Six-carbon aldehydes and alcohols formed by tomato (Lycopersicon esculentum Mill.) leaf and fruit tissue following disruption are believed to be derived from the degradation of lipids and free fatty acids. Collectively, these C-6 volatiles comprise some of the most important aroma impact compounds. If fatty acids are the primary source of tomato volatiles, then an alteration in the fatty acid composition such as that caused by a mutation in the chloroplastic omega-3-fatty acid desaturase (ω-3 FAD), referred to as LeFAD7, found in the mutant line of `Castlemart' termed Lefad7, would be reflected in the volatile profile of disrupted leaf and fruit tissue. Leaves and fruit of the Lefad7 mutant had ≈10% to 15% of the linolenic acid (18:3) levels and about 1.5- to 3-fold higher linoleic acid (18:2) levels found in the parent line. Production of unsaturated C-6 aldehydes Z-3-hexenal, Z-3-hexenol, and E-2-hexenal and the alcohol Z-3-hexenol derived from 18:3 was markedly reduced in disrupted leaf and fruit tissue of the Lefad7 mutant line. Conversely, the production of the saturated C-6 aldehyde hexanal and its alcohol, hexanol, were markedly higher in the mutant line. The shift in the volatile profile brought about by the loss of chloroplastic FAD activity in the Lefad7 line was detected by sensory panels at high significance levels (P < 0.0005) and detrimentally affected fruit sensory quality. The ratios and amounts of C-6 saturated and unsaturated aldehydes and alcohols produced by tomato were dependent on substrate levels, suggesting that practices that alter the content of linoleic and linolenic acids or change their ratios can influence tomato flavor.
Mauricio A. Cañoles, Randolph M. Beaudry, Chuanyou Li, and Gregg Howe
Douglas D. Archbold, Ann M. Clements, T.R. Hamilton-Kemp, and R.W. Collins
Prior work indicated that volatile compounds produced by macerated strawberry fruit occurred at levels capable of affecting pathogen development. To determine if a less-severe injury, such as bruising, would alter the volatile profile of strawberry fruit, the headspace volatiles from ripe `Tribute' strawberry fruit were sampled with SPME fiber during the 15 min immediately following and from 75 to 90 min following application of a compression bruise. The compression bruise was applied with a force gauge, and fruit were kept in a closed bottle at room temperature during the study. Of the 14 major volatile products consistently produced by all fruit, acetate esters derived from hexanal, (E)-2-hexenal, and (Z)-3-hexenal increased most, over 50%, in response to bruising during the first interval. During the later interval, bruised fruit produced over 50% more (E)-2-hexenyl acetate and hexyl acetate than control fruit. Most notably, the ratio of levels of (E)-2-hexenyl acetate produced by bruised compared to control fruit were the highest among all 14 major volatiles, over 150% more after 15 min and 270% more at 90 min. Headspace levels of the 6-carbon acetate esters declined for both control and bruised fruit between 15 and 90 min, while levels of the other major volatiles increased. The other 11 volatile compounds were commonly identified aroma volatiles. Headspace levels of some of these were also higher from bruised than control fruit. In particular, headspace levels of ethyl butyrate were increased by bruising 13% after 15 min but over 100% after 90 min, the most of any volatile product other than (E)-2-hexenyl acetate.
Ji Heun Hong and Ken Gross
Fresh-cut produce continues to be a rapidly growing industry. However, there is little information available on storage conditions for many commodities, particularly for fresh-cut tomato slices. A major problem with fresh-cut tomato slices is their short shelf-life. The best method to extend shelf-life is refrigerated storage, preferably around 4 to 5 °C. Unfortunately, tomato tissue is susceptible to chilling injury at such temperatures. Experiments were conducted to compare changes in quality of slices from red tomato (Lycopersicon esculentum Mill.) fruit during storage at 5 or 10 °C under various modified-atmosphere conditions. In this study, we used the fourth uniform slice from the stem end and analyzed for various quality attributes during the storage period. At both 5 and 10 °C storage temperatures, ethylene concentration in containers sealed with Film A (oxygen transmission rate of 60.3 or 77.9 ml per hour per m2 at 1 atm and 99% relative humidity at 5 or 10 °C, respectively) was higher than that sealed with Film B (oxygen transmission rate of 87.4 or 119.4 ml per hour per m2 at 1 atm and 99% relative humidity at 5 or 10 °C, respectively), during storage. In addition, chilling injury, as measured by percent of slices showing some water soaked-areas, in containers sealed with Film B was higher than that of slices in containers sealed with Film A. The percent of visible fungal growth of slices was roughly correlated with the degree of chilling injury, as measured by the percent of slices showing some water soaked-areas. After 13 days of storage at 5 °C, slices stored in containers with a beginning atmospheric composition of 12% CO2 /1% O2 were firmer, compared to slices given the other treatments. After 9 days of storage at 10 °C, no visible fungal growth was observed on slices in containers with a beginning atmospheric composition of 12% CO2/1% O2 or 12% CO2/20% O2. However, slices in containers with a beginning atmospheric composition of air, or 4% CO2/1 or 20% O2 and 8% CO2/1 or 20% O2 did show visible signs of fungal growth at 25%, 33%, 46%, 29%, and 100% of infected slices, respectively. Slices in containers given all treatments, with the exception of 12% CO2/1% O2, had visible fungal growth after 15 days of storage at 5 °C. Slices in containers containing eight slices had less chilling injury and visible fungal growth than those containing four slices. Chilling injury of slices stored in completely enclosed plastic containers, similar to those commonly observed in grocery food stores, was over 7-fold higher than chilling injury observed in slices containers covered with Film A after 12 days of storage at 5 °C. However, there were no significant differences in the amounts of the volatiles we measured, i.e., ethanol, ethyl acetate, hexanol and hexanal, between the two container types. These results suggested that modified-atmosphere packaging storage can extend shelflife, as well as inhibit chilling injury in fresh-cut tomato slices.
Elizabeth A. Baldwin, John W. Scott, and Jinhe Bai
the years and seasons ( Table 6 ) including acetaldehyde, hexanal, trans -2-pentenal, cis -3-hexanal, trans -2-hexenal, 2 + 3-methylbutanal, trans -2-heptenal, phenylacetaldehyde, methional, benzaldehyde, citral, trans -2, trans -4-decadienal
Hui-Juan Zhou, Zheng-Wen Ye, and Ming-Shen Su
peach fruit ( Rizzolo et al., 2013 ). Aubert et al. (2003) reported that hexanal, benzaldehyde, linalool, γ-decalactone, and δ-decalactone were the major aroma compounds, but Sumitani et al. (1994) reported that hexanal was not an aroma compound. The
Elizabeth Baldwin, Jinhe Bai, Anne Plotto, John Manthey, Smita Raithore, Sophie Deterre, Wei Zhao, Cecilia do Nascimento Nunes, Philip A. Stansly, and James A. Tansey
was highest in hexanal, decanal, ethanol (along with C ), terpinene-4-ol, α -pinene, sabinene, myrcene (along with C ), limonene (along with C ), γ-terpinene, ethyl butanoate, ethyl hexanoate, and acetone (the last three along with C and acetone
Bayram Murat Asma
‘Dilbay’ were 5767 μg/kg fresh weight (FW), the majority of which (5535.5 μg) were positively identified. The major volatile compounds were hexanal (613 μg·kg −1 FW), 2-hexenal (3.186 μg·kg −1 FW), (E)-2-Hexen-1-ol (329.2 μg·kg −1 FW), hexyl acetate
Yan Li, Hongyan Qi, Yazhong Jin, Xiaobin Tian, Linlin Sui, and Yan Qiu
” and “fresh” notes in ripe fruit ( Baldwin et al., 2000 ). First, LOX produces hydroperoxide isomers of FA, which are subsequently cleaved by HPL to form hexanal and hexenal, respectively. Then, these aldehydes are reduced to alcohols by ADH ( Manríquez
Sharon Dea, Jeffrey K. Brecht, Maria Cecilia do Nascimento Nunes, and Elizabeth A. Baldwin
). The changes in volatile content for all of the volatiles that were affected by one or more of the main effects evaluated in this study during storage at 5 °C are presented in Figs. 7–10 . Fig. 7. Changes in acetaldehyde and hexanal in fresh-cut ‘Kent
Ying Wang, Tingting Xue, Xing Han, Lingxiao Guan, Liang Zhang, Hua Wang, and Hua Li
, 2,4-di-tert-butylphenol, 2-methyl-1-butanal, hexanal, octanal, nonanal, decanal, 2-octanone, 2-nonanone, methyl 2-methoxybenzoate, ethyl octoate, ethyl caprate, and (E)-geranylacetone. These changes significantly altered the overall aroma profile