Effect of milled flaxseed and storage conditions on sensory properties and selected bioactive compounds in banana and cinnamon muffins used in a clinical trial

Citation

Santiago, A., Ryland, D., Cui, S., Blewett, H., Aliani, M. (2019). Effect of milled flaxseed and storage conditions on sensory properties and selected bioactive compounds in banana and cinnamon muffins used in a clinical trial, 99(2), 831-843. http://dx.doi.org/10.1002/jsfa.9253

Plain language summary

Clinical trials investigating the health benefits of functional foods require test products to be stored up to 6 months, but the stability of the health promoting bioactives is not assessed. If storage reduces bioactives this may lead to erroneous results. Food manufacturers and the public who are using food for health are interested in both the effect of storage on bioactives in addition to the acceptability of the food product. Consumer panels are typically used to evaluate the acceptability of food products, but this paper is the first to also report the acceptability ratings from participants in a clinical trial investigating the LDL cholesterol lowering effects of flaxseed. Two flavors of muffins (banana and cinnamon) with three amounts of ground flaxseed (0, 20 and 30g) were stored in the freezer (-20°C) for 1 or 6 months. Clinical trial participants generally found the muffins more acceptable than the consumers. Consumers reported decreased acceptability when flax at any level was added to muffins, with 30g the least acceptable. Neither flavoring nor storage appreciably changed muffin acceptability. Cinnamon flavoring showed higher overall acceptability compared to banana. The level of two health promoting bioactives (alpha-linolenic acid and secoisolariciresinol diglucoside) significantly increased with the level of flax and did not decrease with storage. This research shows that storage for up to 6 months at -20°C does not negatively affect the acceptability or level of health promoting bioactives in flaxseed containing muffins. Cinnamon muffins with 20g of flaxseed show the most promise for further commercial development.

Abstract

BACKGROUND: Muffins containing 0, 20, and 30 g of flaxseed were developed for a randomized, controlled cross-over trial on low-density lipoprotein (LDL) cholesterol lowering. The effect of milled flaxseed and storage (−20 °C for 1 and 6 months) of banana and cinnamon muffins on sensory attribute intensities, selected physical properties, bioactive concentrations, and acceptability by two groups – clinical trial participants and consumers – was investigated. RESULTS: The addition of flax increased flax aroma and flavor, sour aroma, and cohesiveness of mass and brown color, and decreased sweet aroma and flavor, banana and cinnamon aroma and flavor, springiness and mouth dryness. Alpha-linolenic acid and secoisolariciresinol diglucoside were significantly increased when flax was increased from 20 to 30 g. Clinical trial participants generally found the muffins more acceptable than the consumers. Consumers reported significantly decreased acceptability when flax at any level was added to muffins, with 30 g the least acceptable. CONCLUSIONS: Muffins with 20 g flaxseed generally had higher mean acceptability values compared to muffins with 30 g. Neither flavoring nor storage at −20 °C for 6 months appreciably changed muffin attributes or acceptability. Future work will optimize the ingredients as well as the amount of flax needed to provide the required amount of bioactive to positively affect LDL cholesterol level and to produce acceptable muffins. © 2018 Society of Chemical Industry.