Abstract: In order to explore the impact of precooling time on their quality and physio-biochemical characteristics, freshly harvested common bean (Phaseolus vulgaris L.) and cowpea (Vigna sinensis) were placed at room temperature ((20.5 ± 4.5) ℃) with a relative humidity of 72% for 0, 6 and 12 h, respectively, and precooled to 9.0 ℃ before 15 d controlled atmosphere storage (gas composition: 3% O2 + 1% CO2 + 96% N2, temperature: (9.0 ± 0.5) ℃, humidity: (80 ± 5)%) followed by 2 d stimulated shelf life at room temperature (temperature: (24.5 ± 4.5) ℃; humidity: (65 ± 2)%). Samples were collected for quality and physio-biochemical analysis after controlled atmosphere storage and shelf life. Results showed that compared with those precooled after 6 and 12 h at room temperature, P. vulgaris L. and V. sinensis precooled immediately after harvest possessed higher sensory evaluation score and higher contents of reducing sugar and chlorophyll as well as lower mass loss rate, respiration intensity, spot index and cellulose content after controlled atmosphere storage and shelf life. Meanwhile, immediate precooling maintained high activities of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) and cellulose (CEL), and low levels of respiration intensity (RI), superoxide anion (O2－·) production rate, hydrogen peroxide (H2O2) and malondialdehyde (MDA). Therefore, immediate precooling could delay the senescence of P. vulgaris L. and V. sinensis during controlled atmosphere storage and shelf life and maintain high quality by improving antioxidant status and reducing oxidative stress.

Key words: Phaseolus vulgaris L., Vigna sinensis, precooling time, quality, physio-biochemical characteristics