Investigation of Bioactivity Degradation During Storage of Sour Cherry (Prunus cerasus L.) Peel Extract

Limited number of researches in the literature have been reported to examine degradation stability by regression methods. Monitoring storage stability of plant extracts containing phytochemicals has become a special field.

This study aims to develop model equations to examine the stability of total phenolic material (TPM) and total anthocyanin (TA) in the sour cherry peel extract under several conditions, such as keeping the samples in a freezer (-20°C), refrigerator (4°C) and room temperature (25°C) conditions. In addition, two types of ambient conditions (under dark and light, respectively) were applied to observe the effect of sunlight on oxidation.

The storage stability was monitored in terms of TPM and TA. 8 different polynomial regression equations were produced for the data obtained under each condition in order to define the deterioration of the TPM and TA during 60 days of the storage.

Keeping the samples in the light at ambient conditions was the least efficient for stability (~10 days), while the shelf life of the product could have been quite long with the storage in the freezer after opening the package of the product.

The most suitable condition for both TPM and TA has been determined as -20°C with the calculation of degradation days as 157 and 115 (R^2 = 0.9874 / 0.9265, and average error rates = 0.207097% / 0.119541%).