Quality variables of "hass" avocado stored in modified atmosphere packaging

Modified atmosphere packaging (MAP) and refrigeration of fruits and vegetables are used to extend their shelf life. The hypothesis of this study is that quality attributes of avocados stored in MAP at 8 degrees C can be preserved for a longer period, compared to room temperature (RT) or refrigeration (REF) storage; however, during post-storage ripening (PSR), these quality variables approach those of refrigeration or room temperature in a brief time. The objective of this research was to evaluate quality variables in avocado (Persea americana Mill.) cv. "Hass" during storage in MAP at 8 degrees C and PSR at 21 degrees C and contrast them to those obtained during storage at RT or REF. Fruits at physiological maturity and MAP bags were used. A completely randomized design was used; factors were type of storage (RT 21 degrees C, REF 8 degrees C, and MAP 8 degrees C), storage time (0, 8, 16, 24, and 32 d), and PSR time at 21 degrees C (0, 2, 4, and 6 d). Quality variables were firmness (penetration force), total colour difference (Delta E) in exocarp and mesocarp (colorimeter), pH (potentiometry), and total soluble solids (TSS, refractometry). Avocados stored in MAP retained firmness, which was higher compared to REF and RT during the storage period. Firmness retention for avocados at RT, REF, and MAP, at day 16, was 5.7, 32.6, and 87.2 %, and at day 32, it was 0 (no reading), 9.5, and 78.2 %, respectively. Total colour difference in exocarp and mesocarp, pH, and TSS ranged from 3.8 to 25.6, 3.2 to 20.3, 6.7 to 7.1, and 5.3 to 7.7 degrees Brix, respectively. During the storage period, fruits stored at MAP showed a firmness, Delta E of exocarp and mesocarp similar to those of fresh fruit. Type of storage showed no effect on pH and TSS, during the storage period. Modified atmosphere at 8 degrees C allows to extend the shelf life of "Hass" avocado for a period twice as long as that at room temperature, based on the changes in firmness and colour are reduced, properties that are important quality benchmarks.