Correlations among quality characteristics of green asparagus affected by the application methods of elevated co2 combined with ma packaging

Abstract

This research investigated the effects of continuous elevated CO2 (20%, (v/v)) application or a 3 day CO2 pretreatment followed by modified atmosphere (MA) or micro-perforated (MP) packaging on the postharvest quality of asparagus. The combination of CO2 pretreatment with MA packaging (Pre-MA) inhibited the yellowing of asparagus and fresh weight loss (FWL), whereas stem firmness slightly increased with all elevated CO2 treatments. CO2 pretreatments increased antioxidant activity in the stem, but not in the tip, in contrast to the continuous flow CO2 (Flow-CO2) treatment. The phenolic and flavonoid contents increased in the elevated CO2 pretreatments and Flow-CO2 treatment. The elevated CO2 treatments, especially Flow-CO2, inhibited the development of microorganisms, and the treated asparagus did not decay. Pre-MA and Flow-CO2 treatments were more effective in maintaining the visual quality and retarding the off-odor of asparagus. Furthermore, significant correlations between sensory quality characteristics and physiological-biochemical attributes were recognized; three principal components were extracted and they explained 86.4% of asparagus characteristics. The results confirmed the importance of visual quality, off-odor, firmness, color parameters, SSC and total phenolic content. In conclusion, elevated CO2 pretreatment followed by MA packaging (Pre-MA) was beneficial for extending asparagus cold storage shelf life, and Flow-CO2 was the best treatment for inhibiting postharvest decay.