Naslov
Growth and survival of Lactobacillus acidophilus La-5 in milk enriched with with ß-glucan

Autori
Matijević, Bojan ; Franjević, Tihana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings of International Scientific Conference on Probiotics and Prebiotics - IPC2012 / - Košice, 2012

ISBN
978-80-89589-03-6

Skup
International Scientific Conference on Probiotics and Prebiotics - IPC2012

Mjesto i datum
Košice, Slovačka, 12.06.2012. - 14.06.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
ß-glucan; growth; Lactobacillus acidophilus La-5; milk; survival

Sažetak
Introduction ß-glucan is a water soluble fiber found in cereals, in particular oats and barley, as well as in yeast, bacteria, algae and mushrooms. Health benefits and functional properties of β- glucans make them interesting food constituents. Due to their viscosity enhancing effect and the fact that they are able to form gels, they are applicable as food hydrocolloids and ingredients in health promoting functional foods. ß-glucan provides numerous beneficial health effects such as reduced bowel transit time, prevention of constipation, reduced risk of colorectal cancer, lower blood cholesterol, better regulated blood glucose levels, production of short chain fatty acids, promotion of the growth of the beneficial bacteria in the colon and improved digestion. Further, ß-glucan in the diet contributes to the intestinal viscosity and thereby reduces cholesterol absorption. The objective of this study was to do research on ß-glucan impact on growth of Lactobacillus acidophilus La-5 in milk and their survival during 28 days of cool storage. Methods The skimmed milk was fermented with probiotic bacteria Lactobacillus acidophilus La-5. To examine the influence on growth and survival of Lactobacillus acidophilus La-5, three samples were prepared as it follows: (a) the first sample was without ß-glucan added (i.e. control), and (b) ß-glucan was added to the other two samples at the rate of 0.25 and 0.5% (w/w), respectively. Milk samples were pasteurized at 85°C for 5 min and cooled to 37°C, inoculated with a Lactobacillus acidophilus La-5 at a ratio of 2.5% (v/v). Fermentation of all samples was stopped after 18 hour. Fermented milk samples were cooled and stored at 6°C for 28 days. pH-value, lactic acid content and viable cell count were observed during storage. Results and Discussion Fermentation of milk with Lactobacillus acidophilus La-5 lasted for 18 hours, and the addition of ß-glukana hasn't influenced the dynamics of fermentation regardless the amount. At the end of fermentation all samples of fermented milk had similar pH-value of about 4.4 and the lactic acid content was 0.66% (w/w). Better growth of Lactobacillus acidophilus La-5 was noticed in milk with 0.25 and 0.5% (w/w) ß-glucan (1.26 and 1.19 Δlog CFU/mL), than in control sample (0.95 Δlog CFU/mL). Determined difference in viable cell count was not statistically important (P=0.919). After 28 days of storage pH dropped in all fermented milk samples, but samples of fermented milk enriched with ß-glucan had about 3.9 lower pH-valued compared to the control sample of about 4.2. ß-glucan did not have statistically significant infuence on changes in pH-value of fermented milk with Lactobacillus acidophilus La-5 during 28 days of storage (P=0.550). Content of lactic acid in fermented milk is closely related to pH-value, and samples enriched with ß-glucan had more lactic acid (about 0.98% (w/w)). During storage bacterium Lactobacillus acidofilus La-5 had survived better in milk enriched with 0.25 and 0.5% (w/w) ß-glucan (0.63 and 0.03 Δlog CFU/mL), than in the control sample (2.20 Δlog CFU/mL). Results show that ß-glucan statistically significantly influences the survival of bacterium Lactobacillus acidophilus La-5 in fermented milk (P=0.012).

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

POVEZANOST RADA