Correlating Volatile Compounds, Physiological Parameters, and Sensory Attributes in Stored Fresh-Cut Cantaloupe

Authors: Beaulieu, John; LANCASTER, VICKI - NEPTUNE & CO. INC.

Submitted to: Journal of Agriculture and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2007
Publication Date: 10/19/2007
Citation: Beaulieu, J.C., Lancaster, V.A. 2007. Correlating volatile compounds, physiological parameters, and sensory attributes in stored fresh-cut cantaloupe. Journal of Agriculture and Food Chemistry. 55:9503-9513.

Interpretive Summary: We believe no attempts have been made to statistically correlate (associate) postharvest quality measurements in stored fresh-cut fruits back to specifically classified harvest maturities. A large multi-faceted study on fresh-cut cantaloupe prepared from various maturity stages was performed. Numerous quality and sensory appraisals and volatile compounds were measured. Regarding data, a statistical analysis of variance (method) was conducted and coefficients of correlation were calculated, then parameters were plotted using a new technique (h-plots) to visualize associations. To interpret the data, only correlations considered moderate were evaluated, and focus was placed on correlations considered strong. In general, several quality measures assessed by sensory panelists (cucurbit and water-like aromas, and textures called hardness, cohesiveness, and denseness) in the stored fresh-cut cubes that are often considered to become negative or unfavorable to consumers were associated positively with increasing amounts of acetate, aromatic acetate, and total aromatic (ring structure) compounds. Most instrumental texture measurements were positively associated with the level of aldehyde, acetate, aromatic (ring structure) acetate, and total aromatic compounds. Hardness was positively associated with aromatic acetate, and aromatic (ring) compounds. Subjective appraisal of desiccation was strongly associated positively with acetates. Increased fruity and sweet sensory scores were negatively associated with the level of acetate, aromatic acetate, total aromatic compounds, and positively associated with the level of non-acetate ester compounds. On the other hand several non-acetate ester compounds such as ethyl 2-methyl propanoate, ethyl butanoate, ethyl 2-methyl butanoate, and ethyl hexanoate were negatively associated with cucurbit. Furthermore, some non-acetate ester compounds, like ethyl hexanoate, were strongly positively associated with fruity and sweet. Acetate compounds are common in fruits, and normally associated with desirable sensory and aroma perception. However, if the acetate levels are exceedingly high, the opposite appraisal might be made, as our data indicate. Overall, relatively strong associations between numerous physiological, volatile, and sensory measures were found in this study. There was an interesting relationship found between acetate compounds and quality factors generally considered undesirable in fresh-cut cantaloupe. Further interpretation and biochemical explanation are needed to rationalize why mainly only non-acetate esters were highly correlated with desirable sensory and quality parameters.

Technical Abstract: Changes in post-cutting volatiles, quality, and sensory attributes during fresh-cut storage (4°C) of cantaloupe (Cucumis melo L. var. reticulatus, Naud., cv. 'Sol Real') harvested at 4 distinct maturities (1/4, 1/2-, 3/4-, and full-slip) were investigated after 0, 2, 5, 7, 9, 12, and 14 days, in a 2-year study. The correlation coefficients were calculated using the year x maturity x day means to test the null hypothesis, Ho; r = 0. Correlations were displayed as angles using h-plots. Increased fruity and sweet attributes were negatively correlated with percent acetates, aromatic acetates, and total aromatic compounds; and positively correlated with percentage non-acetate esters. Cucurbit, water-like, hardness, cohesiveness, and denseness were positively correlated with percentage acetates, aromatic acetates, total aromatic compounds; and negatively correlated with percentage non-acetate esters. Hand-held firmness, L* and subjective measures such as color, desiccation, and average subjective were negatively correlated with percentage non-acetate esters, whereas, many of these measures were positively correlated with percentage acetates, aromatic acetates, and total aromatic compounds. Most instrumental texture measures (nondestructive elastic deformation, bioforce, bioyield area, total force area, and Young’s Modulus) were positively correlated with relative percentage of aldehydes, acetates, aromatic acetates, total aromatic compounds, and conversely, negatively correlated with non-acetate esters. In summary, firmer and denser cubes contained more acetates, and less non-acetate esters. The apparently negative or undesirable attributes cucurbit and water-like were associated with higher acetates and aromatic compounds. Overall, relatively strong correlations between numerous physiological, volatile, and sensory measures were found in this study. This occurred even though samples were randomized from numerous fruits, per maturity, per juice catcher container, over 2 years.