Dulce de leche-like product enriched with emulsified pecan oil: Assessment of physicochemical characteristics, quality attributes, and shelf-life

Abstract

“Dulce de leche” (DL) is a rich, creamy, caramel-like milk-based sauce or spread, prepared by concentrating whole milk with sucrose, reaching a lipid content of about 6% w/w. A DL-like product with pre-emulsified pecan oil as fat source was developed. Nonfat milk, xanthan gum, sugars, pecan oil, and natural tocopherols were included in the formulation prepared in a pilot-plant scale and stored at room temperature. Pecan oil-DL showed physicochemical and rheological characteristics similar to those of commercial DL containing ∼6% milk fat. A slight increase in viscosity was observed after 2 months of storage, remaining almost constant thereafter. Crystal formation was not observed and microbial counts were low. Slight lipid oxidation was experienced after 138 days. DL fatty acid (FA) profile showed high content of unsaturated FA (UFA, 89–90% w/w), mainly oleic and linoleic acids, effectively protected by both tocopherols and antioxidant compounds. Pecan oil-DL presented good sensorial characteristics (above 7 points on a 10 point-hedonic scale), with 82.6% less saturated FA and 200% more UFA than a traditional milk fat-product, being an alternative product with lipid profile enriched in unsaturated fatty acids. Practical applications: The “dulce de leche” (DL) jam-like developed could be considered an alternative to the traditional DL, with better nutritional value considering its lipid composition. It has a fatty acid (FA) balance in favor of unsaturated FA as well as absence of cholesterol in the formulation because it is a product elaborated with nonfat milk. DL formulated with pecan oil showed physicochemical, rheological, and sensory characteristics similar to commercial products that contain about ∼6% milk fat. It showed good stability during storage at room temperature, with no lactose crystal formation, and only slight lipid oxidation. The product was successfully developed in the laboratory and also produced in a pilot plant scale, thus, it is feasible to produce it at an industrial scale. A DL-like product with pre-emulsified pecan oil as fat source was developed. Pecan oil-DL showed physicochemical and rheological characteristics similar to those of commercial DL containing ∼6% milk fat. DL fatty acid (FA) profile showed high content of unsaturated FA (UFA, 89–90% w/w), mainly oleic and linoleic acids, effectively protected by both tocopherols and antioxidant compounds. Pecan oil-DL presented good sensorial characteristics, with 82.6% less saturated FA and 200% more UFA than a traditional milk fat-product, being an alternative product with lipid profile enriched in unsaturated fatty acids.