INFLUENCE OF THE TIME FOR INITIAL COAGULATION AND RENNET GEL COMPACTNESS ON THE PROTEIN LOSSES IN WHEY

Abstract Analyses of the possibilities for early cutting of rennet gel in the production of cheese were made, in order to achieve more efficient use of the technological equipment. The moment of cutting the coagulum was determined by studying the rheological properties of the gel (strength, compactness, elasticit

Effects of lingonberry extract (

In the present work, ice cream mixtures with 5%, 10% and 15% lingonberry extract were studied. The lingonberry (Vaccinium vitis-idaea L.) is a source of anthocyanins and flavonoids, which are the bioactive components with good antioxidant properties. There was a significant increase in antioxidant activity (p<0.05) from 133.3 ± 5.6 mM TE/100 g to 249.8 ± 8.3 mM TE/100 g (ABTS method) with increasing the concentration of the extract from 5% to 15%, respectively. Significant changes (p<0.05) in the acidity and dry matter of the samples with lingonberry extract were recorded. After 30 days of storage, a decrease in the antioxidant properties (p<0.05) of the ice cream samples was observed but higher values (mM TE/100 g) were maintained compared to the sample without extract. The color characteristics of the samples were also influenced by the concentration of the extract used. During storage, the highest stability of the colorimetric index a* (red component) was established, which indicates relative color stability during storage

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.&nbsp; 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&nbsp;&nbsp; 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

Probiotic Yoghurts From Ultrafiltered Concentrated Milk

In this paper, yoghurts from ultrafiltered concentrated whole milk with a volume reduction ratio 0, 2 and 3 with three different probiotic yoghurt starters were obtained. Their physiological, microbiological and rheological properties were examined. The concentrated probiotic yoghurts had high concentration of viable cells of the probiotic strain Lactobacillus delbrueckii ssp. bulgaricus (over 1010cfu/cm3). For the preparation of concentrated probiotic yoghurts the most appropriate volume reduction ratio was 2. The probiotic yoghurts with starters MZ2 and 1CM had the best structure. The concentrated probiotic yoghurts with all starters are functional foods

First Report of DHA-1 Producing Enterobacter cloacae Complex Isolate in Bulgaria

The aim of the present study was to reveal the characteristics of an Enterobacter cloacae complex isolate producing DHA-1 AmpC enzyme recovered from a patient hospitalized in St Marina Hospital, Varna.Materials and methods: Susceptibility testing, conjugation experiments, isoelectric focusing, PCR and sequencing were carrying out.Results: Of 176 Enterobacter spp. isolates only one isolate was positive for blaDHA. The sequencing revealed the presence of blaDHA-1 and blaCTX-M-3. The antimicrobial susceptibility testing showed higher resistance rates to almost all beta-lactams (ceftazidime, cefotaxime, cefepime, amoxicillinclavulanic acid, piperacillin/tazobactam), tobramycin, gentamycin, trimethoprim/sulphomethoxazole and quinolones (ciprofloxacin and levofloxacin). The isolate was susceptible to imipenem, meropenem and amikacin. The isoelectric focusing showed a band at pI 5.4 without ceftazidime and cefotaxime activity; a band at pI 7.8 with cefoxitin activity and another - with pI 8.4 with cefotaxime activity. Conjugation experiments were successful only for blaCTX-M-3 carrying determinants. Conclusions: To the best of our knowledge this is the first report of DHA-1 producing isolate in Bulgaria. The emergence of DHA-1 producing E. cloacae complex demonstrates the possibility for further dissemination of the gene encoding this enzyme. Infectious control measures are needed for the prevention of this phenomenon