Lactic Acid Fermentation Improved Textural Behaviour, Phenolic Compounds and Antioxidant Activity of Chia (Salvia hispanica L.) Dough

U radu su izolirane autohtone bakterije mliječno-kiselog vrenja iz tijesta s dodatkom chia (Salvia hispanica L.) sjemenki, te razvrstane prema kinetici zakiseljavanja i proteolitičkoj aktivnosti. Soj C8 identificiran je kao soj bakterije Lactobacillus plantarum C8, te je upotrijebljen kao starter kultura za dobivanje kiselog tijesta s dodatkom chia sjemenki. Mliječno-kiselim vrenjem povećan je maseni udjel organskih kiselina (mliječne na 12,3 g, octene na 1,0 g i fenilacetatne kiseline na 23,8 μg po kilogramu tijesta), te antioksidacijska aktivnost, koja je porasla za 33-40 % u usporedbi s nefermentiranim tijestom s dodatkom chia sjemenki. Osim toga, ukupni se udjel fenolnih spojeva uvećao za 25 %, a njihov se sastav bitno promijenio nakon 24 h fermentacije s pomoću soja bakterije L. plantarum C8. Klorogena je kiselina pronađena jedino u fermentiranom tijestu (2,5 mg/g), dok je ferulinska kiselina detektirana već na početku vrenja, i to u 32 % većoj količini u kiselom tijestu s dodatkom chia sjemenki (5,6 mg/g). Upotrebom fermentiranog kiselog tijesta s dodatkom chia sjemenki poboljšana su ukupna svojstva bijelog kruha, uključujući fizikalna (npr. smanjena tvrdoća i otpor krušnih mrvica pri žvakanju) i antioksidacijska svojstva (u prosjeku za 25 %). Dobiveni rezultati pokazuju da kiselo tijesto s dodatkom chia sjemenki poboljšava tehnološka i antioksidacijska svojstava pšeničnog kruha. Osim toga, u radu je po prvi puta prikazano da bakterije mliječno-kiselog vrenja mogu fermentirati tijesto s dodatkom chia sjemenki, čime poboljšavaju ukupna svojstva kruha.In this work, autochthonous lactic acid bacteria (LAB) were isolated from chia (Salvia hispanica L.) dough and selected on the basis of the kinetics of acidification and proteolytic activity. Strain no. C8, identified as Lactobacillus plantarum C8, was selected and used as starter to obtain chia sourdough. Lactic acid fermentation increased the organic acid mass fractions (lactic, acetic and phenyl lactic acids to 12.3 g, 1.0 g and 23.8 μg per kg of dough respectively), and antioxidant activities, which increased by approx. 33–40 % compared to unfermented chia flour dough. In addition, total phenolic content increased 25 % and its composition was strongly modified after 24 h of fermentation by L. plantarum C8. Chlorogenic acid was only found in the fermented dough (2.5 mg/g), while ferulic acid was detected from the beginning of fermentation, being 32 % higher in chia sourdough (5.6 mg/g). The use of fermented chia sourdough improved the overall characteristics of white bread, including physical (e.g. reduced hardness and chewiness of the crumb) and antioxidant properties (25 % on average), compared to the white bread. These results indicate that the use of chia sourdough could be a promising alternative to improve the technological and antioxidant properties of wheat bread. In addition, this work has shown, for the first time, that lactic acid bacterium is able to ferment chia dough, improving its overall characteristics

Lactic Acid Fermentation Improved Textural Behaviour, Phenolic Compounds and Antioxidant Activity of Chia (Salvia hispanica L.) Dough

U radu su izolirane autohtone bakterije mliječno-kiselog vrenja iz tijesta s dodatkom chia (Salvia hispanica L.) sjemenki, te razvrstane prema kinetici zakiseljavanja i proteolitičkoj aktivnosti. Soj C8 identificiran je kao soj bakterije Lactobacillus plantarum C8, te je upotrijebljen kao starter kultura za dobivanje kiselog tijesta s dodatkom chia sjemenki. Mliječno-kiselim vrenjem povećan je maseni udjel organskih kiselina (mliječne na 12,3 g, octene na 1,0 g i fenilacetatne kiseline na 23,8 μg po kilogramu tijesta), te antioksidacijska aktivnost, koja je porasla za 33-40 % u usporedbi s nefermentiranim tijestom s dodatkom chia sjemenki. Osim toga, ukupni se udjel fenolnih spojeva uvećao za 25 %, a njihov se sastav bitno promijenio nakon 24 h fermentacije s pomoću soja bakterije L. plantarum C8. Klorogena je kiselina pronađena jedino u fermentiranom tijestu (2,5 mg/g), dok je ferulinska kiselina detektirana već na početku vrenja, i to u 32 % većoj količini u kiselom tijestu s dodatkom chia sjemenki (5,6 mg/g). Upotrebom fermentiranog kiselog tijesta s dodatkom chia sjemenki poboljšana su ukupna svojstva bijelog kruha, uključujući fizikalna (npr. smanjena tvrdoća i otpor krušnih mrvica pri žvakanju) i antioksidacijska svojstva (u prosjeku za 25 %). Dobiveni rezultati pokazuju da kiselo tijesto s dodatkom chia sjemenki poboljšava tehnološka i antioksidacijska svojstava pšeničnog kruha. Osim toga, u radu je po prvi puta prikazano da bakterije mliječno-kiselog vrenja mogu fermentirati tijesto s dodatkom chia sjemenki, čime poboljšavaju ukupna svojstva kruha.In this work, autochthonous lactic acid bacteria (LAB) were isolated from chia (Salvia hispanica L.) dough and selected on the basis of the kinetics of acidification and proteolytic activity. Strain no. C8, identified as Lactobacillus plantarum C8, was selected and used as starter to obtain chia sourdough. Lactic acid fermentation increased the organic acid mass fractions (lactic, acetic and phenyl lactic acids to 12.3 g, 1.0 g and 23.8 μg per kg of dough respectively), and antioxidant activities, which increased by approx. 33–40 % compared to unfermented chia flour dough. In addition, total phenolic content increased 25 % and its composition was strongly modified after 24 h of fermentation by L. plantarum C8. Chlorogenic acid was only found in the fermented dough (2.5 mg/g), while ferulic acid was detected from the beginning of fermentation, being 32 % higher in chia sourdough (5.6 mg/g). The use of fermented chia sourdough improved the overall characteristics of white bread, including physical (e.g. reduced hardness and chewiness of the crumb) and antioxidant properties (25 % on average), compared to the white bread. These results indicate that the use of chia sourdough could be a promising alternative to improve the technological and antioxidant properties of wheat bread. In addition, this work has shown, for the first time, that lactic acid bacterium is able to ferment chia dough, improving its overall characteristics

Effect of Daily Consumption of Lactobacillus reuteri CRL 1098 on Cholesterol Reduction in Hypercholesterolemic Subjects

The effect of daily consumption of a yogurt containing Lactobacillus reuteri CRL 1098 on the lipid profile of hypercholesterolemic subjects was evaluated by performing a prospective, randomized, double-blind, cross-over placebo controlled clinical study. Participants consumed daily a yogurt containing L. reuteri CRL 1098 or a placebo for four weeks, separated by a wash-out period. Total cholesterol, triacylglycerol, high-density (HDL) and low-density (LDL) lipoprotein levels were assessed at the beginning and at the end of each period. We found a statistically significant reduction of total (−7.86 g/dl) and LDL (−7.02 g/dl) cholesterol in absolute changes (before-after) as well as a decreasing trend in the group receiving the yogurt containing L. reuteri with respect to the placebo group, without detecting changes in HDL-cholesterol and triacylglycerol levels. Our results suggest that low amounts of yogurt (125 g/day) and low doses of the CRL 1098 strain (106 CFU) are sufficient to reduce total and LDL-cholesterol levels in hypercholesterolemic subjects.Facultad de Ciencias Médica

Probiotic characterization of lactic acid bacteria from artisanal goat cheese for functional dairy product development

Abstract The increasing interest in functional foods has encouraged the search for new lactic acid bacteria (LAB) with singular characteristics, including technological and probiotic properties, present in natural sources. The present research aimed to isolate and in vitro characterize the probiotic potential of LAB isolated from artisanal goat cheese. In addition, the acidifying and proteolytic capacity of the strains were evaluated in order to develop a functional dairy product. Fifty strains, presumptively identified as LAB, were isolated from artisanal goat cheese. From them, seventeen strains were selected for identification through Matrix-Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) Mass Spectrometry (MS) and 16S gene sequence. None of the tested strains showed hemolytic ability, while all strains showed at least 76% of survival to low pH and conjugated bile salts. Hydrophobicity and auto-aggregation values varied among LAB with ranges between 15.5 ± 1.8 to 84.7 ± 3.2, and 4.72% to 59.2%, respectively. Selected LAB were capable of adhering to intestinal mucus in a range of 5.08 to 6.90 Log CFU/mL. Remarkably, eight strains showed high bile salt hydrolase activity. Autochthons strains were able to grow and acidify milk after 24 h. Besides, proteolytic activity showed a range between 10 and 151 mmol/L amino acids. PCA analysis and technological properties allow us to propose Lactiplantibacillus plantarum CB5, CB8 and Lentilactobacillus parabuchneri CB12 strains as potential probiotic starter cultures. The isolation of new LAB strains with demonstrated functional properties is of interest to academic institutions and the food industry as it allows the design of indigenous dairy cultures with added probiotic and technological properties