Effects of temperature and hydrocolloids on the rheological characteristics of coating batters

Application of batter coating for modulating oil, texture and structure of fried foods: A review

Food surface modulation by batter coating is a promising approach to reduce the presence of oil in fried products. This review critically discussed the functionalities, mechanism of actions, rheology, ingredients of formulation, mathematical modeling of the process, cooking method, safety and regulatory aspects, physicochemical, thermal-microstructural characterization of batter coatings, and future research directions. Enormous list of ingredients could be used in preparation of oil-reducing viscoelastic batter coating that includes mostly flours, hydrocolloids, and starches. Bioactive compounds, enzymes, minerals, herbal extracts, baking agents, sugar alcohols, etc. could be incorporated in batter formulation to affect the taste and texture of coated products. Overall mass-transfer process of batter-coated fried foods could be characterized by several mathematical models (Fick, Newton, Page, Henderson & Pabis, modified Page, Arrhenius). Surface and internal microstructural characterization techniques, thermal probing, physicochemical characterization techniques and artificial intelligence can characterize different functionalities of batter coatings including oil reduction and textural evolution.

Rheological Properties of Corn Starch Gels With the Addition of Hydroxypropyl Methylcellulose of Different Viscosities

The objective of this study is to determine the effect of the addition of hydroxypropyl methylcellulose (HPMC) (from 0.5 to 2.0% w/w, starch basis) with three different viscosities (40–60, 80–120, and 2,600–5,600 mPa⋅s) to corn starch (30% w/w, total basis) gels. Average viscosimetric molecular weights (M_v) of tested HPMC were determined (from 27.2 × 10³ to 82.7 × 10³ g/mol). Water retention capacity of HPMC varied linearly with M_v. The formation and curation of gels were monitored by rheology employing consecutive steps such as heating ramp (25–90°C), time sweep (90°C), cooling ramp (90–25°C), time sweep (25°C), and frequency sweep. Additionally, creep-recovery tests were performed. HPMC above 1.5% w/w delayed the range of gelatinization temperature of starch up to 2°C. Viscoelasticity and stiffness of corn starch gels with HPMC depend on both the amount of polymer added and M_v of the HPMC. Finally, to achieve corn gels with mimetic viscoelastic properties to wheat gel (with constant total solids), HPMC with relatively low viscosity (low M_v) is necessary to be added at certain content.