Stability of uvaia (Eugenia pyriformis Cambess) pulp subjected to freezing by static and forced air

Abstract

Uvaia is a highly perishable exotic fruit. The use of preservation techniques is an important strategy to make uvaia pulp consumption and commercialization viable. This study aimed to evaluate the effect of freezing by static air (SA) and forced air (FA) on the physical, chemical and microbiological stability of uvaia (Eugenia pyriformis Cambess) pulp during 12 months of storage. The uvaia pulp exhibited color changes with a tendency to darkening, reduced pH, carotenoids, total phenolics, vitamin C, and antioxidant activity (AA) and increased titratable acidity throughout storage, despite the freezing method, although the soluble solids content was not influenced by any of the factors. Five phenolic and 12 volatile compounds were identified, the majority being gallic and chlorogenic acids, among the phenolics and ethyl and octanol hexanoate, among the volatiles. The method of freezing by FA was more effective than by SA in retaining phenolics, carotenoids, antioxidants and volatile activity, during storage. Good manufacturing practices guaranteed the microbiological quality of the pulp, preserved for 12 months, despite the freezing method. Frozen uvaia pulp can be considered a vehicle of bioactive compounds, with AA, microbiologically safe, even after 12 months of storage.

Practical Applications: The uvaia pulp has a peculiar flavor and aroma and can be used as an alternative raw material to conventional options in different products (yogurts, ice cream, fermented drinks, juices, and jellies). As it is a seasonal and extremely perishable fruit, freezing the pulp is an alternative to prolong the useful life of the uvaia. Qualitative parameters can be affected by the storage time and freezing method applied. Therefore, the evaluation of the influence of these factors on the quality of uvaia pulp is relevant and can be applied in the food industry to maintain the quality of the pulp.