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.

Effect of pre-drying and post-frying holding treatments on the oil absorption and quality of fried batter-coated peanuts

In this study, the effect of pre-drying and post-frying holding treatments on the oil absorption and the quality of the fried batter-coated peanuts were explored. The results showed that hot air drying and microwave drying induced the gelatinization of starch in the batter before frying. The thermodynamic properties of starch in the batter after frying indicated that pre-drying could protect the orderliness of the starch. CLSM images showed that the pre-drying treatment reduced the number of large oil spots on the surface of batter of fried batter-coated peanuts. SEM observation revealed that the structure of the batter treated with pre-drying was denser and the number of large pores was reduced after frying. The post-frying holding treatment improved the color and texture of the batter-coated peanuts. In conclusion, the pre-drying and post-frying holding treatment can reduce the oil content and improve the fracturability of the fried batter-coated peanuts.

The addition of resistant starch and protein to the batter reduces oil uptake and improves the quality of the fried batter-coated nuts

The batter compositions can affect the oil uptake and texture of fried batter-coated nuts. In this study, the oil uptake and quality of fried batter-coated peanuts and sunflower seeds added with resistant starch and protein were investigated. The results demonstrated that the addition of resistant starch increased the batter hardness and fracturability of the fried batter-coated peanuts by 34.36 % and 33.73 %, respectively. The oil content of fried batter-coated peanuts and sunflower seeds were decreased by 17.98 % and 15.69 %, respectively, with the addition of protein. The microstructure and roughness of the batter revealed that the batter added with protein became denser and uniform. Furthermore, the protein in the batter added with 6 % soy protein isolate had a high surface hydrophobicity. In summary, the addition of resistant starch and protein in batter will be a promising strategy for reducing the oil content and improving the quality of fried batter-coated nuts.

Carboxy Methyl Cellulose, Xanthan Gum, and Carrageenan Coatings Reduced Fat Uptake, Protein Oxidation, and Improved Functionality in Deep-Fried Fish Strips: An Application of the Multiobjective Optimization (MOO) Approach

In this study, a multiobjective optimization (MOO) approach was utilized for effective decision-making when several variables were changing simultaneously during frying. Carboxy methyl cellulose (CMC), xanthan gum, and carrageenan coatings in different concentrations (0.25-1.50%, w/v) were applied on fish strips to reduce the oil uptake and protein oxidation during frying. The pickup of the strips increased significantly (p < 0.05) with increasing concentration. The CMC was effective in oil uptake reduction and protein oxidation, as revealed by the lower carbonyl and sulfhydryl contents in the fried strip. The hardness and chewiness of the coated fish strips were found to be declined significantly (p < 0.05) with increasing coating concentrations. The moisture, lipid, toughness, hardness, cutting force, oiliness, sulfhydryl content (all min), oil uptake reduction, and carbonyl content (both max) were considered as multiple criteria for the MOO technique, and fried strips coated with 1% CMC, followed by 0.75% xanthan gum and 0.75% carrageenan, emerged as the best optimal coating.