## 2 Characteristics of Plant-Based Food Matrices as Carriers of Probiotics
### Survival of Probiotics in Plant-Food Products  
Autochthonous probioticic microorganisms (bacteria, yeast) have strain-related abilities to survive and grow in such an environment. They are usually involved in fruit and vegetable fermentation. The LAB are acidophilic bacteria resistant to many environmental stresses; however, excessive acidifications can be harmful. In the study of [PERSON] et al., LAB strains with proven good survival in fruit juices (_L. rhamnos_ GG, _L. casei_ DN-114 001, _B. lactis_ Bb 12, _L. paracasei_ NFBC43338) were vulnerable to pH < 2.5 in cranberry juice. Despite the acidification, authors also underlined the deleterious role of the probiotic survival in benzoic acid, which is a major phenolic compound of cranberry juice [61]. The adaptation to high sugar concentration and preference of fructose over glucose is an evolutionary strategy of plant indigenous bacteria [25]. [PERSON] et al. (2012) selected frutophilic. LAB, which prefer fructose as an energy substrate (FLAB) [62]. The fermentation of fruits and vegetables is mainly conducted by the native microorganisms. The back-sloping technique is a traditional method based on the reuse of well-adapted native strains that ensure successful fermentation of dairy (cheese, milk) and plant (sauerkraut) products [37]. The use of starter culture in plant-food preservation is not as common a practice as in dairy products. There are concerns that the introduction of starter culture's microorganisms into the plant matrix will suppress the growth of autochthonous microbiota, leading to the textural and sensory changes in the final product [63]. Therefore, the starter culture should be tailored to the different plant matrices, ensuring adequate probiotic viability and quality. In the study of [PERSON] et al. (2015), the viability of commercial LAB strains during fermentation showed a higher rate in apple juice than in grape and orange juices. The most suitable strain for apple juice fermentation was _Lactobacillus acidophilus_ L10 [64]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Product** & **Applied Probiotic** & **Applied Prebiotic** & **Research Issue** & **Reference** \\ \hline \multirow{3}{*}{Jelly candies with enzymatically modified apple pomace} & \multirow{3}{*}{_Bifidobacterium_ _animals_ DSM 20105} & \multirow{3}{*}{-} & Evaluation of the applicational & \multirow{3}{*}{[56]} \\  & & & possibilities of enzymatically modified & \\  & & & apple pomace in jelly candies & \\  & & & with probiotics & \\ \hline \multirow{3}{*}{Rice-based beverages} & \multirow{3}{*}{_L. fermentum_  MG7011} & \multirow{3}{*}{-} & Choice of probiotic starter culture data & \\  & & & & \\ \hline \multirow{3}{*}{Fermented beverages prepared with almonds (_Prunus dulcis_), rice (_Oryza sativa L._), oats (_Avena sativa L._), oats (_Avena sativa L._), oä  
[PERSON] et al. (2014) compared the growth and survival of different _Lactobacillus plantarum_ strains during 21 days of storage of fermented cherry, pineapple, carrot, and tomato juices. Cherry and pineapple juices were stressful for microbial growth, while carrot and tomato juices were assessed as favorable habitats ([PERSON] et al., 2014). In general, plant matrices are thought to be a less favorable environment for probiotic growth than dairy products. Those disadvantages, to some extent, can limit the development of plant functional products ([PERSON] et al., 2014). On the other hand, plant-based food contains sugars and phytochemicals that protect probiotic cells' survival (i.e., antioxidants present in plant food, such as vitamins C and E, can reduce oxidative stress) ([PERSON] et al., 2014). Many plant-food products are seasonal, prone to spoilage, and have a short storage time. To ensure their availability, their preservation is mandatory. However, in various technological processes, the plant food's nutritive value, composition of bioactive components, sensory properties, and microbiome can be changed (Sauerkraut fermentation is conducted at approx.