Effect of freezing rates on α-amylase enzymatic susceptibility, in vitro digestibility, and technological properties of starch microparticles

• Published in: Food chemistry 2024-09, Vol.453, p.139688-139688, Article 139688
• Main Authors: Almeida, Raphael Lucas Jacinto, Santos, Newton Carlos, Morais, Jessica Renaly Fernandes, de Almeida Mota, Mércia Mélo, da Silva Eduardo, Raphael, Muniz, Cecilia Elisa Sousa, de Assis Cavalcante, Josilene, da Costa, Gilsandro Alves, de Almeida Silva, Rebeca, de Oliveira, Bárbara Freire, da Silva Negreiros, Jessica Kelly, da Silva, Paloma Benedita, Albuquerque, Juliana Cruz, de Figueiredo, Maria José, Lima, Soares Elias Rodrigues
• Format: Article
• Language: English
• Subjects: alpha-amylase; alpha-Amylases - chemistry; alpha-Amylases - metabolism; carbohydrate structure; crystal structure; digestibility; Digestion; Double modification; enthalpy; Enzymatic hydrolysis; food chemistry; Freeze-thawing; Freezing; gelatinization; Hydrolysis; ice; liquid nitrogen; Particle Size; refrigerators; starch; Starch - chemistry; Starch - metabolism; Texture; Viscosity
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139688

The aim of this study was to evaluate the effect of freezing rates using direct (LF: Liquid nitrogen) and indirect (RF: Cryogenic refrigerator and UF: ultra-freezer) methods at temperatures of (−20, −80, and − 196 °C) on the enzymatic susceptibility with α-amylase for microparticles. In vitro digestibility parameters and technological properties were also analyzed. Lower rates resulted in larger ice crystals, damaging the starch structure. Hydrolysis was more pronounced at slower rates RF: 0.07 °C/min and UF: 0.14 °C/min, yielding maximum values of RDS: 37.63% and SDS: 59.32% for RF. Type A crystallinity remained unchanged, with only a noted increase in crystallinity of up to 6.50% for FR. Starch pastes were classified as pseudoplastic, with RF exhibiting superior textural parameters and apparent viscosity. (RF: 7.18 J g−1 and UF: 7.34 J g−1) also showed lower values of gelatinization enthalpy. Freezing techniques were viable in facilitating the diffusion of α-amylase and reducing RS by up to 81%. •Lower freezing rates caused more damage to starch.•RF and UF were effective in modifying the in vitro digestibility of rice starch.•The combination of freezing with α-amylase generated pores and cracks on the surface.•RF showed higher crystallinity and particle size, as well as higher viscosity.