Biofunctionality of a new vinegar rich in anthocyanin from red-fleshed Niedzwetzky's apple: An ornamental plant.

In recent years, red-fleshed apple has attracted a lot of attention due to its pleasant appearance, taste, and being a valuable source of anthocyanins. Generally, different types of this apple are known as ornamental apple plants that are rarely found in various regions around the world like New Zealand, Kazakhstan, Kyrgyzstan, Australia, China, and Turkey. This study focused on the accumulation and changes of the bioactive and aroma-related volatile components at different production stages of a red-fleshed apple vinegar. The aim of this study is to produce an anthocyanin- and vitamin C-rich vinegar (NAV) from red-fleshed Niedzwetzky's apple for the first time. According to the results, in this vinegar, it was determined high concentrations of total phenolic content (904.8 mg-GAE/mL), total flavonoid content (0.25 mg-EGCE/mL), vitamin C content (3024.3 mg-AAE/mL), and 1,1-diphenyl-2-picrylhydrazyl (8.33 mmol-TE/mL), as well as FRAP (13.57 mmol-ISE/mL), respectively. Moreover, total anthocyanin content value was found to be 6.46 mg/g. One of the components that provide the specified functional effect in this vinegar is chlorogenic acid, which constitutes the main phenolic compound, and the other one is cyanidin-3-glucoside, which is the major anthocyanin in this vinegar. The main volatile components associated with the aroma of vinegar are -acetic acid, -phenylacetic acid (5067.7 µg/100 mL), -phenethyl alcohol (3096.1 µg/100 mL), and -nonanoic acid (2939.0 µg/100 mL) compounds. Consequently, it is recommended to expand the range of Niedzwetzky's apples in the production and consumption of food products such as functional vinegar. Thus, a new vinegar with high functional properties will be introduced to the worldwide food industry. PRACTICAL APPLICATION: In this study, vinegar was produced from the small and dark-red-flesh-colored fruits of Niedzwetzky's apple tree, which is known in a small part of the world and is generally used as an ornamental plant due to its red-pink flowers. It has been determined that the produced vinegar has high bioavailability due to the apples with red inner flesh and high anthocyanin content and has a desirable aromatic content. Thus, a food product with high functional quality and desirable aroma, accessible to consumers all over the world, has been produced from a little-known fruit.