# Cellulose as a Delivery System of Raspberry Juice Volatiles and Their Stability
## 2 Results
### Evaluation of Volatiles
Ethylhexanoic acid that was not found in the samples prepared by 60 min complexation, and the highest amount of nonanoic acid was seen in the samples prepared for 15 min with 5% of cellulose (8.12 \(\mathrm{\SIUnitSymbolMicro g}\)/kg). Two esters, methyl dihydrojasmonate and hexyl salicate, were also identified on the complexes. Methyl dihydrojasmonate was evaluated in higher amounts after 15 min of complexation while for hexyl salicate, better results were achieved with prolonged complexation. The stability of the obtained complexes was also evaluated during 12 months of storage. The amount of cellulose highly affected the retention of volatiles during storage. During storage (Figures 1 and 2), lower amounts of specific chemical groups were observed in cellulose/raspberry complexes but the tendency was same as after preparation, i.e., terpenes were the most abundant class of volatile compounds, followed by aldehydes and alcohols. Even if terpenes were not found in the highest amount in complexes prepared with 10% of cellulose, their retention during storage was the highest in those complexes indicating their stability. Detailed results of individual volatiles in cellulose/raspberry complexes are given in Table 3.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Compounds** & **2.5\%** & \multicolumn{2}{c}{**5\%**} & \multicolumn{2}{c}{**7.5\%**} & \multicolumn{2}{c}{**10\%**} \\ \hline
**Time of Compeleration** & **15** & **60** & **15** & **60** & **15** & **60** & **15** & **60** \\ \hline
**  
Only 2-hexenal, the volatile with the lowest molecular weight, was completely lost during the storage in all complexes. Liliial was completely lost in the complexes prepared for 15 min, while in the complexes prepared by prolonged complexation this compound was quite stable. Ethyl hexanoic acids had the reverse behavior of liliial, as it was completely lost in complexes prepared by prolonged complexation and stable in complexes prepared by 15 min complexation. Also, 1-phenylethananone was completely lost during storage conditions in the samples prepared for 60 min and it was retained only in the complex with 2.5% of cellulose prepared by 15 min of complexation. There are variations in the retention of esters, alcohols, acids, ketones but it is quite possible that transformation reactions occurred during storage, thus changes of the ratios of these compounds is possible. For example, benzaldehyde was evaluated in much higher amounts, while the amount of ethyl benzaldehyde decreased throughout storage so it is possible that degradation of the latter compound occurred, resulting in the formation of benzaldehyde. Generally, terpen are known for their very pleasant flavor notes responsible for the complete flavor profiles of fruits and they are quite desirable compounds. In all complexes regardless of complexation time, an overall higher retention of this volatile group was achieved with the addition of 7.5% and 10% of cellulose during complexation. From the results, it can be observed that preparation conditions (complexation time and cellulose amount) highly influenced the adsorption of volatiles and different ratio of volatiles were achieved. This ratio of volatiles that was achieved after preparation of complexes also affects stability of the compounds, i.e., losses during storage. Berry flavor (\(\alpha\)-ionol, \(\alpha\)-ionone, \(\beta\)-ionone, dihydro-\(\beta\)-ionone) note was the dominant one in raspberry juice (40% of overall flavor), followed by citrus and woody notes (each around 18% of the overall flavor) and floral, fruity and green (each around 8% of the overall flavor). Even though, cellulose/raspberry complexes had different flavor note profiles, the berry flavor note was still the dominant one in all complexes but its contribution to the complete flavor profile was lower.