Determination of critical storage conditions of coffee oil microcapsules by coupling water sorption isotherms and glass transition temperature

Autor(es)

Frascareli, Elen Cristina ^[1] ; Silva, Vanessa Martins ^[1] ; Tonon, Renata Valeriano ^{[2, 1]} ; Hubinger, Mriam Dupas ^[1]

Afiliação do(s) autor(es)

^[1] Univ Campinas UNICAMP, Sch Food Engn, Dept Food Engn, BR-13083862 Campinas, SP - Brazil

^[2] Embrapa Food Technol, BR-23020470 Rio De Janeiro, RJ - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY; v. 47, n. 5, p. 1044-1054, MAY 2012.
• Citações Web of Science: 17

Resumo

Coffee oil microcapsules were produced by spray-drying using as encapsulating agents gum Arabic, whey protein isolate (WPI) and mixtures of maltodextrin (MD) and WPI, at three different proportions (3:1, 1:1 and 1:3). Sorption isotherms were determined by the gravimetric method, and the glass transition temperature (Tg) was measured by differential scanning calorimetry. Microcapsules produced with gum Arabic showed the highest water adsorption and underwent a stronger water plasticising effect. At the highest water activity (0.843), this sample had a Tg value of -18.3 degrees C, while those produced with WPI at higher proportions showed values around 25 and 30 degrees C. The good fit of experimental data by Guggenheim-Anderson-de Boer and GordonTaylor models allowed the determination of the critical storage conditions, at which powders are not susceptible to deteriorative physical changes. The samples produced with 1:1 and 1:3 of MD/WPI were the most stable ones, showing critical water activity values of 0.890 and 0.938, respectively. (AU)

• Processo FAPESP: 09/54137-1 - EMUS: aquisição de um analisador de distribuição de tamanho de partículas, um medidor de potencial zeta, um spray dryer e um sistema de cromatografia líquida de ultra alta pressão / espectrômetro de massa
• Beneficiário: Miriam Dupas Hubinger
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários