Pre-harvest chelated or nano-chelated zinc treatment impact on enzymatic browning in apple

2021 ◽  
pp. 633-638
Author(s):  
M. Rasouli ◽  
M. Koushesh Saba
2019 ◽  
Vol 19 (10) ◽  
pp. 796-808 ◽  
Author(s):  
Kamal Uddin Zaidi ◽  
Sharique A. Ali ◽  
Ayesha Ali ◽  
Ishrat Naaz

Cutaneous pigmentation plays critical role in determining the color of skin along with photo protection of skin from dreadful effects of ultraviolet radiations. Conversely, abnormal accumulation of melanin is responsible for hyper pigmentary disorders such as melasma, senile lentigines and freckles. Because of the visible nature of dermatologic diseases, they have a considerable psychosomatic effect on affected patients. Tyrosinase inhibitors are molecules that interrelate in some way with the enzyme to prevent it from working in the normal manner. Past many decades witnessed the quest for the development of natural tyrosinase inhibitors due to imperative role played by tyrosinase in the process of melanogenesis and fungi or fruit enzymatic browning. Mechanism of pigmentation is characterized by the intact process of the synthesis of specialized black pigment within melanosomes. Melanin is synthesized by a cascade of enzymatic and chemical reactions. For this reason, melanin production is mainly controlled by the expression and activation of tyrosinase. In the current article, we discussed tyrosinase inhibitors from the natural sources, which can be an essential constituent of cosmetics products and depigmenting agents for the treatment of hyperpigmentory disorders.


2007 ◽  
Vol 3 (6) ◽  
pp. 1-7 ◽  
Author(s):  
Qiang He ◽  
Yaguang Luo
Keyword(s):  

2017 ◽  
Vol 39 (1) ◽  
pp. 103 ◽  
Author(s):  
Luciana Ercoli ◽  
Érica Oliveira Barizão ◽  
Joana Shuelter Boeing ◽  
Marcus Vinícius Kvitschal ◽  
Jesuí Vergilio Visentainer ◽  
...  

In this research, the total phenolic content (TPC) and antioxidant capacity (FRAP and DPPH•× assays) of pulps and peels of advanced selection of apples grown in Brazil were investigated. The correlation analyses between the activity of polyphenoloxidase enzyme (PPO), vitamin C content, total titratable acidity, and color parameters were performed. The results indicated that the data differed significantly among the apple genotypes studied. The peels of the selection Epagri 170-91 and Epagri 170-25 showed the highest TPC and antioxidant capacities. In addition, the pulps of the Epagri 170-91 presented the highest TPC and antioxidant capacities, the lowest enzymatic browning, highest amount of vitamin C and lowest enzymatic activity when compared with other genotypes. The TPC and antioxidant capacities were significantly correlated in all genotypes analyzed. High correlation values between enzymatic browning and factors that affect the apple color were also found in all analyzed pulps, except between enzymatic browning and TPC. The results demonstrated that the enzymatic browning and TPC, as well as the antioxidant capacity and chemical characteristics, vary considerably depending on the apple genotypes and fruit tissues analyzed. 


2005 ◽  
Vol 92 (2) ◽  
pp. 357-363 ◽  
Author(s):  
S OH ◽  
Y LEE ◽  
J LEE ◽  
M KIM ◽  
H YOOK ◽  
...  

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yan Yang ◽  
Ya Li ◽  
Liang Feng ◽  
Ai-Nong Yu ◽  
Bao-Guo Sun ◽  
...  

AbstractThe non-enzymatic browning (NEB) reaction between l-ascorbic acid (ASA) and glycine (Gly), including the effects of temperature (110–150 °C), time (10–150 min) and pH (4.5, 6.8, 8.0 and 9.5) on the formation of un-colored intermediate products (UIPs), browning products (BPs) and volatile products (VPs), were investigated. The results showed that pH had a remarkable effect on the reaction. The characteristics of zero-order kinetics for the formation of UIPs and BPs were discussed, and the corresponding activation energy (Ea) was also calculated. When the pH was 4.5, the Ea for the formation of UIPs was approximate 53.76 kJ/mol and less than that at other pH values; while the Ea for BPs formation was approximate 94.06 kJ/mol and much higher than that at other pH values. The results suggested that an acidic environment facilitated the generation of UIPs, but did not remarkably promote the formation of BPs. The possible reaction pathway between ASA and Gly was proposed according to the experimental results.


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