Acta Agriculturae Zhejiangensis ›› 2022, Vol. 34 ›› Issue (7): 1529-1536.DOI: 10.3969/j.issn.1004-1524.2022.07.21

• Quality and Safety of Agricultural Products • Previous Articles     Next Articles

Effect of malonic acid treatment on postharvest storage quality of cowpea

GUO Xuesong1(), TIAN Libo1, SHANG Sang2,*()   

  1. 1. The Key Laboratory of Tropical Horticultural Crop Quality Regulation of Hainan Province, School of Horticulture, Hainan University, Haikou 570228, China
    2. School of Life Sciences, Hainan University, Haikou 570228, China
  • Received:2020-11-24 Online:2022-07-25 Published:2022-07-26
  • Contact: SHANG Sang

Abstract:

The physiological and biochemical indexes of cowpea treated with malonic acid concentration of 100, 200, 300 and 400 mg·L-1 were studied during storage at (8±2) ℃ with fresh cowpea as experimental material. The results showed that after 12 days of storage, the rust spot index of cowpea treated with malonic acid was significantly lower than that of the control, the effect of cowpea treated with 200, 300 mg·L-1 malonic acid were the best; the weight loss rate of cowpea treated with malonic acid was always lower than that of the control and 300 mg·L-1 malonic acid treatment was significantly lower than that of the control; on the 9th day of storage, the soluble protein content of pods and beans treated with malonic acid was always higher than that of the control. On the 12th day of storage, the soluble protein content of pods treated with 300 mg·L-1 malonic acid was the highest, 68.49% higher than that of the control and the soluble protein content was 6.42% higher than that of the control; the contents of chlorophyll and vitamin C of cowpea decreased during storage, in 300 mg·L-1 malonic acid treatment group were always higher than those in the control group. Soluble sugar content of cowpea pods and beans decreased rapidly during storage, the soluble sugar content of pods treated with 200 and 300 mg·L-1 malonic acid was always higher than that of the control. The cellulose content in cowpea showed an increasing trend, and the cellulose content in cowpea treated with 300 mg· L-1 malonic acid was significantly lower than that in the control group. The activity of polyphenol oxidase (PPO) in cowpea increased, but the PPO activity in malonic acid treatment was always lower than that in the control during storage. The peroxidase (POD) activity of all treatments reached the peak on the 6th day and then decreased. The changes of POD activity were stable in 300 and 400 mg·L-1 malonic acid treatment during storage. Different concentrations of malonic acid could inhibit the increase of cowpea rust index, delay the increase of weight loss rate, cellulose content, PPO activity and the decrease of chlorophyll, soluble sugar and soluble protein contents, and maintain a high level of POD activity to eliminate free radicals, so as to maintain the quality of cowpea after harvest, further improve the postharvest fresh-keeping effect of cowpea. The results showed that 300 mg·L-1 malonic acid had the best effect on the preservation of cowpea.

Key words: malonic acid, cowpea, preservation effect

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