Some low homogenization pressures improve certain probiotic characteristics of yogurt culture bacteria and Lactobacillus acidophilus LA-K

Abstract

Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus salivarius ssp. thermophilus, and Lactobacillus acidophilus are dairy cultures widely used in the manufacture of cultured dairy products. Commonly used homogenization pressures in the dairy industry are 13.80 MPa or less. It is not known whether low homogenization pressures can stimulate bacteria to improve their probiotic characteristics. Objectives were to determine the effect of homogenization at 0, 3.45, 6.90, 10.34, and 13.80 MPa on acid tolerance, bile tolerance, protease activity, and growth of L. delbrueckii ssp. bulgaricus LB-12, S. salivarius ssp. thermophilus ST-M5, and L. acidophilus LA-K. The cultures were individually inoculated in cool autoclaved skim milk (4°C) and homogenized for 5 continuous passes. Growth and bile tolerance of samples were determined hourly for 10h of incubation. Acid tolerance was determined every 20 min for 120 min of incubation. Protease activity was determined at 0, 12, and 24h of incubation. All homogenization pressures studied improved acid tolerance of L. delbrueckii ssp. bulgaricus LB-12 but had no beneficial effect on protease activity and had negative effects on growth and bile tolerance. A pressure of 6.90 MPa improved acid tolerance, bile tolerance, and protease activity of S. salivarius ssp. thermophilus ST-M5, but none of the homogenization pressures studied had an effect on its growth. Homogenization pressures of 13.80 and 6.90 MPa improved acid tolerance and bile tolerance, respectively, of L. acidophilus LA-K but had no effect on protease activity and its growth. Some low homogenization pressures positively influenced some characteristics of yogurt culture bacteria and L. acidophilus LA-K. Culture pretreatment with some low homogenization pressures can be recommended for improvement of certain probiotic characteristics.

Characterization of volatile compounds in fermented milk using solid-phase microextraction methods coupled with gas chromatography-mass spectrometry

“…Yogurt is the most popular fermented milk, and usually produced using mixtures of homofermentative LAB such as Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus as the starter culture (Herve-Jimenez et al, 2009;Muramalla and Aryana, 2011;Kaneko et al, 2014).…”

Understanding probiotics’ role in allergic children

“…To this end, Muramalla and Aryana [52] investigated the effects of low homogenization pressures on some yogurt probiotic features and Lactobacillus acidophilus LA-K, demonstrating that treatments at 13.80 and 6.90 MPa, repeated five times, improved acid and bile tolerance of the strain, but had no effect on its protease activity and growth [52]. In addition, strain safety (i.e.…”

Potential of High Pressure Homogenization and Functional Strains for the Development of Novel Functional Dairy Foods

“…Also other properties of fermented milk, such as acidity, lipid content, the presence of diacetyl, acetaldehyde and acetoin and the nutritional value are important and affect acceptability by consumers. Thus, the ability to impart good sensory properties to the final product is included in the criteria of selection for probiotic strains [24], because fermented milk obtained from the direct and sole use of probiotic strains are often characterized by the lack of desirable sensory features [7].…”

“…Among the non-thermal technologies, the high-pressure homogenization (HPH) represents a potential technology to develop Technological Approaches for Novel Applications in Dairy Processing new functional applications, also easily implementable at industrial level. Several literature reports have highlighted its use in dairy field to increase product functionality by both treating the milk designated to cheese making or fermented product preparation and treating the bacteria cells to increase their probiotic features [5][6][7][8]. Moreover, high pressure homogenization was used also to develop suitable microcapsules to carry the probiotic cultures in order to increase their viability during dairy product storage under refrigeration conditions [9,10].…”