Influence of Storage Temperature and Packaging on Bacteria and Yeast Viability in a Plant-Based Fermented Food

Abstract

Optimization of food storage has become a central issue for food science and biotechnology, especially in the field of functional foods. The aim of this work was to investigate the influence of different storage strategies in a fermented food product (FFP) and further determine whether the regular storage (room temperature (RT) and standard packaging (SP)) could be refined. Eight experimental conditions (four different temperatures × two packaging) were simulated and changes in FFP's microbial ecology (total bacteria, lactic acid bacteria (LAB), and yeasts) and physicochemical characteristics (pH and moisture content (MC)) were determined following 1, 3, 6, and 12 months. All conditions tested showed a decline in microbial content due to the effect of the temperature, 37 • C being the most detrimental condition, while −20 and 4 • C seemed to be better than RT in some parameters. Vacuum packaging (VP) only had a major effect on MC and we found that VP preserved greater MC values than SP at 3, 6, and 12 months. The correlation analysis revealed that total bacteria, LAB, and yeasts were positively associated, and also both pH and MC showed a correlation. According to our results and with the purpose to maintain the load of viable microorganisms, we observed that the best storage conditions should contemplate SP and freezing or cooling temperature during a period no longer than 3 months.

Physicochemical Parameters and Bioaccessibility of Lactic Acid Bacteria Fermented Chayote Leaf (Sechium edule) and Pineapple (Ananas comosus) Smoothies

“…However, after storage for 7 days at 4°C, the pH values of the fermented smoothies significantly increased compared with the pH values at 2 days. The smoothie fermented with combined starters ( LW64 + 75 ) had the lowest pH value (2.50); this is probably due to the induced fermentation with LAB starters that could have reduced the pH during the first 2 days of fermentation, and thereafter the increased pH during storage might be due to the onset of metabolic activities of colonizing bacteria or fungi that utilize lactic acid as a carbon source, thus releasing metabolites that could alter the acidity of foods ( 30 ). The higher pH in the stored samples suggests that the LAB cultures could not survive for 7 days at the stored temperatures.…”

“…The microbial load and LAB count of the samples were evaluated at the beginning, end of fermentation, and storage through the bacteria count using the pour plating techniques ( 30 ). Briefly, successive serial dilutions of smoothie sampled at 0, 2, and 7 days were made in sterile buffered peptone water and then plated on appropriate media.…”

Targeted Delivery of Probiotics: Perspectives on Research and Commercialization

“…The range of encapsulation techniques provides shelf-stable probiotics. However, regulatory issues arise with the shelf-stability of probiotics at ambient conditions during storage [ 32 , 232 , 233 ]. Most of the probiotic products in the market require refrigeration.…”

“…Synbiotics in which prebiotics are considered as a substrate is selectively utilized by the co-administered probiotics (synergistic synbiotic) or by the endogenous micro-organisms (complementary synbiotic) [ 30 ]. Generally, the viability of the microbes highly depends on various factors such as matrix, storage temperature, moisture, pH, and oxygen level [ 28 , 31 , 32 ]. The encapsulation matrix improves the stress tolerance of probiotics [ 33 ].…”

Characterisation of Biologically Active Hydrolysates and Peptide Fractions of Vacuum Packaging String Bean (Phaseolus Vulgaris L.)

“…This technique is most often used for the preservation of meat. Currently, it is increasingly being employed for the packaging of other products such as vegetables or fermented plant foods [ 6 ]. This method may be the most effective process to retain health-promoting compounds in cruciferous vegetables, compared to, e.g., blanching, boiling, or microwaving.…”