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Smart release-control of microencapsulated ingredients from milk protein tablets using spray drying and heating

Tan, Songwen, Ebrahimi, Amirali, Langrish, Timothy
Food hydrocolloids 2019 v.92 pp. 181-188
Fourier transform infrared spectroscopy, acetaminophen, analgesia, ascorbic acid, casein, gastric juice, heat treatment, hydrocolloids, ingredients, microencapsulation, spray drying, whey protein isolate
There have been many materials used for controlled release of ingredients, but only a few are food-grade for humans. The milk proteins, including casein (relatively insoluble) and WPI (soluble whey protein isolates), have been engineered and used as shell materials in spray-dried particles for controlled release of microencapsulated ingredients (acetaminophen, coffee and ascorbic acid) in this work. Smart and customized control of the release time from a few minutes to a few hours, and then to over two days has been achieved using milk proteins with techniques that include acid-gelation, spray drying and/or heat-gelation. The release rate can be easily controlled by varying the ratio of milk proteins, where the casein-gel tablets require 24 h to be degraded in SGF (simulated gastric fluid) at 37 °C but WPI tablets can be degraded within 1.5 h. The time required for releasing 80% of the ingredients from milk protein tablets follows the order: casein-acetaminophen > casein-coffee > casein-ascorbic acid > casein-WPI-acetaminophen > casein-WPI-coffee > casein-WPI-ascorbic acid > WPI-acetaminophen > WPI-coffee > WPI-ascorbic acid. Characteristics of the spray-dried particles have been studied by FTIR and DSC. After the heat treatment, the milk protein tablets containing acetaminophen (for pain relief) have shown slower release rates. Typically, only 80% acetaminophen has been released within 24 h from the heated casein-acetaminophen tablet, and the release period is over two days.