**3.4. Effect of growth factors on the dynamics of the lactic acid fermentation of the carrot juices by Lactobacillus acidophilus LA-5**

Kinetic parameters such as the time to reach pH 5.0 and the maximum rate of acidification are important in terms of the shelf life of the fermented vegetable juices. These ones were differently modified by the presence of the amino acids or of the yeast extract at the initial moment of fermentation. From Table 2 we deduced that a highest influence on both tpH 5.0 and vmax was exerted by cysteine, added to the juice in amount by 0.2% (w/v). Compared with the other supplements, the yeast extract had a relative good effect on the analyzed parameters. At the used concentrations, the behavior of valine and lysine seems to be unobservable from this point of view, excepting the poor effect of lysine on the maximum rate of acidification. Time to complete the fermentation (tpH 4.2, h) ranged between 7.4 (YE) and 10.42 (Leu), trend that underline the statement that in the above mentioned experimental conditions *Lactobacillus acidophilus* growing faster.


1)The notations used for the samples are in agreement with the nutrients added, as follows: L-Cysteine (Cys\_1 sample with 0.1% cysteine and Cys\_2 sample with 0.2% cysteine), L-Leucine (Leu), L-Valine (Val), L-Lysine (Lys) and yeast extract (YE) respectively

2)The data were obtained by dividing the kinetic parameters of the control to the corresponding values of the samples 3)The data were obtained by dividing the kinetic parameters of the samples to the corresponding values of the control Subunit or null values should be considered as lack of effect on the analyzed parameters.

**Table 2.** Effect of supplements on the kinetic parameters

MRS broth used for lactobacilli enumeration often incorporates L-cysteine to improve the recovery of these ones, especially due to the fact that *Lactobacillus acidophilus* LA-5 is microaerophilic. Cysteine, a sulfur containing amino acid, could provide amino nitrogen as a growth factor while reducing the redox potential. [22] reported that the incubation time to reach a pH of 4.5 was greatly affected by the addition of cysteine in yogurts made with different commercial cultures, although their viability was adversely affected in function of the amount of supplement and the type of the starter culture.

Lactic acid is the major metabolite of *Lactobacillus acidophilus*, influencing both the preservation of the fermented products and the sensorial characteristics of these ones. The effect of the amino acids and of the yeast extract on the dynamics of the lactic acid, assessed against the control, is underlined through the data from Table 3. The buffering capacity of the amino acids prevented a direct proportionality between the pH values and the lactic acid content.

184 Lactic Acid Bacteria – R & D for Food, Health and Livestock Purposes

**the carrot juices by Lactobacillus acidophilus LA-5** 

experimental conditions *Lactobacillus acidophilus* growing faster.

Kinetic parameter Supplements1)

Subunit or null values should be considered as lack of effect on the analyzed parameters.

the amount of supplement and the type of the starter culture.

**Table 2.** Effect of supplements on the kinetic parameters

Time-decreasing of tpH 5.02) 1.28 0.85 0 0 1.69 1.1 Time-increasing of vmax3) 0.82 0.84 0.98 1.05 1.1 1.05 1)The notations used for the samples are in agreement with the nutrients added, as follows: L-Cysteine (Cys\_1 sample with 0.1% cysteine and Cys\_2 sample with 0.2% cysteine), L-Leucine (Leu), L-Valine (Val), L-Lysine (Lys) and yeast

2)The data were obtained by dividing the kinetic parameters of the control to the corresponding values of the samples 3)The data were obtained by dividing the kinetic parameters of the samples to the corresponding values of the control

MRS broth used for lactobacilli enumeration often incorporates L-cysteine to improve the recovery of these ones, especially due to the fact that *Lactobacillus acidophilus* LA-5 is microaerophilic. Cysteine, a sulfur containing amino acid, could provide amino nitrogen as a growth factor while reducing the redox potential. [22] reported that the incubation time to reach a pH of 4.5 was greatly affected by the addition of cysteine in yogurts made with different commercial cultures, although their viability was adversely affected in function of

being very close to unit.

with 0.7 in the sample Cc.

extract (YE) respectively

The relationship between the growth of *Lactobacillus acidophilus*, the substrate metabolization and the lactic acid accumulation is shown in Figure 8. The prediction functions of the values of the analyzed parameters in all the samples were defined as polynomial, the R squared

Correlating the number of viable cells with the dynamics of the lactic acid, the values were lower until 6 hours in the red cabbage juice and cucumber juice with onion juice added respectively. The differences were lessened in the next period of the process. However, the final yield of the lactic acid production was better in the sample CcO, by 0.78, comparatively

**3.4. Effect of growth factors on the dynamics of the lactic acid fermentation of** 

Kinetic parameters such as the time to reach pH 5.0 and the maximum rate of acidification are important in terms of the shelf life of the fermented vegetable juices. These ones were differently modified by the presence of the amino acids or of the yeast extract at the initial moment of fermentation. From Table 2 we deduced that a highest influence on both tpH 5.0 and vmax was exerted by cysteine, added to the juice in amount by 0.2% (w/v). Compared with the other supplements, the yeast extract had a relative good effect on the analyzed parameters. At the used concentrations, the behavior of valine and lysine seems to be unobservable from this point of view, excepting the poor effect of lysine on the maximum rate of acidification. Time to complete the fermentation (tpH 4.2, h) ranged between 7.4 (YE) and 10.42 (Leu), trend that underline the statement that in the above mentioned

Cys\_1 Leu Val Lys Cys\_2 YE


**Table 3.** Time-increasing of lactic acid during 24h of lactic acid fermentation of carrot juices by *Lactobacillus acidophilus* LA-5

The values were expressed in percents by reporting the difference between sample and control to the control, at the same moment of time

Negative values shows that for the corresponding interval of time the supplements had not influence on the lactic acid production at the used levels.

Analyzing the whole process, only the samples with a minimum amount of cysteine added and those with yeast extract have been a great effect on the time-increasing of lactic acid. At the other opposite were found the samples with leucine added, this amino acid with nonpolar hydrophobic chains clumsying the fermentation. From the viewpoint of increase the lactic acid content in the final stages of the process, the supplementation of the carrot juices with 0.2% (w/v) cysteine seems to be undesirable.

The beneficial effect of cysteine on the lactic acid accumulation in vegetable juices can occur due to its buffering capacity, which may diminish the toxic effects of organic acids on lactobacilli. Referring to the yeast extract, which contains more cell growth factors, being used generally as a source of assimilable nitrogen, vitamins and minerals, its influence at the level of 0.2%(w/v) on the time-increasing of lactic acid could be characterized as moderate. If some authors reported different maximum lactic acid concentration in media supplemented with yeast extract, several possible explanations include the strain of microorganism, the chemical composition of the substrate, the fermentation system, and generally the conditions employed during fermentation ([12]).

Effect of supplements on the performance of lactic acid production was evaluated based on lactic acid productivity and lactic acid yield, respectively on glucose ratio (Table 4).

The previous conclusion referring to the positive influence of the yeast extract and cysteine (in minimum amount) on the development of the lactic acid fermentation of vegetable juices is confirmed by the data from Table 4. Good values of lactic acid productivity were obtained

after 24 h of fermentation in the samples with valine and lysine added, although in these ones the substrate consumption seems to be directed to the increasing of biomass, aspect emphasized by the average values of the lactic acid yield.

Fermentation of Vegetable Juices by *Lactobacillus Acidophilus* LA-5 187

The presence of ascorbic acid into vegetable juices submitted to fermentation by probiotic bacteria, especially by *Lactobacillus acidophilus* strains, is desired not only from the nutritional point of view, but also due to the fact that it could promote anaerobic conditions, acting as an oxygen scavenger. [24] have shown also that the fruit juices may be an alternative vehicle for the incorporation of probiotics because they are rich in nutrients and do not contain starter cultures that compete for nutrients with probiotics. Furthermore, fruit juices are often supplemented with oxygen scavenging ingredients such as ascorbic acid,

L-cysteine, a sulfur-containing amino acid known as a powerful reducing agent, caused the reduction of dehydroascorbic acid to ascorbic acid, which led a different behavior of the samples Cys\_1 and Cys\_2 by the others. The increase of this parameter was by 80% and 56.4% respectively, after 2h from the initial moment of fermentation. Subsequently, the

The losses occurred after 24h of lactic acid fermentation of carrot juices with *Lactobacillus acidophilus* LA-5 ranged from 48.39% (YE) to 61.9% (control). The possible reason could be

In order to evaluate the probiotic feature of the vegetable juices, the study of the effect of supplements on *Lactobacillus acidophilus* growth is from overwhelming importance, both

Between the analyzed samples, those with yeast extract and 0.1% (w/v) cysteine added registered a higher increase of the number of viable cells till 14.4 - 14.5 log CFU/ml in the first 8h of the process. Concerning the yeast extract, the most possible explanation is due to an enhanced availability of minerals, which are growth promoters for *L. acidophilus* ([25]), while discussing the factors that affect the activity of endogenous probiotics, (26) mentioned that some of the growth promoters in cow milk were apparently cysteine-containing peptides.

Referring to the juices with leucine, lower values were determined comparative with the control during 24h, while in the samples with 0.2% (w/v) cysteine added the trend of the survival of lactobacilli was slow down in the period 6 - 8h, the level being by 13.5 and 13.6 log CFU/ml respectively. The last observation agrees with this one of [27], which have shown that the increasing of cysteine concentration improved the viability of *B. bifidum* in bio-yogurt, although it had no important effect on the viability of *Lactobacillus acidophilus.* 

The batches supplemented with valine and lysine had occupied an intermediate position, the growth until 14.2 log CFU/ml after 8h of fermentation making from the utilization of these amino acids a promising variant in the future, with a view to optimize the conditions of the process unfolding. In the period 8 - 24h the number of viable cells decreased, as result

The correlation between the most important parameters of the lactic acid fermentation of the carrot juices with *Lactobacillus acidophilus* LA-5 were evaluated using Pearson correlation

analyzed parameter had the same diminishing tendency as in the other batches.

during the lactic acid fermentation and during the storage of the final products.

the oxygen traces that cause the chemical oxidation of the vitamin C.

of the lack of tolerance at lower pH of the analyzed strain.

analysis (significance level *p* < 0.01; confidence level of 99%).

thus promoting anaerobic conditions.


1)The data from the table were obtained by dividing the corresponding values for the samples to those of the control 2)Lactic acid yield was calculated by dividing the amount of lactic acid produced to the amount of glucose consumed 3)Lactic acid productivity was defined as the amount of lactic acid produced per hour per liter 4)Glucose conversion ratio was calculated by dividing the amount of glucose consumed to the initial amount of

glucose.

**Table 4.** Effect of supplements on lactic/acetic acid production after 48 h of fermentation1)

The effect of supplements (amino acids and yeast extract) on the ascorbic acid dynamics is shown in Figure 9. L-Ascorbic acid (AA), also known as vitamin C, is a representative watersoluble vitamin possessing a variety of biological, pharmaceutical, and dermatological functions; it promotes collagen biosynthesis, provides photoprotection, causes melanin reduction, scavenges free radicals, and enhances immunity ([23]).

Due to the heat treatment applied with a view to destroy the epiphytic microbiota of the fresh vegetable juices, the losses occurred in the ascorbic acid content represented about 65%.

**Figure 9.** Time-course (0-24h) of the relative levels of ascorbic acid

(●Cys\_1, ■Cys\_2, ○YE, □Leu, ▲Val, x Lis). The data shown are average values of two independent replicate experiments

The presence of ascorbic acid into vegetable juices submitted to fermentation by probiotic bacteria, especially by *Lactobacillus acidophilus* strains, is desired not only from the nutritional point of view, but also due to the fact that it could promote anaerobic conditions, acting as an oxygen scavenger. [24] have shown also that the fruit juices may be an alternative vehicle for the incorporation of probiotics because they are rich in nutrients and do not contain starter cultures that compete for nutrients with probiotics. Furthermore, fruit juices are often supplemented with oxygen scavenging ingredients such as ascorbic acid, thus promoting anaerobic conditions.

186 Lactic Acid Bacteria – R & D for Food, Health and Livestock Purposes

Lactic acid

glucose.

65%.

replicate experiments

Glucose conversion

emphasized by the average values of the lactic acid yield.

after 24 h of fermentation in the samples with valine and lysine added, although in these ones the substrate consumption seems to be directed to the increasing of biomass, aspect

Parameter Cys\_1 Leu Val Lys Cys\_2 YE Lactic acid yield2) 1.1 0.85 0.88 0.79 0.85 1.15

productivity3) 1.01 0.99 1.06 1.05 0.7 1.13

ratio4) 1.1 0.9 1.2 1.05 0.92 1.25 1)The data from the table were obtained by dividing the corresponding values for the samples to those of the control 2)Lactic acid yield was calculated by dividing the amount of lactic acid produced to the amount of glucose consumed

4)Glucose conversion ratio was calculated by dividing the amount of glucose consumed to the initial amount of

The effect of supplements (amino acids and yeast extract) on the ascorbic acid dynamics is shown in Figure 9. L-Ascorbic acid (AA), also known as vitamin C, is a representative watersoluble vitamin possessing a variety of biological, pharmaceutical, and dermatological functions; it promotes collagen biosynthesis, provides photoprotection, causes melanin

Due to the heat treatment applied with a view to destroy the epiphytic microbiota of the fresh vegetable juices, the losses occurred in the ascorbic acid content represented about

**Table 4.** Effect of supplements on lactic/acetic acid production after 48 h of fermentation1)

3)Lactic acid productivity was defined as the amount of lactic acid produced per hour per liter

reduction, scavenges free radicals, and enhances immunity ([23]).

**Figure 9.** Time-course (0-24h) of the relative levels of ascorbic acid

0

50

100

150

ascorbic acid (mg/100ml)

200

250

300

(●Cys\_1, ■Cys\_2, ○YE, □Leu, ▲Val, x Lis). The data shown are average values of two independent

0 4 8 12 16 20 24 Time (h)

L-cysteine, a sulfur-containing amino acid known as a powerful reducing agent, caused the reduction of dehydroascorbic acid to ascorbic acid, which led a different behavior of the samples Cys\_1 and Cys\_2 by the others. The increase of this parameter was by 80% and 56.4% respectively, after 2h from the initial moment of fermentation. Subsequently, the analyzed parameter had the same diminishing tendency as in the other batches.

The losses occurred after 24h of lactic acid fermentation of carrot juices with *Lactobacillus acidophilus* LA-5 ranged from 48.39% (YE) to 61.9% (control). The possible reason could be the oxygen traces that cause the chemical oxidation of the vitamin C.

In order to evaluate the probiotic feature of the vegetable juices, the study of the effect of supplements on *Lactobacillus acidophilus* growth is from overwhelming importance, both during the lactic acid fermentation and during the storage of the final products.

Between the analyzed samples, those with yeast extract and 0.1% (w/v) cysteine added registered a higher increase of the number of viable cells till 14.4 - 14.5 log CFU/ml in the first 8h of the process. Concerning the yeast extract, the most possible explanation is due to an enhanced availability of minerals, which are growth promoters for *L. acidophilus* ([25]), while discussing the factors that affect the activity of endogenous probiotics, (26) mentioned that some of the growth promoters in cow milk were apparently cysteine-containing peptides.

Referring to the juices with leucine, lower values were determined comparative with the control during 24h, while in the samples with 0.2% (w/v) cysteine added the trend of the survival of lactobacilli was slow down in the period 6 - 8h, the level being by 13.5 and 13.6 log CFU/ml respectively. The last observation agrees with this one of [27], which have shown that the increasing of cysteine concentration improved the viability of *B. bifidum* in bio-yogurt, although it had no important effect on the viability of *Lactobacillus acidophilus.* 

The batches supplemented with valine and lysine had occupied an intermediate position, the growth until 14.2 log CFU/ml after 8h of fermentation making from the utilization of these amino acids a promising variant in the future, with a view to optimize the conditions of the process unfolding. In the period 8 - 24h the number of viable cells decreased, as result of the lack of tolerance at lower pH of the analyzed strain.

The correlation between the most important parameters of the lactic acid fermentation of the carrot juices with *Lactobacillus acidophilus* LA-5 were evaluated using Pearson correlation analysis (significance level *p* < 0.01; confidence level of 99%).

188 Lactic Acid Bacteria – R & D for Food, Health and Livestock Purposes


Fermentation of Vegetable Juices by *Lactobacillus Acidophilus* LA-5 189

**Figure 10.** Component plot in rotated space

leucine at 4th h of fermentation (C\_4 and Leu\_4);

Cys\_8, (Val\_4 - Val\_8), (YE\_4 - YE\_8).

66.9% and PC2 21.3%).

properties, as follows:

at 8th h of fermentation ;

Applying PCA to the lactic acid fermentation of cabbage juices with various microorganisms, [29] established that the original 7 analytical variables were reduced also to 2 independent components that explained 88.2% from total variance of input data (PC1

Cluster Analysis (CA) is a statistic method whose purpose is to join data into clusters with a view to increase their withingroup homogeneity. Usually, the FA is considered the first step of CA, with a view to reduce the data dimensionality. In order to better distinguish among experimental samples, the cluster method of the nearest neighbour was used. The distances between objects were measured as squared Euclidean distance. K-Means Cluster Analysis divided the experimental data into three groups, characterized by similar analytical

 cluster 1: all the carrot juices (control samples and the batches with amino acids and yeast extract added) at the initial moment of fermentation, respectively at 2th h of fermentation. Supplementary, this cluster included the control and the sample with

cluster 2: all the carrot juices at 24th h of fermentation and the sample with lysine added

 cluster 3: the carrot juices with leucine and lysine added, respectively the control, at 6th and 8th h of fermentation (Leu\_6, Leu\_8, Lys\_6, Lys\_8, C\_6, C\_8); the carrot juices with cysteine, valine, respectively yeast extract from 4th to 8th h of fermentation (Cys\_4 -

\*\* Correlation is significant at the 0.01 level (2-tailed)

\* Not significant

**Table 5.** The Pearson coefficients for the experimental batches

The correlations are strong between pH and lactic acid, respectively pH and glucose, while a very strong relationship pH - viable cells could be considered (Table 5). A non-existent relationship between ascorbic acid / amino acids content (expressed as glycine) and the other analyzed parameters was determined.

A firm correlation between glucose and lactic acid was expected, but on the one hand it is known that the practical yield of sugars conversion to lactic acid of the strains of the group *Lb. acidophilus* is about 85%, while on the other hand the analysis does not include supplementary data referring to other factors that might be involved in the dynamics of the lactic acid fermentation of vegetable juices.

Factor Analysis (FA) is a multidimensional statistic method whose purpose is the analysis of the structure of mutual dependences of variables. The method is similar to the Principal Component Analysis (PCA) with the exception of the factor weights that are scaled ([28]).

Applying FA to the experimental data, the analytical variables were reduced to two principal components, which accounted for 59.72% (PC1) and respectively 18.95% (PC2) from the total variance. According to the component matrix, respectively to the values of the component loadings expressed by the first second principal components (rotation method: Varimax with Kaiser normalization), the most notable variables were pH and lactic acid (equal loading values by 0.954). Higher values were obtained also for viable cells (loading 0.939) and glucose (loading 0.933).

The combination of PC1 and PC2 (Figure 10) underlined the lack of correlation between amino acids content / ascorbic acid and all the other parameters taking into account both control and supplemented samples. While PC1 affected the dependent and independent variables involved in the progress of the lactic acid fermentation of vegetable juices, respectively in their probiotic feature, PC2 separated the variables which contribute to the nutritional characteristics of the final products.

**Figure 10.** Component plot in rotated space

pH 1 -0.889\*\* 0.829\*\* -0.940\*\* 0.099\*

lactic acid 1 -0.891\*\* 0.843\*\* -0.201\*

glucose 1 -0.789\*\* 0.093\*

viable cells 1 -0.061\*

glycine 1 -0.103\*

The correlations are strong between pH and lactic acid, respectively pH and glucose, while a very strong relationship pH - viable cells could be considered (Table 5). A non-existent relationship between ascorbic acid / amino acids content (expressed as glycine) and the

A firm correlation between glucose and lactic acid was expected, but on the one hand it is known that the practical yield of sugars conversion to lactic acid of the strains of the group *Lb. acidophilus* is about 85%, while on the other hand the analysis does not include supplementary data referring to other factors that might be involved in the dynamics of the

Factor Analysis (FA) is a multidimensional statistic method whose purpose is the analysis of the structure of mutual dependences of variables. The method is similar to the Principal Component Analysis (PCA) with the exception of the factor weights that are scaled ([28]).

Applying FA to the experimental data, the analytical variables were reduced to two principal components, which accounted for 59.72% (PC1) and respectively 18.95% (PC2) from the total variance. According to the component matrix, respectively to the values of the component loadings expressed by the first second principal components (rotation method: Varimax with Kaiser normalization), the most notable variables were pH and lactic acid (equal loading values by 0.954). Higher values were obtained also for viable cells (loading

The combination of PC1 and PC2 (Figure 10) underlined the lack of correlation between amino acids content / ascorbic acid and all the other parameters taking into account both control and supplemented samples. While PC1 affected the dependent and independent variables involved in the progress of the lactic acid fermentation of vegetable juices, respectively in their probiotic feature, PC2 separated the variables which contribute to the

ascorbic acid 1

acid glucose viable cells glycine ascorbic

acid


0.016\*

0.084\*

0.066\*

variables pH lactic

\*\* Correlation is significant at the 0.01 level (2-tailed)

other analyzed parameters was determined.

lactic acid fermentation of vegetable juices.

0.939) and glucose (loading 0.933).

nutritional characteristics of the final products.

**Table 5.** The Pearson coefficients for the experimental batches

Analytical

\* Not significant

Applying PCA to the lactic acid fermentation of cabbage juices with various microorganisms, [29] established that the original 7 analytical variables were reduced also to 2 independent components that explained 88.2% from total variance of input data (PC1 66.9% and PC2 21.3%).

Cluster Analysis (CA) is a statistic method whose purpose is to join data into clusters with a view to increase their withingroup homogeneity. Usually, the FA is considered the first step of CA, with a view to reduce the data dimensionality. In order to better distinguish among experimental samples, the cluster method of the nearest neighbour was used. The distances between objects were measured as squared Euclidean distance. K-Means Cluster Analysis divided the experimental data into three groups, characterized by similar analytical properties, as follows:


Fermentation of Vegetable Juices by *Lactobacillus Acidophilus* LA-5 191

The samples included in the third cluster best describes a vigorous process, being characterized through average values of the main parameters involved in the dynamics of

The usefulness of the methods of statistical analysis is underlined by a lot of applications of CA that could be reported: in evaluation of analytical and sensory characteristics of vegetable juices ([28], [29]), in distinguishing between wines aged a different number of

The importance of consuming probiotic foods for the improvement of the quality of life increasingly more in the last years, being underlined by the scientific literature. The diversification of the market from this point of view could be strong correlated with the

Our further researches are needed in order to optimize the level of nutrients (individually and in combination) and in the same time their influence on growth and viability of probiotics (in particular of *Lactobacillus acidophilus*, single strain or in combination with other probiotics), not

Different vegetable juices are suitable and alternative food matrices for the production of functional foods with *Lactobacillus acidophilus* LA-5, a probiotic strain which is not present in the epiphytic microbiota. Although some differences between the growths trends were determined, all the analyzed vegetables could be considered proper in order to obtain lactic acid fermented juices with a higher self-life. Application of Principal Component Analysis selected the most important parameters from analytical point of view: pH, lactic acid, biomass and viable cells, while the Cluster Analysis divided the experimental variables into

*Department of Food Engineering, Faculty of Environmental Engineering and Biotechnology,* 

(ID\_1359). The microorganisms were kindly provided by Chr. Hansen, Romania.

The research was funded by Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI) in the frame of the Project PN-II-ID-PCE-2008-2

only during fermentation but especially during the storage of the final products.

the lactic acid fermentation of vegetable juices.

increasing of the life expectancy worldwide.

Lavinia Claudia Buruleanu, Magda Gabriela Bratu,

*Valahia University of Targoviste, Romania* 

Iuliana Manea, Daniela Avram and Carmen Leane Nicolescu

months ([30]).

**4. Further research** 

**5. Conclusions** 

three groups.

**Author details** 

**Acknowledgement** 

**Figure 11.** Clusters plotting in coordinate of two selected variables: lactic acid - viable cells and lactic acid - glucose

The clusters in axes of two selected variables (Figure 11) denote that the samples from the first cluster were marked with a higher content of substrate, null or very lower lactate amount and pH values more than 5. The corresponding time was both 0 and 2h (C, Val, Leu, and YE) or the entire interval 0 - 4h (Leu and control).

The samples at the final moment of fermentation and those with lysine after 8h of the process were included in the second cluster, characterized through lower or average values of glucose content, higher lactic acid amount and pH values close to 4.2. This cluster marks the achievement of the optimum characteristics of the lactic acid fermented products.

The samples included in the third cluster best describes a vigorous process, being characterized through average values of the main parameters involved in the dynamics of the lactic acid fermentation of vegetable juices.

The usefulness of the methods of statistical analysis is underlined by a lot of applications of CA that could be reported: in evaluation of analytical and sensory characteristics of vegetable juices ([28], [29]), in distinguishing between wines aged a different number of months ([30]).
