Influence of Lipid Content and Lipoxygenase on Flavor Volatiles in the Tomato Peel and Flesh
Abstract: Ten different varieties of tomatoes were separated into peel and flesh and each portion was measured separately. Headspace volatiles were measured in real time using selected ion flow tube mass spectrometry. Lipoxygenase activity was measured using the adsorption of conjugated dienes formed by lipoxygenase. Lipid was extracted and fatty acids were quantified using a gas chromatograph. Volatiles were significantly greater in the peel than flesh when there was a significant difference. The lipoxygenase activity of flesh and peel correlated with the volatiles produced by the lipoxygenase pathway. There was no correlation with other volatiles, which are not dependent on lipid oxidation by lipoxygenase. The lipoxygenase activity, total fatty acid content, and linolenic acid of the peel were greater than the flesh, which is directly related to an increase in fresh, green volatiles. Addition of exogenous lipoxygenase had no effect on lipoxygenase‐derived volatiles formed. The addition of linoleic acid caused an increase in hexanal, 1‐hexanol, and (E)‐2‐heptenal in the flesh and (E)‐2‐heptenal in the peel. Stored unrefrigerated peel had higher volatile concentrations, whereas refrigerated peel had significantly lower concentration than day 0. Storage decreased lipoxygenase activity in the unrefrigerated and refrigerated peel, but had no effect on the fatty acid content. Overall, linolenic acid was the most important to the formation of headspace volatiles, but lipoxygenase activity and unknown factors are also important.
Practical Application: The peel of a tomato is most beneficial to the production of volatiles associated with the fresh aroma of tomatoes; therefore, it should be used in the processing of tomato products to produce a fresh, green aroma rather than being removed. Knowledge of the effects of lipoxygenase activity, total fatty acid content, and fatty acid profile on flavor volatiles will allow for better selection of a variety for raw consumption.
The dominant view of children's memory is that it is slow to develop and is inferior to adults’. Here we pitted 4‐year‐old children against adults in a test of verbatim recall of verbal material. Parents read a novel rhyming verse (and an integrated word list) as their child's b ... more
Self‐propelled motion is a powerful cue that conveys information that an object is animate. In this case, animate refers to an entity's capacity to initiate motion without an applied external force. Sensitivity to this motion cue is present in infants that are a few months old, ... more
Past research has shown that young monolingual children exhibit language‐based social biases: they prefer native language to foreign language speakers. The current research investigated how children's language preferences are influenced by their own bilingualism and by a speaker ... more
Smart skin that can respond to external stimuli could have important applications in medicine and robotics. Using only items found in a typical household, researchers have created multi-sensor artificial skin that's capable of sensing pressure, temperature, humidity, proximity, pH, and air ... more
Some doctors may recommend that patients with the flu take acetaminophen, or paracetemol, to relieve their symptoms; however, a new randomized clinical trial found no benefits to the over-the-counter medication in terms of fighting the influenza virus or reducing patients' temperature or ot ... more
A new study that investigated the potential of certain psychological traits for predisposing heterosexuals to have negative attitudes towards homosexual people found that psychoticism - which is present in severe psychopathological conditions but may also contribute to less severe states of ... more