Impact of processing on odour-active compounds of a mixed tomato-onion puree

Discrimination of 11 Malaysian Durian Cultivars Based on Sulfur-Containing Volatiles and Esters Using Multivariate Data Analysis

There are reports documenting the volatile oils of several durian cultivars in Malaysia. However, there is limited information on the rapid discrimination of the durian cultivars based on the composition of the total volatiles and individual volatile compounds. Thus, the present work aims to discriminate 11 Malaysian durian cultivars based on their volatile compositions using multivariate data analysis. Sulfur-containing volatiles are the major volatiles in D175 (Udang Merah), D88 (Darling), D13 (Golden Bun), DXO (D24 Special), D17 (Green Bamboo), D2 (Dato Nina), and D168 (Hajah Hasmah) durian cultivars, while esters are predominant in D99 (Kop Kecil), D24 (Bukit Merah), and D160 (Musang Queen) durian cultivars. D197 (Musang King) cultivar has an almost equal composition of sulfur-containing volatiles and esters. In the ester predominated volatile durian oil, ethyl 2-methylbutanoate and propyl 2-methylbutanoate are the major volatile compounds, while the durian cultivars with predominant sulfur-containing volatiles mainly contain diethyl disulfide, diethyl trisulfide, and 3,5-dimethyl-1,2,4-trithiolane. The durian cultivars were clustered into 8 clusters using principal component analysis, with 3 clusters consisting of 2 cultivars, and with the remaining cultivars clustered individually. The highly sought-after durian cultivars, D160 and D197, were clustered into one. Hierarchal clustering analysis identified the distinct compounds which discriminate every durian cultivar.

Characterising the sensory quality and volatile aroma profile of clean-label sucrose reduced sponge cakes

The sensory and aroma quality of 30% (w/w) sucrose reduced sponge cakes incorporating clean-label replacers were investigated. The sensory quality of the reformulated sponge cakes varied, with those containing apple pomace powder (APP) showing the greatest difference to the control (SC100). Volatile profiles mainly differed in relation to compounds derived from the Maillard reaction, caramelisation and lipid oxidation. Thrity six aroma active volatile compounds were identified in the SC100, APP and oligofructose (OLIGO) sponge cakes by olfactometry. Furfural 'spicy bready' contributed most to the overall aroma of all samples, with factor dilution values differing the most for heptanal 'fatty cake crust', methional 'potato damp', and 2,5-dimethylpyrazine 'cake crust, nutty'. This study provides an in-depth insight into the impact of sugar reduction reformulation on the sensory perception of sponge cakes and demonstrates how this approach can be used to improve the sensory perception of reduced sucrose sponge cakes.

A D-optimal mixture design of tomato-based sauce formulations: effects of onion and EVOO on lycopene isomerization and bioaccessibility

A D-optimal mixture design was used to study the effects of onion and extra virgin olive oil (EVOO) on lycopene Z-isomerization, lycopene diffusion into oil (expressed as a partition factor between tomato-based puree and oil) and in vitro bioaccessibility of lycopene isomers after thermal treatment of tomato-based puree consisting of tomato (75-100%), onion (0-20%) and EVOO (0-5%). A decrease of tomato puree could improve lycopene Z-isomerization, lycopene diffusion and lycopene bioaccessibility. The component interactions had an important influence on the Z-isomerization of lycopene, besides the linear mixtures of components. However, only linear mixtures of components appeared to have significant effects on the diffusion and bioaccessibility of lycopene, in which EVOO had the highest positive effect followed by onion. The bioaccessibility of lycopene isomers in every tomato-based sauce formulation decreased in the order: 13-Z-lycopene > 9-Z-lycopene > 5-Z-lycopene > all-E-lycopene. The bioaccessibility of total-Z-lycopene was at least 10 times higher than that of all-E-lycopene. Proportions of total-Z-lycopene were correlated positively with the partition factor and bioaccessibility of total-lycopene, with an r over 0.730 (p = 0.0031). Therefore, increased Z-lycopene proportions probably contributed to enhanced lycopene diffusion and bioaccessibility. The positive effects of components, especially onion, on total-lycopene diffusion and bioaccessibility were probably because the components increased the Z-isomerization of lycopene during heating of tomato-based puree.

The Blossoming of Technology for the Analysis of Complex Aroma Bouquets-A Review on Flavour and Odorant Multidimensional and Comprehensive Gas Chromatography Applications

Multidimensional approaches in gas chromatography have been established as potent tools to (almost) attain fully resolved analyses. Flavours and odours are important application fields for these techniques since they include complex matrices, and are of interest for both scientific study and to consumers. This article is a review of the main research studies in the above theme, discussing the achievements and challenges that demonstrate a maturing of analytical separation technology.

Heating tomato puree in the presence of lipids and onion: The impact of onion on lycopene isomerization

Z-lycopene isomers are more bioavailable than all-E-lycopene, especially 5-Z-lycopene. Based on our observations, the addition of unblanched onion could favor Z-isomerization of lycopene (by more than 94%) during heating tomato-onion-extra virgin olive oil (EVOO) purees at 90 °C for 2 h. The increase in Z-lycopene was correlated linearly with the addition of unblanched onion, with R² > 0.92, and increased rates of 5-Z-lycopene were 3-4 times higher than for 9-Z-lycopene and 13-Z-lycopene. Diallyl disulfide (DADS), formed by alliinase-catalyzed breakdown of non-volatile precursors in onion, contributed to these increases and correlated linearly (R² > 0.79, 0-0.50 mg/g puree) with increased Z-lycopene. Increased rates of 5-Z-lycopene were also 3-4 times higher than for 9-Z-lycopene and 13-Z-lycopene. However, blanching of onion, in tomato-onion-EVOO purees, before heating, significantly decreased the effect of onion on Z-isomerization of lycopene.

Flavor formation in frying process of green onion (Allium fistulosum L.) deep-fried oil

Fried allium oil has been widely used in traditional Chinese home cooking and recently has grown in popularity in the food manufacturing industry. Thus, physical and chemical changes during frying process were measured to investigate the flavor formation mechanism in green onion (Allium fistulosum L.) deep-fried oil. With the increase of the oil temperature, important variations took place when the temperature rose above 140 °C during the whole frying process. A detailed study of these changes was made from both macro and micro aspects. From a macro perspective, sensory attributes including burnt, fried, oily, cooked vegetable and salty were strengthened. Meanwhile, the reference points of the oil samples on the fingerprint chart were distinguishable from others by electronic nose. In addition, contents of furans and furanones, sulfur-containing compounds, aldehydes and alcohols increased sharply according to SAFE-GC-MS analysis from a microscopic point of view, and contents of unsaturated fatty acids dropped remarkably while the saturated ones increased. These changes were considered to be caused by interactions between carbohydrates, proteins and fats in the deep-fried system and thermo degradations of sugars, amino acids and fats. The results indicated that the stage, when frying at temperatures ranging from 140 °C to 165 °C, was the most significant period for the flavor formation of the deep-fried oil.

Scientific Opinion on Flavouring Group Evaluation 226 Revision 1 (FGE.226Rev1): consideration of genotoxicity data on one α,β-unsaturated aldehyde from chemical subgroup 1.1.1(b) of FGE.19

The EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids was requested to evaluate the genotoxic potential of one flavouring substance from subgroup 1.1.1(b) of FGE.19 in the Flavouring Group Evaluation 226 (FGE.226). The flavour industry provided genotoxicity studies for the substance 4,5-epoxydec-2(trans)-enal [FL-no: 16.071]. Based on these data, the Panel concluded in FGE.226 that 4,5-epoxydec-2(trans)-enal did not induce gene mutations in bacterial cells but was positive in an in vitro micronucleus assay, so, 4,5-epoxydec-2(trans)-enal is considered an in vitro genotoxic agent. The negative results obtained in an in vivo micronucleus assay cannot overrule the positive results of the in vitro micronucleus assay with and without S9-mix due to the lack of demonstration of bone marrow exposure. Following this, the flavour industry has provided plasma analysis of a satellite group of rats treated with 4,5-epoxydec-2(trans)-enal in order to investigate the systemic exposure of animals in the in vivo micronucleus assay. However, the plasma analysis did not provide enough evidence of target tissue exposure. An in vivo Comet assay in rodents was recommended in FGE.226, in order to investigate possible genotoxic effects at the first site of contact (e.g. stomach/duodenum cells) and in the liver. An in vivo Comet assay in liver and duodenum was provided that suggests that 4,5-epoxydec-2(trans)-enal [FL-no: 16.071] did not induce DNA damage in the duodenum of rats. However, the genotoxic effect observed in vitro was confirmed in the in vivo Comet assay in the liver of rats. The Panel concluded that 4,5-epoxydec-2(trans)-enal [FL-no: 16.071] does raise a safety concern with respect to genotoxicity and, therefore, it cannot be evaluated according to the Procedure.