Function of the polygalacturonase convertor in ripening tomato fruit

1991 ◽  
Vol 82 (2) ◽  
pp. 237-242 ◽  
Author(s):  
Erik Knegt ◽  
Evert Vermeer ◽  
Caroline Pak ◽  
Johan Bruinsma
Keyword(s):  
Tomato Fruit

Assessment of locally produced waxing materials on the shelf life and fruit quality of two tomato varieties (Solanum lycopersicum)

2017 ◽  
Vol 4 (1) ◽  
pp. 36-47
Author(s):  
R. Osae G. Essilfie J. O. Anim
Keyword(s):  
Shelf Life ◽  
Tomato Fruit ◽  
Chemical Properties ◽  
Storage Period ◽  
Cassava Starch ◽  
Soluble Solids ◽  
Shea Butter ◽  
Tomato Fruits ◽  
Randomized Design ◽  
Colour Development

The study was conducted to assess the effect of different waxing materials on the quality attributes of tomato fruits. A 2 x8 factorial experiment layout in complete randomized design with 16 treatment combinations and 3 replication was adopted.The materials that were used for the experiment are two (2) varieties of tomatoes (Pectomech and Power Rano) and seven(7) waxing material (shea butter, cassava starch, beeswax, and a combination of shea butter + cassava starch, shea butter + beeswax, cassava starch + beeswax, shea butter + cassava starch + beeswax) and a control. Results from the experiment indicated that all waxing treatments delayed the development of weight loss, firmness, pH, total soluble solids, and total titrable acidity. The results also suggested that edible wax coatings delayed the ripening process and colour development of tomato fruits during the storage period and extended the shelf life. However Beewax treatment and its combinations performed better than the other treatments. It was therefore recommended that locally produced wax such as Beewax, Shea butter, Cassava Starch treatments and their combinations could be a good technology for preserving the quality and extending the shelf life of fresh tomato fruit as well as maintaining the physical and chemical properties.

138 LIPID CHANGES IN TOMATO FRUIT MICROSOMAL MEMBRANES DURING RIPENING

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 448d-448
Author(s):  
Bruce D. Whitaker
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Physical Properties ◽  
Free Sterol ◽  
Tomato Fruit ◽  
Sterol Composition ◽  
Steryl Glycoside ◽  
Microsomal Membranes ◽  
Fruit Pericarp ◽  
Total Membrane

A previous study of lipids from pericarp tissue of tomato fruit ranging from mature-green to red-ripe showed a large increase in total sterols accompanied by dramatic changes in sterol composition and conjugation with ripening. This study was conducted to determine whether similar changes occur in microsomal membranes derived from tomato fruit pericarp. Acylated steryl glycoside (ASG), the predominant steryl lipid, declined during ripening, with increases in steryl glycoside (SG) and free sterol (FS). Only minor changes in fatty acid composition were associated with the drop in ASG. The stigmasterol:sitosterol ratio increased throughout ripening, but much more in Fs than in SG or ASG. The ratio of FS to phospholipid (PL) increased with ripening. However, FS was never greater than 10 percent of the total membrane sterol (TMS), and TMS:PL actually declined over the middle stages of ripening. It is not known why tomato tissues maintain such high levels of ASG and SG, but sterol conjugation is thought to regulate the physical properties of cell membranes.

Nondestructive Quality Evaluation of Tomatoes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 544c-544
Author(s):  
A. Hakim ◽  
A. Purvis ◽  
E. Pehu ◽  
I. Voipio ◽  
E. Kaukovirta
Keyword(s):  
Quality Evaluation ◽  
Tomato Fruit ◽  
Quality Attributes ◽  
Internal Quality ◽  
Attractive Alternative ◽  
Fluorescence Techniques ◽  
Nondestructive Quality ◽  
Alternative Techniques ◽  
Evaluation Techniques

Both external and internal quality of fruits such as tomatoes can be evaluated by different methods, but all most all of the methods are destructive. For this reason, there is a need to reassess some of the alternative techniques. Nondestructive quality evaluation is an attractive alternative. The principles of different nondestructive quality evaluation techniques such as optical, physical, and fluorescence techniques applied to tomato fruit is explained. Successful application of these techniques that could be used for evaluation of different quality attributes are illustrated. The advantages of nondestructive quality evaluation techniques are that they are very fast, easy, labor- and time-intensive, and inexpensive. These techniques could also be useful to evaluate the quality of other vegetables.

Effect of pH and NH4NO3 as a Spray Additive on Penetration of NAA Through Isolated Tomato Fruit Cuticle

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 550a-550 ◽  
Author(s):  
Royal G. Fader ◽  
Martin J. Bukovac
Keyword(s):  
Direct Measurement ◽  
Sodium Citrate ◽  
Tomato Fruit ◽  
Initial Slope ◽  
Control Effect ◽  
Solution Ph ◽  
Ph Change ◽  
Effect Of Ph ◽  
Spray Droplets ◽  
Partition Behavior

We have reported that NH4NO3 (AN, 8 mM, pH 4.2), applied as simulated spray droplets, enhanced penetration of 14C-NAA through isolated leaf and fruit cuticles. One explanation for this response is that AN depresses NAA (pKa= 4.2) dissociation, increasing the nondissociated moiety, which penetrates more readily than the anion (NAA'). Direct measurement of AN (concn. 0-800 mM) effect on NAA (215 μM) dissociation as indexed by change in solution pH revealed no significant effect, with a pH change from 4.19 to 4.05. This change is not sufficient to account for the observed enhancement. When 14C-NAA, buffered (20 mM sodium citrate) at pH 3.2, 4.2, 5.2, 6.2, was partitioned against chloroform, there was a marked increase in NAA partitioning into chloroform as pH was decreased. AN (8 mM) did not alter this partition behavior, also indicating no effect on NAA dissociation. However, in cuticle penetration studies, using a finite dose system with 14C-NAA buffered at pH 3.2, 4.2, 5.2, 6.2, and in the presence and absence of 8 mM AN, there was no marked or consistent pH or AN (-70 to + 232 % of no AN control) effect on penetration as indexed by initial slope (4-12 h) or penetration after 120 h. The possible effects of AN and buffer on penetration of 14C-NAA from the droplet deposit will be discussed.

Sign in / Sign up

Export Citation Format

Share Document