Tetrathionate Protects Proteolytic Activity of Simulated Papaya Latex and Crude Papain

Arteaga, G.E.; Nakai, S.

doi:10.1111/j.1365-2621.1990.tb03610.x

Cited by 2 publications

(5 citation statements)

References 12 publications

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“…EAR, respectively. These results are similar to those found by Arteaga and Nakai (1990) in their study on the effect of sodium tetrathionate in rehydrated crude papain. They reported that addition of 1&dquo;« sodium tetrathionate decreased significantly the loss of proteolytic activity of rehydrated crude papain after being dried at 55 °C (96,« of the original activity present in rehydrated crude papain was retained).…”

Section: Effect Of Concentration Of Protective Agentssupporting

confidence: 94%

“…The chemicals used to determine the effect of concentration were categorized into three groups: (i) antioxidants used in the food industry (Branen, 1990): ascorbic acid, sodium ascorbate, erythorbic acid, sodium erythorbate, TBHQ, rutin, a-tocopherol and 4-hexylresorcinol (Monsalve-González ct c~l., 1995). (ii) additives used to protect enzyme activity of papain: sodium metabisulfite (Ortiz et 171., 1980), and sodium tetrathionate (Arteaga and Nakai, 1990). (iii) sugars that have shown to be good stabilizers of proteins when subjected to different stresses such as freezing, drying, and heating (Arakawa and Timasheff, 1982;Carpenter et al, 1987): trehalose (Roser and Colaco;1993) and sucrose.…”

Section: Sample Preparationmentioning

confidence: 98%

“…Papain is obtained by tapping the green papaya fruit and drying the latex obtained. This method often produces papain with poor activity (Poulter and Caygill, 1985;Arteaga and Nakai, 1990). The major causes of the loss of proteolytic activity of crude papain during its isolation, storage and subsequent drying are: action of natural protease inhibitors; microbial degradation of the enzyme, autoproteolysis, irreversible oxidation of cysteine residues, and light sensitivity of the histidine residue which is essential for its activity (Ortiz et al, 1980;Brocklehurst ~ rrl., 1981).…”

Section: Introductionmentioning

confidence: 97%

“…These include harvesting of trunks, leaves, and green fruits, and even the whole tree (Jones and Mercier, 1974;Poulter and Caygill, 1985), chemical stabilization by addition of sodium metabisulfite or sodium tetrathionate to the latex before drying (Arteaga and Nakai, 1990), and the use of vacuum or spray drying (Jones and Mercier, 1974). While tapping of younger fruits produces a latex of higher proteolytic activity, it increases the ripening rate and decreases fruit production (Poulter and Caygill, 1985), which means high economic losses to the producers not only because of the decreasing yield of latex, but also because the fruit obtained is of a lower economic value.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stabilization of papain from papaya peels / Estabilización de la papaína de la cáscara de papaya

Espin

Islam

1998

Food sci. technol. int.

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Crude papain in papaya peels was stabilized before drying by the addition of various chemicals (ascorbic acid, sodium ascorbate, erythorbic acid, sodium erythorbate, sodium metabisulfite, sodium tetrathionate, 4-hexylresorcinol, t-butyl hydroquinone [TBHQ], rutin, α-tocopherol, trehalose, and sucrose). Chemicals were added to the ground papaya peels at 0, 0.12, 0.25, 0.5, 0.75, 1, 1.25, and 1.5% (w /w). Drying temperatures were 40, 55 and 60 °C. Enzyme activity was measured before and after drying by the casein digestion method. Percentage of enzyme activity retained (% EAR) was calculated by assigning a value of 100% EAR to fresh peels. Possible synergism between chemicals was also studied for a 1:1 ratio chemical/chemical at 1% total concentration. The highest % EAR was obtained at 55 °C for all chemicals except for sucrose and trehalose which showed their best effect at 40 °C. TBHQ rutin, α-tocopherol and 4-hexylresorcinol showed a destabilizing effect. Maximum protective effect occurred at 1% concentration. At this concentration sodium tetrathionate showed the best protective effect (90% EAR) followed by sodium metabisulfite (85% EAR), while both sodium ascorbate and sodium erythorbate retained 75% of the original activity. Ascorbic acid and erythorbic acid were 10% less effective than their corresponding sodium salts, possibly due to lower pH. Trehalose showed only 57 % EAR while sucrose failed to produce any appreciable effect. No synergistic effect was shown by any combination of chemicals. Se ha estudiado la estabilización de la papaína cruda presente en cáscara de papaya antes de su deshidratado mediante reactivos quimicos (ácido ascórbico, ascórbato de sodio, ácido eritórbico, eritorbato de sodio, metabisulfito de sodio, tetrationato de sodio, 4-hexilresorcinol, TBHQ, rutin, α-tocoferol, trehalosa, y sacarosa). Los reactivos químicos se añadieron a las cáscaras de papaya molidas en concentraciones de 0,12, 0,25, 0,50, 0,75, 1,00, 1,25, y 1,50% (p/p). Las temperaturas de secado fueron de 40, 55 y 60 °C. La actividad enzimática se midió antes y después del proceso de secado mediante el método de digestión de la caseína. El porcentaje de actividad enzimática retenida (% EAR) se calculó dando el valor de 100% a las cáscaras frescas. También se estudió el posible sinergismo entre reactivos químicos con una relación 1:1 para una concentración total del 1%. El mayor valor de % EAR se obtuvo a 55 °C para todos los reactivos químicos, excepto para sacarosa y trehalosa, que fue a 40 °C. TBHQ, rutin, α-tocoferol y 4-hexilresorcinol demostraron tener efectos inhibitorios. El máximo efecto estabilizador se obtuvo con un 1 % de reactivos químicos; concentración a la cual, el tetrationato de sodio demostró tener el mejor efecto (90 % EAR), seguido por el metabisulf...

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Section: Effect Of Concentration Of Protective Agentssupporting

confidence: 94%

Section: Sample Preparationmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Stabilization of papain from papaya peels / Estabilización de la papaína de la cáscara de papaya

Espin

Islam

1998

Food sci. technol. int.

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“…It is well know that the thiol group of cysteine is sensitive to oxidation and that papain can be inactivated in the presence of oxygen (Gomes et al, 1997). It is reasonable to think that the formation of the thioimidate with the nitrile protects the cysteine from irreversible oxidation in the same way tetrathionate does (Arteaga and Nakai, 1990).…”

Section: Hydrolysis Of Peptide Nitrilesmentioning

confidence: 98%

Enzymatic hydrolysis of nitrides by an engineered nitrile hydratase (Papain Gln19Glu) in aqueous‐organic media

Versari

Ménard

Lortie

2002

Biotech & Bioengineering

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A mutant of the cysteine protease papain, displaying nitrile hydratase and amidase activities, was expressed in Pichia pastoris and used for the hydrolysis of peptide nitriles in aqueous-organic media. The rate of hydrolysis of these nitriles is lowered by increasing acetone concentration. This is caused by an increase of the Michaelis constant, and a variation of Vmax proportional to the amount of water in the mixture. The hydrolysis of the amide is less affected by the increase in co-solvent, which results in lower accumulation of this intermediate product. With the peptide nitrile tested, high nitrile concentrations could be used to promote the production of the amide and prevent its hydrolysis to the acid by diminishing the relative rate of amide hydrolysis. A number of non-peptidyl nitriles were also tested as potential substrates but activity was detected for only one compound with structural resemblance to peptide nitriles.

show abstract

Tetrathionate Protects Proteolytic Activity of Simulated Papaya Latex and Crude Papain

Cited by 2 publications

References 12 publications

Stabilization of papain from papaya peels / Estabilización de la papaína de la cáscara de papaya

Stabilization of papain from papaya peels / Estabilización de la papaína de la cáscara de papaya

Enzymatic hydrolysis of nitrides by an engineered nitrile hydratase (Papain Gln19Glu) in aqueous‐organic media

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