The comparison of the physicochemical parameters and antioxidant activity of homemade and commercial pomegranate juices [pdf

Abstract

BACKGROUND The pomegranate (Punica granatum L.) has gained a reputation as a fruit with many health- promoting properties. It is considered to help prevent or treat various disease risk factors including high blood pressure, high cholesterol, oxidative stress, hyperglycemia and inflammatory activities. It has been demonstrated that certain components of pomegranates, such as polyphenols, have potential antioxidant, anti-inflammatory and anticarcinogenic effects. METHODS Five commercially available (CA) and three homemade (HM) pomegranate (Puni- ca granatum L.) juices were evaluated for their physicochemical properties including titratable acidity (TA), pH and total soluble solids (TSS), as well as antioxidant properties such as anthocyanin content, ascorbic acid content (AA), antioxidant activity (DPPH), total phenolic compounds (TPC) and ferric reducing antioxidant power (FRAP). Moreover, the concentrations of 18 different elements (Ca, K, Mg, P, S, Na, Cr, Cu, Fe, Mn, Mo, Sr, Zn, Al, Cd, Ni, Pb, Hg) were determined using the ICP-OES method, with prior wet mineralization. RESULTS TA was significantly lower (P < 0.05) in homemade than in commercial juices (0.380 and 1.318% citric acid respectively). The TPC and FRAP parameters were about 50% higher in commercial than in homemade juices. Polyphenols were strongly correlated with antioxidant activity measured by FRAP and DPPH tests (r = 0.958 and 0.886 respectively), and a significant correlation for anthocyanins and vitamin C (r = 0.849) was observed. The most common mineral in each tested juice was potassium (132.69–3151.87 mg/dm3) and a high level of magnesium (23.42–123.63 mg/dm3) was found. CONCLUSIONS Obtaining juices from whole fruits (peel and arils), as in commercial production, enhanced the content of polyphenol compounds and the antioxidant activity of the juice. However, a better mineral compo- sition was observed in homemade juices.