title: Survival and bioactivities of selected probiotic lactobacilli in yogurt fermentation and cold storage: New insights for developing a bi-functional dairy food.
abstract: In previous work, we demonstrated that two probiotic strains, namely Lactobacillus casei PRA205 and Lactobacillus rhamnosus PRA331, produce fermented milks with potent angiotensin-converting enzyme (ACE)-inhibitory and antioxidant activities. Here, we tested these strains for the survivability and the release of antihypertensive and antioxidant peptides in yogurt fermentation and cold storage. For these purposes three yogurt batches were compared: one prepared using yogurt starters alone (Lactobacillus delbrueckii subspecies bulgaricus 1932 and Streptococcus thermophilus 99), and the remaining two containing either PRA205 or PRA331 in addition to yogurt starters. Despite the lower viable counts at the fermentation end compared to PRA331, PRA205 overcame PRA331 in survivability during refrigerated storage for 28 days, leading to viable counts (>10(8) CFU/g) higher than the minimum therapeutic threshold (10(6) CFU/g). Analyses of in vitro ACE-inhibitory and antioxidant activities of peptide fractions revealed that yogurt supplemented with PRA205 displays higher amounts of antihypertensive and antioxidant peptides than that produced with PRA331 at the end of fermentation and over storage. Two ACE-inhibitory peptides, Valine-Proline-Proline (VPP) and Isoleucine-Proline-Proline (IPP), were identified and quantified. This study demonstrated that L. casei PRA205 could be used as adjunct culture for producing bi-functional yogurt enriched in bioactive peptides and in viable cells, which bring health benefits to the host as probiotics.
authors.affiliation: Department of Life Sciences, University of Modena and Reggio Emilia, Via Amendola 2, Besta Building, 42122 Reggio Emilia, Italy.
authors.forename: Giuseppina Sefora
authors.initials: GS
authors.lastname: Rutella
authors.affiliation: Department of Life Sciences, University of Modena and Reggio Emilia, Via Amendola 2, Besta Building, 42122 Reggio Emilia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Tagliazucchi
authors.affiliation: Department of Life Sciences, University of Modena and Reggio Emilia, Via Amendola 2, Besta Building, 42122 Reggio Emilia, Italy. Electronic address: lisa.solieri@unimore.it.
authors.forename: Lisa
authors.initials: L
authors.lastname: Solieri
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis; D000818:Animals; D000975:Antioxidants; D003080:Cold Temperature; D043302:Cultured Milk Products / Q000032:analysis / Q000382:microbiology / Q000592:standards; D005285:Fermentation; D061353:Food Storage; D007780:Lacticaseibacillus casei / Q000737:chemistry / Q000254:growth & development / Q000502:physiology; D052201:Lacticaseibacillus rhamnosus / Q000737:chemistry / Q000254:growth & development / Q000502:physiology; D050296:Microbial Viability; D008892:Milk / Q000382:microbiology; D009842:Oligopeptides / Q000032:analysis; D010452:Peptide Biosynthesis; D019936:Probiotics / Q000737:chemistry / Q000378:metabolism*; D048249:Streptococcus thermophilus / Q000737:chemistry / Q000502:physiology; D015014:Yogurt / Q000032:analysis* / Q000382:microbiology*
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000975:Antioxidants; D009842:Oligopeptides; C489031:valyl-prolyl-proline
keywords: Antihypertensive peptides; Antioxidant peptides; Lactobacillus; Probiotics; Yogurt