Effects of vinegar production process on bioactivity of some traditional fruits

The aim of this thesis is to evaluate persimmon (Diospyros kaki L.), hawthorn (Crataegus orientalis Pall. Ex M.Bieb.), medlar (Mespilus germanica L.) and blueberry (Vaccinium myrtillus L.) which is rich in bioactive compound for the production of vinegar and to determine the changes that will occur in antioxidant capacity. Also grape whose vinegar consumes commonly is used for control. Primarily, all samples are fermented to wine by alcohol fermentation and then fermented 2 months to vinegar by acetic acid fermentation. The bioactivity analyses and physicochemical analyses are performed once for fresh fruits, marc, wine and for vinegar twice a week. 80% ethanol/water mixture was used as solvent for preparation of bioactive compound extracts of samples. DPPH and CUPRAC methods are used for determination of the antioxidant capacity, and Folin-Ciocalteu is used for the total phenolic compounds. Grape vinegar which is control, the antioxidant capacity of fresh fruit, marc, wine and vinegar were determined as 0.043, 0.145, 0.343, 0.15 mg TEAC/mL respectively according to DPPH method; 2.97, 1.76, 1.76, 1.17 mg TEAC/mL according to CUPRAC method; and total phenolic compound is 51.07, 96.91, 123.33 89.4 mg GAE/L. For persimmon vinegar the antioxidant capacity of fresh fruit, marc, wine and vinegar were determined as 0.515, 0.347, 0.649, 0.106 mg TEAC/mL respectively according to DPPH method; 0.75, 1.24, 1.67, 0.93 mg TEAC/mL according to CUPRAC method; and total phenolic compound was determined as 316.34, 78.59, 144.65, 408.32 mg GAE/L. For blueberry vinegar the antioxidant capacity of fresh fruit, marc, wine and vinegar were determined as 0.205, 0.487, 0.602, 0.15 mg TEAC/mL respectively according to DPPH method; 0.8, 2.21, 2.67, 1.13 mg TEAC/mL according to CUPRAC method; and total phenolic compound was determined as 165.58, 221.23, 167.18, 267.78 mg GAE/L. For medlar vinegar the antioxidant capacity of fresh fruit, marc, wine and vinegar were determined as 0.014, 0.529, 0.051, 0.234 mg TEAC/mL respectively according to DPPH method; 0.5, 1.66, 3.05, 2.6 mg TEAC/mL according to CUPRAC method; and total phenolic compound was determined as 52.87, 202.58, 229.94 733.24 mg GAE/L. For hawthorn vinegar the antioxidant capacity of fresh fruit, marc, wine and vinegar were determined as 0.316, 0.701, 1.238, 0.229 mg TEAC/mL respectively according to DPPH method; 0.3, 4.53, 7.1, 3.41 mg TEAC/mL according to CUPRAC method; and total phenolic compound was determined as 94.2, 453.45, 623.33 683.78 mg GAE/L. As a result, the antioxidant activities and total phenolic contents of the medlar, hawthorn, blueberry and persimmon vinegars increased along the acetic acid fermentation. The maximum increase is observed at hawthorn and medlar vinegar. The total phenolic contents and antioxidant activities of the medlar, hawthorn, blueberry and persimmon fruits and vinegars are higher than those of control group (the grape fruit and vinegar).