Effect of different chemical treatments on the chemical and sensory properties of C. pubescens hawthorn fruits during cryopreservation

Abstract

This research was carried out in the laboratories of the Department of Food Sciences at the Faculty of Agriculture, Damascus University, and the Laboratory of Food Biotechnology at the General Authority for Biotechnology. The aim of this research is to study the chemical and sensory changes that occur on hawthorn fruits C. pubescens growing in the countryside of Lattakia city after being treated with different concentrations of citric acid and sodium metabisulfite and stored at a temperature of 4 °C for a period of 90 days. The content of flavonoids stored only by refrigeration without any chemical treatment at the end of the storage period decreased significantly to 4.70 mg/100g, while this decrease was less in the samples treated with citric acid 3% and metabisulfite 2% in the same storage period, as it reached 5.60 mg/100g and 6. 40 mg/100 g, respectively. The treatment of the fruits with a 4% sodium metabisulfite solution was superior to all other treatments, as there was no significant change in the fruit content of reference sugars, vitamin C, total phenols, and antioxidant activity after two weeks of storage (9.15%, 14.76 mg/100g, and 13.19 mg/100g and 55.86%), respectively. While the change was significant after the same period of storage for the fruit content of vitamin C, total phenols, flavonoids, and antioxidant activity when treated with citric acid 2%, citric acid 3%, and metabisulfite 2%. No significant change was observed in the reducing sugars content of the fruits after two weeks of storage when stored in refrigeration only without any treatment and when treated with 3% citric acid. The vitamin C content of

the fruits decreased at the end of the storage period to 13.21 mg/100g, 12.99 mg/100g, 12.10 mg/100g, 11.90 mg/100g, and 11.30 mg/100g when treated with 4% metabisulfite, 2% metabisulfite, and acid. Citric 3%, citric acid 2%, and the refrigerated-stored sample only without any treatment, respectively. Also, the antioxidant activity decreased at the end of the storage period for fruits treated with 4% metabisulfite, 2% metabisulfite, 3% citric acid, 2% citric acid, and the refrigerated-stored sample without any treatment to 54.32%, 54.14%, 53.10%, 52.50%, and 51%. .26%, respectively. The results of the sensory tests showed that the fruits treated with sodium metabisulfite solutions were more acceptable in terms of color and taste and less acceptable in terms of texture compared to the fruits treated with citric acid and the fruits stored in refrigeration without any treatment, while the fruits treated with citric acid were more acceptable in terms of texture and less acceptable than color. At the end of the storage period, the fruits stored in refrigeration without any chemical treatment were less acceptable in terms of taste, color and texture compared to samples treated with sodium metabisulfite and citric acid.