ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Heat treatments delay ripening and postharvest decay of strawberry fruit.

Civello, P. M.; Martinez, G. A.; Chaves, A. R.; Anon, M. C.;

Journal of Agricultural and Food Chemistry Year: 1997 Vol: 45 Issue: 12 Pages: 4589-4594 Ref: 28 ref.

1997

บทคัดย่อ

Fully red strawberry (cv. Selva) fruits were treated for 1-5 h at 39-50 deg C. After treatment, fruits were placed at 0 deg overnight and held at 20 deg for 3 days. Most of the heat treatments improved shelf life, with best results obtained for fruits heated at 42 or 48 deg for 3 h. Heat treatments prevented fungal development and decreased the number of damaged fruits. The effects of these treatments on fruits which were 50-75% red on firmness, surface colour, anthocyanin content, phenylalanine ammonia-lyase (PAL) activity, polypeptide composition and protein synthesis were investigated. Softening rate and external colour development was less in fruits heated at 48 deg compared with the control, while treatment at 42 deg did not significantly affect these parameters. However, both treatments reduced anthocyanin accumulation and PAL activity relative to the controls. Treatment at 48 deg for 3 h reduced protein synthesis, but this effect was partially reversed after holding fruits at 20 deg for 4

8 h. Heat treatments (42 and 48 deg ) led to the accumulation of 5 heat shock proteins (88, 76.5, 69, 19 and 17 kDa). In addition, treatment at 42 deg induced the synthesis of a 22-kDa polypeptide that was not observed in the 48 deg treatment. Fruits treated at 48 deg continued the synthesis of 69-, 19- and 17-kDa polypeptides even after 48 h at 20 deg . The lower fungal development and slower ripening shown by heat-treated fruits suggested that this physical method could be useful to extend shelf life.