Quality of yogurt fortified with magnesium lactate.
During the tests carried out with rats the organic complex magnesium gluconate was examined for its bioavailability and its stress-reducing properties after oral application. The increase of magnesium concentration in serum achieved by means of magnesium gluconate turned out to be higher than the increase of concentration due to the administration of magnesium chloride. Just like other organic magnesium complexes, magnesium gluconate, administered for three days via feed to rats under stress conditions of immobilization, the substance causes a significant reduction in the increase in catecholamine and corticosterone concentration in serum. Regarding the reduction of stress in rats, the optimal concentration in feed is between 500 and 1000 mg of magnesium as magnesium gluconate per kg.
BACKGROUND: Magnesium is a micronutrient which plays an important role in a wide range of fundamental cellular reactions. Deficiency of magnesium leads to serious biochemical and symptomatic changes. The present study was carried out to establish the influence of magnesium lactate fortification on the physico- chemical, microbiological and rheological properties of fat-free yogurt manufactured using different starters.
METHODS: In this study, yogurts were produced from fat-free milk, standardized with skimmed milk powder to 6% protein content, and then divided into two parts. One part was left without supplementa- tion as a control and in the second part, magnesium L-lactate hydrate was added in the amount of 317.30 mg 100 g–1, which was equal to 35 mg of Mg2+ 100 g–1 of milk. Both mixtures were blended, pasteurized at 85°C for 30 minutes, cooled to 45°C and then divided into three parts, inoculated with: (1) YC-X11 yogurt cul- ture, (2) YF-L811 yogurt culture and (3) VITAL yogurt culture supplemented with probiotics (Lactobacillus acidophilus, Bifidobacterium lactis) respectively. Fermentation was performed at 43°C and the final yogurts were cooled to 5°C. After 24 hours of cold storage, the pH values, titratable acidity, syneresis, color, texture profile, viscosity, sensory analysis and microbiology of the yogurts were analyzed.
RESULTS: The results showed that addition of magnesium lactate significantly reduced syneresis and increased the hardness of fat-free yogurts. There was no impact on the viability of starter bacteria in the yogurts after 24 hours of refrigerated storage.
CONCLUSIONS: Magnesium lactate showed good potential for the fortification of dairy foods, according to physicochemical data. Further research is needed regarding the influence of storage time and to establish whether the observed effects are largely due to the magnesium cation or lactate anion.