The 2012 ASHS Annual Conference

Mandarins (Citrus reticulata Blanco) have relatively short maturity windows , typically lasting ca. 4–8 weeks.  Although maturity windows for standard mandarin cultivars are well know, it needs to be determined for recently developed mandarin hybrids.   Our objective was to quantify changes in flavor of new mandarin hybrids over two harvest seasons in order to better define time of optimum maturity; standard commercial mandarin cultivars were included for comparison. Fruit flavor was evaluated by a panel (n = 10) trained to evaluate citrus fruit. Nine descriptors of fresh mandarin flavor were agreed upon by the panelists prior to evaluation.  Fruit were harvested in the 2010–11 and 2011–12 seasons. At each harvest, fruit were washed, sanitized, peeled, and halved longitudinally; one half of each fruit was evaluated by the taste panel, and the other half was analyzed for quality parameters (total soluble solids, titratable acidity, and flavor volatiles).  Prior to serving, mandarin segments were sliced, cut and mixed in a bowl to assure that each panelist would evaluate a sample from multiple fruits.  There was a sharp contrast in weather pattern between the two seasons, with multiple freezes in the first year (2010–11) and unusually warm weather in the second year (2011–12). Fruit harvested in the 2010–11 season had higher TA and lower soluble solids compared with fruit from the 2011–12 season. In general, panelists perception of  increased maturity was related to a perceived increase in sweetness, and decreases in sourness and bitterness.  ‘Murcott’ was never rated high for sweetness and tangerine flavor in the first year, while it was rated as very sweet with high ratings for juiciness and floral flavor in the second year.  The mandarin x sweet orange hybrid ‘Temple’ had optimum quality in February of 2011 and January and February of 2012, with high ratings for fruity and floral flavors, as well as juiciness. The University of Florida hybrid “411” did not reach high levels of sugars until the end of January 2011; bitterness and sourness were rated high in December 2010 and early January 2011. In contrast, 411 tangerine flavor was rated high in early December 2011, and sweetness and fruity flavor were rated high as early as January 2012.  The quality evaluation of new mandarin hybrids across their potential seasons of maturity helps to determine optimum harvest.