scholarly journals Determination of Post-Harvest Biochemical Composition, Enzymatic Activities, and Oxidative Browning in 14 Apple Cultivars

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 186
Author(s):  
Sara Serra ◽  
Brendon Anthony ◽  
Francesca Boscolo Sesillo ◽  
Andrea Masia ◽  
Stefano Musacchi
Keyword(s):  
Phenolic Compounds ◽  
Enzymatic Activity ◽  
Flesh Color ◽  
Alternative Pathways ◽  
Polyphenol Oxidases ◽  
Post Harvest ◽  
Apple Cultivars ◽  
High Enzymatic Activity ◽  
Fruit Surface

Phenolic compounds in fruit provide human health benefits, and they contribute to color, taste, and the preservation of post-harvest fruit quality. Phenolic compounds also serve as modifiers of enzymatic activity, whether inhibition or stimulation. Polyphenol oxidases (PPO) and peroxidases (POD) use phenolic compounds as substrates in oxidative browning. Apple browning leads to flesh color, taste, texture, and flavor degradation, representing a drawback for the variety and its’ market appraisal. This study was conducted to investigate the process of browning in 14 apple cultivars throughout post-harvest at three-time points: immediately (T0), one hour (T1), and 24 h (T2) after apples were cut in half. Color parameters L* (lightness), a* (red/green), b* (yellow/blue) were measured, and chroma (ΔC*) and color (ΔE) were calculated to quantify differences between T0₋T1 and T1₋T2 on the fruit surface. Enzymatic activity (PPO, POD) and phenolic composition were also quantified for each cultivar. ‘Granny Smith’ and ‘Cripps Pink’ browned minimally. In contrast, ‘Fiesta’ and ‘Mondial Gala’ browned severely, reporting high enzymatic activity and quantified phenolic concentration (QPC). Phenolic compound polymerization appears to play a significant role in enzymatic inhibition. ‘Topaz’ does not fit the high QPC, PPO, and browning formula, suggesting alternative pathways that contribute to apple browning.

scholarly journals A comparative study on fungal laccases immobilized on chitosan

2005 ◽  
Vol 48 (spe) ◽  
pp. 1-6 ◽  
Author(s):  
José Hilton Bernardino de Araújo ◽  
Vinicius Oliveira Uemura ◽  
Flavio Faria de Moraes ◽  
Aneli de Melo Barbosa ◽  
Gisella Maria Zanin
Keyword(s):  
Phenolic Compounds ◽  
Enzymatic Activity ◽  
Pleurotus Ostreatus ◽  
Immobilized Enzyme ◽  
Immobilized Enzymes ◽  
Fungal Laccases ◽  
White Wines ◽  
Aspergillus Sp ◽  
High Enzymatic Activity

The phenoloxidase enzyme laccase from the cultures of the Pleurotus ostreatus and Botryosphaeria sp. and a commercial laccase from Aspergillus sp. were immobilized on chitosan of pharmaceutical degree by adsorption followed by crosslinking. Different immobilization conditions in relation to the granulometry of support and amount of enzymatic laccase extract used were tested, aiming at reaching high enzymatic activity with the immobilized enzyme. Two different substrates, ABTS and DMP, were used for the determination of enzymatic activity. The highest enzymatic activity was obtained when 1.0mg/mL of the enzymatic laccase extract from Botryosphaeria sp. was used with 1.0g of support (200 mesh). These immobilized enzymes are to be applied to the improvement of white wines by the degradation of undesirable phenolic compounds.

scholarly journals Recovery of Active Polyphenol Oxidase and Peroxidase from Plant Tissues with High Phenolics and Chlorophylls

2018 ◽  
Author(s):  
Sarana Rose Sommano
Keyword(s):  
Phase Separation ◽  
High Temperature ◽  
Enzymatic Activity ◽  
Polyphenol Oxidase ◽  
Plant Tissues ◽  
Rich Phase ◽  
Post Harvest ◽  
Membrane Bound ◽  
Triton X ◽  
High Enzymatic Activity

The present protocol described extraction of active polyphenol oxidase and peroxidase from a plant rich in phenolics and chlorophylls in the post-harvest browning syndrome of B. myrtifolia.  Initially, general optimisation using conventional enzyme extractions was performed.  However, along with membrane-bound proteins, chlorophylls and phenols were also released with Triton X (TTX).  With a view to obtaining high enzymatic activity, removal of the released chlorophylls and phenols by formation of TTX-114 micelles in the detergent rich phase after high-temperature induced phase separation was tested.

A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg
Keyword(s):  
Enzymatic Activity ◽  
Colorimetric Determination ◽  
Health And Disease ◽  
Urine Serum

Advances in the Chromatographic Separation and Determination of Bioactive Compounds for Assessing the Nutrient Profile of Nuts

2020 ◽  
Vol 16 ◽  
Author(s):  
Natasa P. Kalogiouri ◽  
Natalia Manousi ◽  
Erwin Rosenberg ◽  
George A. Zachariadis ◽  
Victoria F. Samanidou
Keyword(s):  
Fatty Acids ◽  
Phenolic Compounds ◽  
Bioactive Compounds ◽  
High Performance ◽  
Unsaturated Fatty Acids ◽  
Nutritional Deficiencies ◽  
Analytical Technique ◽  
High Volatility ◽  
Analytical Approaches

Background:: Nuts have been incorporated into guidelines for healthy eating since they contain considerable amounts of antioxidants and their effects are related to health benefits since they contribute to the prevention of nutritional deficiencies. The micronutrient characterization is based mainly on the determination of phenolics which is the most abundant class of bioactive compounds in nuts. Terpenes constitute another class of bioactive compounds that are present in nuts and show high volatility. The analysis of phenolic compounds and terpenes are very demanding tasks that require optimization of the chromatographic conditions to improve the separation of the components. Moreover, nuts are rich in unsaturated fatty acids and they are therefore considered as cardioprotective. Gas chromatography is the predominant instrumental analytical technique for the determination of derivatized fatty acids and terpenes in food matrices, while high performance liquid chromatography is currently the most popular technique for the determination of phenolic compounds Objective:: This review summarizes all the recent advances in the optimization of the chromatographic conditions for the determination of phenolic compounds, fatty acids and terpenes in nuts Conclusion:: The state-of-the art in the technology available is critically discussed, exploring new analytical approaches to reduce the time of analysis and improve the performance of the chromatographic systems in terms of precision, reproducibility, limits of detection and quantification and overall quality of the results

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