1. BIOPRESERVATION POTENTIAL OF LACTIC ACID BACTERIA FROM ANDEAN FERMENTED PRODUCTS
Alba Yépez 1, Carlos Luz 4, Giuseppe Meca 4, Rosa Aznar1,2,3
1Microbiology and Ecology, University of Valencia, Spain; 2Biotechnology, IATA-CSIC, Paterna, Spain; 3CECT, University of Valencia, Spain;
4Laboratory of Food Chemistry and Toxicology, Faculty of Pharmacy, University of Valencia, Spain
INTRODUCTION
Lactic acid bacteria (LAB) are commonly used for a large variety of food fermentations because of their biosynthetic capacity and their metabolic versatility. In addition, LAB may exhibit antimicrobial activity, which represents a huge potential in biopreservation. Food spoilage caused by mycotoxigenic molds is among the challenges in food safety. In this context, some LAB strains are able to produce low molecular weight compounds, generally with antioxidant activity, related to phenolic acids with important antifungal activities. Provided LAB are food grade organisms and many species are in the system “Qualified Presumption of Safety” (QPS) introduced by the “European Food Safety Agency” (EFSA), they are suitable to be used in the formulation of shelf-life/foodsafety enhanced products.
MATERIAL & METHODS
Characteristics of the study strains
Antimicrobial tests vs. food toxigenic molds
1 Lactobacillus fermentum, 1 Lactobacillus sakei,
6 Lactobacillus plantarum, 3 Leuconostoc mesenteroides
11 LAB strains
Concentrated by lyophilisation
Antimicrobial activity
Riboflavin production
> 100 ng/ml
Folate production
Phytate degradation activity
Functional properties
Foodborne pathogens
Fusarium verticilloides CECT 2987
(Aflatoxin producer)
(Patulin producer)
(Fumonisin producer)
Aspergillus parasiticus CECT 2681
Penicillium expansum CECT 2278
Salmonella enterica CECT 4138
Escherichia coli O157:H7 CECT 5947
Spoiler fungi
Pichia guillermondii CECT 1021
Aspergillus oryzae CECT 2094
Penicillium roqueforti CECT 2905
Kirby-Bauer assay (antibiogram method)
RESULTS & DISCUSSION
Characterization of the antifungal compounds
LC-DAD and LC MS/MS
LAB strain
LAB specie
A. parasiticus
P. expansum
F. verticilloides
M5MA1
Lb. plantarum + -
M9MG2
M9MG6
M9MM1
M9MM4
M9Y2
T1M3
Lc. mesenteroides
T2MM5
T2MM6
T3M3
Lb. fermentum
T3M7
Lb. sakei
Compound (mg/L)
M5MA1
M9MG6
T3M3
Phenyllactic acid
90.00
65.00 -
3-(4hydroxy-3-methoxyphenyl)propanoic acid
7.50
Synapic acid
9.50
2-Deoxycytidine
15.00
15.50
Cyclo (L-His-L Pro)
4.45
Cyclo (L-Tyr-L Pro)
6.50
0.95
10.00
Phenylpyruvic acid
4.55
0.85
cis-Caftaric acid a
1.37
Protocatechuic acid hexoside
1.65
Caffeic acid derivative
5.50
Hydroxycinnamic acid derivative
24.00
Quercetin pentoside
20.00
Quinic acid derivative
22.50
Caffeoyl hexose-deoxyhexoside
2.95
2.75
3,5-Di-O-caffeoylquinic acid
24.15
18.00
Antifungal activity against at least to one of the three moulds was observed in all Lb. plantarum and Lb. fermentum
One strain of Lb. plantarum inhibited all three molds.
CONCLUSIONS
Due to the multi-antimicrobial activity shown by some of the LAB, particularly among the Lb. plantarum, these strains would be a good candidates to be used in the formulation of sourdough-based products to extend their shelf life.
Three of the strains produce some compounds which have been described to show antifungal activity, among them, phenolic acids.
Acknowledgements
PROMETEO/2012/040 (Generalitat Valenciana, España)
FPU2013/03398 (Spanish Ministery of Education, Culture ans Sport