Composition of tomato fruit. III.—Juices from whole fruit and locules at different stages of ripeness

Abstract

4 simple formula has been adopted to determine a figure that might be regarded as the expected additive effect of two chemicals, i.e., by taking the percentage weed control achieved by the bipyridyl alone and applying this to the percentage uncontrolled by the residual alone. The sum of this and the response obtained by the residual may be regarded as the expected additive effect. The responses obtained by the three residual herbicides are broadly similar and means of these have been treated in this manner for simplicity. The expected additive effect figures are shown in parentheses in Table 111. This adequately demonstrates the value to be obtained in weed control over a whole growing season by applying mixtures of bipyridyls and residual weed killers. This applies particularly in the case of paraquat and the result is far greater than the initial advantage obtained by the rapid action of the bipyridyls.Paraquat is undoubtedly the most effective material in this r61e and examination of the results shows that each of the residuals has benefited outstandingly from its addition. This may be due in part to its effect upon grasses, including many perennial grasses, and its greater translocation capacity than that of diquat.These mixtures of bipyridyls and residual weed killers are interesting and much work remains to be done to utilise them to maximum effect and usage. ConclusionOne main conclusion can be drawn from these trials, that is, that in the field of total weed control one is working on the problem of selectivity no less than in the field of selective crop protection. The discovery of the substituted ureas and triazines has indeed revolutionised total weed control but the problem of selectivity remains. Until a herbicide is found which is, at once, effective as a post-emergence application for deep-rooted perennial plants, and also as a pre-emergence application with, preferably, the capacity to destroy the ungerminated seed, mixtures of herbicides for total weed control are still required.Changes in t h e composition of tomato fruit during ripening have been studied with particular reference t o titratable acidity, sugars and soluble solids. The analyses were made on juices expressctl from whole fruit, and also on free juices from the locules.The content of sugars and of total solids in juices from whole fruit, and of sugars in the locular juices, increased from t h e niatui-e grecn t o t h e orange-red or red stages of ripening.The acidity of t h e juices decreased progrcssivcly as orange and red pigments developed in the outer walls, the highest values in the locules gencrally occurring in the rnaturc green fruit mhercas for whole fruit a maximum was found at t h c first appearance of yellow areas in the malls.Storage of orange-red tomatoes at room temperature for 6 days caused a significant decrease in sugars and titratable acidity in the expressed juices.* P a r t I1 : IntroductionIn previous studies of the composition of normal, ' blotchy ' and ' waxy ' tomatoesl> 2 the results were based on analyses o...

Effect of Stages of Maturity and Ripening Conditions on the Biochemical Characteristics of Tomato

“…For all maturity stages, TSS increased gradually with the advancement of ripening process. [19] also reported similar trend of results. Ripening conditions were also found to have significant effects on change in TSS content of tomato juice at 0, 3 and 9th day of storage (Table 8).…”

“…The highest quantity of total sugar (4.03%) was recorded in full ripen tomatoes while it was lowest quantity (3.30%) in mature green tomatoes at 12th day of storage. Winsor et al [19] .obtained similar result also. Ripening condition was found to be affecting significantly total sugar content of tomato at different storage duration (Table 5).…”

“…They also reported that citric acid was the major constituent of total acid and malic acid occurred in small concentration and decrease at the fruit ripened. [19] found that maximum acidity is at the pink stage of tomato fruits with subsequent fall. [17] found that sugar content varied from 3.9-4.4% in the tomato variety.…”

“…During maturation and ripening of fruit there are changes in total soluble solid. The total soluble solid increase from mature green stage to red ripe stage [19] . [7] reported that 4.80-8.80% total soluble solid in tomato juice.…”

Studies on the Atopic Allergen in Ripe Tomato Fruits

“…Marked biochemical alterations have been reported to occur during the ripening process of tomatoes: from the green to the red ripe stage the total amount of reducing sugars increases to about 4%, the total amount of free acids increases, together with the nitrogen content of the soluble material, while the softening process is thought to be due to conversion of the insoluble propectins of the middle lamellae to water-soluble pectins, which arc subject to further cleavage by the enzyme pcctinesterase (13,17,18). Moreover, noncnzymatic internal browning of tomato fruit is a wellknown pheno menon (15,16).…”