Effects of Storage on the Quality Characteristics of Psidium cattleyanum

Abstract

Background: Psidium cattleyanum, commonly known as strawberry guava, is a tropical fruit native to Brazil and widely appreciated for its aromatic flavor, vibrant red or yellow skin and high nutritional value, including rich contents of vitamin C, antioxidants and dietary fiber. However, as a climacteric fruit with high metabolic activity, it undergoes rapid postharvest deterioration, leading to significant losses in quality attributes such as firmness, color and bioactive compounds during storage. In tropical and subtropical regions where strawberry guava is cultivated, inadequate storage practices exacerbate food waste, impacting economic viability and nutritional availability. Understanding the effects of different storage conditions on its physicochemical and biochemical properties is crucial for extending shelf life and maintaining market quality.

Objective: The primary objective of this study was to evaluate the impact of various storage conditions on the quality characteristics of Psidium cattleyanum fruits, focusing on physicochemical parameters like weight loss, firmness, Total Soluble Solids (TSS), Titratable Acidity (TA) and pH, as well as biochemical attributes including Total Phenolic Content (TPC) and antioxidant activity. By simulating common postharvest storage scenarios, the research aimed to identify optimal conditions that minimize deterioration and preserve the fruit's sensory and nutritional profile.

Materials and Methods: Mature red Psidium cattleyanum fruits were harvested from a commercial orchard in a subtropical region and divided into three storage treatments: Ambient temperature (25±2°C, 60-70% relative humidity), refrigerated storage (10±1°C, 85-90% RH) and modified atmosphere packaging (MAP) in low-density polyethylene bags at 10±1°C. Samples were analyzed at 0, 7, 14 and 21 days for weight loss, firmness using a texture analyzer, TSS and TA via standard refractometry and titration methods, pH with a digital meter, TPC by Folin-Ciocalteu assay and antioxidant activity using DPPH radical scavenging assay. Data were subjected to one-way ANOVA followed by Tukey's post-hoc test at p<0.05 significance level.

Results: Storage under refrigeration and MAP significantly reduced weight loss to 5.2 and 4.1%, respectively after 21 days, compared to 12.3% at ambient temperature. Firmness retention was highest in MAP-stored fruits (18.5 N at day 21) versus 12.1 N in refrigerated and 8.4 N in ambient samples. TSS increased gradually across all treatments, reaching 14.2°Brix in MAP, while TA decreased from 0.45% to 0.32% under optimal conditions. TPC and antioxidant activity declined least in MAP (from 25.6 mg GAE/100 g to 20.1 mg GAE/100g and 78-62% inhibition, respectively), highlighting the protective role of controlled atmospheres.

Conclusion: The findings demonstrate that MAP combined with refrigeration effectively preserves the quality characteristics of Psidium cattleyanum, extending shelf life up to 21 days with minimal losses in physicochemical and biochemical attributes. These results underscore the potential of simple, low-cost storage interventions to reduce postharvest waste and enhance the fruit's commercial value, recommending their adoption in supply chains for tropical fruits.