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ARS Home » Pacific West Area » Corvallis, Oregon » National Clonal Germplasm Repository » Research » Publications at this Location » Publication #289036
Title: Phytochemicals in fruits of Hawaiian wild cranberry relatives

Author
item Hummer, Kim
item DURST, ROBERT - Oregon State University
item Zee, Francis

Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/23/2013
Publication Date: 11/20/2013
Citation: Hummer, K.E., Durst, R., Zee, F.T. 2013. Phytochemicals in fruits of Hawaiian wild cranberry relatives. Journal of the Science of Food and Agriculture. doi: 10.1002/jsfa.6453.

Interpretive Summary: The nutrients of the Hawaiian Native ohelo, a blueberry relative, have not been thoroughly described. Our objective was to evaluate the composition of wild and cultivated samples of the low-growing ohelo. In 2009, ripe fruit samples were collected from the Islands of Hawaii and Maui, and in 2010, from Hawaii. These samples were immediately frozen and sent to Oregon for analysis of sugars, acids, and antioxidants. Samples were also characterized qualitatively for a chemical called PAC, which is a positive influence in urinary tract disorders. Cranberry fruit were analyzed for comparison. Fruits of ohelo tasted bland and had sour, bitter, or low acid qualities. These fruit had a range of surface coloration including yellow, salmon, red, dark red, and purple. In the wild, the skins of lighter colored fruit usually had solid coloration, but were sometimes observed to be speckled with darker colored flecks. Unlike cranberry fruit which had red skin over white flesh, the internal color of ohelo fruit matched that of the skin. The constituents of ohelo fruit are described in the article. Analysis confirmed that PAC compounds are found in ohelo fruit, similar in quantity to that of cranberry. More work is needed to identify specific compounds. These findings suggests the potential of ‘ohelo berries as a functional food.

Technical Abstract: The phytochemical profile of the Hawaiian Native Vaccinium (family Ericaceae) has not been thoroughly described. Our objective was to evaluate the chemical composition of diverse wild and cultivated samples of the low-growing ‘ohelo, V. reticulatum Smith. In 2009, ripe fruit samples were collected from the Islands of Hawaii and Maui, and in 2010, from Hawaii. These samples were immediately frozen and sent to Oregon for analysis of sugars, acids, anthocyanins, phenolics, and antioxidant capacity. Samples were also characterized qualitatively for proanthocyanidins (PAC). Cranberry (V. macrocarpon Aiton) fruit was analyzed for comparison. Fruits of V. reticulatum tasted bland and had sour, bitter, or low acid qualities. These fruit had a range of surface coloration including yellow, salmon, red, dark red, and purple. In the wild, the skins of lighter colored fruit usually had solid coloration, but were sometimes observed to be speckled with darker colored flecks. Unlike cranberry fruit which had red skin over white flesh, the internal color of V. reticulatum fruit matched that of the skin. The mean values for V. reticulatum fruit were significantly lower than those corresponding to V. macrocarpon fruit for oBrix and titratable acidity, although the pH was not different. The oBrix/acid ratio was higher than in cranberry. As with other Vaccinium species, V. reticulatum fruit had an invert glucose/fructose ratio which is about a third to a quarter of that found in cranberry, which is unusually high in glucose. Sucrose, fructose, and total sugars were not different from cranberry. The total non-volatile organic acid profiles were lower than that of cranberry, and the amounts of quinic, malic, and citric acids, were each significantly lower. Total anthocyanins of V. reticulatum fruit were not quantitatively different than the amount found in cranberry but cyd-3-gal and cyd-3-arab were higher in V. reticulatum though peonidin compounds were significantly lower. T Mean vitamin C of the V. reticulatum samples (from 1 to 1.27 mg/100g fresh wt.) was significantly lower than that of cranberry. For V. reticulatum, the mean antioxidant capacity, as determined by ORAC, was about half that of cranberry. In 2009, the mean of total phenolics for the V. reticulatum samples were 316 + 139 mg GAE/100g fresh wt and, in 2010, were 232 (+ 34) which is in the range of that found in cranberry. HPLC-fluorescence-MS results confirmed the presence of PAC compounds in V. reticulatum, similar in quantity to that of cranberry. More work is needed to identify specific compounds. This chemical profile suggests the potential of ‘ohelo berries as a functional food.