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Starch fruit ripening

Starch. Starch is an Important polysaccharide present in fruits such as apple, banana, mango and others. Wright and Heatherbell (19) reported that kiwifruit contains 5-8% starch, and Pratt and Reid (17) reported that young kiwifruit has a high starch content. The changes in starch during ripening at 20°C in the presence of 5 ppm ethylene are presented in Table II. [Pg.310]

Several alkenes occur naturally in living organisms. Some of these alkenes act as hormones and control biological functions. Plants produce ethene as a hormone to stimulate flower and seed production and to ripen fruits. Ethene stimulates enzymes in the plants to convert starch and acids of unripe fruit into sugars. The enzymes also soften fruit by breaking down pectin in cell walls. [Pg.173]

Application of ethylene-,4C to plants resulted in only a 2.4% conversion into soluble carbohydrates, 11% into ether-soluble materials, 6.9% into phytol, 31.7% into cellulose and lignin, and 9.6% into soluble protein and non-protein material, mainly phosphates. 9 Treatment of detached fruit (such as apples, bananas, peaches, figs, and pears) with synthetic auxins, especially (2,4,5-trichlorophenoxy) acetic acid, speeded up ripening, as indicated by color, taste, softness, and starch breakdown. 7 Other fruits have been similarly ripened, 8 and the treatments are effective both on climacteric and non-climacteric fruit. [Pg.430]

The production of ethylene in fruit tissue and in small amounts in leaves may justify its consideration as a hormone, functioning in the gaseous state, Cherimoyas and some varieties of pear produce 1000 times the effective physiological concentration. Ethylene formation is closely linked to oxidation and may be centered in the mitochondria. Its effects are to promote cell-wall softening, starch hydrolysis, and organic add disappearance in fruits—the syndrome known as ripening. Ethylene also decreases the geotiopic responses of stems and petioles. [Pg.1314]

Amylases. In the case of pome fruits other enzyme activities are sometimes required. When fruit has been picked before maturity and then ripened under controlled atmospheric conditions in a cool store, there is a likelihood of starch retention originating from the unripe fruit. This starch can become gelatinised during juice processing and can give rise to precipitation and haze effects in the final product. Amylases are used here to break down any residual starch and overcome such problems. [Pg.49]

It should be emphasized that nonclimacteric fruits generally ripen on the plants and contain no starch. The differing effects of ethylene on the two types of fruits are covered in Section 18.1.4.2. [Pg.844]

Pectin is the dominant polysaccharide in fruits, which also contain (in smaller amounts) some other polysaccharides, cellulose and hemiceUuloses (the predominant components are xyloglucans) and Ugnin. Starch is only found in immature fruits (e.g. about 2.5% in immature apples) and its content decreases during ripening, and is virtuaUy absent in ripe fruits. The exceptions are bananas, which... [Pg.245]


See other pages where Starch fruit ripening is mentioned: [Pg.2260]    [Pg.221]    [Pg.317]    [Pg.21]    [Pg.167]    [Pg.234]    [Pg.316]    [Pg.413]    [Pg.877]    [Pg.341]    [Pg.93]    [Pg.394]    [Pg.430]    [Pg.478]    [Pg.39]    [Pg.155]    [Pg.85]    [Pg.273]    [Pg.5]    [Pg.148]    [Pg.250]    [Pg.400]    [Pg.305]    [Pg.306]    [Pg.266]    [Pg.231]    [Pg.20]    [Pg.45]    [Pg.241]    [Pg.400]    [Pg.818]    [Pg.216]    [Pg.245]    [Pg.128]    [Pg.658]    [Pg.879]   
See also in sourсe #XX -- [ Pg.845 ]




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Fruit ripening

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