The effect of churning temperature (10 8C vs. 22 8C) is evaluated with respect to water
content, rheology, microstructure and stability of butter produced using the batch churning
method with a temperature ramp of 4 8C/min. Using pulsed-nuclear magnetic resonance, an
increase in relative solid fat content from 44% to 49.5% was observed when decreasing the
churning temperature. Due to lower solid fat content formed upon churning at high
temperatures, average water droplet size significantly increased from 5.5 mm to 18.5 mm
and less water could be incorporated into the butter during mixing. Using differential
scanning calorimetry, it was observed that water addition as well as churning at low
temperatures induced a transition toward more stable crystal structures, as the melting
point in the high melting fraction was slightly lower for butter churned at high temperature.
This did, however, not reflect in any changes in terms of crystal polymorphism, and all
butters contained primarily b0
-crystals with traces of a- and b-crystals. Despite the observed
changes, small deformation rheology revealed no difference as a function of churning
temperature or water content. During isothermal storage at 5 8C, the solid fat content
increased in all butters, but only butter churned at 10 8C showed an increase in hardness
during storage. However, no difference in rheological behavior was observed among the
butters. Thus it can be concluded that low temperature allows more water to be incorporated
in the system without inducing any changes in rheological behavior or crystal
polymorphism after four weeks of storage.
The effect of churning temperature (10 8C vs. 22 8C) is evaluated with respect to watercontent, rheology, microstructure and stability of butter produced using the batch churningmethod with a temperature ramp of 4 8C/min. Using pulsed-nuclear magnetic resonance, anincrease in relative solid fat content from 44% to 49.5% was observed when decreasing thechurning temperature. Due to lower solid fat content formed upon churning at hightemperatures, average water droplet size significantly increased from 5.5 mm to 18.5 mmand less water could be incorporated into the butter during mixing. Using differentialscanning calorimetry, it was observed that water addition as well as churning at lowtemperatures induced a transition toward more stable crystal structures, as the meltingpoint in the high melting fraction was slightly lower for butter churned at high temperature.This did, however, not reflect in any changes in terms of crystal polymorphism, and allbutters contained primarily b0-crystals with traces of a- and b-crystals. Despite the observedchanges, small deformation rheology revealed no difference as a function of churningtemperature or water content. During isothermal storage at 5 8C, the solid fat contentincreased in all butters, but only butter churned at 10 8C showed an increase in hardnessduring storage. However, no difference in rheological behavior was observed among thebutters. Thus it can be concluded that low temperature allows more water to be incorporatedในระบบโดยไม่มีการเปลี่ยนแปลงในลักษณะ rheological หรือคริสตัล inducingโพลิมอร์ฟิซึมหลังจาก 4 สัปดาห์ของการจัดเก็บ
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