Sumac fibers for purification of malic acid contained in aqueous sumac extract

Different parts of the sumac (Rhus Coriaria) plant, rich in phenolic substances, are used for different purposes. Anthocyanin and malic acid are found in many plants and are very beneficial for health. The aim of this study is to prepare natural fibers from sumac pericarps to absorb anthocyanin from the aqueous extract of sumac berries and to test their performance. Malic acid was purified by adsorbing anthocyanin from sumac extracts using sumac fibers. Four types of fibers and three types of extracts were used as absorbers and adsorbents respectively in column chromatography. These are sumac fibers in a particle size range of 425-850 µm, 850 µm-1 mm and 1-2 mm, and a synthetic resin (XAD7HP). Sumac extracts are those treated with ultrasound, untreated, and those likely to crystallize. It was observed that sumac fibers selectively absorb anthocyanin in the prepared columns. The moisture content, the water holding capacity, and the water activity of sumac fibers were 5.41%, 154.7%, and 0.437 respectively. Water holding capacity, oil holding capacity, water activity, and weight gain of the acetylated fibers were 36.2%, 16.5%, 0.375, and 4.16% respectively. The supernatants eluted in column chromatography were crystallized, and analyzed by FTIR and GC-MS. The purity of malic acid in the crystals was determined to be 97.6%. Anthocyanin and phenolic substances used in column chromatography were recovered in ethyl alcohol. The total amount of monomeric anthocyanin and the total amount of phenolic substances adsorbed in column chromatography were determined by the pH difference and Folin-Ciocalteu methods respectively.