Biochemistry of Fruits

Paliyath, Gopinadhan; Murr, Dennis P.

doi:10.1002/9780470277577.ch21

Cited by 22 publications

(24 citation statements)

References 41 publications

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“…Fruit maturation is a complex process characterized by a set of physiological, biochemical, and organoleptic changes such as anthocyanins biosynthesis, chlorophyll degradation, increase of enzymatic degradation in the cell wall, sugar content, respiratory activities, ethylene production, and changes in aromatic compounds (Paliyath and Murr 2006). During the maturation of starch-rich fruit, the starch is converted into sugar by a catabolic degradation while the organic acids are converted into sugar by the process of gluconeogenesis (Sharma et al 2008).…”

Section: Introductionmentioning

confidence: 99%

The role of hydrolases in the loss of firmness and of the changes in sugar content during the post-harvest maturation of Carica papaya L. var solo 8

et al. 2012

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Fruit ripening is associated with many hydrolase activities involved in the softening of the fruit during the maturation. This study investigates the relationship between the loss of firmness along with the changes of sugar content and the enzymatic activities in Carica papaya L.var solo 8 during post-harvest storage. Three maturation stages (green immature: the fruit is entirely green, green mature: the fruit shows 1/32 yellow skin and fully mature: the fruit shows 1/8 yellow skin) have been selected and stored at 15, 22 and 28°C. The reduction of fruit firmness, total sugar contents, refractive index (% Brix) and enzymatic activities were measured. Low enzymatic activities (0.035 μmol/min/mg) were recorded in fruit harvested at the green immature stage with no significant (p≥0.05) effect on the softening while fruit harvested at the green mature and fully mature stages showed enzymatic activities 7 times as high as those of the green immature stage. These high enzymatic activities were responsible for the loss of firmness of the fruit. Accordingly, papayas at the green mature and fully mature stages displayed higher maxima of sugar content (4.8 g/100 g at 28°C at day 12, and 10.2 g/100 g at 22°C at day 8, respectively) at higher temperatures. Meanwhile in green immature papayas, the maximum was only 4.3 g/100 g at 22°C and day 12 of storage. The results show that the loss of firmness of the papaya was highly related to the hydrolytic enzyme activities and the sweet taste to the presence of simple sugars such as galactose liberated from the polysaccharide complexes.

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Section: Introductionmentioning

confidence: 99%

The role of hydrolases in the loss of firmness and of the changes in sugar content during the post-harvest maturation of Carica papaya L. var solo 8

et al. 2012

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“…blood, xylem or phloem), then nutritional requirements may exert a powerful influence on the gene content of endosymbiotic partner(s) as selection will favour the retention of functional biosynthetic pathways that can yield essential products lacking in the diet. Armoured scale insects feed on contents of parenchyma cells that are enriched with carbohydrates, as either sugar-rich photo-assimilate (primarily leaves and stems) and/or vacuole-bound starch (primarily fruits), as well as various salts, vitamins and hydrolytic enzymes; proteins are generally in low abundance in these plant tissues (Avigad and Dey, 1997;Paliyath et al, 2012). Thus, parenchyma cell extracts are not expected to provide balanced amino acid profiles, Based on its genome sequence and on findings for other insect-symbiont systems, Uzinura likely plays a role as a supplier of amino acids typically scarce in parenchyma cells.…”

Section: Discussionmentioning

confidence: 99%

“…Chloroplasts are prevalent in mesophyll cells in leaves and stems and are the source of photosynthetic products that are composed primarily of sugars (Avigad and Dey, 1997). Vacuoles in mesophyll cells can harbour nitrogenous products, salts, hydrolytic enzymes and metabolic wastes, while those in mesocarp cells in fruits are generally highly enriched in carbohydrates with negligible amounts of protein (Paliyath et al, 2012). Since diaspidids have a discontinuous digestive system and do not produce honeydew (liquid faeces), they discard excess water and waste by regurgitating it while feeding (McClure, 1990).…”

Section: Introductionmentioning

confidence: 99%

The nutrient supplying capabilities of Uzinura, an endosymbiont of armoured scale insects

Sabree

Huang

Okusu

et al. 2013

Environmental Microbiology

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An emerging common physiological feature of plant sap-feeding insects is the presence of bacterial endosymbionts capable of providing essential nutrients to their host. These microbial partners are inviable outside of specialized host tissues, and therefore a cultivation-independent approach, namely high-throughput next-generation genome sequencing, can be used to characterize their gene content and metabolic potential. To this end, we sequenced the first complete genome of the obligate endosymbiont, Candidatus 'Uzinura diaspidicola', of armoured scale insects. At 263 431 bp, Uzinura has an extremely reduced genome that is composed largely of genes encoding enzymes involved in translation and amino acid biosynthesis. The tiny size of the Uzinura genome parallels that observed in some other insect endosymbionts. Despite this extreme genome reduction, the absence of a known obligate partner bacterial symbiont suggests that Uzinura alone can supply sufficient nutrients to its host.

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“…Michaelis-Menten type models are monotonic models that represent firmness loss, and contain different parameters for characterising the dataset (Benge, De Silva, Banks, & Jeffery, 2000), while reciprocal, power and reciprocal quadratic models (Westcott & Callan, 1990) represent models that can be used to fit storage potential parameters. The most studied physiological mechanisms that regulate decreasing kiwifruit firmness include the disassembly of polysaccharide networks in cell walls, pectin degradation, hydrolysis of starch celluloses and hemicellulose (Hertog, Nicholson, & Jeffery, 2004;Macrae, Lallu, Searle, & Bowen, 1989;Macrae, Stec, & Triggs, 1990;Paliyath & Murr, 2008;Pyke, Hopkirk, Alspach, & Cooper, 1996).…”

Section: Michaelis-menten Type Complementary Gompertz and Jointedmentioning

confidence: 99%

Prediction models for the softening of new commercialActinidiacultivars

Giuggioli

Girgenti

Baudino

et al. 2017

J Food Process Preserv

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Empirical models for the softening of Actinidia deliciosa fruits (exponential decay, complementary Gompertz and modified Boltzmann models) were applied to the 'Hortgem Tahi of Actinidia chinensis Planch., all of which are emerging cultivars in the baby kiwi and yellow pulp kiwifruit markets. A texture analyser collected firmness data for kiwifruits stored up to 18 days at 2 and 248C, for use in prediction models. The dry matter, soluble solid, and vitamin C content was also determined for these new commercial cultivars, which were compared to the control 'Hayward' cultivar. The Boltzmann model, which is known to perform well for the 'Hayward' cultivar, was confirmed as the best fit for baby kiwi 'Rua ® ' and yellow 'Jingold ® Jintao' cultivars for all studied conditions, whereas the exponential decay model was the best fit for the 'Tahi ® ' cultivar. Practical applicationsIn the postharvest sector, models or equations can represent effective tools for the prediction and characterization of physiological and qualitative changes during fruit ripening in different storage conditions. We evaluated the softening of new commercial cultivars of the Actinidia genus, which could improve our understanding of the behavior of these fruits under different temperatures, as well as allowing prediction of their shelf-life. Moreover, the evaluation of mathematical models on softening could facilitate the scheduling of the post-harvest management of kiwifruit. This would assist with managing this product for distant or demanding markets, as well as other operations such as packaging, where this information could help to reduce economic losses associated with excessive softening.

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Biochemistry of Fruits

Cited by 22 publications

References 41 publications

The role of hydrolases in the loss of firmness and of the changes in sugar content during the post-harvest maturation of Carica papaya L. var solo 8

The role of hydrolases in the loss of firmness and of the changes in sugar content during the post-harvest maturation of Carica papaya L. var solo 8

The nutrient supplying capabilities of Uzinura, an endosymbiont of armoured scale insects

Prediction models for the softening of new commercialActinidiacultivars

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