Pistachio hull is a substantial source of natural polyphenols, but a substantial volume is being wasted annually. Aqueous pistachio green hull extract (PGHE) was subjected to two-stage membrane process in order to separate a polyphenol rich fraction. The membrane conditions of each stage were investigated. Total phenolic content and antioxidant activity were determined by Folin–Ciocalteu and DPPH·assay; also membrane fouling was monitored. The use of the 1 kDa cellulose membrane accompanied by 4 bar pressure and 250 rpm stirring speed was observed to be successful in the separation of a fraction with the highest amount of phenolic compound and antioxidant activity, in the retentate part. UHPLC/MSncharacterization of PGHE polyphenols enabled us to identify 34 compounds, including the most abundant galloylshikimic acids, gallic acid, theogallin, galloyl-O-hexoside, quercetin-O-hexoside and pyrogallol.
Evaluation of polyphenolic compounds in membrane concentrated pistachio hull extract / Seifzadeh, N.; Ali Sahari, M.; Barzegar, M.; Ahmadi Gavlighi, H.; Calani, L.; Del Rio, D.; Galaverna, G.. - In: FOOD CHEMISTRY. - ISSN 0308-8146. - 277:(2019), pp. 398-406. [10.1016/j.foodchem.2018.10.001]
Evaluation of polyphenolic compounds in membrane concentrated pistachio hull extract
Calani L.;Del Rio D.;Galaverna G.
2019-01-01
Abstract
Pistachio hull is a substantial source of natural polyphenols, but a substantial volume is being wasted annually. Aqueous pistachio green hull extract (PGHE) was subjected to two-stage membrane process in order to separate a polyphenol rich fraction. The membrane conditions of each stage were investigated. Total phenolic content and antioxidant activity were determined by Folin–Ciocalteu and DPPH·assay; also membrane fouling was monitored. The use of the 1 kDa cellulose membrane accompanied by 4 bar pressure and 250 rpm stirring speed was observed to be successful in the separation of a fraction with the highest amount of phenolic compound and antioxidant activity, in the retentate part. UHPLC/MSncharacterization of PGHE polyphenols enabled us to identify 34 compounds, including the most abundant galloylshikimic acids, gallic acid, theogallin, galloyl-O-hexoside, quercetin-O-hexoside and pyrogallol.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
