Researcher: Dr. Vincent Yeung, Cal Poly SLO
• Milk protein concentrates (MPC) and reduced calcium MPC (RCMPC) are natural emulsifiers derived from milk protein powders that could improve a food’s texture, increase its protein content, and be used in place of synthetic emulsifiers for “clean label” products.
• Ice cream samples with MPC and RCMPC (at 85% protein) at three different levels were produced and tested for viscosity, storage capability, and texture.
• Results support the use of MPC above 1% and RCMPC at 1%, 2%, and 3% as natural emulsifiers in ice cream. These emulsifiers improved the storage stability of ice cream, maintained viscosity within the typical range, and increased protein content without influencing fat or total solids.
BACKGROUND AND OBJECTIVE
“Clean label” is a rising trend in the food industry as more than 80% of consumers prefer simple, easy-to-understand ingredients on their food labels. Dairy ingredients are well positioned to meet the demand for clean label foods through milk protein concentrates (MPC). MPCs are natural emulsifiers that could potentially increase a food’s protein content while improving texture. The object of this research project was to investigate the textural properties, shrinkage (% volume lost), and meltdown rates of ice cream made with two milk-based emulsifiers, MPC and reduced-calcium milk protein concentrate (RCMPC) (both at 85% protein) to determine their suitability as natural alternatives to synthetic emulsifiers.
METHODS, FINDINGS AND OUTCOMES
Ice cream samples used in analyses included one control (3% non-fat dry milk and no added emulsifiers) and six experimental ice creams: 1% MPC, 2% MPC, 3% MPC, 1% RCMPC, 2% RCMPC, and 3% RCMPC. Different levels of MPC or RCMPC were produced by replacing equivalent amounts of non-fat dry milk and keeping the total solids content unchanged. Substituting non-fat dry milk with MPC or RCMPC did not influence the fat, moisture, or total solids in the ice cream mixes but did increase the protein content. Additions of MPC or RCMPC at 1%, 2%, and 3% were associated with protein increases of 15%, 30%, and 45% respectively.
All experimental ice creams had higher viscosities than the control and higher levels of MPC or RCMPC were associated with higher viscosities. Ice cream samples were analyzed for meltdown rate, shrinkage, and textural properties on days 1, 14, 30, 60, 90, and 180. On day 1, there were no differences in meltdown rate across samples. RCMPC had the lowest meltdown rate by days 90 and 180. Both the control and MPC 1% showed significant shrinkage over the study period in a household freezer whereas none of the RCMPC samples demonstrated any shrinkage in a household freezer. These findings indicate that MPC at 2% or higher and RCMPC at 1% or higher could function effectively as natural emulsifiers in clean label ice creams.
It is highly beneficial for dairy manufacturers to align with the consumer trend toward clean label foods and reformulate existing products to minimize the use of synthetic ingredients. Study results support the use of MPC or RCMPC (both at 85% protein) as a natural emulsifier to improve the storage stability of ice cream. While MPC and RCMPC both increased ice cream viscosity, all treatments remained within the typical range for ice cream processing. Every 1% increase of the emulsifier was associated with a 15% increase in the protein content of the ice cream sample. Because many ice cream manufacturers already use non-fat dry milk as an ingredient, the formulations developed in this study could be easily adopted for clean label formulations that improve protein content.