Benzyl-aminopurine (BAP) treatments delay wall degradation and softening, improving quality maintenance of refrigerated summer squash.

MASSOLO JF; LEMOINE ML; CHAVES AR; CONCELLON A; VICENTE AR

POSTHARVEST BIOLOGY AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 93 p. 122 - 129

0925-5214

Round summer squashes are harvested before reaching full maturity and even though they are highly perishable, fruit postharvest handling is mostly based in storage at non-chilling temperatures. Finding complementary treatments minimizing deterioration and reducing postharvest losses would be extremely useful. In this work we evaluated the effect of postharvest cytokinin (CK) treatments on refrigerated round soft rind squashes. Fruit was harvested at commercial maturity and sprayed with 1 mmol L-1 benzylaminopurine (BAP) or water (control) prior to storage at 5 °C for 0, 13 or 25 days. Quality was assessed upon removal from cold storage as well as after a 2-day shelf life period at 20 ºC. CK-treated fruit showed lower deterioration and dehydration remaining firmer than the control. Instead, BAP sprays did not affect color, respiration or sugar-acid balance. The treatments prevented phenolic compounds accumulation decreased pectin solubilization. By the end of the storage period BAP-treated squashes had higher levels (45%) of tightly-bound polyuronides than untreated controls, indicating a substantial delay in cell wall dismantling. CK sprays also reduced pectin side chain removal but caused no changes were found in the cross-linking glycans or cellulose. To our knowledge this is the first work showing that CK can regulate pectin disassembly in developing fruits. Postharvest BAP sprays preventing texture deterioration may be a simple treatment to complement refrigeration of round, soft rind, summer squashes.