Nitrite Scavenging and Inhibition of N-Nitrosamines Formation by Phenolic Extracts From Diospyros lotus L. Leaves and Active Ingredients

Abstract

Diospyros lotus L. leaves are used as a functional tea and folk medicine in several Asian countries. This study aimed to evaluate the effects of phenolic extracts of the leaves on scavenging nitrite and inhibiting N-nitrosamines (NAs) formation and to determine the active ingredients responsible for these effects. Of the 7 fractions (Fr1-Fr7) prepared from the extract of D. lotus leaves, Fr5 contained the highest phenolic content and exhibited the strongest activity. Five active ingredients of Fr5 were discovered, and 4 of them were identified as myricitrin (Mytr), myricetin (Myt), myricetin-3- O-β-d-glucoside (Myt-Glc), and myricetin-3- O-β-d-galactoside (Myt-Gal). The content of Mytr was much higher than those of the other 3 ingredients, both in Fr5 and extracts of D. lotus leaves. Finally, Mytr and Myt were proved to have stronger activities by the 1,1-diphenyl-2-trinitrophenyl hydrazine scavenging, nitrite scavenging, and inhibition of NAs formation assays. These results indicated that Mytr was the main active ingredient of D. lotus leaves. Myt, Mytr, and Fr5 from the leaves could be used as natural agents for antioxidant, nitrite scavenging, and inhibition of NAs formation in food and the human body.

Phytochemical Composition, Antibacterial Activity, and Antioxidant Properties of the Artocarpus altilis Fruits to Promote Their Consumption in the Comoros Islands as Potential Health-Promoting Food or a Source of Bioactive Molecules for the Food Industry

“…Coumaric acid presents antioxidant properties [ 52 ]. It may show a role in reducing the risk of stomach cancer by reducing the formation of carcinogenic nitrosamines [ 53 ].…”

Olive Leaf Extract (OLE) Addition as Tool to Reduce Nitrate and Nitrite in Ripened Sausages

“…However, several population studies associated the high meat intake, especially of red and processed meat, with the development of cardiovascular diseases and colorectal cancer in a dose-dependent manner [2]. These risks are mainly due to the high-fat content, particularly richness in saturated fatty acids and cholesterol, and to the carcinogen compounds generated from processing and as a consequence of the additives transformation [3].…”

“…Among the latter, nitrites and nitrates are common meat additives which allow: (i) stability of the intense red colour, particularly appreciated by the consumers; (ii) inhibition of the growth of undesirable bacteria, such as Clostridium botulinum and toxin production; (iii) improvement of the oxidative stability; (iv) contribution to flavour formation [3,4]. Nevertheless, the addition of nitrates and nitrites to processed meat can induce the development of N-nitroso compounds linked with genotoxicity and metabolic disturbances in the large intestine mucosa [2], with the subsequent risk to potentially develop colorectal cancer [5].…”

“…N-nitrosamines (NAs) could also be formed in the human stomach and mouth from residual nitrites in cured-meat products [6,7]. Furthermore, humans are continuously exposed to NAs, considered as environmental pollutants with high toxicity and carcinogenity [3,8]. For these reasons, over the years, great attention has been paid to nitrite reaction products in foods and NAs production [9].…”

“…Over time, a lot of reports about nitrite scavenging and inhibition of NAs formation by natural ingredients, essential oils, extracts from fruits, or vegetables spices have been carried out [3,6]. Furthermore, wastes and by-products from the agricultural and food industry sectors contain highly valuable bioactive substances such as polyphenols, showing antioxidants and antimicrobial activities [12,13].…”