Physiological Changes Associated with Development of Mealiness of Apple Fruit during Cool Storage

Abstract

<jats:p>The relationships between cellular characteristics of cortical tissue from `Braeburn' apple fruit <jats:italic>(Malus domestica</jats:italic> Borkh.) that had been harvested at two maturities and changes in texture that occurred during storage at 0C were studied. Tensile tests were used to measure adhesion between neighboring cells, and turgor pressure was manipulated to determine the pressures required to burst cells. Apples of advanced maturity became mealy during cool storage, while those of less advanced maturity did not. Mealiness was associated with low adhesion between neighboring cells, and a relatively high resistance to cell rupture.</jats:p>

Analysis of the dynamic mechanical properties of apple tissue and relationships with the intracellular water status, gas distribution, histological properties and chemical composition

“…The Young's modulus and the storage modulus for all cultivars decreased with storage time as previously measured by Small Amplitude Oscillatory Shear on Granny Smith and Golden Delicious cultivars (Costa et al, 2012;Varela et al, 2007). Moreover, previous studies reported a decrease in firmness measured by sensory analysis (Gwanpua et al, 2014;Harker and Hallett, 1992;Johnston et al, 2002). The damping factor (tan d) was significantly higher for EC (Table 1B, statistics group c) than for other fruits (Table 1B, modulus, variations in the damping factor were not significant over the three months' storage.…”

Down-regulation of POLYGALACTURONASE1 alters firmness, tensile strength and water loss in apple (Malus x domestica) fruit

“…Sensory studies have shown that upon biting and chewing, the primary walls of apple fruit rupture and the cellular juices are released, resulting in juiciness [41]. The link between sensory juiciness and free fluid in pulled-apart sections in apple has been correlated with differences in pectin composition of which the most notable is a reduced galacturonic acid content in the water-soluble pectin fraction [42].…”

Multifractal properties of pore-size distribution in apple tissue using X-ray imaging

“…Therefore, the characterization of these intercellular air spaces and distribution based on microstructural properties is important for agricultural applications since this may improve our understanding of fruit physiology and postharvest quality of the fruit during preservation. Fruit with greater porosity have been shown to be softer (Volz et al, 2004;Yearsley et al, 1997a,b), or more mealy (Harker and Hallet, 1992;Tu et al, 1996) and to have greater internal gas diffusion rates Rajapakse et al, 1990). Furthermore, the volume of these intercellular air spaces continues to increase during storage, and therefore, its measurement can be used to define the age of the fruit and also to characterize the effect of different storage conditions on its quality (Harker et al, 1999;Khan and Vincent, 1990;Tu et al, 1996).…”