Firmness and Decay of Apples following Postharvest Pressure Infiltration of Calcium and Heat Treatment

Abstract

<jats:p>Heating `Golden Delicious' apples (Malus <jats:italic>domestica</jats:italic> Borkh.) for 4 days at 38C or pressure-infiltrating them with a 4% CaCl<jats:sub>2</jats:sub> solution reduced decay and maintained fruit firmness during 6 months of storage at 0C. Heating reduced decay caused by <jats:italic>Penicillium expansum</jats:italic> Link ex Thorn by ≈30%, while pressure infiltration with CaCl<jats:sub>2</jats:sub> reduced decay by &gt;60%. Pressure infiltration with CaCl<jats:sub>2</jats:sub> after heating reduced decay by ≈40%. Pressure infiltration maintained firmness best (&gt;84 N), as measured with a manually driven electronic fruit-firmness probe, followed by heat and CaCl<jats:sub>2</jats:sub> (76 N), heat alone (71 N), and no treatment (control) (60 N). Force vs. deformation (FD) curves from a puncture test with a fruit-firmness probe mounted in a universal testing machine showed that fruit heated before storage were firmer than all nonheated fruit, except those pressure-infiltrated with 4% CaCl<jats:sub>2</jats:sub>. However, FD curves also showed that apples pressure-infiltrated with 4% CaCl<jats:sub>2</jats:sub> differed quantitatively from apples in all other treatments, including those heated.</jats:p>

Impact of harvesting time and fruit firmness on the tolerance to fungal storage diseases in an apple germplasm collection

“…However, cultivars with a high tolerance to storage diseases thus appear to have not only above-average firmness at harvest but also less softening during storage. The positive effect of higher firmness (due to calcium infiltration) on fungal decay has already been well studied, indicating that improvement of fruit firmness can improve storability in several ways (Conway et al, 1991;Sams et al, 1993).…”

“…So far, no major genes providing resistance against the storage diseases have been identified but quantitatively inherited traits associated with chemical contents, fruit texture, structure of the fruit epidermis and ripening behavior may affect the ability of different cultivars to withstand fungal attacks (Prusky et al, 2004;Blazek et al, 2007;Nybom et al, 2008;Johnston et al, 2009). Positive effects of increased firmness and less softening due to calcium spraying, have been documented in a series of pre-and postharvest treatments of apple fruit, indicating that fungal decay caused by P. expansum, Botrytis cinerea and Glomerella cingulata can be significantly reduced (Conway et al, 1991;Sams et al, 1993;Conway et al, 2002).…”

Differential expression of calcium/calmodulin‐regulated SlSRs in response to abiotic and biotic stresses in tomato fruit

“…Calcium is most frequently associated with stress tolerance, fruit firmness, ripening and senescence (Shear , Poovaiah , Martin‐Diana et al ). Pre‐ and Postharvest calcium treatments maintain fruit firmness and prevent decay in both climacteric and nonclimacteric fruits (Poovaiah and Shekhar , Conway and Sams , Abbott et al , Sams et al , Saftner et al , Saftner et al , Park et al , Ritenour et al ). Calcium is directly and integrally involved in texture changes and in maintaining fruit quality (Raese and Drake , Raese and Drake ).…”

Prestorage heat treatment reduces pathogenicity of Penicillium expansum in apple fruit

“…A synergistic effect was observed when heated fruit were dipped in CaCl 2 solutions prior to storage (Klein & Lurie, 1994). Sams et al (1993) reported that heating 'Golden Delicious' apples for 4 days at 388C and then infiltrating them with calcium reduced decay caused by P. expansum by 30% and maintained fruit firmness during 6 months storage at 08C. The response of apples to heat treatments may vary according to cultivar, as 'Golden Delicious' and 'Delicious' showed relatively strong tolerance heat (Kim et al, 1993).…”