Food chemistry and biochemistry of enzymatic browning

Author(s):  
Masatsune Murata
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. 


Author(s):  
Manuel Gronbach ◽  
Laura Kraußer ◽  
Timo Broese ◽  
Christina Oppermann ◽  
Udo Kragl

AbstractIn this article, we describe the benefits of sublimation for natural product and food chemistry. The direct sublimation of substances from dried plant powders has not received much attention in research in the past, just like the sublimation of substances from dried plant extracts. We used sublimation to study dried sea buckthorn berry powders and dried sea buckthorn berry extracts. The results of the powder sublimations were compared to that of dried chokeberry, wolfberry, and European cornel powder. 52 marker substances of which 27 are specific for sea buckthorn were found in the sea buckthorn powder sublimates using LC/MS. The majority of them are not described in the literature and were obtained by direct sublimation. Accordingly, sublimation can help to identify new plant constituents. Our identification method was validated by the analysis of four commercially available fruit powders. The sea buckthorn powder showed an almost 80% correlation with the determined marker substances, whereas the other fruit powders did not achieve more than 38% correlation. The sublimates of sea buckthorn extracts show additional marker substances compared to the fruit powder sublimate, and we think that both techniques can be used to fight food fraud.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 482 ◽  
Author(s):  
Antonello Santini ◽  
Nicola Cicero

The Special Issue entitled: “Development of Food Chemistry, Natural Products, and Nutrition Research” is focused on the recent development of food chemistry research, including natural products’ sources and nutrition research, with the objectives of triggering interest towards new perspectives related to foods and opening a novel horizon for research in the food area. The published papers collected in this Special Issue are studies that refer to different aspects of food, ranging from food chemistry and analytical aspects, to composition, natural products, and nutrition, all examined from different perspectives and points of view. Overall, this Special Issue gives a current picture of the main topics of interest in the research and proposes studies and analyses that may prompt and address the efforts of research in the food area to find novel foods and novel applications and stimulate an environmentally-friendly approach for the re-use of the by-products of the agro-food area. This notwithstanding, the main challenge is currently addressed to achieve a full comprehension of the mechanisms of action of food components, the nutrients, outlining their high potential impact as preventive and/or therapeutic tools, not only as a source of macro- and/or micro-nutrients, which are necessary for all the metabolic and body functions.


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