Controlling the Risk of Bacillus in Food Using Berries

Abstract

Introduction: Increasing the shelf life of foods without the addition of synthetic additives is a demand from both producers and consumers. Spore-forming bacteria are a problem in the food industry. To reduce their impact, it is necessary to use complex technologies, as well as ingredients with antibacterial or antibiotic properties. The aim of this study was to develop initial symbiotic combinations between lactic acid bacteria and berries to control food quality. The relevant ability of lactic acid bacteria in the presence of berry additives to inhibit the growth of Bacillus strains that degrade bakery products and dairy products was investigated. The antibacterial effect of berries on the growth of Bacillus mesentericus was studied. Methods: In this study was used inhibition zone test, also called Kirby-Bauer Test. The growth rate of bacteria was based on the measurement of the optical density at 600 nm (OD600). The method of Thompson et al . has been used to research the development of ropiness disease in wheat bread samples. Results: The diameter of the Bacillus pumilus growth inhibition zones under the berries action was as follows: aronia −18.0 ± 0.6 mm; raspberry −16.0 ± 0.4 mm; strawberry −15.0 ± 0.5 mm. Lactic bacteria in the presence of berry additives showed a growth rate, measured by optical density (OD) at 600 from 0.073 to 0.651 (for aronia) from 0.071 to 0.609 (for raspberries), from 0.073 to 0.597 compared to the increase in environments without added fruit, which amounted to −0.050 to 0.410. In the yogurt with added fruit, a synergism was formed with Streptococcus thermophilus , Lactobacillus delbrueckii subsp. Bulgaricus , Lactococcus lactis subsp Lactis biovar diacetilactis . The influence of fat-soluble extracts of sea buckthorn, rose-hip, and hawthorn fruits on the development of ropiness disease when storing wheat bread was investigated. The general Pearson coefficient (microbial count and pH) for all fruit yogurt samples is 0.95066. Conclusion: The combined use of lactic acid bacteria and berries (aronia, raspberry and strawberry) had a synergistic effect on the risk posed by Bacillus bacteria. 1% of fat-soluble extract from the vegetable matter reduced the risk of ropiness disease in wheat bread. This is due to the cumulative effect of the berries chemical composition (antioxidants, organic acids, etc.), increased acidity, lowered pH, and water activity of the food environment, below the development values of Bacillus .