Abstract:
In order to study effects of
γ-aminobutyric acid(GABA)treatment on the storage quality and physiological characteristics of post-harvested okra at room temperature,the okra was treated with different concentrations(5,10,15 mmol/L)of GABA for 3 min and then was stored at room temperature(25℃),and water treatment group was used as a control. All physiological indexes such as weight loss rate,chlorophyll,V
C and malondialdehyde content and antioxidant enzyme activity were regularly determined. The results showed that 10 mmol/L GABA treatment showed the best preserving effects,which could significantly reduce the post-harvest water loss of okra,delay the degradation of chlorophyll and V
C,significantly increase catalase(CAT)activity and superoxide dismutase(SOD)activity,decrease peroxidase(POD)activity and accumulation of malondialdehyde(MDA). Chlorophyll content at 21 d was 37.49% higher than that of the control group(0.074 mg/g),V
C content was 69.23% higher than that of the control group(3.61 mg/100 g)and SOD activity was 30.35% higher than that of the control group(47.05 U/g). Correlation and principal component analysis(PCA)showed that weight loss rate and MDA were positively correlated with storage time of okra(
P<0.01),while chlorophyll content,V
C content,POD activity and CAT activity were negatively correlated with storage time(
P<0.01). The storage quality and comprehensive evaluation index of okra decreased gradually with storage time,different concentration of GABA treatment could delay the decline of okra storage quality. The results suggest that appropriate concentration of GABA treatment can delay the postharvest senescence of okra pod and maintain the good postharvest quality and nutritional value of okra,which provides a new theoretical basis for the application of GABA and post-harvest preservation of okra.