engleski

Physicochemical parameters and polyphenolics in fresh and processed mandarins

Croatia in the Neretva valley produces remarkable quantities of mandarins and usually it is not possible to consume whole yield like fresh fruit so some of them are processed into jams. Mandarin like other citrus fruit is rich on polyphenolic compounds which are liable to quantitative and qualitative changes during processing. Therefore, the aim of this research work was to investigate polyphenolic content (total phenols, flavonoids and nonflavonoids by spectrophotometric method) and antioxidant capacity (FRAP method) as well as physicochemical parameters (dry matter, pH, total acidity, sugars and colorimetrically pectic substances) in fresh mandarins’ pulp and peel and in related jams. Two mandarin species Citrus unshiu (cultivar Saigon) and Citrus clementine (cultivar Corsica SRA 63) (grown in Neretva valley) and jams produced according to several recipes with fruit level variations were investigated. Pulp and peel of both investigated mandarin cultivars had very similar values of physicochemical parameters, whereas cv. Citrus clementine had a little bit higher all values except content of pectin substances. Similar values of physicochemical parameters were established in pulp and peel of both investigated mandarin cultivars unless in cv. Citrus Clementine where all values, except content of pectic substances were slightly higher. Also, higher amount of investigated polyphenolics was determined in Citrus clementine (fresh pulp, peel and jams) and flavonoids were most abounded group (55-85%) of polyphenolics in all jams what is contrary with pulp and peel where amount of nonflavonoids was higher (approximately 60% in total phenols) than flavonoids. Furthermore, the amount of polyphenolics and antioxidant capacity decreased during processing into jams and the losses considerably depend on fruit level, so higher amount of polyphenolics as well as antioxidant capacity were determined in jams with higher fruit level.

Mandarin; Clementine; pectic substances; polyphenolic compounds; jam

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