Effect of some postharvest treatments on quality of fresh full and cut snap bean pods during cold storage

الملخص EN

Great economic losses to harvested vegetable fruits are raised by postharvest chilling injury during transportation and storage, which can be safety controlled by some polysaccharide materials as chitosan.

The effect of different dipping treatments viz; control (tap water for 5 min.

) and chitosan at 0.5 and 1% for 5 min.

as well as nano chitosan at 25 and 50 ppm for 5 min.

on quality of full and cutting pods of snap bean (Phaseolus vulgaris L.

) cv.

Paulista during cold storage.

So, two experiments were conducted at Agric.

Res.

Farm, El-Kassasien Hort.

Res.

Station, Ismalia Governorate, and Handling Lab.

, Hort.

Dept.

, Fac.

Agric.

, Zagazig University, Egypt during the two autumn consecutive seasons of 2016/ 2017 and 2017/2018.

Pods weight loss (% ), general appearance score, total chlorophyll content (SPAD unit), firmness (g/cm²), total soluble solids (TSS as Brix°), crude fiber (% ), total microbial count (log 10 CFU/g), polyphenol oxidase activity (unit/g as fresh weight), total phenol content (mg/g as fresh weight) and crude protein (% ) of snap bean pods were evaluated at 0, 4, 8, 12 and 16 days of storage at 4°C and 90% relative humidity.

The obtained results referred to that the dipping full pods in the solutions of chitosan at 1% or nano chitosan at 50 and/or 25 ppm presented more effective preservative effect on decreasing weight loss percentage, total soluble solids, crude fiber, total microbial count and polyphenol oxidase activity and maintained pod quality and gave pods with good appearance, total chlorophyll, firmness and total phenolic after 12 days of storage at 4ºC and 90% relative humidity than other treatments or control during different cold storage periods.