Utilisation of water-in-oil-water (W 1 /O/W 2 ) double emulsion in a set-type yogurt model for the delivery of probiotic Lactobacillus paracasei

Abstract

W/O/W emulsion in set-type yogurt has the potential to segregate probiotics in order to avoid interference with the starter culture as well as protection against harsh processing and digestion conditions. Lactobacillus paracasei subsp. paracasei DC 412 probiotic cells in milk-based W/O/W emulsions were incorporated in yogurt, in addition to starter cultures Lactobacillus bulgaricus and Streptococcus thermophilus, and the effect on the fermentation, bacterial growth kinetics, physicochemical properties, and structural characteristics was investigated. Stability of W/O/W was monitored with optical microscopy and cryo-SEM and localisation of encapsulated L. paracasei in yogurt was monitored using fluorescent microscopy. During fermentation, starter culture was not affected by introduction of L. paracasei and/or W/O/W emulsion. The viability of L. paracasei encapsulated in W/O/W emulsion was enhanced during storage and after exposure to simulated gastrointestinal conditions. L. paracasei remained within the inner W phase till the end of the storage period (28 days at 4 °C). Moreover, W/O/W emulsion altered physicochemical and textural properties; however, these were within acceptable range. These results demonstrate the capability of W/O/W emulsion to be utilised for probiotic fortification of yogurt to increase functionality without interfering with starter culture and fermentation.

Soymilk fermentation: effect of cooling protocol on cell viability during storage and in vitro gastrointestinal stress

“…The accelerated growth of St likely slowed that of Lp. Counts of St in ternary culture after DC (8.62-9.04 log CFU/mL) were very close to that observed in fermented milk (9 log CFU/mL) after a similar cooling protocol [21].…”

“…Moreover, consistently with the well-known Lb ability to stimulate St growth through a synergistic relationship, Lb counts in binary culture were several orders of magnitude lower than those of St. Likewise, both St and Lb showed improved viability when used together with a probiotic to ferment soybean extract or milk [3,19,21].…”

“…Regarding the acidification profiles of soymilk fermentation at 37°C by lactic acid bacteria, the Lp monoculture took longer (15.2 h) to reach pH 4.5 than StLb (9.0 h), as expected by the well-known synergism between these last two species [18][19][20][21]. Table 2 lists the cell counts of L. paracasei, S. thermophilus, and L. bulgaricus in Lp monoculture, StLb, and StLbLp in fermented soymilk after direct cooling (DC) or two-phase cooling (TPC).…”

W/O/W Multiple Emulsions as the Functional Component of Dairy Products

“…W/o/w emulsions can also reduce the loss of compounds during digestion because of their encapsulation in the internal water phase. Various models have been developed for the preparation of dairy products: fresh white cheese with reduced fat content, set , and stirred yogurt with a low fat content , soybean milk fortified with Ca , cheeses fortified with vitamin B , yogurt fortified with caffeine or inulin , and milk‐based dessert fortified with ferrous sulfate . Other developments include the encapsulation of anthocyanins , or microorganisms, e.g., encapsulation of Lactobacillus salivarius and Lactobacillus delbrueckii , protection of Lactobacillus acidophilus against gastric juice , and bile acids .…”

Effects of double emulsification on Lactobacillus plantarum NBRC 3070 stability and physicochemical properties of soursop juice during storage

“…Double emulsion, which is also known as water-in-oil-in-water (W1/O/W2) emulsion, are multi-compartmentalized systems in which the inner aqueous phase (W1) is dispersed into the oil phase and then subsequently into the outer aqueous phase (W2) (Cofrades et al, 2013;Safiah et al, 2020). The encapsulation of probiotics in double emulsion helps in enhancing cells viability in functional food products during the storage period (El-Kadri et al, 2018). Currently, research on functional food supplemented with probiotics is gaining attention.…”