Open Access(173) Phytonutrient Accumulation and Antioxidant Capacity at Eight Developmental Stages of Black Raspberry Fruit
Author(s) -
Murat Özgen,
Artemio Z. Tulio,
Ann M. Cha,
N. Janakiraman,
R. Neil Reese,
Alexander Miller,
Joseph C. Scheerens
Publication year - 2006
Publication title -
hortscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.518
H-Index - 90
eISSN - 2327-9834
pISSN - 0018-5345
DOI - 10.21273/hortsci.41.4.1082c
Subject(s) - abts , ripening , chemistry , anthocyanin , sugar , food science , fructose , horticulture , antioxidant , dry weight , botany , biology , dpph , biochemistry
To investigate phytonutrient accumulation in black raspberries, fruits of `Jewel' and `MacBlack' were harvested at stages from the onset of color development (S1) to ripe fruit (S7). S1–S7 samples were characterized for color reflectance and then frozen at –28 °C within an hour of harvest. Additional ripe fruit were maintained at 20 °C for 3 days to overripen (S8) before freezing. After storage, samples were analyzed for dry weight (DW), total soluble solids (TSS), fructose (FRU), glucose (GLU), and organic acid (ORG) contents; total phenolic (PHE) and anthocyanin (ACY) contents; individual cyanidin glycoside levels (ICG); and antioxidant capacity (FRAP and ABTS) by standard methodology. `Jewel' and `MacBlack' ripened similarly. Chroma values and DW percentage decreased while TSS levels, sugar contents (FRU+GLU), PHE, ACY, the ACY: PHE ratio, and ICG increased with progressive ripening stages (S1–S7). Values of PHE, ACY, and ICG were highly correlated ( r < +0.95) with FRAP and ABTS values. ACY levels in S6 fruit were 18% to 23% less than those of S7; lower S6 ACY levels were associated with reduced antioxidant capacity in `MacBlack', but not `Jewel'. Overripened fruit (S8) exhibited increased DW (11% to 25%) and decreased sugar contents (16% to 17%), consistent with moisture and respiratory losses after harvest. After correction for these losses, S7 and S8 levels of PHE, ACY, FRAP, and ABTS were similar in `MacBlack'. However, as `Jewel' overripened, ACY levels and antioxidant activity increased 44% and 22% to 26%, respectively. Our data suggests that significant changes in the antioxidant behavior of black raspberries can occur during the periods surrounding peak ripeness.