Silkworm pupae protein-based odorless food ingredient: Rutin-facilitated modification for off-odor volatile removal

Silkworm (Bombyx mori) pupae are a popular insect-based food source, particularly in Southeast Asia. However, their off-flavors can hinder their widespread acceptance in food applications. To further develop insects as viable food resources, it is crucial to identify and eliminate the off-odor volatile compounds present. This study aimed to identify and eliminate off-odor volatiles from silkworm pupae. A total of 34 odor volatiles were detected from five silkworm pupae components using solid-phase microextraction gas chromatography (SPME-GC-MS). High concentrations of aldehydes, such as nonanal (1.4 microg/g) and decanal (0.14 microg/g), were identified as the primary contributors to the off-odor. Additionally, silkworm pupae protein was found to be a major carrier of these volatiles. To effectively remove the off-odor compounds, polyphenols were used to facilitate the release of aldehydes from the pupae proteins. Specifically, 160 microM rutin increased the release rate of nonanal by 2.2-fold by competing for tryptophan and tyrosine residue sites on the proteins. After a 6 h heat treatment, nonanal release reached over 97 % (p < 0.05). This research provides an effective, cost-efficient strategy for eliminating off-odor volatiles, paving the way for the development of odorless silkworm pupae protein for food applications.