Journal of Food Processing & Technology

Effects of sulfuring at different concentrations on polyphenols and polyphenol oxidase activity in dried apricots

4^th International Conference and Exhibition on Food Processing & Technology

August 10-12, 2015 London, UK

Melek Altindag, Meltem Turkyilmaz and Mehmet Ozkan

Posters-Accepted Abstracts: J Food Process Technol

Abstract:

Effects of various sulfur dioxide (SO2) concentrations (451, 832, 1594 and 2112 mg/kg SO2) on polyphenols, polyphenol oxidase
(PPO) activity and browning values of dried apricots were investigated. Moreover, the correlations between browning with
polyphenols and PPO activity were also determined. The apricots were sulfured by SO2 gas from liquefied SO2 tank in the same sulfur
house and the sulfured apricots were then sun-dried. Dried apricots containing no SO2 were evaluated as a control group. Eight
polyphenols (chlorogenic acid, ferulic acid, caffeic acid, gallic acid, pyrocatechol, catechin, epicatechin and rutin) were identified in
the samples. The major polyphenol was determined as chlorogenic acid (84%). Strong correlation (r=0.917) was found between SO2
concentrations and polyphenols contents of the samples. High PPO activity was determined in control group while PPO activity was
not determined in the samples containing SO2 even at the lowest level (451 mg SO2/kg). However, as SO2 concentration increased,
browning value of the samples decreased (r=0.977). Although there was no PPO activity in none of the dried sulfured-apricots,
their browning values were different. Thus, SO2 prevented the browning due to not only inactivation effect on PPO but also their
antioxidant activity. Taking into consideration of the safety of sulfites, we suggest 451 mg SO2 per kg apricot for the inactivation of
PPO and the preservation of desirable golden-color in dried apricots.

Biography :

Melek Altindag was graduated from Department of Food Engineering at Ankara University as honor student in 2008 and then she worked in different private firms as a
food engineer in Ankara. Currently, she is doing her Master degree in the Department of Food Engineering at Ankara University. At the same time, she is working in a spice
producing firm as a Quality Control Engineer.