Effect of temperature abuse and improper atmosphere packaging on volatile profile and quality of rocket leaves

This study aimed to investigate the effect of temperature abuse and improper packaging on volatiles profile, vitamin C and sensorial attributes of rocket leaves packaged in modified atmosphere. Leaves packed in suboptimal conditions (high ratio of product weight/bag surface) were stored for 10 days at 0 and 5 °C, and for 8 days at 15 °C. Rocket leaves were kept in macroperforated bags in order to prevent modification of atmosphere within the headspace (as control). The packed rockets at 0 °C retained ascorbic acid content while it decreased during storage at higher temperatures. The main losses in the appearance and vitamin C content were observed when the O2 level reached about 0 kPa corresponding to the highest CO2 accumulation in the bag (25 kPa). The off-odors from dimethyl sulfide (DMS), dimethyl disulfides (DMDS) and other volatiles were produced at 5° and 15 °C, changing the initial headspace fingerprint, which was best preserved at 0 °C. Results of this work showed that improper packaging condition may decrease the shelf-life of rocket leaves compared to storage in air, inducing loss of appearance score, the production of off-odors and the degradation of Vitamin C. No additional benefit was obtained by optimal gas composition when bags were stored at 0 °C, indicating that the use of low temperature was effective to slowing down degradation reactions.