Effect of Polyphenol Oxidase Activity and Total Phenolic Content on Browning and Quality of Dried-Persimmon According to Maturity Degree of Astringent Persimmon

2015 ◽  
Vol 33 (2) ◽  
pp. 65-68
Author(s):  
Kyung-Mi Jung ◽  
◽  
In-Gyu Song ◽  
Se-Jong Kim ◽  
Sang-Han Lee
Keyword(s):  
Polyphenol Oxidase ◽  
Total Phenolic Content ◽  
Oxidase Activity ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Polyphenol Oxidase Activity ◽  
Maturity Degree

Enzymatic and phytochemical stabilization of orange–strawberry–banana beverages by high hydrostatic pressure and mild heat

2016 ◽  
Vol 23 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Zamantha Escobedo-Avellaneda ◽  
Izaskun Pérez-Simón ◽  
María Lavilla-Martín ◽  
Ana Baranda-González ◽  
Jorge Welti-Chanes
Keyword(s):  
Ascorbic Acid ◽  
Hydrostatic Pressure ◽  
Thermal Treatment ◽  
Polyphenol Oxidase ◽  
High Hydrostatic Pressure ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Ascorbic Acid Content ◽  
Pectin Methylesterase ◽  
Total Phenolic

A new approach to the use of high hydrostatic pressure is its combination with high and intermediate temperatures applied to obtain safe foods of high quality. The effect of high hydrostatic pressure on color, residual polyphenol oxidase and pectin methylesterase activity, and total phenolic and l-ascorbic acid contents of orange–strawberry–banana beverages was evaluated. Beverages were treated at 500 and 600 MPa at 19–64 ℃ during 2–10 min. The effect of the come up time was also evaluated and results were compared with the untreated and the thermally processed (80 ℃/7 min) products. Untreated beverages had total phenolic content of 210.2±12.3 mg gallic acid/100 g and 19.1 ± 0.6 mg l-ascorbic acid/100 g. For most high hydrostatic pressure treatment conditions, total phenolic content, l-ascorbic acid, and color did not change significantly. Maximum levels of inactivation of polyphenol oxidase and pectin methylesterase were 96.2 and 48% at 600 MPa/64 ℃/10 min, while the thermal treatment led to inactivation of 99.6 and 94.1% of both enzymes, but with negative color changes. l-ascorbic acid content was slightly decreased with the thermal treatment while total phenolic content was not affected. High hydrostatic pressure treatments of beverages at 600 MPa/64 ℃/10 min are recommended to retain maximal total phenolic content and l-ascorbic acid and achieve an acceptable polyphenol oxidase inactivation level.

scholarly journals Modificarea activității peroxidazei și a polifenoloxidazei în fructele de prun în funcție de influența SBA Reglalg, microelementelor (B, Zn, Mn, Mo) și a metodelor de păstrare

2020 ◽  
Author(s):  
Ana Popovici ◽  
◽  
Nicolae Bujoreanu ◽  
Valentina Svetlicenco ◽  
◽  
...  
Keyword(s):  
Polyphenol Oxidase ◽  
Oxidase Activity ◽  
Atmospheric Conditions ◽  
Lower Intensity ◽  
Polyphenol Oxidase Activity ◽  
Synthetic Inhibitor ◽  
Duration Of Storage ◽  
Storage Methods ◽  
Fruit Preservation

When storaging the plum fruits of the varieties Stenley under normal atmospheric conditions and by the method of treating them with the synthetic inhibitor of ethylene Fitomag, the modification of peroxidase and polyphenol oxidase activity in fruits depended on the conditions and duration of storage, metabolic processes course in fruit during storage, the particularities of the varieties and their storage methods. The gradual decrease in peroxidase activity and the increase in polyphenol oxidase activity occurred in the case of fruit preservation by both methods. In the fruits storaged by the Fitomag method, the values of these enzymes were lower compared to those in the ordinary atmosphere. The lower intensity of the redox processes has beneficially influenced the preservation of the quality of the fruits preserved by this method compared to the usual atmosphere. There were also essential differences between the control and the variants treated with SBA Reglalg and microelements, as well as between varieties.

scholarly journals Farklı Kurutma Uygulamalarının Armut Meyvesinin Bazı Kalite Özellikleri Üzerine Etkileri

2018 ◽  
Vol 6 (4) ◽  
pp. 479 ◽  
Author(s):  
Gökçen İzli
Keyword(s):  
Antioxidant Capacity ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Dry Weight ◽  
Total Phenolic ◽  
Fresh Sample ◽  
Color Parameters ◽  
Hot Air ◽  
Drying Conditions

In this study; the effects of microwave-hot air combined drying method on color parameters, total phenolic content and antioxidant capacity of pear fruit cut as cubes and rings were determined. In experiments using a laboratory microwave-hot air oven have been performed with two different microwave powers (90W and 160W) and three different drying temperatures (55, 65 ve 75C). The color values of the samples obtained from all drying conditions were found to be in statistically significant different. A decrease in L* (brightness) values and an increase in a* (greenness(-)/redness(+)) values of pear samples were observed with an increasing microwave power and drying temperature. The closest values to the color parameters of fresh pears (∆e=9.90) were obtained from the ring-shaped samples, dried by 160W-55C application. While the highest total phenolic content (164.75 mg GA/100g of dry weight) were determined in the ring-cut form samples dried by 160W-65C, the highest antioxidant capacity was determined in the fresh sample (5.13 µmol troloks/g of dry weight). It was determined that the drying parameters and the cut types immediately affected the quality of the product. Especially, the better color values and total phenolic content results were obtained from the ring-shaped dried pear samples.

scholarly journals Effect of multilayer nylon packages on the oxidative damage of minimally processed yam

2019 ◽  
Vol 22 ◽  
Author(s):  
Adriano do Nascimento Simões ◽  
Daniel Gomes Coelho ◽  
Kelem Silva Fonseca ◽  
Aurélio Paes Barros Júnior ◽  
Sergio Luiz Ferreira-Silva ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Shelf Life ◽  
Polyphenol Oxidase ◽  
Oxidase Activity ◽  
Quality Loss ◽  
Minimally Processed ◽  
Polyphenol Oxidase Activity ◽  
Processed Products ◽  
Physiological And Biochemical

Abstract Appropriate storage packaging is an important aspect to minimize physiological deterioration and enhance the shelf-life of minimally processed products. Thus, the goal of this study was to evaluate the physiological and biochemical changes associated with the quality loss of minimally processed yam, maintained in two different packages at 5 ± 2 °C. The yam roots were selected, washed and conserved at 8 ± 2 °C for 24 hours. They were then peeled and cut into slices about 3 cm thick and minimally processed. Approximately 300 g of minimally processed yam roots were packed in polypropylene (PP, 4 μm thick) and multilayer nylon (NY, 15 μm thick) 15 cm wide x 20 cm long bags, which were stored at 5 ± 2 °C for 14 days. The minimally processed yam conserved in PP packaging presented fluorescence on the surface of the segments, characteristic symptoms of Pseudomonas spp., and showed higher peroxidase and catalase activities. The nylon packaging was more efficient in reducing oxidative damage and also inhibited polyphenol oxidase activity and decreased the accumulation of soluble proteins, resulting in decreased deterioration during storage. Thus, the quality of the minimally processed yam maintained in NY packaging was conserved for 14 days at 5 ± 2 °C.

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