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Literature summary for 3.1.1.11 extracted from

  • Garcia-Betanzos, C.I.; Hernandez-Sanchez, H.; Bernal-Couoh, T.F.; Quintanar-Guerrero, D.; Zambrano-Zaragoza, M.L.
    Physicochemical, total phenols and pectin methylesterase changes on quality maintenance on guava fruit (Psidium guajava L.) coated with candeuba wax solid lipid nanoparticles-xanthan gum (2017), Food Res. Int., 101, 218-227 .
    View publication on PubMed
Search for more literature for 3.1.1.11

Activating Compound

Activating Compound Comment Organism Structure
additional information an increase in ethylene accumulation and pH contribute to the activation of the enzyme PME Psidium guajava

Inhibitors

Inhibitors Comment Organism Structure
additional information inhibition of the activation of the enzyme PME retardes the hydrolysis of pectin and texture softening during storage, e.g. by lowering pH and ethylene concentration Psidium guajava

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
pectin + n H2O Psidium guajava
-
 n methanol + pectate
-
 ?

Organism

Organism UniProt Comment Textmining
Psidium guajava
-
 var. Media china
-

Source Tissue

Source Tissue Comment Organism Textmining
fruit the fruits pass from the ripe to overripe stage with increased pectin hydrolysis Psidium guajava
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
pectin + n H2O
-
 Psidium guajava n methanol + pectate
-
 ?

Synonyms

Synonyms Comment Organism
pectin esterase
-
 Psidium guajava
pectin methylesterase
-
 Psidium guajava
PME
-
 Psidium guajava

General Information

General Information Comment Organism
malfunction inhibition of the activation of the enzyme PME retardes the hydrolysis of pectin and texture softening during storage, e.g. by lowering pH and ethylene concentration Psidium guajava
physiological function enzyme pectin methylesterase catalyzes hydrolysis of the methoxyl group of pectins, producing pectin acid. The decrease in the degree of pectin methoxylation may, in turn, trigger various processes that can affect fruit texture and firmness. PME activity is related to fruit softening with the disintegration of the cell wall and modifications of the pectin fraction. Because their principal substrate is the methoxyl group of pectins, hydrolysis of these compounds occurs. The fruits pass from the ripe to overripe stage with increased pectin hydrolysis. Activity of pectin methylesterase affets the layer of candeuba wax solid lipid nanoparticles (SLN) and xanthan gum (XG, xanthan gum derived from Xanthomonas campestris) as coatings on guava fruits, that shall inhibit the maturation process of the fruits. The best results are achieved from the fruits coated with 65 g/L of SLN and stored at 10°C, as they show the lowest O2 and CO2 respiration rates and, consequently, less weight loss. They also have the best retention of ascorbic acid and total phenol content, with less change in fruit color compared to the control guava and those coated only with XG. These findings indicate that this batch continues the natural maturation process, but at a slower rate than the other samples. The firmness is affected by the activity of the enzyme pectin methylesterase, but results show that the 65 g/l coating is efficient in maintaining fruit texture. 75 g/l Coating produces epoxy compounds in the fruit, causing physiological damage, and the guava coated with XG only have a maturation rate similar to that of the control fruit. Coating with lower concentration of submicron particles presenting a greater firmness can be related to its higher total phenol content, phenolic-pectin interactions demonstrate conservation of cell wall integrity explained by the cross-linking between a hydroxycinnamic acid, such as gallic acid, and the polysaccharide, such as pectin, in the cell wall, which leads to the formation of esterified phenolic compounds. This crosslinking may increase plant cell wall rigidity which helps to preserve firmness Psidium guajava