3.2. Microbial Properties
TMAB and LAB counts of cheese samples were analyzed during the study. Although lactococci are the most critical group of LAB in general use, they are used as a starter culture in many fermented milk products, especially in cheese [20
]. Şengül [22
] found the number of Lactococcus in pasteurized milk cheese as 2.3 × 106
CFU/g and the number of Lactococcus in raw cheese as 4.1 × 106
CFU/g. They indicated the addition of starter culture to cheese produced from pasteurized milk as the reason for the high number of Lactococcus. Kesenkas et al. [23
], in a study where they examined the village cheeses produced in three different enterprises in the Izmir region, determined the number of Lactococcus as 6.26–7.74 log CFU/g in the first day of the cheeses. Cankurt [7
] reported that the number of lactococci measured during the storage of the produced cheeses increased until the 15th day in general and decreased again after the 15th day, and that the increase during storage was statistically significant (Table 4
TMAB increased in all samples during storage. The number of bacteria was quite high. At the end of the storage, the highest values were recorded in the cheeses kept in brine with carrageenan.
The effect of stabilizers against lactic acid bacteria, used as the starter culture, was also investigated. When the data were examined, it was seen that there was an inverse relationship between the increase in the amount of gum and the number of bacteria, although it is not entirely linear. It was also seen that the number of LAB of all cheese samples salted with 8% brine increased throughout the storage, except, for example, with 0.5% guar gum. In the first day, the lowest numbers were recorded in the cheese samples with gelatin in brine and the same cheese had the lowest number of LAB at the end of storage. The counts of TMAB were parallel to the counts of LAB; both were found in very high numbers in all samples. It was observed that the use of stabilizers did not have a significant negative effect on starter culture. In general, the highest values were determined in the control cheese samples. Cheeses kept in brine with gelatin were found to contain a lower number of LAB than others, although not in severe proportions (Table 5
3.3. Textural Properties
In this study, the textural properties of white cheese with different stabilizer and salt content in their brine were performed using texture profile analysis (TPA). In this method, the hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, and resilience of the cheese samples were measured.
Hardness is known as the resistance of the product against deformation [24
]. Hardness value in literature is usually expressed with g (kg), while Newton (N) is used in some studies [25
]. In general, the hardness values of samples kept in brine with 8% salt were increased from 1 to 15 days first, and then decreased. However, the hardness of all cheese samples kept in brine with gelatin increased continuously. There were significant increases in cheeses with brine containing 12% salt. Hardness values increased consistently in cheeses with brine containing 12% salt. A surprising result was that all of the cheeses being in brine with 8% salt enriched in 0.75% guar gum, 0.75% xanthan gum, and gelatin were harder than the control cheese kept in brine with 12% salt. It is understood from here that, despite being in brine with 8% salt, harder but less salty cheeses can be produced compared to the control cheese maintained in brine with 12% salt (Table 6
The formation of texture in cheese varies with various processes. Some of them are the composition of milk and processing stage of milk [26
]. In their studies, Akalın and Karaman [27
] found the hardness values of the samples they stored in packaging with brine and vacuum packaging without brine as 1080 g and 1130 g, respectively, at the end of storage. Kaya [28
] found the hardness value of Gaziantep cheese in five different brine concentrations, which were 5%, 10%, 15%, 20%, and 25% and salt solutions were as 3.45, 5.67, 10.75, 34.87, and 38.36 N, respectively. In their study, Kırkın et al. [29
] found the hardness values between 2.7 and 9.4 N at the end of 13 weeks, and Sahingil et al. [30
] found the hardness values as 3.07 N, 4.72 N, and 3.66 N, respectively. Sener reported that [24
] the hardness values of control cheeses increased until the 30th day and then did not change until the end of storage in the study where transglutaminase enzyme was used in cheese production. In a study by Cankurt [7
], the hardness values of samples during storage were increased first, then decreased, and increased again. Koyuncu showed that [31
] the hardness values of the cheeses in his study had been reduced despite the fluctuating course compared to the beginning of storage. The results of our study are consistent with the results in the literature.
Cohesiveness is expressed as the force of intimate bonds between proteins and fats, forming the three-dimensional structure in cheese [24
]. When the cohesiveness values of white cheese samples kept in brine with stabilizer were examined, it was seen that the samples exhibited significant changes within themselves and among each other during storage. The cohesiveness values of our samples also followed a fluctuating course like hardness values. Cohesiveness values on the first day were very close to each other in all samples. Although there was no severe decline from the first 15 days at the end of storage, the cohesiveness values of the samples decreased by more than half. While the lowest cohesiveness values were recorded in the control cheeses with brine containing 8% salt, cohesiveness values were among the highest values in cheeses with brine containing 12% salt. The changes in the texture of the cheese during ripening can be explained by the constant breakdown and re-establishment of the protein bonds [32
]. Ghoddushi [33
] reported that the starter culture used in cheese production was active on cohesiveness values. Yerlikaya [34
] in his research on the production of cheese with capers found that the cohesiveness values of the cheese were 0.44–0.68 at the beginning of the storage and 0.15–0.29 at the end of the storage. Şener [24
] found the cohesiveness values of the samples in the range of 0.21–0.56 in the research using transglutaminase enzyme in cheese production. In a study by Cankurt [7
], it was stated that the cohesiveness values of the cheese were in the range of 0.77–0.89. The cohesiveness value in our study was found to be lower than those reported in the literature. It is considered that this can be caused by the high concentration of salt in cheese (Table 7
Chewiness is a not characteristic of cheese that is directly defined, but rather it is calculated using multiple variables [35
]. Hardness, cohesiveness, and springiness values are used in the calculation of chewiness [24
]. The higher the chewiness value of cheese, the more force is needed to chew the sample, and the chewiness value can be expressed as non-chewability (Table 8
It is clear that the stabilizers are significantly useful on the chewiness value. According to the benefits of the first day, the chewiness values of the samples can be said to be close to each other. Although there was an increase in all the examples, there was a continuous decline in both control samples. The control sample showed the highest decline among the cheeses with brine containing 8% salt. The cheeses with the highest mean were the cheeses kept in brine with gelatin. In cheeses with brine containing 12% salt, the lowest value was 112.91 g in cheese samples with brine fortified with 0.50% guar gum, while the highest value was 0.75% in the case of brine with 0.75% guar gum. When all data were examined, no correlation was found between the use of stabilizer and chewiness values except for the continuous decrease of the control sample. When the chewiness values of white cheese were examined, different results were obtained. Şener [24
] investigated the effect of using different enzymes on the texture of cheese and found that chewiness values in the control cheeses were 180 at the beginning of storage and 90 at the end of storage. Cankurt [7
] reported that the chewiness values in the cheese samples with hydrosol fluctuated throughout the storage and showed a significant decline at the end of storage. The chewiness results in our study are similar to results showed by Cankurt [7
Adhesiveness can be defined as a force, which allows the elimination of the force of attraction between food and surfaces such as the palate, tongue, or teeth during the consumption of food [36
]. Adhesiveness values were very close to each other on the first day of storage and followed a fluctuating course according to storage days (Table 9
). No meaningful interpretation and comparison could be made due to this fluctuation.
] stated that the value of adhesiveness in the cheeses produced decreased at the end of the storage. Cankurt [7
] noted that the adhesiveness values of the cheeses produced with hydrosol were between −3.19 and −4.81 g.sn at the beginning of the storage and between −2.70 and −3.36 g.sn at the end of storage.
Gumminess can be expressed as the braking force needed to prepare the semi-solid food for ingestion [35
]. It is also defined as the value found by multiplication of hardness and cohesiveness [34
]. The gumminess values of our samples were close to each other on the first day, like other parameters (Table 10
). In all cheese samples, it was observed that the gumminess value increased from 1 to 15 days and then decreased again. The lowest value in samples with brine containing 8% salt was recorded in the control sample while the highest values were obtained in samples kept in brine with gelatin. Among the cheese samples with brine containing 12% salt, the highest values were also obtained in those in brine with gelatin. Accordingly, the use of gelatin can be considered to increase the gumminess of cheeses. Cankurt [7
], measuring the gumminess value of cheeses produced with hydrosol, reported the highest level of 282.03 g for the control sample and the lowest level of 191.9 g for the cheese sample with garlic hydrosol on the first day, while at the end of storage, the highest value was in the sample with garlic hydrosol as 223.1 g and the lowest value was in the control sample as 107.9 g.
Resilience values were similar to each other on the first day. No serious decline was observed during the first fifteen days, but at the end of storage, the resilience values of the samples decreased by more than half (Table 11
In the samples with brine containing 8% salt, the lowest value was recorded in the control sample, while the highest values were among the samples with brine containing 12% salt. The linear relationship between resilience values and cohesiveness values is remarkable. Similar changes are observed when the values of these two parameters are compared. Cankurt [7
] reported that the resilience values of the cheeses produced with hydrosol increased until the 60th day in general and then decreased again, and that the first day values were between 0.39–0.45 g and the last day between 0.44–0.48 g. When the resilience results of our study are examined, a decline is observed towards the end of storage.
Springiness can be defined as the degree of being able to return to its previous state after the removal of the deformation force applied on an item [24
]. At the end of storage, all of the samples with brine containing 8% salt had a decrease in springiness values. In general, springiness values tended to increase first and then decrease again. On the first day, it was observed that the springiest samples were control samples. At the end of storage, it was the control sample which lost the most springiness among the samples with brine containing 8% salt. Among the samples with brine containing 12% salt, the highest loss was observed in the sample with 1% gelatin (Table 12
There is an inverse correlation between the rate of proteolysis and springiness in cheese during the ripening phase [33
]. In a study by Yerlikaya [34
] on cheese production with capers, the value of springiness was found as 0.87–0.94 on the first day of storage, and it was between 0.80–0.87 at the end of 90 days of storage. Cankurt [7
] reported that the springiness values of the cheeses produced with hydrosol were between 0.92 and 1.
3.4. Sensorial Properties
Samples were scored by an average of 15 panelists during the first day and storage. The panelists evaluated the appearance, texture, taste, and general acceptance of the samples. When the samples were assessed in terms of appearance, they received very close scores on the first day, and there was no statistical difference among them (Table 13
). During storage, there were a constant decline in appearance values. This was because the products softened towards the end of storage.
In general, the samples received high scores for their appearance until the end of storage. However, some cheeses did not comply with this trend. These are the samples with brine containing 8% salt and 0.25% guar gum and the control sample. Samples that were kept in brine containing 12% salt and could not maintain their appearance at a high level were samples with 0.5% guar gum and control samples. In other words, in both cases, the control sample was among the examples that received the lowest score in terms of appearance.
When the texture values are taken into consideration, it is seen that cheeses stored in brine containing 8% salt scored the lower degrees. The real problem was manifested in samples kept in brine with guar and in control sample. In samples kept in brine with guar gum, the scores given to the texture decreased as the gum ratio decreased. In the cheeses with brine containing 12% salt, the lowest score was received by the control sample and after the example with guar gum (Table 14
Taste scores are also parallel to texture scores. The taste of the samples decreased with storage. Again, the lowest scoring problematic samples in terms of taste were the cheese kept in brine with guar gum and the control cheese. The sample kept in brine 3% gelatin received a relatively lower score compared to other samples in terms of taste at the end of one-month storage. Scores given to the samples with brine containing 12% salt were lower. This was because samples were characterized as salty by panelists. Apart from salinity, strange taste and smell were not reported. There was only a slight unfamiliar taste and odor that could not be described in the sample with 3% gelatin (Table 15
When all the sensory characteristics considered as general acceptance were examined the lower values were received by samples with brine containing 8% salt and 0.25% or 0.5% guar gum and control samples. Samples with brine containing 8% and 12% salt received the same score at the end of storage. The most-liked samples were those with gelatin and carrageenan (Table 16