Effects of Controlled Atmosphere and 1-MCP Treatment on Quality of Yuhuangli Plum During Refrigeration

This study aimed to investigate the effects of 1-methylcyclopropene (1-MCP) and controlled atmosphere (CA) storage on the preservation and internal quality of YuHuangli plums, to identify the optimal storage strategies, so as to provide the theoretical and technical references for industrial-scale storage.

YuHuangli plums were subjected to four storage treatments: 1.0 μL·L^-1 1-MCP, CA storage with 3% O₂ + 1% CO₂, CA storage with 3% O₂ + 5% CO₂, and normal cold storage as a control (CK). Fruit samples were analyzed at 0, 30, 60, and 90 days of storage. External and internal quality indices—including peel color, texture, sugar-acid composition, respiration intensity, and aroma-were measured using a colorimeter, texture analyzer, gas chromatograph, high-performance liquid chromatograph, and gas chromatography–mass spectrometer.

Compared with CK, both 1-MCP and CA treatments delayed the decline in fruit firmness and titratable acidity, maintained higher levels of soluble solids, vitamin C, and polyphenols, reduced respiration rates, and slowed the reduction of cohesiveness, springiness, gumminess, chewiness, rupture force, rupture deformation, yield force, and yield deformation, thus better preserving fruit texture. Both treatments also partially inhibited the degradation of sugar-acid components, with acidity being better maintained after 60 days. Peel color parameters (L*, a*, b*, and C*) declined during storage, with the fastest decrease under CK, followed by 3% O₂ + 5% CO₂, then 3% O₂ + 1% CO₂, and the slowest under 1-MCP treatment, significantly suppressing browning and darkening (P < 0.05). After 60 days, 1-MCP exhibited the most pronounced preservation effect, followed by 3% O₂ + 1% CO₂ and 3% O₂ + 5% CO₂, while CK showed the greatest quality deterioration. At this stage, the flavor profile of YuHuangli plum was dominated by aldehydes, alcohols, and esters, with trans-2-hexenal and hexanal accounting for about 84% of the total relative content. Over time, the relative content of aldehydes and alcohols decreased in the 1-MCP and CA groups, whereas esters increased.

Both 1-MCP (1.0 μL·L^-1) and CA storage (3% O₂ + 1% CO₂) effectively preserved the quality of ‘YuHuangli’ plums during cold storage. Among them, 1-MCP provided the most comprehensive maintenance of overall fruit quality—including texture, color, and flavor—with the optimal preservation observed after 60 days.