Retention of phenolic compounds in Ora-pro-nóbis during storage in different packages

The ora-pro-nóbis (Pereskia aculeata Mill.) is some unconventional food plant rich in nutrients, such as minerals, vitamins and proteins. Its leaves, in addition to bioactive compounds with antioxidant properties, present between 15 to 28% protein content, a high value when compared to leafy vegetable usually consumed in Brazil. Its planting is regionalized and does not occur on a commercial scale, which makes relevant information about the storage conditions of its leaves, aiming at its distribution beyond the place of cultivation. The objective of this study was to evaluate the influence of the packaging on the content of bioactive compounds of ora-pro-nóbis. The leaves were harvested from the “Non-Conventional Vegetable Bank” of EPAMIG in Prudente de Morais / MG, washed, sanitized and dryed. A portion of the leaves were divided into 100 g portions and these were packed in rigid polyethylene (PET) packages (Type 1 packaging), which gave only mechanical protection to the product. Another part was packed in 100 g portions in packages that besides the mechanical protection involved the application of a high barrier plastic film, with hermetic closure in order to avoid gas exchanges between the external and internal means (Type 2 packaging). The packages containing the leaves were stored at 7 ° C ± 2 for 15 days. Samples for evaluations of phenolic compounds, flavonoids and total anthocyanins contents were taken immediately before and at 15 days of storage. Data were submitted to ANOVA in a completely randomized design in the factorial scheme, with 3 replicates ( = 5% - statistical program R). Considering the Type 1 packaging, phenolic content ranged from 0.94 to 1.41 g EAG100 g-1, flavonoids from 80.83 to 95.77 mg100 g-1 and anthocyanins from 13.15 to 10.62 mg100 g-1 fresh sample during storage. Considering Type 2 packaging, phenolic content ranged from 0.94 to 1.51 mg EAG100 g-1, flavonoids from 80.83 to 93.92 mg100 g-1 and anthocyanins from 13.15 to 10.49 mg 100 g-1 fresh sample during storage. However, there was no significant difference between phenolic and total anthocyanin contents of the leaves stored in the different packages at the end of the 15 days of storage, but it was observed that the leaves stored in the Type 2 packages showed a 4% higher retention of Phenolics when compared to the leaves stored in the Type 1 package. It was found that over the storage time the flavonoid contents increased by 15.61% in Type 1 packaging and 13.94% in Type 2 packaging. The total anthocyanins content was significantly reduced for both the leaves stored in Type 1 packaging (19.27%) and those stored in Type 2 packaging (20.23%), but it should be noted that there was no significant influence of packaging on the percentage of retention of anthocyanins under these conditions. Thus, it were concluded that there was little variation between the packages during the storage period, but the Type 2 packaging achieved a better retention of the compound contents in the ora-pro-nóbis leaves during the 15 days of storage.