abstract
The application of freeze dried hydroxypropyl methylcellulose (HPMC) and methylcellulose (MC) as
stabilizers in peanut butter were investigated. These cellulose derivatives were dispersed in water and
subsequently freeze dried and chopped to produce a stabilizer that is able to absorb high amounts of oil.
Without this templating approach, HPMC and MC had no effect on peanut butter stability and texture. An
alternative spray drying approach was attempted, however, it was found that high incorporation levels
were required to have any stabilizing effect, which is undesirable. Centrifugal accelerated stability testing
showed a significant reduction in oil leakage for samples stabilized with freeze dried HPMC and MC at
addition levels as low as 0.2 wt% in peanut butter, while at addition levels of 2.2 wt%, no oil loss was
observed. With the addition of >1 wt% HPMC/MC, peanut butters were shelf stable for 6 months or
longer. Textural quality of the peanut butter was investigated using a penetration test. Addition of freeze
dried HPMC/MC increased sample firmness and adhesiveness which mimicked the properties of traditional
peanut butter products stabilized with hydrogenated vegetable oils. Light and scanning electron
micrographs showed morphology differences among the stabilizer preparation methods and minimal
structural changes in stabilized peanut butter samples. These experiments helped gain insight into the
mechanism of oil entrapment and demonstrated the potential of these food-grade polymers as stabilizers
in food systems.
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