Fruit flavor is a function of sensory perception of taste, aromatic and chemical feeling factor components in the mouth. The specific role of sugars and acids in potentiating flavor perception of volatile compounds and chemical feeling factors is not well known for many fruits. This study was conducted to determine the effects of selected levels of sugars and acids on perception of 3 taste (sweet, sour, bitter), 6 aromatic (banana, grassy, orange peel, peach, pine/turpentine, sweet potato), and 2 chemical feeling factor (astringent, biting) flavor notes in diluted, fresh mango homogenate using a trained descriptive panel. Perception of all flavor descriptors except sour were enhanced by increasing the sugar concentration. An increase in acid concentration enhanced perception of sweet, sour and biting notes while lowering perception of the astringent, peach and pine/turpentine notes. Brix-to-acid ratio (BAR) was found to be an effective chemical indicator for perception of sourness but was not effective for perception of sweetness. These results provide insight into optimum balances of sugars and acids as they influence mango flavor perception specifically in preparation of juice blends, selection of cultivars for specific fresh markets, or determination of optimum ripeness in the marketplace.
T.M.M. Malundo, E.A. Baldwin, R.L. Shewfelt, H. Sisson, and G.O. Ware
R.J. Bender, J.K. Brecht, E.A. Baldwin, and T.M.M. Malundo
To determine the effects of fruit maturity, storage temperature, and controlled atmosphere (CA) on aroma volatiles, mature-green (MG) and tree-ripe (TR) `Tommy Atkins' mangoes (Mangifera indica L.) were stored for 21 days in air or in CA (5% O2 plus 10% or 25% CO2). The MG fruit were stored at 12 °C and the TR fruit at either 8 or 12 °C. Homogenized mesocarp tissue from fruit that had ripened for 2 days in air at 20 °C after the 21-day storage period was used for aroma volatile analysis. The TR mangoes produced much higher levels of all aroma volatiles except hexanal than did MG fruit. Both MG and TR mangoes stored in 25% CO2 tended to have lower terpene (especially p-cymene) and hexanal concentrations than did those stored in 10% CO2 and air-stored fruit. Acetaldehyde and ethanol levels tended to be higher in TR mangoes from 25% CO2 than in those from 10% CO2 or air storage, especially at 8 °C. Inhibition of volatile production by 25% CO2 was greater in MG than in TR mangoes, and at 8 °C compared to 12 °C for TR fruit. However, aroma volatile levels in TR mangoes from the 25% CO2 treatment were in all cases equal to or greater than those in MG fruit treatments. The results suggest that properly selected atmospheres, which prolong mango shelf life by slowing ripening processes, can allow TR mangoes to be stored or shipped without sacrificing their superior aroma quality.
E.A. Baldwin, T.M.M. Malundo, R. Bender, and J.K. Brecht
Mango fruit, cv. Tommy Atkins, were harvested from two grove sites in south Florida at mature green (MG) and tree ripe (TR) maturities. The fruit were either coated with one of two coatings (NS = Nature Seal® 4000, a polysaccharide coating, or CW = carnauba wax) or left uncoated (control) and stored in humidified air or held in a controlled atmosphere (CA = 5% O2 plus 25% CO2) at 12 °C for 21 days followed by 2 days in air at 20 °C. There were 12 fruit for each treatment/maturity stage combination replicated by grove site. After storage, the pulp was homogenized for later consumer or descriptive panel analysis. Measurements for total soluble solids (SS), pH, titratable acidity (TA), and flavor volatile compounds were also made. TR-harvested fruit were sweeter and generally more aromatic than MG-fruit as determined by sensory and/or chemical analysis. NS-coated fruit were more sour, bitter, and astringent compared to controls and CA-treated fruit. NS-coated fruit received lower overall consumer scores than CW-coated fruit, but were not different from controls or CA-treated fruit. This was reflected also in descriptive panel ratings. There were no differences based on storage treatment for SS, pH, or TA; however, NS-coated fruit were higher in acetaldehyde, methanol and ethanol compared to control or CA-treated fruit. Correlation and regression analysis showed significant relationships between sensory and chemical data.
T.M.M. Malundo, R.L. Shewfelt, G.O. Ware, and E.A. Baldwin
Information on important flavor components for fruit and vegetables is lacking and would be useful for breeders and molecular biologists. Effects of sugar and acid levels on mango (Mangifera indica L.) flavor perception were analyzed. Twelve treatments, identified using a constrained simplex lattice mixture design, were formulated by adding sugar (60%), citric acid (40%), and water to an equal volume of mango homogenate. Using 150-mm nonstructured line scales, a trained panel evaluated the treatments according to 11 flavor descriptors. Titratable acidity (TA), pH, and total soluble solids (TSS) were also determined. Acid concentration affected ratings for sweet, sour, peachy, pine/terpentine, astringent, and biting. Except for sour taste, all descriptors were affected by sugar content while increasing water increased intensities of all flavor notes. TA, pH, and TSS/TA correlated (P < 0.01) with and were useful predictors (r > 0.80) of sour taste and chemical feeling descriptors astringent and biting. TSS, however, was not a particularly good indicator of sweetness (r = 0.72) or any other descriptor except possibly peachy (r = 0.79). It is evident from this study that sugars and acids enhance human perception of specific flavor notes in mango, including aromatics.
E.A. Baldwin, J.W. Scott, T.M. Malundo, and R.L. Shewfelt
Sugars, acids, and flavor volatiles are components of flavor that have been measured instrumentally, revealing differences among tomato cultigens. For objective measurements to be useful, however, they need to relate to sensory data. In this study, objective and sensory analyses of tomato flavor were compared. Seven tomato cultigens were ranked for sweetness, sourness, and flavor and rated for overall acceptability by a panel of 32 experienced judges. Sucrose equivalents (SE), measured by HPLC, but not soluble solids correlated with sweetness at P = 0.10. In addition, SE highly correlated with flavor (P = 0.03), while titratable acidity (TA) negatively correlated with overall acceptability (P = 0.03). Regression analysis indicated that 2+3-methylbutanol, cis-3-hexenal, and 6-methyl-5-hepten-2-one significantly contributed to flavor at a 5% level of significance. It is apparent from this study that sucrose equivalents are more meaningful than soluble solids for measurement of sweetness, and that certain flavor volatiles play a role in tomato flavor.
E.A. Baldwin, J.W. Scott, M.A. Einstein, T.M.M. Malundo, B.T. Carr, R.L. Shewfelt, and K.S. Tandon
The major components of flavor in tomato (Lycopersicon esculentum Mill.) and other fruit are thought to be sugars, acids, and flavor volatiles. Tomato overall acceptability, tomato-like flavor, sweetness, and sourness for six to nine tomato cultivars were analyzed by experienced panels using a nine-point scale and by trained descriptive analysis panels using a 15-cm line scale for sweetness, sourness, three to five aroma and three to seven taste descriptors in three seasons. Relationships between sensory data and instrumental analyses, including flavor volatiles, soluble solids (SS), individual sugars converted to sucrose equivalents (SE), titratable acidity (TA), pH, SS/TA, and SE/TA, were established using correlation and multiple linear regression. For instrumental data, SS/TA, SE/TA, TA, and cis-3-hexenol correlated with overall acceptability (P = 0.05); SE, SE/TA (P≤0.03), geranylacetone, 2+3-methylbutanol and 6-methyl-5-hepten-2-one (P = 0.11) with tomato-like flavor; SE, pH, cis-3-hexenal, trans-2-hexenal, hexanal, cis-3-hexenol, geranylacetone, 2+3-methylbutanol, trans-2 heptenal, 6-methyl-5-hepten-2-one, and 1-nitro-2-phenylethane (P≤0.11) with sweetness; and SS, pH, acetaldehyde, aceton, 2-isobutylthiazole, geranlyacetone, β-ionone, ethanol, hexanal and cis-3-hexenal with sourness (P≤0.15) for experienced or trained panel data. Measurements for SS/TA correlated with overall taste (P=0.09) and SS with astringency, bitter aftertaste, and saltiness (P≤0.07) for trained panel data. In addition to the above mentioned flavor volatiles, methanol and 1-penten-3-one significantly affected sensory responses (P = 0.13) for certain aroma descriptors. Levels of aroma compounds affected perception of sweetness and sourness and measurements of SS showed a closer relationship to sourness, astringency, and bitterness than to sweetness.