## 2 Results and Discussion
### Volatiles Composition and Sensory Evaluation  
The composition of headspace volatile compounds that were identified using HS-SPME/GC-MS in the initial (NFP) and fermented pomegranate (FP) beverage at 0 and 24 h of fermentation as well as at the first and the last (fourth) week of storage are presented in Table 1. Statistical analysis was employed between the normalized peak area % of each volatile of NFP and FP for each time period of fermentation or storage. A total of 51 different volatile compounds were identified using HS-SPME/GC-MS. Specifically, the produced pomegranate beverages contained 11 alcohols, 11 aldehydes, 11 ketones, 10 esters, 7 terpenoids, and furfural that varied between samples. The identified volatile compoundswere verified by the literature as they have also been detected by previous studies in fresh or concentrated pomergnate beverages, pomergnate fruit/seeds, fermented pomergnate beverages through lactic acid fermentation, and other fruits (apples, berries, plums, citrus, exotic fruit, etc.) or fruit beverages [13; 15; 16; 17; 18; 19; 20; 21; 22; 23]. The groups of volatile compounds that were mainly affected by the fermentation process and storage time were aldehydes, ketones, alcohols, and esters. Specifically, at the first, and more obviously at the fourth week, of pomergnate beverage storage the differences are very significant statistically. At these periods of storage, the volatile composition of NFP decreased significantly regarding the levels of alcohols, ketones, and esters. It is noteworthy that at the first week of storage NFP contained 11 aldehydes in a percentage of 52.5%, while at the fourth week of storage contained 10 aldehydes in a percentage of 59%. In the contrary, at the same time, FP contained less aldehydes (five aldehydes in a percentage of 6.7% at the first week, while at the fourth week of storage contained six aldehydes in a percentage of 13%). This finding was very interesting since it has been noted that aldehydes cause off flavors and are non-desirable compounds in pomergnate beverages [13; 24]. In addition, high proportions of aldehydes in pomergnate beverage are not acceptable from the consumers [25]. Regarding the composition of ketones, NFP contained 10 ketones (4.8%) at the first week of storage and 4 (1.1%) at the fourth week of storage, while FP contained 11 ketones (12.3%) at the first week of storage and 9 (16.4%) at the fourth week of storage. This outcome is extra evidence of FP distinction over NFP because it has been demonstrated that in general ketones can deliver several positive sensory/aroma attributes [26]. Likewise, fermentation of the pomergnate beverage through _Lactobacillus paracasei_ K5 certainly enhanced the aromatic profile of the pomergnate beverage through the production of desirable volatile compounds. This outcome is in accordance with other investigations proving that lactic acid fermentation enhances the volatile composition of the pomergnate beverage [13; 14]. Regarding furan products, furfural was identified. Furfural is related with unpleasant coffee-like aromas [27] and was also affected by lactic acid fermentation since it had almost disappeared in the case of FP after the 24 h of fermentation and during storage, which is in accordance with other investigations [14]. Regarding the composition of esters, NFP contained 3 esters (1.7%) at the first week of storage and 2 esters (1.9%) at the fourth week of storage, while FP contained 10 esters (7.1%) at the first week of storage and 8 esters (7.2%) at the fourth week. This result shows also that lactic acid fermentation positively affected the flavor of the pomergnate beverage because esters play an important role in contributing to fruity notes of fruit juices [28]. Respectable amounts of esters also may be produced by fermentation processes depending on the availability of the alcohol precursors [28]. Finally, respectable amounts of terpen were found in both NFP and FP (Table 1).