Sugars (sucrose, glucose, fructose, or glucose/fructose in combination) were added to coarsely chopped, deodorized tomato puree, increasing the sugar level of the puree by 2% to 3%. Sugars (equal amounts of glucose and fructose) along with citric acid were also added to another puree, at two different levels, to create a range of sugar: acid ratios (4.88–19.07). This second puree was then spiked with two different levels of aroma volatiles, reported to affect tomato flavor, in order to understand the influence of the sugar: acid background on tomato aroma and taste perception. The tomato puree was presented to a trained panel and was rated for intensity of aroma and taste descriptors on a 15-cm unstructured line scale. For the puree spiked with sugars only, panelists detected differences for overall aroma, ripe aroma, overall taste, sweetness and sourness intensities (P< 0.15). Adding sweet sugars, like fructose and sucrose, resulted in decreased ratings for aroma descriptors, apparently detracting from panelists' perception of aroma. The sugar: acid ratio of the second tomato puree was found to correlate with perception of taste descriptors sweet (+), sour (–), bitter (–) (P< 0.05), and citrus (–) (P< 0.15) for most volatiles tested. Correlations were also found for the sugar: acid ratio with overall aftertaste (–) when the puree was spiked with furanol, trans-2-hexenal, geranylacetone, or acetaldehyde; fruity (+) with β-ionone and linalool; and tropical (+) with cis-3-hexenal and geranylacetone (P< 0.15). The study suggests that increasing taste factors, like sweetness, result in decreased perception of tomato aroma in general, and affect how aroma compounds influence sensory descriptors.
Elizabeth Baldwin, Kevin Goodner, and Karen Pritchett
Kanjana Mahattanatawee, Elizabeth Baldwin, Kevin Goodner, John Manthey, and Gary Luzio
Fourteen tropical fruits from southern Florida [red guava, white guava, carambola, red pitaya (red dragon), white pitaya (white dragon), mamey, sapodilla, lychee, longan, green mango, ripe mango, green papaya and ripe papaya] were evaluated for antioxidant activity, ascorbic acid (vitamin C), total fiber and pectin. ORAC (oxygen radical absorbance capacity) and DPPH (1,1-diphenyl-2-picrylhydrazyl, radical scavenging activity) assays were used to determine antioxidant activity. The total soluble phenolics (TSP), ORAC, and DPPH ranged from 205.4 to 2316.7 μg gallic acid equivalent/g puree, 0.03 to 16.7 μmole Trolox equivalent/g puree and 2.1 to 620.2 μg gallic acid equivalent/g puree, respectively. Total ascorbic acid (TAA), total dietary fiber (TDF) and pectin ranged from 13.6 to 159.6 mg/100 g, 0.88 to 7.25 g/100 g and 0.2 to 1.04 g/100 g, respectively. The antioxidant activities, TSP, TAA, TDF and pectin appeared to be influenced by cultivar (papaya, guava and dragon fruit) and ripening stage (papaya and/or mango). Data demonstrate the potential benefits of several of these fruits for human health.
Céline Jouquand, Craig Chandler, Anne Plotto, and Kevin Goodner
The aim of this study was to understand the flavor components of eating quality of several strawberry (Fragaria ×ananassa Duch.) genotypes grown in Florida over two harvest seasons. Five selections and one cultivar of the University of Florida Breeding program as well as two new cultivars from Australia (Rubygem and Sugarbaby) harvested on different dates from the same grower were evaluated by sensory evaluation. Festival, the main strawberry cultivar grown in Florida, had low ratings for flavor and sweetness in January and March. Selection FL 00-51 and ‘Rubygem’ had relatively high and consistent ratings for flavor and sweetness compared with the other selections. Genotypes with low flavor ratings were always judged as “not sweet enough” by the panelists, thus linking flavor to sweetness preference. Instrumental analysis confirmed that typically these selections had low soluble solids content (SSC) and/or high titratable acidity (TA), thus explaining their lack of sweetness. Volatile compounds that varied only quantitatively did not seem to influence the flavor rating except for ‘Sugarbaby’. This cultivar contained between seven and 40 times less total ester content than the other selections and was disliked by panelists despite its high sugar content and perceived sweetness. It was perceived as having an artificial peach- or blueberry-like flavor. A principal component analysis was performed with chemical parameters (SSC, TA, and volatile content) and selections over the two harvest seasons. Chemical composition was mainly influenced by harvest date, except for FL 00-51. This selection maintained high volatile content and SSC throughout the seasons, explaining consistently high flavor ratings.
Jinhe Bai, Elizabeth A. Baldwin, Kevin L. Goodner, James P. Mattheis, and Jeffrey K. Brecht
Apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf. (`Gala', `Delicious', `Granny Smith' and `Fuji')], pretreated or nontreated with 1-methylcyclopropene (1-MCP, 0.6 to 1.0 μL·L–1 for 18 hours at 20 °C), were stored in controlled atmosphere (CA, 1 to 1.5 kPa O2; 1 to 2 kPa CO2) or in regular atmosphere (RA) for up to 8 months at 1 °C. Firmness, titratable acidity (TA), soluble solids content (SSC), and volatile abundance were analyzed every month directly or after transfer to air at 20 °C for 1 week to determine effect of 1-MCP, storage atmosphere and storage time on apple quality immediately after cold storage and after simulated marketing conditions at 20 °C. The 1-MCP ± CA treatments delayed ripening and prolonged storage life as indicated by delayed loss of firmness and TA in all four cultivars during storage. The 1-MCP ± CA also slightly delayed loss of SSC for `Gala' but had no effect on SSC levels for the other cultivars. There were differences among treatments for firmness and TA content [(1-MCP + RA) > CA] for `Gala', `Delicious', and `Granny Smith' apples, but not for `Fuji'. These differences were generally exacerbated after transfer of fruit to 20 °C for 1 week. A combination of 1-MCP + CA was generally best [(1-MCP + CA) > (1-MCP + RA) or CA] for maintaining `Delicious' firmness and TA. However, the treatments that were most effective at retaining TA and firmness also retained the least volatiles. The results indicate that the efficacy of 1-MCP and CA in maintaining apple quality factors is cultivar dependent and that 1-MCP + RA may be a viable alternative to CA for optimal eating quality for some cultivars.