Obtaining and encapsulation of a hydrolysate with antifungal potential from the fermentation of sub-products of tortilla corn with lactic acid bacteria

For the industry tortilla corn, it is possible to obtain tortilla of high quality and safe (from a microbiological point of view) for short periods of time. The efficiency of different methods for microbial growing different to the conventional conservatives has been proved. Amongst these methods, using and application of lactic acid bacteria highlights from the rest. Packed tortilla industry in Guanajuato stat faces the challenge of not-sell product, which leads to important economic losses (between 10-20% per year). For this, technological strategies to allow the exploitation and valuation of sub products of tortilla corn are required. The objective of the present work as to obtained and microencapsulate a hydrolysate fermented using lactic acid bacteria (for increase antifungal activity) from tortilla corn sub-products. For this, residues of tortilla corn were obtained, which were hydrolyzed with amylase, during 36 hours at 50°C. After this, it was inoculated separately with four different lactic acid bacteria (Lactococcus lactis var. lactis, Lactobacillus plantarum, Lactobacillus rhamnosus and lactobacillus paracasei was left to incubate during 24 hours at 48°C. The counting of lactic acid bacteria, pH and acidity was monitored both at the beginning and the end of the fermentation. The antifungal activity of the lactic acid bacteria was evaluated by diffusion and radial assays with mould obtained from time out tortilla corn. Hydrolysate fermented with Lactobacillus rhamnosus showed the highest inhibition percentages against the mould tested, therefore it considered as the most viable alternative for obtaining a hydrolysate ingredient for tortilla corn selfconservation. Finally, the hydrolyzed fermented with lactobacillus rhamnosus was mixed with maltodextrin to be microencapsulated by spray drying, using a box-behnken response surface design. Spray drying encapsulation conditions according to the optimized model were 120°C inlet temperature, 1:4.3 extract-maltodextrin (w/w) ratio and 5mL/min feed. Encapsulation efficiency and performance of 88.99% and 77.99% respectively was obtained. In conclusion, lactic acid bacteria can functionalize hydrolysate tortilla corn sub-products, through the production of antifungal compound and the microencapsulation process preserves antifungal activity to increase shelf life.