Protein Modification During Ingredient Preparation and Food Processing: Approaches to Improve Food Processability and Nutrition

Global populations are growing and ageing, with each generation expecting a higher standard of living than their predecessor. Proteins are essential in daily diets because of their nutritional value and roles in food structure, and proteins are generally expensive. Rising awareness of food security and meeting the needs of ageing populations motivate food researchers to explore alternative protein sources and sustainable and optimized use of proteins to increase their bioavailability and digestibility. Proteins behave differently as a function of pH, ionic strength, temperature, pressure or enzymatic mechanism, prompting approaches to modify their structure and functionality. Proteins may lose their native structure and impart sensory changes as a result of processing and storage. Modified proteins are considered as value-added food ingredients, i.e. specialty proteins prepared using enzymatic reactions, hydrolysis, fermentation, heat treatment, acidification, dehydration, emulsification and ultrafiltration. Food formulation influences proteins at both molecular and macro-polymer levels. This review presents case studies from previous research and demonstrates approaches for improving protein stability, extractability and bioactivity. The need for combining protein modification and smart food formulation is highlighted. Synergies achieved between conventional ingredients and added bioactives through careful food formulation and processing are emphasized. Comprehensive characterization of chemical composition, particle size, surface activity, microstructure, freezing-thawing properties of proteins and derived foods is required, to explain structure-function relationships. Data suggest that specialty proteins will play an increasing role in current and future global food sectors. Convenient concept foods for addressing the global food security and ageing population issues are proposed.