Tyrosinase‐catalysed grafting of food‐grade gallates to chitosan: Surface properties of novel functional coatings

Jari Vartiainen (Corresponding Author), Marjaana Rättö, Raija Lantto, Kalle Nättinen, Eero Hurme

Research output: Contribution to journalArticleScientificpeer-review

25 Citations (Scopus)

Abstract

Plasma‐activated biaxially oriented polypropylene (BOPP) films and paper substrate have been coated with functional chitosan solutions. Plasma treatment increased the amount of surface peroxide groups and carboxyl groups on the BOPP films. As a result of plasma activation, the surface energy increased from 30 to 50 dynes/cm. The enzyme tyrosinase catalysed the grafting of octyl gallate and dodecyl gallate to amino groups of chitosan polysaccharide. Resulting coatings exhibited strong antimicrobial activity against Gram‐positive Staphylococcus aureus and Gram‐negative Listeria innocua. After 24 h of incubation, a total reduction in both bacteria cell numbers varied between >4.9 and 1.4 logarithmic units. Grafted dodecyl gallate and octyl gallate at pH 6 were found to have the lowest reduction values of <3 logarithmic units for S. aureus, while 1.4 logarithmic reduction value was obtained for grafted dodecyl gallate at pH 6 against L. innocua. Chitosan coatings were also effective barrier layers against oxygen transmission although the transmission rates clearly increased in high‐humidity conditions. In dry conditions, however, the transmission rate of 2 cm3/(m2 · 24 h) was obtained with chitosan‐coated BOPP. Coatings did not have any effects on water vapour transmission. Both gallates were successfully grafted at pH 6. As increased flocculation and colour formation indicated, the tyrosinase‐catalysed grafting was more powerful with octyl gallate. Dodecyl gallate containing chitosan coatings was more hydrophobic as compared to octyl gallate. Total migration of substances into 95% ethanol was ≥5 mg/dm2, thus materials may be exploitable in packaging purposes in direct contact with certain foodstuffs.
Original languageEnglish
Pages (from-to)317 - 328
Number of pages12
JournalPackaging Technology and Science
Volume21
Issue number6
DOIs
Publication statusPublished - 2008
MoE publication typeA1 Journal article-refereed

Fingerprint

Chitosan
Surface properties
Polypropylenes
Coatings
Listeria
Plasmas
Monophenol Monooxygenase
Peroxides
Steam
Flocculation
Polysaccharides
Interfacial energy
Water vapor
Bacteria
Packaging
Ethanol
Enzymes
Chemical activation
Oxygen
Color

Keywords

  • tyrosinase
  • chitosan
  • gallate
  • antimicrobial activity
  • plasma
  • packaging

Cite this

Vartiainen, Jari ; Rättö, Marjaana ; Lantto, Raija ; Nättinen, Kalle ; Hurme, Eero. / Tyrosinase‐catalysed grafting of food‐grade gallates to chitosan : Surface properties of novel functional coatings. In: Packaging Technology and Science. 2008 ; Vol. 21, No. 6. pp. 317 - 328.
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abstract = "Plasma‐activated biaxially oriented polypropylene (BOPP) films and paper substrate have been coated with functional chitosan solutions. Plasma treatment increased the amount of surface peroxide groups and carboxyl groups on the BOPP films. As a result of plasma activation, the surface energy increased from 30 to 50 dynes/cm. The enzyme tyrosinase catalysed the grafting of octyl gallate and dodecyl gallate to amino groups of chitosan polysaccharide. Resulting coatings exhibited strong antimicrobial activity against Gram‐positive Staphylococcus aureus and Gram‐negative Listeria innocua. After 24 h of incubation, a total reduction in both bacteria cell numbers varied between >4.9 and 1.4 logarithmic units. Grafted dodecyl gallate and octyl gallate at pH 6 were found to have the lowest reduction values of <3 logarithmic units for S. aureus, while 1.4 logarithmic reduction value was obtained for grafted dodecyl gallate at pH 6 against L. innocua. Chitosan coatings were also effective barrier layers against oxygen transmission although the transmission rates clearly increased in high‐humidity conditions. In dry conditions, however, the transmission rate of 2 cm3/(m2 · 24 h) was obtained with chitosan‐coated BOPP. Coatings did not have any effects on water vapour transmission. Both gallates were successfully grafted at pH 6. As increased flocculation and colour formation indicated, the tyrosinase‐catalysed grafting was more powerful with octyl gallate. Dodecyl gallate containing chitosan coatings was more hydrophobic as compared to octyl gallate. Total migration of substances into 95{\%} ethanol was ≥5 mg/dm2, thus materials may be exploitable in packaging purposes in direct contact with certain foodstuffs.",
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Tyrosinase‐catalysed grafting of food‐grade gallates to chitosan : Surface properties of novel functional coatings. / Vartiainen, Jari (Corresponding Author); Rättö, Marjaana; Lantto, Raija; Nättinen, Kalle; Hurme, Eero.

In: Packaging Technology and Science, Vol. 21, No. 6, 2008, p. 317 - 328.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Tyrosinase‐catalysed grafting of food‐grade gallates to chitosan

T2 - Surface properties of novel functional coatings

AU - Vartiainen, Jari

AU - Rättö, Marjaana

AU - Lantto, Raija

AU - Nättinen, Kalle

AU - Hurme, Eero

PY - 2008

Y1 - 2008

N2 - Plasma‐activated biaxially oriented polypropylene (BOPP) films and paper substrate have been coated with functional chitosan solutions. Plasma treatment increased the amount of surface peroxide groups and carboxyl groups on the BOPP films. As a result of plasma activation, the surface energy increased from 30 to 50 dynes/cm. The enzyme tyrosinase catalysed the grafting of octyl gallate and dodecyl gallate to amino groups of chitosan polysaccharide. Resulting coatings exhibited strong antimicrobial activity against Gram‐positive Staphylococcus aureus and Gram‐negative Listeria innocua. After 24 h of incubation, a total reduction in both bacteria cell numbers varied between >4.9 and 1.4 logarithmic units. Grafted dodecyl gallate and octyl gallate at pH 6 were found to have the lowest reduction values of <3 logarithmic units for S. aureus, while 1.4 logarithmic reduction value was obtained for grafted dodecyl gallate at pH 6 against L. innocua. Chitosan coatings were also effective barrier layers against oxygen transmission although the transmission rates clearly increased in high‐humidity conditions. In dry conditions, however, the transmission rate of 2 cm3/(m2 · 24 h) was obtained with chitosan‐coated BOPP. Coatings did not have any effects on water vapour transmission. Both gallates were successfully grafted at pH 6. As increased flocculation and colour formation indicated, the tyrosinase‐catalysed grafting was more powerful with octyl gallate. Dodecyl gallate containing chitosan coatings was more hydrophobic as compared to octyl gallate. Total migration of substances into 95% ethanol was ≥5 mg/dm2, thus materials may be exploitable in packaging purposes in direct contact with certain foodstuffs.

AB - Plasma‐activated biaxially oriented polypropylene (BOPP) films and paper substrate have been coated with functional chitosan solutions. Plasma treatment increased the amount of surface peroxide groups and carboxyl groups on the BOPP films. As a result of plasma activation, the surface energy increased from 30 to 50 dynes/cm. The enzyme tyrosinase catalysed the grafting of octyl gallate and dodecyl gallate to amino groups of chitosan polysaccharide. Resulting coatings exhibited strong antimicrobial activity against Gram‐positive Staphylococcus aureus and Gram‐negative Listeria innocua. After 24 h of incubation, a total reduction in both bacteria cell numbers varied between >4.9 and 1.4 logarithmic units. Grafted dodecyl gallate and octyl gallate at pH 6 were found to have the lowest reduction values of <3 logarithmic units for S. aureus, while 1.4 logarithmic reduction value was obtained for grafted dodecyl gallate at pH 6 against L. innocua. Chitosan coatings were also effective barrier layers against oxygen transmission although the transmission rates clearly increased in high‐humidity conditions. In dry conditions, however, the transmission rate of 2 cm3/(m2 · 24 h) was obtained with chitosan‐coated BOPP. Coatings did not have any effects on water vapour transmission. Both gallates were successfully grafted at pH 6. As increased flocculation and colour formation indicated, the tyrosinase‐catalysed grafting was more powerful with octyl gallate. Dodecyl gallate containing chitosan coatings was more hydrophobic as compared to octyl gallate. Total migration of substances into 95% ethanol was ≥5 mg/dm2, thus materials may be exploitable in packaging purposes in direct contact with certain foodstuffs.

KW - tyrosinase

KW - chitosan

KW - gallate

KW - antimicrobial activity

KW - plasma

KW - packaging

U2 - 10.1002/pts.813

DO - 10.1002/pts.813

M3 - Article

VL - 21

SP - 317

EP - 328

JO - Packaging Technology and Science

JF - Packaging Technology and Science

SN - 0894-3214

IS - 6

ER -