Analyses of microstructure and cell wall polysaccharides of flesh tissues provide insights into cultivar difference in mealy patterns developed in apple fruit. (15th August 2020)

• Record Type: Journal Article
• Authors: Li, Qianqian; Xu, Ranran; Fang, Qiong; Yuan, Yang; Cao, Jiankang; Jiang, Weibo
• Is Part Of: Food chemistry. Volume 321(2020)
• Publication Date: 2020-08-15
• Subjects: ATR attenuated total reflection -- CDTA cyclohexanetrans-1, 2-diamine tetra-acetic acid -- CSP chelator-soluble pectin -- CWM cell wall material -- FTIR Fourier transform infrared -- FWHM full width at half maximum -- GalA d-galacturonic acid -- HG homogalacturonan -- LF-NMR low-field nuclear magnetic resonance -- LHC loosely-bonding hemicellulose -- PCA principal component analysis -- RG rhamnogalacturonan -- SEM scanning electron microscopy -- SSP sodium carbonate-soluble pectin -- T2 transverse relaxation time -- THC tightly-bonding hemicellulose -- WSP water-soluble pectin -- XRD X-ray diffraction; Pectin (PubChem CID: 441476) -- α-d-Galacturonic acid (PubChem CID: 445929); Apple fruit -- Mealiness -- Cell wall polysaccharide -- Pectin -- Hemicellulose -- Low-field nuclear magnetic resonance; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2020.126707
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Four patterns of mealiness involving five apple cultivars were identified. Parenchyma cells of mealy apples became detached and remained intact. The crystalline micelles in CWM increased in the rapid and moderate mealy apples. Heavy loss of CWM and its water-insoluble fractions were related to the mealiness. The loosening of hemicellulose was prompted during mealiness progress. Abstract: Mealiness is one of the most important textural failure of apple fruit and four patterns of mealiness involving five apple cultivars were identified as the rapid, moderate, slow and none, requiring 3, 7, 14, 49 days at 25 °C, respectively. In comparison with the non-mealy 'Fuji' apple, parenchyma cells of mealy apples became detached and remained intact. Highly methyl-esterified homogalacturonan was strongly immunolabeled in the cell wall of slow and non-mealy apples. The mobility of water was enhanced in the cell wall during mealiness. Principal components analysis of FTIR spectra discriminated the cell wall materials (CWM) based on the mealiness progress. Heavy loss of CWM and its water-insoluble fractions but limited increase of water-soluble fractions, and the increase of crystalline micelles of CWM were closely associated with the mealiness progress. Overall, the occurrence of mealiness might attribute to structural, physical and biochemical modifications of CWM during tissue senescence.