studies to predict the change in conductivity during acid coagulation

Effect of

Spirulina platensis is a cyanobacterium (blue-green algae) that grows in alkaline waters. In food industry, Spirulina’s phycocyanin is used as a natural colorant and stabilizer. The influence of three different concentrations of Spirulina platensis (0.5%, 1% and 1.5%) on physicochemical, textural, antioxidant and sensory parameters of ice cream was studied. It was found that with increasing spirulina concentration, the overrun increases from 30.6% (IC–0) to 48.3% (IC–3). The analysis of texture profile (hardness, adhesiveness, cohesiveness, gumminess) of samples showed a statistically significant difference (p<0.05) between reported values for control sample (IC–0) and the samples with spirulina. Ice cream samples supplemented with spirulina differed with significant increase (p<0.05) in antioxidant activity from 2.8±2.2 mM TE/100 g DW (control sample) to 112.9±4.1 mM TE/100 g DW (IC–3). The addition of Spirulina platensis in ice cream mixture improves its quality and antioxidant properties