Time filter

Source Type

San Miguel de Tucumán, Argentina

Sosa O.A.,National University of Tucuman | Sosa O.A.,CONICET | Farias M.E.,National University of Tucuman | Farias M.E.,Reference Center for Lactobacilli | Farias M.E.,CONICET
Food Technology and Biotechnology | Year: 2012

The current work examines the environmental conditions to control the expression of self-flocculation of Kloeckera apiculata mc1 isolated from Argentinian grapes with proven beneficial effect on wine aroma. Temperature had a direct effect on the expression of flocculation resulting in an increase in the number of zymolectin sites determined with a BSA--Gal-FITC probe and quantified with the Scatchard plot. Agitation had a positive effect on yeast flocculation and the effect did not correlate with an increase in the hydrophobic index. The addition of glucose, fructose or ethanol to yeast nitrogen base medium without amino acids or ammonium sulphate stimulated flocculation. Assimilative nitrogen sources had a negative impact on flocculation in the absence of an energy source. During winemaking, control of flocculation by environmental factors such as temperature and the presence of nutrients could be applied in order to optimize the fermentation process and hence the quality of the final product. Knowledge of the effect of different parameters on flocculation of the wine yeast K. apiculata mc1 allows prediction of the behaviour of this yeast during fermentation.

Rodriguez-Vaquero M.J.,National University of Tucuman | Rodriguez-Vaquero M.J.,Reference Center for Lactobacilli | Aredes-Fernandez P.A.,Reference Center for Lactobacilli | de Nadra M.C.M.,National University of Tucuman | de Nadra M.C.M.,Reference Center for Lactobacilli
Food Technology and Biotechnology | Year: 2013

The aim of this work is to investigate the antibacterial effect of phenolic compound combinations and total polyphenols of Argentinean red wine varieties against Escherichia coli ATCC 35218 and Listeria monocytogenes using commercial fish meat as model food. Rutin-quercetin combination and three wine varieties (Cabernet Sauvignon, Malbec and Merlot) caused cellular death of both bacteria on fish meat at 4 °C. Rutin-quercetin combination was effective on fish meat even at 20 °C. Clarified wines did not affect the bacteria, indicating that wine polyphenols are responsible for the observed effect. The use of wine phenolic compounds as antibacterial agent could be used to prevent contamination and extend the shelf life of fish meat. A big finding of this work is the use of rutin-quercetin combination as preservative for the conservation of fish meat and its transport to the fish market, which is an effective antibacterial agent even when the transport temperature is not constant.

Vaquero M.J.R.,Reference Center for Lactobacilli | Vaquero M.J.R.,National University of Tucuman | Fernandez P.A.A.,Reference Center for Lactobacilli | de Nadra M.C.M.,Reference Center for Lactobacilli | de Nadra M.C.M.,National University of Tucuman
Food Technology and Biotechnology | Year: 2011

The aim of this work is to investigate the synergistic antibacterial effect of phenolic compound mixtures against Listeria monocytogenes in brain heart infusion (BHI) medium, and to select the best mixture for testing their antibacterial activity in a meat model system. In BHI medium, the most effective mixtures were those of gallic and caffeic acids, gallic and protocatechuic acids, and rutin and quercetin. At the concentration of 200 mg/L, the mixtures of gallic and protocatechuic, then gallic and caffeic acids, and quercetin and rutin reduced the number of inoculated cells. At the concentration of 100 mg/L, only the quer-cetin and rutin mixture produced the same synergistic effect. These combinations were selected for testing in meat. At 20 °C, 100 mg/L of gallic and protocatechuic, then gallic and caffeic acid, and rutin and quercetin mixtures decreased the growth of L. monocytogenes, as compared to the control. The inhibitory effect of gallic and protocatechuic acid mixtures increased at the concentration of 200 mg/L. The death of inoculated cells was observed in the treatment with 100 mg/L of all combinations at 4 °C. With the addition of 200 mg/L of these combinations, the lethal effect increased. Gallic and caffeic acid, and rutin and quer-cetin were the most effective mixtures since after 14 days of incubation no viable cells of Listeria monocytogenes were detected. The lowest decimal reduction times of 1.0 and 0.95 day were found for gallic and caffeic acid, and rutin and quercetin mixtures, respectively. These results demonstrate that phenolic compound mixtures have synergistic antilisterial effect with an important bacterial reduction in meat. Therefore, it is possible to search for strategies to combine the synergistic antimicrobial effects of phenolic compounds with their natural biological properties.

Cavallini D.C.U.,Sao Paulo State University | Manzoni M.S.J.,Sao Paulo State University | Bedani R.,University of Sao Paulo | Roselino M.N.,Sao Paulo State University | And 8 more authors.
Nutrients | Year: 2016

Background: Cardiovascular disease is the leading cause of worldwide morbidity and mortality. Several studies have demonstrated that specific probiotics affect the host’s metabolism and may influence the cardiovascular disease risk. Objectives: The aim of this study was to investigate the influence of an isoflavone-supplemented soy product fermented with Enterococcus faecium CRL 183 and Lactobacillus helveticus 416 on cardiovascular risk markers in moderately hypercholesterolemic subjects. Design: Randomized placebo-controlled double-blind trial Setting: São Paulo State University in Araraquara, SP, Brazil. Participants: 49 male healthy men with total cholesterol (TC) >5.17 mmol/L and <6.21 mmol/L Intervention: The volunteers have consumed 200 mL of the probiotic soy product (group SP-1010 CFU/day), isoflavone-supplemented probiotic soy product (group ISP-probiotic plus 50 mg of total isoflavones/100 g) or unfermented soy product (group USP-placebo) for 42 days in a randomized, double-blind study. Main outcome measures: Lipid profile and additional cardiovascular biomarkers were analyzed on days 0, 30 and 42. Urine samples (24 h) were collected at baseline and at the end of the experiment so as to determine the isoflavones profile. Results: After 42 days, the ISP consumption led to improved total cholesterol, non-HDL-C (LDL + IDL + VLDL cholesterol fractions) and electronegative LDL concentrations (reduction of 13.8%, 14.7% and 24.2%, respectively, p < 0.05). The ISP and SP have prevented the reduction of HDL-C level after 42 days. The C-reactive protein and fibrinogen levels were not improved. The equol production by the ISP group subjects was inversely correlated with electronegative LDL concentration. Conclusions: The results suggest that a regular consumption of this probiotic soy product, supplemented with isoflavones, could contribute to reducing the risk of cardiovascular diseases in moderately hypercholesterolemic men, through the an improvement in lipid profile and antioxidant properties. © 2016 by the authors; licensee MDPI, Basel, Switzerland.

Rodriguez Vaquero M.J.,Reference Center for Lactobacilli | Rodriguez Vaquero M.J.,National University of Tucuman | Aredes Fernandez P.A.,Reference Center for Lactobacilli | Manca De Nadra M.C.,Reference Center for Lactobacilli | And 2 more authors.
Journal of Food Biochemistry | Year: 2013

In this work, the effectiveness of phenolic compounds of different varieties of wines as antibacterial agent in a meat model system was determined. Total phenolic, flavonoid and flavanol compounds concentrations were greater in Merlot and Malbec wines compared with Cabernet Sauvignon variety. In meat, the best antibacterial effect of wine phenolic compounds against both bacteria was observed with Merlot and Malbec wine varieties at 4C, even when inhibitory effect was also observed at 20C. The lowest decimal reduction time was obtained with Merlot wine for Listeriamonocytogenes and with Malbec and Merlot wines for Escherichiacoli. From our results, we propose the use of wine phenolic compounds as natural biopreservatives for meat in combination with low temperatures. These natural products provide the additional human health benefit inherent to polyphenols properties. © 2012 Wiley Periodicals, Inc.

Discover hidden collaborations