# Probiotics and Beneficial Microorganisms in Biopreservation of Plant-Based Foods and Beverages
## 4 Biopreservative Properties of Probiotics
### Fruits
#### 5.1.2 Apple  
The potential probiotictic strain _Lactiplanttibacillus plantarum_ CIT3, isolated from apple, showed a significant inhibitory effect against _E. coli_ and _L. monocytogenes_ in sliced apples. Products inoculated with _Lb. plantarum_ CIT3 showed significantly accelerated the death of _E. coli_, lowering the pathogen numbers to undetectable levels within 7 days of storage at 6 \({}^{\circ}\)C. Moreover, _Lb. plantarum_ CIT3 inhibited the growth of _L. monocytogenes_ until the end of the storage period. _Lacticaseibacillus paracasei_ (_Lb. paracasei_) M3B6 also showed promising inhibitory effects against _E. coli_ and _L. monocytogenes_, although to a lesser extent. These two potential biocontrol agents are found to be effective when they are present at levels higher than 1.5 log CFU/g. Results suggest that these biocontrol agents create an effective hurdle against _L. monocytogenes_ for at least 16 days of refrigerated storage, while increasing the safety against _E. coli_. Furthermore, these probiotic biocontrol agents were able to significantly inhibit the growth of yeast, although the sensory properties of these products were negatively affected as these biocontrol agents resulted in the premature browning of the products. However, the color of the samples remained acceptable for up to 7 days of storage at 6 \({}^{\circ}\)C [65]. [PERSON] et al. [66] studied the applicability of _Lacticaseibacillus rhamnus_ (_Lb. rhamnus_) GG (LGG) to fresh-cut apple wedges and its effect on instrumental eating quality parameters and sensory acceptability. Apple samples were cut into skin-on wedges and were dipped in an edible buffer solution containing approximately 10\({}^{10}\) CFU/mL of LGG. The viable LGG counts at the end of the 10-day long storage (at 2-4 \({}^{\circ}\)C) period was above 10\({}^{8}\) CFU/g. No significant difference was observed in instrumental color values, shear values, soluble solid contents, titratable acidity, pH and overall acceptability between the probiotic apple wedges and control which did not contain probiotics [66]. Another study demonstrated that LGG survived at concentrations higher than 10\({}^{6}\) CFU/g on minimally processed apple wedges for over 28 days of storage at 5 and 10 \({}^{\circ}\)C without any quality deterioration. In the presence of LGG, _L. monocytogenes_ counts were reduced by 1-log units. Although _L. monocytogenes_ counts were reduced by 1 log unit, _Salmonella_ was not affected by co-inoculation with LGG. This demonstrates the strain specificity of the pathogen inhibition ability of probiotics. Further, the viable counts of LGG after the simulated gastrointestinal digestion were satisfactory and within the recommended levels (10\({}^{6}\) CFU/g) only during the first 14 days of storage. This indicates the additional probiotic benefits of the product in addition to the biopreservation effect during the early days of product shelf life [67]. Not only LAB, but certain other bacterial strains reported to possess probiotic properties have also been reported to have antagonistic effects against food-borne pathogens. _Gluconobacter asaii_, isolated from apple surfaces, exhibited antagonistic effects against _Listeria monocytogenes_ and _Salmonella enterica_ Serovar Poona on cut Golden Delicious apples during storage. _G. asaii_ was able to grow on cut apples and significantly reduced the _L. monocytogenes_ populations after 2 days of storage at 25 \({}^{\circ}\)C. At 10 \({}^{\circ}\)C, although the reduction in pathogenic populations was not significant, _G. asaii_ reduced the _L. monocytogenes_ population by \(\sim\)2.1-2.8 log units after 5 days of storage. At high inoculation levels of the pathogen, _G asaii_ is still able to reduce the populations within 7 days of storage at both temperatures. In addition, _G. asaii_ significantly reduced _S. enterica_ Serova Poona populations within 5 days of storage at 25 \({}^{\circ}\)C. _S. enterica_ Serova Poona did not grow properly at 10 \({}^{\circ}\)C as it is not a psychrotroph. Most importantly, _G.