# Effect of Processing on Volatile Organic Compounds Formation of Meat--Review
## 3 Non-Thermal Processing
### Packging and Storage  
Packaging and storage parameters may impact the quality of meat. Packaging systems such as active packaging [35; 36], MAP and vacuum packaging [37] may provide alternatives to air-packed meat by improving their sensory quality. Another primary parameter which can compound the meat quality is storage time. The impact of prolonged storage time and different packaging methods was also examined in different studies [38; 39]. [PERSON] et al. [37] focused on the impact of different systems of packaging on the formation of VOCs in raw beef over time. Three packaged sirloin steaks with the same best before date were bought in a local supermarket. The packaging systems were MAP containing 80% O\({}_{2}\) and 20% CO\({}_{2}\), vacuum packaging, and cling-wrapped packaging. The SPME method was used for extraction of VOCs and GC coupled with accurate mass quadrupole time-of-flight mass spectrometry, with helium as the carrier gas used for volatiles analysis. Retention index and mass accuracy from libraries were used for identification. Thirty-five VOCs were identified. Three VOCs were common to all packaging systems and five were present in at least two packaging systems. This work showed that many compounds which were assumed to be generated by thermal processes are also obtained from a specific packaging system of raw beef without application of heat treatment. It was also stated that some of the VOCs which were detected in the research are meat spoilage indicators and give information about the freshness of packaged meat. The objective of the study [38] was to analyze the performance of hyperbaric storage (HS) to preserve meat at two different conditions for 60 days of storage. Raw pork in pieces and raw minced bovine meat was analyzed. The conditions used for HS were 60 MPa/10 \({}^{\circ}\)C and 75 MPa/25 \({}^{\circ}\)C. Refrigeration was used as the control method. HS-SPME was used for extraction and GCMS with helium as carrier gas was used for volatiles determination. Identification was based on a mass spectra database and individual standards. Seven aldehydes, six alcohols, and two ketones were present in both meat samples. Significant changes were observed throughout storage for volatile compounds. It was concluded that 60 MPa/10 \({}^{\circ}\)C hyperbaric storage up to 60 days characterized high potential for raw meat preservation, as it showed better preservation compared to refrigeration. The objective of the research [39] was to compare the evaluation of VOCs in beef meat under vacuum and air packaging. Fresh beef tenderloin samples were stored for 11 and 21 days at 4 \({}^{\circ}\)C. Extraction was conducted using carboxen/polydimethylsiloxane fiber and, for analysis, GC coupled with a time-of-flight mass spectrometer was used. The volatiles were identified by comparing their mass spectra with those available in libraries. The results showed that VOCs in air-stored samples were more diverse compared with those in vacuum-packaged samples. The amount of volatile compounds in beef stored in air conditions gradually increased during the storage. The highest amounts were mostly produced between 9 and 11 days of storage. For vacuum packaging, the amount of VOCs remained stable, with the highest increase occurring between 11 and 21 days. It was stated that most of the identified volatiles were previously associated with beef spoilage. The results of this study indicated that some of the microbial volatile compounds' metabolites could be used as spoilage indicators, but further study is required in order to determine the permissible values of volatiles used as indicators. In one study [36], active packaging with the use of olive leaf extract, high-pressure processing (HPP), and its combination was studied. The effect on volatiles of dry-cured meat during storage was evaluated. Four treatments were analyzed; all of them were vacuum packaged (VP).