Enzymatic browning in marula fruit 1: Effect of endogenous antioxidants on marula fruit polyphenol oxidase

Kwaneli Mdluli, Richard Owusu-Apenten

Research output: Contribution to journalArticle

Abstract

Spectrophotometric assays of marula fruit polyphenol oxidase showed a pronounced lag phase due to the presence of endogenous antioxidants. ne total antioxidant capacity (TAC) was quantified in terms of the equivalent concentration of L-ascorbic acid (L-ASC. eq). Freeze-dried marula fruit juice had 2960 mg L-ASC.eq. per 100 g (pH 4.5) or 1872 mg L-ASC.eq per 100 g of sample (PH 7 0) assayed with ABTS. The values compare with the known L-A SC content of 2017 mg per 100 g. The vitamin C content of marula fruit accounts for about 70 % of the TAC. The TAC estimate for marula fruit was 20-40 times greater than levels reported in most other fruits.
LanguageEnglish
Pages67-82
JournalJournal of Food Biochemistry
Volume27
Issue number1
Publication statusPublished - Mar 2003

Fingerprint

enzymatic browning
catechol oxidase
antioxidants
fruits
ascorbic acid
fruit juices
Sclerocarya birrea subsp. caffra
assays
sampling

Keywords

  • ASCORBIC-ACID
  • PLANT FOODS
  • CAPACITY
  • AFRICA

Cite this

@article{4865721076854cbaac9e94d8cb104689,
title = "Enzymatic browning in marula fruit 1: Effect of endogenous antioxidants on marula fruit polyphenol oxidase",
abstract = "Spectrophotometric assays of marula fruit polyphenol oxidase showed a pronounced lag phase due to the presence of endogenous antioxidants. ne total antioxidant capacity (TAC) was quantified in terms of the equivalent concentration of L-ascorbic acid (L-ASC. eq). Freeze-dried marula fruit juice had 2960 mg L-ASC.eq. per 100 g (pH 4.5) or 1872 mg L-ASC.eq per 100 g of sample (PH 7 0) assayed with ABTS. The values compare with the known L-A SC content of 2017 mg per 100 g. The vitamin C content of marula fruit accounts for about 70 {\%} of the TAC. The TAC estimate for marula fruit was 20-40 times greater than levels reported in most other fruits.",
keywords = "ASCORBIC-ACID, PLANT FOODS, CAPACITY, AFRICA",
author = "Kwaneli Mdluli and Richard Owusu-Apenten",
note = "Reference text: 1. ARNAO MB Inhibition by L-ascorbic acid and other antioxidants of the 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) oxidation catalyzed by peroxidase: A new approach for determining total antioxidant status of foods ANALYTICAL BIOCHEMISTRY 236 : 255 1996 2. AUGUSTIN MA POLYPHENOLOXIDASE FROM GUAVA (PSIDIUM-GUAJAVA L) JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 36 : 1259 1985 3. BALLSCHMEITER HMB FOOD IND S AFRICA 26 : 22 1973 4. BALLSCHMEITER HMB FOOD IND S AFRICA 26 : 23 1973 5. BALLSCHMEITER HMB FOOD IND S AFRICA 26 : 25 1973 6. COOPER MJ CLIN CHIM ACTA 202 : 102 1991 7. EROMOSELE IC EVALUATION OF MINERAL ELEMENTS AND ASCORBIC-ACID CONTENTS IN FRUITS OF SOME WILD PLANTS PLANT FOODS FOR HUMAN NUTRITION 41 : 151 1991 8. GOLANGOLDHIRSH A EFFECT OF ASCORBIC-ACID, SODIUM BISULFITE, AND THIOL COMPOUNDS ON MUSHROOM POLYPHENOL OXIDASE JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 32 : 1003 1984 9. GOUS F SELECTION AND PROCESSING OF MARULA FRUIT (SCLEROCARYA-BIRREA SUBSP CAFFRA) LEBENSMITTEL-WISSENSCHAFT & TECHNOLOGIE 21 : 259 1988 10. GRESSWELL DM VITAMIN C RECENT ASP : 136 1974 11. JOHNSON IT NUTR RES REV 7 : 175 1994 12. KHOKHAR SK IN PRESS FOOD CHEM : 2002 13. MCKENNA R KINETIC-ANALYSIS OF THE FREE-RADICAL-INDUCED LIPID-PEROXIDATION IN HUMAN ERYTHROCYTE-MEMBRANES - EVALUATION OF POTENTIAL ANTIOXIDANTS USING CIS-PARINARIC ACID TO MONITOR PEROXIDATION ANALYTICAL BIOCHEMISTRY 196 : 443 1991 14. MILLER NJ A NOVEL METHOD FOR MEASURING ANTIOXIDANT CAPACITY AND ITS APPLICATION TO MONITORING THE ANTIOXIDANT STATUS IN PREMATURE NEONATES CLINICAL SCIENCE 84 : 407 1993 15. RAMARATHNAM N THE CONTRIBUTION OF PLANT FOOD ANTIOXIDANTS TO HUMAN HEALTH TRENDS IN FOOD SCIENCE & TECHNOLOGY 6 : 75 1995 16. RICEEVANS C TOTAL ANTIOXIDANT STATUS IN PLASMA AND BODY-FLUIDS OXYGEN RADICALS IN BIOLOGICAL SYSTEMS, PT D 234 : 279 1994 17. SHACKLETON CM Potential stimulation of local rural economies by harvesting secondary products: A case study of the central Transvaal lowveld, South Africa AMBIO 25 : 33 1996 18. SMITH GC Mineral values of selected plant foods common to southern Burkina Faso and to Niamey, Niger, West Africa INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION 47 : 41 1996 19. VALERO E KINETIC-STUDY OF THE EFFECT OF METABISULFITE ON POLYPHENOL OXIDASE JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 40 : 904 1992 20. WALKER JR ACS SYM SER 600 : 2 1995 21. WHITEHEAD TP ENHANCED CHEMILUMINESCENT ASSAY FOR ANTIOXIDANT CAPACITY IN BIOLOGICAL-FLUIDS ANALYTICA CHIMICA ACTA 266 : 265 1992",
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Enzymatic browning in marula fruit 1: Effect of endogenous antioxidants on marula fruit polyphenol oxidase. / Mdluli, Kwaneli; Owusu-Apenten, Richard.

In: Journal of Food Biochemistry, Vol. 27, No. 1, 03.2003, p. 67-82.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Enzymatic browning in marula fruit 1: Effect of endogenous antioxidants on marula fruit polyphenol oxidase

AU - Mdluli, Kwaneli

AU - Owusu-Apenten, Richard

N1 - Reference text: 1. ARNAO MB Inhibition by L-ascorbic acid and other antioxidants of the 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) oxidation catalyzed by peroxidase: A new approach for determining total antioxidant status of foods ANALYTICAL BIOCHEMISTRY 236 : 255 1996 2. AUGUSTIN MA POLYPHENOLOXIDASE FROM GUAVA (PSIDIUM-GUAJAVA L) JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 36 : 1259 1985 3. BALLSCHMEITER HMB FOOD IND S AFRICA 26 : 22 1973 4. BALLSCHMEITER HMB FOOD IND S AFRICA 26 : 23 1973 5. BALLSCHMEITER HMB FOOD IND S AFRICA 26 : 25 1973 6. COOPER MJ CLIN CHIM ACTA 202 : 102 1991 7. EROMOSELE IC EVALUATION OF MINERAL ELEMENTS AND ASCORBIC-ACID CONTENTS IN FRUITS OF SOME WILD PLANTS PLANT FOODS FOR HUMAN NUTRITION 41 : 151 1991 8. GOLANGOLDHIRSH A EFFECT OF ASCORBIC-ACID, SODIUM BISULFITE, AND THIOL COMPOUNDS ON MUSHROOM POLYPHENOL OXIDASE JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 32 : 1003 1984 9. GOUS F SELECTION AND PROCESSING OF MARULA FRUIT (SCLEROCARYA-BIRREA SUBSP CAFFRA) LEBENSMITTEL-WISSENSCHAFT & TECHNOLOGIE 21 : 259 1988 10. GRESSWELL DM VITAMIN C RECENT ASP : 136 1974 11. JOHNSON IT NUTR RES REV 7 : 175 1994 12. KHOKHAR SK IN PRESS FOOD CHEM : 2002 13. MCKENNA R KINETIC-ANALYSIS OF THE FREE-RADICAL-INDUCED LIPID-PEROXIDATION IN HUMAN ERYTHROCYTE-MEMBRANES - EVALUATION OF POTENTIAL ANTIOXIDANTS USING CIS-PARINARIC ACID TO MONITOR PEROXIDATION ANALYTICAL BIOCHEMISTRY 196 : 443 1991 14. MILLER NJ A NOVEL METHOD FOR MEASURING ANTIOXIDANT CAPACITY AND ITS APPLICATION TO MONITORING THE ANTIOXIDANT STATUS IN PREMATURE NEONATES CLINICAL SCIENCE 84 : 407 1993 15. RAMARATHNAM N THE CONTRIBUTION OF PLANT FOOD ANTIOXIDANTS TO HUMAN HEALTH TRENDS IN FOOD SCIENCE & TECHNOLOGY 6 : 75 1995 16. RICEEVANS C TOTAL ANTIOXIDANT STATUS IN PLASMA AND BODY-FLUIDS OXYGEN RADICALS IN BIOLOGICAL SYSTEMS, PT D 234 : 279 1994 17. SHACKLETON CM Potential stimulation of local rural economies by harvesting secondary products: A case study of the central Transvaal lowveld, South Africa AMBIO 25 : 33 1996 18. SMITH GC Mineral values of selected plant foods common to southern Burkina Faso and to Niamey, Niger, West Africa INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION 47 : 41 1996 19. VALERO E KINETIC-STUDY OF THE EFFECT OF METABISULFITE ON POLYPHENOL OXIDASE JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 40 : 904 1992 20. WALKER JR ACS SYM SER 600 : 2 1995 21. WHITEHEAD TP ENHANCED CHEMILUMINESCENT ASSAY FOR ANTIOXIDANT CAPACITY IN BIOLOGICAL-FLUIDS ANALYTICA CHIMICA ACTA 266 : 265 1992

PY - 2003/3

Y1 - 2003/3

N2 - Spectrophotometric assays of marula fruit polyphenol oxidase showed a pronounced lag phase due to the presence of endogenous antioxidants. ne total antioxidant capacity (TAC) was quantified in terms of the equivalent concentration of L-ascorbic acid (L-ASC. eq). Freeze-dried marula fruit juice had 2960 mg L-ASC.eq. per 100 g (pH 4.5) or 1872 mg L-ASC.eq per 100 g of sample (PH 7 0) assayed with ABTS. The values compare with the known L-A SC content of 2017 mg per 100 g. The vitamin C content of marula fruit accounts for about 70 % of the TAC. The TAC estimate for marula fruit was 20-40 times greater than levels reported in most other fruits.

AB - Spectrophotometric assays of marula fruit polyphenol oxidase showed a pronounced lag phase due to the presence of endogenous antioxidants. ne total antioxidant capacity (TAC) was quantified in terms of the equivalent concentration of L-ascorbic acid (L-ASC. eq). Freeze-dried marula fruit juice had 2960 mg L-ASC.eq. per 100 g (pH 4.5) or 1872 mg L-ASC.eq per 100 g of sample (PH 7 0) assayed with ABTS. The values compare with the known L-A SC content of 2017 mg per 100 g. The vitamin C content of marula fruit accounts for about 70 % of the TAC. The TAC estimate for marula fruit was 20-40 times greater than levels reported in most other fruits.

KW - ASCORBIC-ACID

KW - PLANT FOODS

KW - CAPACITY

KW - AFRICA

M3 - Article

VL - 27

SP - 67

EP - 82

JO - Journal of Food Biochemistry

T2 - Journal of Food Biochemistry

JF - Journal of Food Biochemistry

SN - 0145-8884

IS - 1

ER -