PL
Celem pracy było określenie możliwości wzbogacania mleczanami wapnia oraz magnezu mleka fermentowanego przez Bifidobacterium animalis ssp. lactis Bb-12 oraz określenie wpływu dodanych makroelementów na właściwości fizykochemiczne, sensoryczne, teksturę oraz liczbę komórek bakterii. Mleka wzbogacono mleczanem magnezu (30 i 50 mg Mg∙100 g⁻¹) oraz mleczanem wapnia (80 i 100 mg Ca∙100 g⁻¹). Inkubację zaszczepionego DVS – Bb-12 mleka prowadzono w temperaturze 37°C przez 10–13 godzin. W napojach oznaczano: pH, synerezę, teksturę i barwę. Ocenę sensoryczną wykonano metodą profilowania, a ocenę preferencji metodą szeregowania. Posiewy komórek bifidobakterii wykonywano z zastosowaniem metody płytkowej. Dodatek magnezu w dawkach 30 i 50 mg Mg∙100 g⁻¹ korzystnie wpłynął na liczbę komórek Bifidobacterium animalis ssp. lactis Bb-12 i ograniczył synerezę napojów. Wzbogacanie mleka wapniem w ilości 80 mg Ca∙100 g⁻¹ oraz 100 mg Ca∙100 g⁻¹ nie wpłynęło na rozwój komórek Bifidobacterium animalis ssp. lactis Bb-12 i skutkowało otrzymaniem napoju o liczbie komórek bakterii zbliżonej do napoju kontrolnego. Napoje wzbogacane mleczanami magnezu (30 i 50 mg Mg∙100 g⁻¹) i wapnia (80 i 100 mg Ca∙100 g⁻¹) cechowały się mniejszą twardością i sprężystością.
EN
The aim of this study was to determine the possibility of calcium and magnesium lactate enrichment of fermented milk beverages and to evaluate the effect of macroelements on the physicochemical, sensory and texture properties as well as the number of bacteria. The milk was fortified with magnesium in the amount of 30 and 50 mg Mg∙100 g⁻¹ and with calcium lactate in an amount of 80 and 100 mg Mg∙100 g⁻¹, respectively. The milk was homogenized, the pH was determined and the 0.02% of DVS probiotic cultures of Bifidobacterium animalis ssp. lactis Bb-12 were added. Incubation of milk was carried out at 37°C. Samples were analyzed at day 7 of storage. The pH, total acidity, syneresis, color parameters (L*, a*, b*), TPA texture and sensory characteristics were evaluated. To evaluate consumer acceptance and sensory profile of the samples, 20 panelists investigated randomly coded beverages samples. Viable counts of Bifidobacterium animalis ssp. lactis Bb-12 were determined on the MRS agar (Biocorp, Poland) at 37°C for 72 h. Fortification of fermented beverages with magnesium and calcium lactate decreased pH of milk before fermentation. The addition of magnesium at doses of 30 and 50 mg Mg∙100 g⁻¹ beneficially influenced the number of Bifidobacterium animalis ssp. lactis Bb-12 and reduced the syneresis effect. Moreover, the use of calcium lactate for fortification resulted in acid gels form with a high level of syneresis effect. The addition of calcium in the amount of 80 mg increased syneresis about 5.29%, and in the amount, 100 mg up to 7.70% respectively, compared to the amount of expelling liquid in the control sample. Milk fortification with calcium in the amount of 80 and 100 mg Ca∙100 g⁻¹ did not affect the number of Bifidobacterium animalis ssp. lactis Bb-12 and resulted in similar bacteria number in control sample. Addition of magnesium and calcium lactates caused that after incubation time the pH value of enriched beverages was higher than unfortified beverages, which directly influenced the ability to form a curd and its compactness. The milk beverages fortified with magnesium (30 and 50 mg Mg∙100 g⁻¹) and calcium (80 and 100 mg Ca∙100 g⁻¹) were characterized by lower hardness and springiness. Beverages fortified with magnesium and calcium lactate gave significantly darker color than control ones. With the increase of the dose of these micronutrients, the darkening color of beverages fermented by Bifidobacterium Bb-12 was detected. Regarding sensory analysis, the notes granted by panelists for the color of beverages fortified with calcium and magnesium were lower than the controls, however, these differences were not significant. In this case, the instrumentally indicated changes in color parameters were not so large as to be perceived by consumers. The color values a* and b* marked for fortified beverages with magnesium and calcium lactates testify to the displacement of the color scale in space towards the green and yellow color, compared to the control ones. The results of the preference test showed that the most panelists selected beverage with magnesium addition, especially in amount 30 mg, taking into account the intense milky-cream flavor, moderately sour and undetectable foreign taste. Calcium-fortified beverages characterized by less consistency and a more intense off-flavors. These two quality factors contributed to the less acceptance of calcium-enriched beverages.