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ARS Home » Southeast Area » Little Rock, Arkansas » Arkansas Children's Nutrition Center » Research » Publications at this Location » Publication #244059
Title: Polyphenolic composition and antioxidant capacity of extruded cranberry pomace

Author
item WHITE, BRITTANY - University Of Arkansas
item HOWARD, LUKE - University Of Arkansas
item Prior, Ronald

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2009
Publication Date: 4/14/2010
Citation: White, B.L., Howard, L.R., Prior, R.L. 2010. Polyphenolic composition and antioxidant capacity of extruded cranberry pomace. Journal of Agricultural and Food Chemistry. 58(7):4037-4042.

Interpretive Summary: Cranberry pomace is the by-product of the cranberry processing industry and is composed of skin, seeds, and stems, which remain after the fruit has been pressed for juice, or prepared for canning. Applications for cranberry pomace are limited. Its low protein content makes it unsuitable for animal feeds, and its low pH presents problems when it is disposed of in the soil. Cranberries are recognized for their ability to prevent urinary tract infections. These benefits have been attributed to the presence of polyphenolic compounds, notably procyanidins. These compounds are found primarily in the seeds and skins of the fruit; thus, many are retained in the pomace. Cranberry pomace, therefore, should be explored as a source of polyphenolic compounds. Cranberry pomace was mixed with corn starch in various ratios (30/70, 40/60, 50/50 pomace/corn starch), and extruded using a twin-screw extruder at three temperatures (150, 170, 190 C), and two screw speeds (150, 200 rpm). Anthocyanin retention was dependent upon barrel temperature and percent pomace. The highest retention was observed at 150 C and 30% pomace. Flavonols increased by 30 to 34% upon extrusion, compared to an un-extruded control. An increase in monomer and dimer procyanidins was also observed; however, a decrease was observed in higher oligomers. These data suggest that extrusion alters the polyphenolic distribution of cranberry pomace and has application in the nutraceutical industry as a means of improving the functionality of this co-product.

Technical Abstract: Cranberry pomace was mixed with corn starch in various ratios (30/70, 40/60, 50/50 pomace/corn starch), and extruded using a twin-screw extruder at three temperatures (150, 170, 190 C), and two screw speeds (150, 200 rpm). Changes in the anthocyanin, flavonol, and procyanidin contents due to extrusion were determined by HPLC. Antioxidant capacity of the extrudates was determined using Oxygen Radical Absorbance Capacity (ORAC). Anthocyanin retention was dependent upon barrel temperature and percent pomace. The highest retention was observed at 150 C and 30% pomace. Flavonols increased by 30 to 34% upon extrusion, compared to an un-extruded control. ORAC values increased upon extrusion at 170 and 190 C. An increase in DP1 and DP2 procyanidins was also observed; however, a decrease was observed in DP4 through DP9 oligomers. These data suggest that extrusion alters the polyphenolic distribution of cranberry pomace and has application in the nutraceutical industry as a means of improving the functionality of this co-product.