Changes in the nutritional value of celery during preparation and maintenance as frozen

In modern life, access to fresh vegetables is limited and proper processing and storage techniques for vegetables are essential. Cabbage quality decreased over time, especially after 2-month storage. The bleaching and freezing can affect it. It is important for the industry to know how to treated cabbage after harvest till supermarket to decrease after harvest damage. The results of this research showed that vitamin C, phenolic compound and antioxidant decreased with storage. Vitamin C is decreased more than other characteristics of cabbage after storage almost 90%. Blanching methods affect the nutrient content of cabbage and Both freezing and storage times decreased cabbage texture (Turkmen et al. 2004). Therefore, in this study, a factorial experiment based on RCBD was designed with 3 replicates to investigate the effect of blanching and freezing method over time on frozen cabbage. by measuring the amount of vitamin C, phenolic compounds, antioxidant activity and elements, the effects of blanching (boiled water and steam) and freezing of two methods domestic (-18 °C) and semi-industrial (40° C) on the nutritional value of celery (Appium graviolens var. Dulce) was evaluated. The results showed that in general, after six months, the antioxidant activity,
vitamin C and phenolic compounds decreased and blanching with boiling water significantly reduced the amount of vitamin C and antioxidant capacity compared to blanching with steam treatment in celery. Over first two months, the reduction in phenolic compounds and antioxidant capacity was more than that of four and six months, but declined over time as the process slowed down. As time progressed, all elements reduced in celery. Vitamin C, has many biological activities in the human body. More than 85% of vitamin C in human diets is supplied by fruits and vegetables (Sahlin et al. 2004). The content of vitamin C among Brassica vegetables varies significantly between and within their subspecies. Generally, among Brassica vegetables, white cabbage is the poorest source of vitamin C (Saari et al. 1995). However, it is a very popular species of Brassica vegetables in Iran. According to our results, freezing of cabbage more than 2 months decreased vitamin C drastically. Loss of vitamin C after 7 and 14 days’ storage at 20 °C decreased to 44% and to 28% in broccoli However, when broccoli was stored at 4 °C, and did not decrease after 7 days and 20% loss after 21 days. Vitamin C content in broccoli reduced by 26% after 3 days of storage at room temperature, by reducing of the storage temperature to 5 °C resulted in an increase (25%) of vitamin C content in broccoli (Lisiewska and Kmiecik 1996). Before vegetables freezing, they washed and blanched to inactivate enzyme systems, especially oxidative enzymes (e.g. polyphenoloxidase, ascorbic oxidase, peroxidase) (Perry and Klein 1982). The effect of blanching in the retention time of vitamin C in different Brassica was investigated, although it depends on temperature and time of blanching method. Vitamin C after blanching was 84% for cauliflower, 70% of cabbage, loss of vitamin C was 28–32% in cauliflower, 41–42% in broccoli, 34% in broccoli (Leja et al. 2001). There was different report was shown that freezing decreased vitamin C in different Brassica differently. After blanching and freezing, about 30% in broccoli. The freezing did not change vitamin C in broccoli and
cauliflower during a 12-month storage and decreased by 3–18% for broccoli and 6–13% for cauliflower and 30%for cabbage (Saari et al. 1995; Leja et al. 2001). there are some reports was shown that Phenolic compounds in broccoli, which are stored 7 days at 1 °C, showed more decreased than ascorbic acid. Storage time effect on Phenolic compounds in different Brassica (Lisiewska and Kmiecik 1996). Phenolic compounds in broccoli, which are stored 7 days decreased 2–3 times (Papetti et al. 2002) On the contrary, total polyphenols did not significantly change in broccoli during 7 days’ storage (Leja et al. 2001; Lisiewska and Kmiecik 1996). Generally, among the qualitative characteristics of celery, reduction of vitamin C more than other traits was affected by different treatments. the type of freezing did not have a significant effect, but storage time was significant so that the values were reduced more rapidly in the first two months of storage.